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HomeMy WebLinkAboutEIR 04-02; Carlsbad Drainage Master Plan Update Part 2; Environmental Impact Report; 2007-12-014.5 Air Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.5-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.5 AIR QUALITY This section includes an assessment of impacts of the proposed DMP Update project components on air quality within Carlsbad. 4.5.1 Existing Conditions 4.5.1.1 Environmental Setting, Climate, and Meteorology Carlsbad is located within the San Diego Air Basin (SDAB), which is geographically defined by the borders of San Diego County. The climate of San Diego County is generally characterized by warm, dry summers and mild, wet winters. One of the main determinants of the regional climatology is a semipermanent high-pressure area in the eastern Pacific Ocean (the Pacific High). In the summer, this pressure center is located well to the north, causing storm tracks to be directed north of California and maintaining clear skies in southern California for much of the year. When the Pacific High moves southward during the winter, this pattern changes, and low- pressure storms are brought into the region, causing widespread precipitation. In San Diego County, the heaviest precipitation typically occurs in October through March and averages approximately 9 to 14 inches annually. The mean temperature within the county is 62.2 degrees Fahrenheit (°F), while the mean maximum and mean minimum temperatures are 75.7°F and 48.5°F, respectively. A common atmospheric condition known as a temperature inversion affects air quality in San Diego County. Inversion layers are important elements of local air quality because they inhibit the dispersion of pollutants, thus resulting in a temporary degradation of air quality. Subsidence inversions occur during the warmer months (May through October) as descending air associated with the Pacific High comes into contact with cool marine air. During an inversion, air temperatures increase with increasing height, causing pollutants to become trapped in the dense, cool air below. The inversion layer is generally located approximately 2,000 feet above mean sea level during the months of May through October. During the winter months (November through April), the temperature inversion boundary increases to approximately 3,000 feet above mean sea level. 4.5 Air Quality Page 4.5-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.5.1.2 Applicable Regulations, Plans, and Policies Federal and State Standards The Federal Clean Air Act (CAA) (USC Section 7401) required the adoption of National Ambient Air Quality Standards (NAAQS) to protect the public health, safety, and welfare from known or anticipated effects of air pollution. The NAAQS have been occasionally updated, and current national standards are set for sulfur dioxide (SO2), carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), respirable particulate matter (PM10), fine particulate matter (PM2.5), and lead. Pollutants with established NAAQS are collectively referred to as criteria pollutants. The State of California Air Resources Board (CARB) has established the California Ambient Air Quality Standards (CAAQS), which are generally more restrictive than the NAAQS. Federal and state standards are shown in Table 4.5-1. On June 15, 2005, the USEPA revoked the federal one-hour O3 standard for all areas except those designated as “Early Action Compact Areas” (EACs). EACs are areas that do not have an effective date for the federal 8-hour O3 designation. No EAC occurs within California thus the federal 1-hour O3 is effectively revoked in the state. Regional Standards In San Diego County, the San Diego Air Pollution Control District (SDAPCD) is the agency responsible for protecting public health and welfare through the administration of federal and state air quality laws and policies. Included in the SDAPCD’s tasks are the monitoring of air pollution, the preparation of the San Diego County portion of the State Implementation Plan (SIP), and the promulgation of Rules and Regulations. The SIP includes strategies and tactics to be used to attain and maintain acceptable air quality in the county; this list of strategies is called the Regional Air Quality Strategy (RAQS). The Rules and Regulations include procedures and requirements to control the emission of pollutants and prevent significant adverse impacts to sensitive receptors. One rule particularly applicable to the proposed DMP Update is SDAPCD Rule 51, Nuisance. Rule 51 states, in part, that “a person shall not discharge from any source whatsoever such quantities of air contaminants or other material which cause injury, detriment, nuisance or annoyance to any considerable number of persons or to the public or which endanger the comfort, repose, health or safety of any such persons or the public or which cause or have a natural tendency to cause injury or damage to business or property.” 4.5 Air Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.5-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.5-1 National and California Ambient Air Quality Standards NAAQS1 CAAQS2 Pollutant Averaging Time Primary3 Secondary4 Concentration5 1-Hour - - 0.09 ppm (180 μg/m3) Ozone (O3)6 8-Hour 0.08 ppm (157 μg/m3)Same as Primary Standard 0.070 ppm (137 μg/m3) 9 8-Hour 9.0 ppm (10 mg/m3) 9.0 ppm (10 mg/m3) Carbon Monoxide (CO) 1-Hour 35 ppm (40 mg/m3) None 20 ppm (23 mg/m3) Annual Average 0.053 ppm (100 μg/m3)- Nitrogen Dioxide (NO2) 1-Hour - Same as Primary Standard 0.25 ppm (470 μg/m3) Annual Average 0.03 ppm (80 μg/m3) - - 24-Hour 0.14 ppm (365 μg/m3) - 0.04 ppm (105 μg/m3) 3-Hour - 0.5 ppm (1300 μg/m3)- Sulfur Dioxide (SO2) 1-Hour - - 0.25 ppm (655 μg/m3) 24-Hour 150 μg/m3 - 50 μg/m3 Suspended Particulate Matter (PM10) Annual Arithmetic Mean 50 μg/m3 Same as Primary Standard 20 μg/m3 note 7 24-Hour 65 μg/m3 - - Fine Particulate Matter (PM2.5)6 Annual Arithmetic Mean 15 μg/m3 Same as Primary Standard 12 μg/m3 note 7 30-Day Average - - 1.5 μg/m3 Lead (Pb)8 Calendar Quarter 1.5 μg/m3 Same as Primary Standard - Hydrogen Sulfide (HS) 1-Hour 0.03 ppm (42 μg/m3) Sulfates (SO4) 24-Hour 25 μg/m3 Visibility Reducing Particles 8-Hour (10 am to 6 pm, Pacific Standard Time) In sufficient amount to produce an extinction coefficient of 0.23 per km due to particles when the relative humidity is less than 70 percent. Vinyl chloride8 24-Hour No Federal Standards 0.01 ppm (26 μg/m3) 1 NAAQS (other than O3, particulate matter, and those based on annual averages or annual arithmetic mean) are not to be exceeded more than once a year. The O3 standard is attained when the fourth highest 8-hour concentration in a year, averaged over 3 years, is equal to or less than the standard. For PM10, the 24-hour standard is not to be exceeded more than once per year. The annual standard is attained when the 3-year average of the weighted annual mean at each monitor within an area does not exceed 50 μg/m3. For PM2.5, the 24-hour standard is attained when 98 percent of the daily concentrations, averaged over 3 years, do not exceed 65 μg/m3. The annual standard is attained when the 3-year average of the weighted annual mean at single or multiple community-oriented monitors does not exceed 15 μg/m3. 2 California Ambient Air Quality Standards for O3, CO (except Lake Tahoe), SO2 (1- and 24-hour), NO2, PM10, and visibility reducing particles, are values that are not to be exceeded. All others are not to be equaled or exceeded. 3 National Primary Standards: The levels of air quality necessary, with an adequate margin of safety, to protect the public health. 4 National Secondary Standards: The levels of air quality necessary to protect the public welfare from any known or anticipated adverse effects of a pollutant. 5 Concentration expressed first in units in which it was promulgated. Ppm in this table refers to ppm by volume or micromoles of pollutant per mole of gas. 6 The federal 1-hour O3 standard was revoked for most areas of the United States, including all of California on 15 June 2005. 7 On 5 June 2003, the Office of Administrative Law approved the amendments to the regulations for the state ambient air quality standards for particulate matter and sulfates. Those amendments established a new annual average standard for PM2.5 of 12 μg/m3 and reduced the level of the annual average standard for PM10 to 20 μg/m3. The approved amendments were filed with the Secretary of State on 5 June 2003. The regulations became effective on 5 July 2003. 8 The CARB has identified lead and vinyl chloride as “toxic air contaminants” with no threshold level of exposure for adverse health effects determined. These actions allow for the implementation of control measures at levels below the ambient concentrations specified for these pollutants. 9 Effective May 17, 2006. ppm = parts per million; µg/m3 = micrograms per cubic meter; mg/m3 = milligrams per cubic meter; km = kilometer Source: CARB 2005a; USEPA 2005 4.5 Air Quality Page 4.5-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.5.1.3 Program Level Regional Air Quality Specific geographic areas are classified as either “attainment” or “nonattainment” areas for each pollutant based on the comparison of measured data with federal and state standards. If an area is redesignated from nonattainment to attainment, the CAA requires a revision to the SIP, and the preparation of a maintenance plan. The maintenance plan is required to demonstrate how the air quality standard will be maintained for at least 10 years. The SDAB currently meets the federal standards for all criteria pollutants except O3 and meets state standards for all criteria pollutants except O3, PM2.5, and PM10. San Diego County completed 3 years within the federal 1-hour O3 standard on November 15, 2001, becoming eligible for redesignation as an attainment area. Formal redesignation by the USEPA as an O3 attainment area occurred on July 28, 2003, and a maintenance plan was approved. On April 15, 2004, the USEPA issued the initial designations for the 8-hour O3 standard, and the SDAB is classified as “basic” nonattainment. Basic is the least severe of the six degrees of O3 nonattainment. The SDAPCD must submit an air quality plan to the USEPA in 2007; the plan must demonstrate how the 8-hour O3 standard will be attained by 2009 (SDAPCD 2004). While the federal 1-hour O3 standard has been repealed, the maintenance plan will remain in effect until the 8-hour O3 plan has been approved by the USEPA. The SDAB is currently classified as a state “serious” O3 nonattainment area and a state nonattainment area for PM10. For PM2.5, the SDAB is currently classified as a state nonattainment area. The SDAB currently falls under a federal “maintenance plan” for CO, following a 1998 redesignation as a CO attainment area. Ambient air pollutant concentrations in the SDAB are measured at 10 air quality monitoring stations operated by the SDAPCD. The closest SDAPCD air quality monitoring station to the project site is the Del Mar-Mira Costa College monitoring station located at 225 Ninth Street, Del Mar, approximately 13 miles south of Carlsbad. The Del Mar-Mira Costa College monitoring station is representative for coastal environments. The Del Mar station monitors O3 (Table 4.5-2). No other monitoring stations are located close enough to Carlsbad to be used to characterize other criteria pollutants such as CO, PM10, and PM2.5 in a coastal environment. Table 4.5-2 summarizes the exceedances of standards and the highest O3 levels recorded at this station for the years 2001 to 2005. 4.5 Air Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.5-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.5-2 Ambient Air Quality Summary for Mira Costa Monitoring Station, Del Mar Maximum Concentrations(1) Number of Days Exceeding Federal Standard(2) Number of Days Exceeding State Standard(2) Pollutant Averaging Time California Air Quality Standards Federal Primary Standards2001 2002 2003 2004 2005 2001 20022003 20042005 200120022003200420051-hour 0.09 ppm 0.12 ppm 0.135 0.112 0.107 0.105 0.082 1 0 0 0 0 9 3 2 6 0 Ozone 8-hour none 0.08 ppm 0.094 0.090 0.083 0.087 0.070 1 1 0 2 0 – – - - - “–” = data not available or applicable. (1) Concentration units for ozone are in parts per million (ppm). (2) For annual standards, a value of 1 indicates that the standard has been exceeded. Source: CARB 2006a 4.5 Air Quality Page 4.5-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Sources of Regional Pollution Table 4.5-3 shows the estimated quantities of pollutant emissions in the SDAB in 2004. The most significant regional sources of PM10 and PM2.5 are construction and demolition and dust from vehicle use on paved and unpaved roads, which accounted for 67 percent of the estimated emissions in San Diego County. Coarser particles are directly emitted from activities that disturb the soil, including entrained dust from travel on paved and unpaved roads, construction, mining, and agricultural operations. Other sources include windblown dust, pollen, salts, brake dust, and tire wear. The most significant regional sources of O3, NO2, and CO, are automobiles and other on-road vehicles. O3 is formed by the reaction of reactive organic gases (ROG) and oxides of nitrogen (NOX), which are combustion products from gas and diesel engines. Other important sources of ROG are paints, coatings, and process solvents. Combustion sources like vehicles, diesel engines, and industrial facilities also emit the fine particulate matter, PM10 and PM2.5. Table 4.5-3 2004 Estimated Annual Average Emissions - San Diego Air Basin Annual Emissions – Tons per day PM10 PM2.5 CO SOX ROG NOX Stationary Sources 008.0 06.4 0,031.8 0.5 054.2 009.4 Areawide Sources 097.6 27.0 0,067.8 0.3 040.7 003.0 Mobile Sources 010.5 08.6 0,931.9 2.2 100.2 171.6 Natural Sources 013.9 11.8 0,137.6 1.3 076.1 004.2 Total 130.0 53.8 1,169.1 4.3 271.2 188.2 Source: CARB 2006b Table 4.5-4 shows the forecast quantities of pollutant emissions in the SDAB in 2020. Significant reductions in ROG, NOX, and CO emissions are forecast for on-road and off-road vehicles, while there would be increases in emissions from stationary and areawide sources. Sensitive Receptors Sensitive land uses are defined as locations where people reside or where the presence of pollutant emissions could adversely affect existing or proposed land use. Typical sensitive receptors include residents, schoolchildren, hospital patients, and the elderly. Carlsbad encompasses a number of facilities that provide services to such receptors, including parks, hospitals, day care centers, and senior facilities. These are located at various locations throughout the city. 4.5 Air Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.5-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.5-4 2020 Forecast Annual Average Emissions - San Diego Air Basin Annual Emissions – Tons per day PM10 PM2.5 CO SOX ROG NOX Stationary Sources 012.5 10.5 053.3 00.6 077.4 13.7 Areawide Sources 115.5 31.3 074.9 00.3 046.5 03.1 Mobile Sources 011.3 09.1 473.6 11.6 048.7 90.0 Natural Sources 013.9 11.8 137.6 01.3 076.1 04.2 Total 153.2 62.7 739.40 13.8 248.7 111.0 Source: CARB 2006b 4.5.1.4 Project Level Sources of Emissions The principal sources of emissions in and near Agua Hedionda and Calavera creeks (project components B and BN) are vehicles on El Camino Real and Cannon Road. Other sources include agricultural machinery and operations. Vehicle travel on unpaved roads and agricultural operations are sources of particulate emissions. Emissions associated with unpaved roads and agricultural operations are anticipated to decrease as the area becomes more urbanized. Sensitive Receptors Agua Hedionda and Calavera creeks are located adjacent to the Rancho Carlsbad residential community, which includes elderly residents. There are no schools or health care facilities near the project area. 4.5.2 Significance Criteria The proposed DMP Update components would result in potentially significant impacts to air quality if they would: • conflict with or obstruct implementation of the RAQS; • violate the NAAQS or CAAQS or contribute substantially to an existing or projected air quality violation; • violate thresholds established by the USEPA, as shown in Section 4.5.3.2 Table 4.5-5 below; 4.5 Air Quality Page 4.5-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 • result in a cumulatively considerable net increase of any criteria pollutant for which the project region is in nonattainment under an applicable federal or state ambient air quality standard (including releasing emissions that exceed quantitative thresholds for O3 precursors); • expose sensitive receptors to substantial pollutant concentrations; or • expose sensitive receptors to objectionable odors for more than a 1-week period. 4.5.3 Impact Analysis 4.5.3.1 Program Level The principal sources of gaseous emissions and some particulate emissions associated with implementation of the DMP Update components would be the engine exhaust of diesel engine- driven construction equipment, including bulldozers, cranes, backhoes, heavy trucks, and paving equipment. Trucks would be used to haul demolished and excavated materials off-site, and to bring new pipelines, concrete, riprap, and other materials to the site. Principal sources of particulate emissions would be grading and soil disturbance, and vehicle operations on unpaved and paved surfaces. Emissions would be minimized by the implementation of standard design and construction practices. For example, water and dust control agents would be applied to active grading areas, unpaved surfaces, and dirt stockpiles to prevent or suppress airborne particulates. Trucks and equipment would not idle for more than 15 minutes when not in service. Air filters and other pollution control devices on construction equipment would be properly operated and maintained. Measures such as these and others included in Table 3-6 would minimize particulate emissions during construction activity. Potential impacts would be less than significant. There would be a potential for emissions of odors from disturbance of wet sediments or from paving activities. If these odors occurred, they would dissipate relatively rapidly and would not be anticipated to be noticeable for more than 1 week. Potential impacts would be less than significant. With the implementation of the identified standard design and construction practices, emissions would not be of a magnitude to conflict with existing attainment and maintenance plans, violate air quality standards, or make a considerable contribution to the existing regional pollutant concentrations. The construction and operations activities would not expose sensitive receptors 4.5 Air Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.5-9 04080135 Carlsbad DMP EIR.doc 12/11/2007 to substantial pollutant concentrations, nor would there be objectionable odors that would affect sensitive receptors for an extended period of time. Potential impacts would be less than significant. 4.5.3.2 Operation and Maintenance Operation and maintenance of existing and proposed drainage facilities would require the use of various pieces of construction equipment and trucks for cleaning channels, repairing culverts, replacing bridges, and other activities as described in Section 3.3.6. Emissions would be minimized by the implementation of project design features/methods and construction practices described above for PLDA and non-PLDA projects and included in Table 3-6. Potential impacts would be less than significant. With the implementation of the identified standard design and construction practices, emissions would not be of a magnitude to conflict with existing attainment and maintenance plans, violate air quality standards, or make a considerable contribution to the existing regional pollutant concentrations. The construction and operations activities would not expose sensitive receptors to substantial pollutant concentrations, nor would there be objectionable odors that would affect a substantial number of people. Potential impacts would be less than significant. 4.5.3.3 Project Level PLDA Project Components Air emissions resulting from implementation of the proposed drainage improvements in Agua Hedionda and Calavera creeks (PLDA components B and BN) were estimated by use of the URBEMIS 2002 software package, version 8.7 (CARB 2005b). URBEMIS is a calculation tool designed to estimate air emissions from land use development projects based on development type and size. The model contains data that are specific for each California air basin. Data relevant to the proposed DMP Update are based on the project elements and schedule described in Section 3.3 of this EIR. URBEMIS data sheets are attached as Appendix C. For purposes of estimating emissions, it was assumed that the project would last for 4 to 6 months (see Chapter 3.0 [Project Description]). During that period, construction equipment operations would be the equivalent of one bulldozer, two loader/backhoes, and two heavy trucks operating for the entire period, and one scraper and one crane operating for 75 percent of the period. It was also assumed that 30,000 cy of dredged and excavated materials would be hauled 4.5 Air Quality Page 4.5-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 off-site (with up to 28,000 cy potentially transported to the South Carlsbad beach replenishment site). The estimated emissions are shown in Table 4.5-5. Table 4.5-5 Estimated Construction Emissions tons/year ROG NOX CO PM10 Construction emissions 1.0 6.7 7.9 0.51 Guidance Thresholds 100 100 100 70 1 PM10 emissions would be 0.4 ton with watering of active grading surfaces when required, which is included in standard construction practices. Source: USEPA 1993 The SDAPCD has no quantitative emissions criteria for CEQA evaluations. Therefore, for guidance, the thresholds used for assessment of conformity of federal projects to the state air quality plans were used and are shown in Table 4.5-5 (USEPA 1993). As shown in Table 4.5-5, estimated project emissions are considerably less than the threshold values. There would be a potential for odor emissions from the dredging and removal of wet sediments from the creek channels. The duration of odor would be limited to the time required to remove the odorous materials or for the odor emissions to be minimized by drying of the materials. Potential air quality impacts associated with stockpiles of dredge material would be minimized with implementation of the project design features/measures and construction practices identified in Table 3-6, and would be similar to those described under the program level analysis. Estimated emissions would be less than 8 percent of the guidance emissions thresholds. Thus, emissions would not be of a magnitude to conflict with existing attainment and maintenance plans, violate air quality standards, or make a considerable contribution to the existing regional pollutant concentrations. The construction activities would not expose sensitive receptors to substantial pollutant concentrations, nor would there be objectionable odors that would affect sensitive receptors over more than a 1-week period. Potential air quality impacts would be less than significant. 4.5 Air Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.5-11 04080135 Carlsbad DMP EIR.doc 12/11/2007 Non-PLDA Project Components The improvements to Agua Hedionda and Calavera creeks would involve long-term maintenance efforts (non-PLDA project components B and BN). Similar to the PLDA components, the principal sources of emissions would be construction equipment. The intensity and duration of operations would be less than for the construction efforts, and emissions would be less than shown in Table 4.5-5. Potential air quality impacts would be less than significant. 4.5.4 Significance of Impacts 4.5.4.1 Program Level No direct or indirect potentially significant short- or long-term air quality impacts would occur with implementation of the program level DMP Update components. 4.5.4.2 Operation and Maintenance No direct or indirect potentially significant short- or long-term air quality impacts would occur during proposed operation and maintenance activities. 4.5.4.3 Project Level No direct or indirect potentially significant short- or long-term air quality impacts would occur with implementation of the project level DMP Update components. 4.5.5 Mitigation Measures 4.5.5.1 Program Level No potentially significant impacts were identified, and no mitigation measures would be required. 4.5.5.2 Operation and Maintenance No potentially significant impacts were identified, and no mitigation measures would be required. 4.5 Air Quality Page 4.5-12 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.5.5.3 Project Level No potentially significant impacts were identified, and no mitigation measures would be required. 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.6 NOISE This section includes a discussion of existing conditions and standards/guidelines associated with noise impacts, followed by an analysis of potential noise impacts resulting from implementation of DMP Update components and mitigation necessary to reduce impacts to a less than significant level. 4.6.1 Existing Conditions 4.6.1.1 Noise Descriptors Noise is generally defined as unwanted or objectionable sound. The unit of measurement used to describe a noise level is the decibel (dB). Decibels are measured on a logarithmic scale that quantifies sound intensity in a manner similar to the Richter scale used for earthquake magnitudes. Thus, a doubling of the energy of a noise source, such as doubling of traffic volume, would increase the noise level by 3 dB; a halving of the energy would result in a 3 dB decrease. The human ear is not equally sensitive to all frequencies within the sound spectrum. Therefore, a method called “A weighting” is used to filter noise frequencies that are not audible to the human ear, and the abbreviation dBA notes the A-weighted decibel. Typical noise levels for common outdoor and indoor activities are shown in Table 4.6-1. Average noise levels over a period of minutes or hours are usually expressed as dBA Leq, or the equivalent noise level for that period. The period of time average may be specified; Leq(3) would be a 3-hour average; when no period is specified, a 1-hour average is assumed. Day-night level (Ldn) is the energy average of the A-weighted sound levels occurring during a 24-hour period, with 10 dBA added to the A-weighted sound levels occurring during the period from 10:00 p.m. to 7:00 a.m. Vibration Construction operations have the potential to result in varying degrees of temporary ground vibration, depending on the specific construction equipment used and operations involved. Ground vibration generated by construction equipment spreads through the ground and diminishes in magnitude with increases in distance. The effects of ground vibration may be imperceptible at the lowest levels, low rumbling sounds and detectable vibrations at moderate levels, and damage to nearby structures at the highest levels. To assess the potential for 4.6 Noise Page 4.6-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.6-1 Typical Noise Levels Common Outdoor Activities Noise Level dBA Common Indoor Activities Jet Fly-over at 1,000 feet (300 meters) Gas Lawn Mower at 3 feet (1 meter) Diesel Truck at 50 feet (15 meters), at 50 mph (80 km/hr) Noisy Urban Area, Daytime Gas Lawn Mower, 100 feet (30 meters) Commercial Area Heavy Traffic at 300 feet (90 meters) Quiet Urban Daytime Quiet Urban Nighttime Quiet Suburban Nighttime Quiet Rural Nighttime Lowest Threshold of Human Hearing --110-- --100-- --90-- --80-- --70-- --60-- --50-- --40-- --30-- --20-- --10-- --0-- Rock Band Food Blender at 3 feet (1 meter) Garbage Disposal at 3 feet (1 meter) Vacuum Cleaner at 10 feet (3 meters) Normal Speech at 3 feet (1 meter) Large Business Office Dishwasher Next Room Theater, Large Conference Room (background) Library Bedroom at Night, Concert Hall (background) Broadcast/Recording Studio Lowest Threshold of Human Hearing Source: Caltrans 1998 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 structural damage associated with vibration from construction activities, the vibratory ground motion in the vicinity of an affected structure is measured in terms of peak particle velocity (ppv), typically in units of inches per second (in/sec). 4.6.1.2 Regulatory Framework Noise The City of Carlsbad Municipal Code, Section 8.48.010 Limitation of Hours for Construction (City of Carlsbad 1978), states the following: “The erection, demolition, alteration, or repair of any building or structure or the grading or excavation of land in such manner as to create disturbing, excessive or offensive noise during the following hours, except as hereinafter provided, is a violation of this code: (1) After sunset on any day, and before seven a.m., Monday through Friday, and before eight a.m. on Saturday; (2) All day on Sunday, New Year’s Day, Memorial Day, Independence Day, Labor Day, Veterans Day, Thanksgiving Day and Christmas Day.” Section 8.48.020, Exceptions, provides the following: The city manager may grant exceptions to Section 8.48.010 by issuing a permit in the following circumstances: (A) When emergency repairs are required to protect the health and safety of any member of the community; (B) In nonresidential zones, provided there are no inhabited dwellings within one thousand feet of the building or structure being erected, demolished, altered or repaired or the exterior boundaries of the site being graded or excavated. The Municipal Code does not include quantitative limits for construction noise. The City of San Diego and the County of San Diego noise ordinances state a standard of 75 dBA Leq, averaged over an 8- to 12-hour period, but in practice, each jurisdiction uses 75 dBA Leq averaged over 1 hour as a CEQA significance threshold. The Federal Transit Administration’s 4.6 Noise Page 4.6-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 (FTA) guideline for residential receptors is 90 dBA averaged over 1 hour in the daytime, and 80 dBA averaged over 8 hours in the daytime. The duration of the noise impact is also a factor to consider. If high noise levels persist for days or weeks, the impact is much greater than for a construction project that lasts for one or a few days. For proposed DMP Update PLDA project components, noise levels would be potentially significant if the noise at a sensitive receptor exceeded 75 dBA Leq, averaged over 1 hour, and this noise level occurred for more than 3 consecutive days. The City’s Noise Guidelines Manual includes conditions that may be applied to a project to minimize construction-generated noise impacts (City of Carlsbad 1995). Prior to project approval, the project proponent may be required to produce evidence acceptable to the City that: a. All construction vehicles or equipment, fixed or mobile, operated within 1,000 feet of a dwelling or noise sensitive use shall be equipped with properly operating and maintained mufflers. b. Stockpiling and/or vehicle staging areas shall be located as far as practicable from dwellings and other noise sensitive receptors. Vibration There are no City or state standards for vibration impacts. The professional standard has been that construction vibrations pose no threat to buildings and structures due to the short-term nature of the vibrations from project activities (Caltrans 2002). Both Caltrans and the FTA recommend a 0.2 in/sec ppv level for assessment of vibrations (Caltrans 2002; FTA 1995). This is the level that would annoy people in buildings, and where there would be a risk of architectural damage. 4.6.1.3 Sensitive Noise Receptors Noise sensitive receptors are generally considered humans engaging in activities or utilizing land uses, who may be subject to the stress of significant interference from noise. Activities usually associated with sensitive receptors include, but are not limited to, talking, reading, and sleeping. Land uses often associated with sensitive receptors include residential dwellings, hotels, motels, hospitals, nursing homes, education facilities, and libraries. Noise sensitive receptors also may include wildlife, including certain songbirds. 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.6.1.4 Program Level Noise Levels Noise levels in Carlsbad vary widely. A principal source of noise is vehicles on roadways. Average noise levels near I-5 can be in the range of 75 to 80 dBA Leq, while noise levels in rural areas, away from major roads and other noise sources, may be in the 40 to 45 dBA Leq range in the daytime and less than 40 dBA Leq at night. A second notable source of noise is McClellan- Palomar Airport. The runway is oriented in the east-west direction near the boundary between Basin B and Basin C, and elevated noise levels occur principally west of the runway. The railway along the coast is another source of noise. Average noise levels near the railway when the train is passing through can be in the range of 50 to 75 dBA Leq. Sensitive Receptors Sensitive receptors, including residences, schools, libraries, and hotels/motels, are located throughout the city. Section 4.10 (Biological Resources) addresses the locations of noise-sensitive threatened and endangered species. 4.6.1.5 Project Level Noise Levels Noise level measurements were conducted within the Agua Hedionda and Calavera creeks project boundary (project components B and BN), on April 11, 2006, between 11:00 a.m. and 4:00 p.m. The weather was clear and dry with moderate breezes from the west averaging 1 to 2 miles per hour (mph) with occasional gusts of 5 to 8 mph. Noise measurements were taken with a Larson Davis Laboratories 820 (LD-820) sound level meter set on “fast” response and “A-weighting.” The meter was positioned 5 feet above the existing ground elevation at all measurement locations. During the measurements, traffic on El Camino Real and Cannon Road was moving at approximately 40 mph. The results of the field noise measurements are summarized in Table 4.6-2 and the noise measurement locations are shown in Figure 4.6-1. 4.6 Noise Page 4.6-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.6-2 Noise Measurement Data Site ID* Location Time Leq (dBA) Lmin (dBA) Lmax (dBA) Noise Sources 1 Along El Camino Real (Environmentally Sensitive Habitat) 10:41 a.m. - 10:56 a.m. 55 49 69 Airplane, traffic 2 5102 Don Mata, south of construction staging area (Rancho Carlsbad) 11:02 a.m.- 11:17 a.m. 49 41 67 Traffic, airplane, birds chirping 3 317 Don Porfirio, along Calavera Creek (Rancho Carlsbad) 11:23 a.m. – 11:38 a.m. 54 43 69 Traffic, airplane, birds chirping 4 3349 Don Pablo, along Agua Hedionda Creek (Rancho Carlsbad) 12:02 p.m. – 12:17 p.m. 54 45 69 Traffic, airplane, birds chirping, yard work from a distance 5 5279 Don Ricardo, along Agua Hedionda Creek (Rancho Carlsbad) 12:24 p.m. – 12:39 p.m. 54 45 72 Traffic, airplane, birds chirping, yard work from a distance 6 Along Don Carlos, near weir wall, northeast area of the project site 12:46 p.m. – 1:15 p.m. 53 48 63 Traffic, airplane, birds chirping, yard work from a distance, water from Calavera Creek *The Site ID corresponds to locations shown in Figures 4.6-1 and 4.6-2 Figure 4.6-1. Results from the noise monitoring conducted on April 11, 2006, show existing average noise levels near the project area range from 49 to 55 dBA Leq. Noise measurements taken along Calavera Creek within the Rancho Carlsbad residential community indicate existing noise levels ranged from 53 to 54 dBA Leq. Noise measurements taken along Agua Hedionda Creek within the Rancho Carlsbad residential community indicate existing noise levels ranged from 49 to 54 dBA Leq. Noise measurements taken near sensitive habitat indicate noise levels ranging from 54 to 55 dBA. Sensitive Receptors Residents of the Rancho Carlsbad residential community are considered sensitive noise receptors in the project area. Section 4.10 (Biological Resources) addresses the locations of noise sensitive threatened and endangered species. Page x-xx!.!.!.!.!.!.Cannon RoadEl Camino RealRancho CarlsbadDon Arturo DrDon Porfirio DrMerwin DrDon Mata DrR a n c h o C a r l s b a d D rDon Pablo Dr634521City of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:3,600; 1 inch = 300 feetFigure 4.6-1Noise Monitoring Locations withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Noise Monitoring.mxd, 05/08/07, marraccinib300 0 300150 Feet!.Noise Monitoring LocationsProject AreaILEGEND 4.6 Noise Page 4.6-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-9 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.6.2 Significance Criteria The DMP Update project components would result in significant noise impacts if they would: • expose persons within 50 feet of the project to generation of groundborne vibration in excess of 0.2 in/sec ppv; • result in increased nighttime ambient noise levels; • result in noise levels of more than 75 dBA Leq (or above ambient levels, if above 75 dBA Leq) over a period of more than 3 consecutive days; or • expose people residing or working in the project area to excessive noise levels (for a project located within an airport land use plan or, where such a plan has not been adopted, within 2 miles of a public airport or public use airport). 4.6.3 Impact Analysis 4.6.3.1 Program Level PLDA Project Components Construction equipment would be the principal source of noise during implementation of proposed PLDA project components. For most equipment, such as bulldozers, trucks, loaders, and scrapers, the diesel engines of the equipment would be the loudest noise source. If jackhammers or other sorts of pavement breakers are used, the noise of the impact tool would be dominant. Table 4.6-3 shows some typical maximum noises at a distance of 50 feet from the equipment. Table 4.6-3 Typical Construction Equipment Noise (dBA) Equipment Typical Noise Level (dBA Lmax) 50 Feet from Source Backhoe 80 Grader 85 Loader 85 Pile Driver 96-101 Jackhammer 88 Bulldozer 85 Truck 88 Scraper 89 Source: FTA 1995 4.6 Noise Page 4.6-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Noise from two or more pieces of equipment would be greater than for one piece of equipment. Average noise levels would be less than maximum noise levels because equipment does not operate at full power all of the time, nor does it always stay in one location. With these considerations, an average noise level of 75 dBA Leq at a distance of 50 feet is a conservative value for these projects, assuming pile drivers would not be required during construction of the proposed projects. Construction equipment may be considered a point source, with noise attenuation (reduction) of 6 dBA for each doubling of distance from the source. Thus, a noise level of 80 dBA at 50 feet would be 74 dBA at 100 feet, 68 dBA at 200 feet, etc. Many proposed DMP Update project components would be linear in nature and the noise at adjacent residences or sensitive land uses would be loudest for only a period of hours. Many projects would be located more than 50 feet from sensitive receptors, and noise levels would not be anticipated to exceed 75 dBA Leq averaged over 1 hour. Therefore, potentially significant impacts would be limited to those projects with a relatively small area of work, duration of more than a few days, and a location near sensitive receptors. There would also be a potentially significant impact for any component that would require the use of pile drivers. However, noise impacts would be minimized by the implementation of project design features/methods and construction practices described in Table 3-6 of this EIR. Although the Carlsbad Municipal Code does not specifically allow an exception to the hours of construction for nonemergency work or work within 1,000 feet of a residence, it is recognized that nighttime work may be necessary to avoid significant traffic impacts. To allow nonemergency work within the stated distance from a residence at night, the City would be required to amend Muncipal Code Section 8.48.020, which would be a separate action and is not proposed as part of the DMP Update. Nighttime construction work near sensitive receptors could interfere with sleep, which would be a potentially significant impact. Vibration Ground vibration levels associated with various types of construction equipment are summarized in Table 4.6-4. Table 4.6-5 presents the vibration level thresholds for architectural and structural damage and human perception thresholds. As stated above, both Caltrans and the FTA recommend a 0.2 in/sec level for assessment of impact (Caltrans 2002; FTA 1995). 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-11 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.6-4 Representative Vibration Source Levels for Typical Construction Equipment Equipment ppv at 25 feet (in/sec) upper range 1.518 Pile Driver (impact) Typical 0.644 upper range 0.734 Pile Driver (sonic) Typical 0.170 Large Bulldozer 0.089 Loaded Trucks 0.076 Jackhammer 0.035 Small Bulldozer 0.003 Source: FTA 1995 in/sec = inches per second ppv = peak particle velocity Table 4.6-5 Reaction of People and Damage to Buildings at Various Continuous1 Vibration Levels Effects on Structures Effects on People Vibration Level (in/sec ppv) Architectural damage and possibly minor structural damage Considered unpleasant 0.4-0.6 Threshold of risk of architectural damage to normal dwelling with plastered walls and ceilings Annoying to people in buildings 0.2 Virtually no risk of damage Threshold of annoyance 0.1 Recommended upper level for ruins and ancient monuments Vibrations readily perceptible 0.08 Unlikely to cause damage of any type Threshold of perception; possibility of intrusion 0.006-0.019 1 Caltrans considers most construction vibrations, with the exception of pile driving and blasting, to be continuous. Source: Caltrans 2002 in/sec = inches per second ppv = peak particle velocity It is seen from the tables that, if no pile driving is performed and the work is more than 25 feet from a receptor, then the vibration would be less than half of the 0.2 in/sec ppv threshold used by Caltrans and the FTA. 4.6 Noise Page 4.6-12 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Non-PLDA Project Components Noise impacts for non-PLDA project components would be the same as for PLDA project components. The use of standard design and construction practices would be the same for the non-PLDA project components as for the PLDA project components. 4.6.3.2 Operation and Maintenance Operation and maintenance of the existing and proposed drainage facilities would require the use of various pieces of construction equipment and trucks for cleaning channels, repairing culverts, replacing bridges, and other activities as described in Section 3.3.6. Potential impacts would be similar to those described for program level PLDA project components but less likely to occur because maintenance operations would usually be of shorter duration than new construction. 4.6.3.3 Project Level PLDA Project Components The noise sources and generalized noise levels discussed above for the program level PLDA project components are applicable to the proposed drainage improvements within Agua Hedionda and Calavera creeks (components B and BN). Dredging and sediment removal in Agua Hedionda and Calavera creeks would occur adjacent to the homes of Rancho Carlsbad and some equipment operations would occur within 50 feet of residences. Construction activities would only occur during daylight hours, as permitted by the City’s noise ordinance. When equipment is within 50 feet, short-term noise levels would exceed 75 dBA, and 1-hour average noise levels would be likely to exceed 75 dBA. The duration of noise impact at any residence is anticipated to generally be 1 to 3 days as the dredging would proceed along each creek at approximately 50 to 100 feet per day. Because construction activity would not result in excessive noise levels (i.e., greater than 75 dBA) for a period of longer than 3 days, construction-related noise impacts would be considered less than significant. Vibration No pile driving would occur during construction of the project, nor would large bulldozers be anticipated in proximity to the homes. Maximum vibration at the nearest receptors would be 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-13 04080135 Carlsbad DMP EIR.doc 12/11/2007 anticipated to be less than 0.06 in/sec ppv and would likely be less than the level of perception. Vibration levels would be less than the 0.2 in/sec ppv Caltrans standard and less than significant. Non-PLDA Project Components The project level non-PLDA components B and BN involve long-term maintenance efforts in Agua Hedionda and Calavera creeks. The principal sources of noise and vibration would be construction equipment. The intensity and duration of operations would be less than for the construction efforts, and the impacts would be less than described for the PLDA elements of the components. 4.6.4 Significance of Impacts 4.6.4.1 Program Level Based on the analysis discussed above, the following potentially significant noise impacts would occur. • There would be a potentially significant noise impact if a proposed DMP Update component would require the use of heavy construction equipment, generating noise of 75 dBA or greater within 50 feet of a sensitive receptor for a period of longer than 3 days, or if a proposed DMP Update project component would require work to be done after sunset or before 7:00 a.m., excluding holidays. (Noise-1) • There would be a potentially significant vibration impact if a proposed DMP Update component would require the use of pile drivers, generating a vibration of 0.2 in/sec or greater at a sensitive receptor. (Noise-2) 4.6.4.2 Operation and Maintenance Based on the analysis discussed above, the following potentially significant noise impacts would occur. • There would be a potentially significant noise impact if a proposed operation and maintenance activity would require the use of construction equipment generating noise of 75 dBA or greater within 50 feet of a sensitive receptor for a period of longer than 3 days, 4.6 Noise Page 4.6-14 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 or if a proposed operation and maintenance activity would require work to be done after sunset or before 7:00 a.m. (Noise-1) 4.6.4.3 Project Level Short-term noise and vibration impacts associated with the proposed project level components would be less than significant. No long-term noise impacts would occur. 4.6.5 Mitigation Measures 4.6.5.1 Program Level The following mitigation measures shall be applicable to DMP Update components that shall result in potentially significant noise impacts (Noise-1 and/or Noise-2) during construction activities. Implementation of these mitigation measures will reduce impacts to a less than significant level. Noise-1 If a proposed project component would require the use of construction equipment that may generate noise of 75 dBA or greater within 50 feet of a sensitive receptor for a period of longer than 3 days, or would require work to be done between sunset and 7:00 a.m., as permitted by Municipal Code Section 8.48.020, preparation and implementation of a project level noise evaluation shall be required. The evaluation shall assess potential noise levels and require the implementation of appropriate noise attenuation measures to reduce potential noise impacts to less than 75 dBA Leq during the daytime or to 60 dBA Leq at nighttime. The noise evaluation shall consider the use of temporary noise walls, noise blankets, noise-reducing enclosures for individual pieces of equipment, and engines with special mufflers as potential noise attenuation measures. Monitoring shall be required to demonstrate the effectiveness of the project-specific measures to reduce noise levels to this limit. If monitoring results indicate that the measures are not reducing noise to acceptable levels, work will cease until further environmental analysis is performed that recommends additional noise attenuation measures. For emergency projects as defined in Municipal Code Section 8.48.020(A), the requirement for evaluation, monitoring, and potential additional mitigation measures shall be performed if determined feasible by the City Engineer. 4.6 Noise City of Carlsbad Drainage Master Plan Update EIR Page 4.6-15 04080135 Carlsbad DMP EIR.doc 12/11/2007 Noise-2 If a proposed project component would require the use of pile drivers, preparation and implementation of a project level vibration evaluation shall be required. The evaluation shall consider the potential vibration levels associated with project construction at the nearest structure locations. The analysis shall demonstrate that vibration levels at those structures remain below 0.2 in/sec, or a different construction technique resulting in vibration less than 0.2 in/sec shall be required. 4.6.5.2 Operation and Maintenance Mitigation measures Noise-1 and Noise-2 above will be applicable to proposed operation and maintenance activities that would result in potentially significant noise impacts, as defined in Section 4.6.4.1. Implementation of these mitigation measures would reduce impacts to a less than significant level. 4.6.5.3 Project Level Short-term noise and vibration impacts would be less than significant during implementation of project level DMP Update components. No mitigation measures would be required. 4.6 Noise Page 4.6-16 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.7 Recreation City of Carlsbad Drainage Master Plan Update EIR Page 4.7-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.7 RECREATION This section focuses on the potential effect of implementation of the DMP Update on the city’s recreational facilities and demand for services. A brief description of the recreational resources in Carlsbad is provided, followed by an impact analysis of the DMP Update project components. 4.7.1 Existing Conditions 4.7.1.1 Applicable Policies The following plans, policies, and regulations address recreational uses within Carlsbad and are applicable to implementation of the proposed DMP Update components (program and project levels). These include the General Plan Parks and Recreation Element (City of Carlsbad 1994a) and the General Plan Open Space and Conservation Element (City of Carlsbad 1994b). General Plan Parks and Recreation Element The Parks and Recreation Element of the General Plan establishes the foundation for the current operation and future development of park facilities and recreation programs (City of Carlsbad 1994b). This element designates three categories of parks, as defined below: Community Parks – Leisure facilities, generally 20 to 50 acres in size, designed to serve the recreational needs of several neighborhoods and encourage use from the nearby vicinity on a daily basis. Primary access is vehicular. Special Use Areas – Local facilities, between 1 and 5 acres, that typically contain one or two activity types (passive or active), including swimming, tennis, or racquetball facilities; meeting halls; athletic complexes; off-leash dog parks; skateboard parks; play lots; or picnic and interpretive walk areas. Access can be vehicular, bicycle, or pedestrian. Special Resource Areas – Local amenities typically encompassing more than 100 acres, with either a citywide or regionally significant quality (e.g., beaches). Access can be vehicular, bicycle, or pedestrian. The Parks and Recreation Element, first prepared in 1994 and amended in 2003, also anticipates the future development of 12 new park projects. Many of these facilities have now been 4.7 Recreation Page 4.7-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 completed. Park development and recreational programming would be consistent with the General Plan Open Space and Conservation Element (City of Carlsbad 1994a). General Plan Open Space and Conservation Element The City’s General Plan designates recreational land uses as Open Space for Outdoor Recreation (City of Carlsbad 1994a). The City considers this type of open space designation as a Category 1 (highest priority) for future open space planning. This designation includes Community Parks, Special Use Areas, and Special Resource Areas, as designated in the General Plan Parks and Recreation Element described above. Trails are also considered a Category 1 priority for open space planning. Facilities Standards have been established for each category of park to ensure that recreational facilities meet the needs of Carlsbad residents, employees, and tourists. Open space areas in relation to the City’s HMP preserve areas is discussed in Chapter 4.1 (Land Use) of this document. 4.7.1.2 Program Level Carlsbad offers a variety of indoor and outdoor facilities and other recreational areas that are open to the general public (City of Carlsbad 2006, 2007), including: • 39 parks, totaling 295 acres • 490625 acres of designated open space • 17.27 miles of public recreational trails • 48 miles of bike lanes • 1 California State Beach • Over 6 miles of coastal and public beaches Major parks and recreational facilities in the city include amenities such as lighted baseball fields, outdoor basketball courts, picnic areas, lighted tennis courts, soccer fields, and gymnasium centers. Carlsbad State Beach, located along Pacific Coast Highway approximately 1.6 miles south of Palomar Airport Road, features a large bluff-top campground with public access to the beach. Trails are located throughout open space areas of the city, including around the lagoons. Personal water craft, powerboats, and passive vessels are permitted for use in Agua Hedionda Lagoon, although anchoring is prohibited. Currently, fishing is allowed only in the designated “Passive Use” area in the lower east end of Agua Hedionda Lagoon and along South Coast Highway at the western end of Buena Vista Lagoon. 4.7 Recreation City of Carlsbad Drainage Master Plan Update EIR Page 4.7-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.7.1.3 Project Level No city parks or other recreational facilities currently exist within or adjacent to Agua Hedionda and Calavera creeks (project components B and BN) within the proposed project boundary. However, a city trail system is proposed northeast of the project area, which would run north/south to the east of the existing BJB Basin. The Rancho Carlsbad residential community does have a neighborhood pool within development located approximately 300 feet from the proposed work area. 4.7.2 Significance Criteria The DMP Update would result in a potentially significant impact to recreation in Carlsbad if it would: • result in adverse impacts to recreational opportunities in the city. 4.7.3 Impact Analysis 4.7.3.1 Program Level Proposed DMP Update components are intended to provide storm water conveyance and flood control for planned development in Carlsbad and would not involve the construction of recreational components or improvements to existing or proposed recreational facilities. Therefore, proposed DMP Update components would not affect the use of existing neighborhood and regional parks or other recreational facilities and would not generate demand for such facilities. Some proposed PLDA facilities would be located within or adjacent to existing open space and park areas (see Section 4.1 [Land Use]). Construction of proposed facilities in these areas could temporarily impact recreational uses within open space and parks. Potential impacts to recreational areas such as parking or facility use during construction of DMP Update components would be short term, and alternative recreational facilities within the city would remain available for use. Existing public trail systems would remain open during construction or adequate alternative trail routes would remain available. If necessary, alternative routes and detours would be identified during project-specific design, in coordination with the City Park Planning Department. Potential impacts to recreational opportunities within the city would be less than significant. 4.7 Recreation Page 4.7-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.7.3.2 Operation and Maintenance Proposed operation and maintenance activities would occur at existing or proposed DMP facilities and would not involve the construction of recreational components or improvements to existing or proposed recreational facilities. Therefore, proposed operation and maintenance activities would not affect the use of existing neighborhood and regional parks or other recreational facilities. Some proposed operation and maintenance activities could occur within or adjacent to existing open space and park areas and could temporarily impact recreational uses within open space and parks. Potential impacts to recreational areas such as parking or facility use during operation and maintenance activities would be short term, and alternative recreational facilities within the city would remain available for use. Existing public trail systems would remain open during operation and maintenance activities or adequate alternative trail routes would remain available. Potential impacts would be less than significant. 4.7.3.3 Project Level PLDA Project Components The proposed drainage improvements in Agua Hedionda and Calavera creeks (PLDA components B and BN) would not involve the construction or expansion of recreational facilities. No state, regional, or local parks or recreational facilities currently exist within or adjacent to the proposed project. The proposed trail system northeast of the project area would not be affected by construction for improvements to the basin. The Rancho Carlsbad residential community has a neighborhood pool located approximately 300 feet from the proposed work area. However, the pool is not located within the project construction area and use of the facility by residents would not be altered by implementation of the proposed drainage improvements. Potential impacts to recreational opportunities would be less than significant. Non-PLDA Project Components Non-PLDA components B and BN involve long-term channel maintenance in Agua Hedionda and Calavera creeks, respectively, and would require periodic inspections; sediment, debris, and vegetation removal; and repair of eroded surfaces associated with drainage and bridge appurtenances. Long-term channel maintenance would occur in existing channels and would not affect the use of the existing pool facility mentioned above or other recreational facilities. Long- term channel maintenance would not involve existing recreational facilities or require the construction or expansion of recreational facilities. Therefore, long-term channel maintenance 4.7 Recreation City of Carlsbad Drainage Master Plan Update EIR Page 4.7-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 activities proposed for non-PLDA project components B and BN would not affect recreational facilities or services. Potential impacts to recreational opportunities would be less than significant. 4.7.4 Significance of Impacts 4.7.4.1 Program Level Direct or indirect impacts to recreation from proposed program level DMP Update components would be temporary, localized, and less than significant. No long-term impacts would occur. 4.7.4.2 Operation and Maintenance Direct or indirect impacts to recreation from implementation proposed operation and maintenance activities would be temporary, localized, and less than significant. No long-term impacts would occur. 4.7.4.3 Project Level No direct or indirect impacts to recreation from proposed project level DMP Update components are anticipated to occur. 4.7.5 Mitigation Measures 4.7.5.1 Program Level Impacts from implementation of proposed program level DMP Update components would be less than significant; therefore, no mitigation would be required. 4.7.5.2 Operation and Maintenance Impacts from proposed operation and maintenance activities would be less than significant; therefore, no mitigation would be required. 4.7 Recreation Page 4.7-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.7.5.3 Project Level No impacts from proposed project level DMP Update components were identified; therefore, no mitigation would be required. 4.8 Geology/Soils City of Carlsbad Drainage Master Plan Update EIR Page 4.8-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.8 GEOLOGY/SOILS This section assesses general geologic conditions and identifies potential geologic impacts, geotechnical hazards, and effects to mineral resources within Carlsbad. This analysis is based on information contained in applicable resource and planning documents and pertinent geological and soils reports and maps for the City of Carlsbad and San Diego County. 4.8.1 Existing Conditions 4.8.1.1 Program Level Soils Carlsbad contains seven general soil associations as mapped by the United States Department of Agriculture (USDA 1973). Soils associations are useful for developing a general idea of the soils in an area and for determining the value of an area for certain uses. The following discussion outlines these soil classifications. Marina-Chesterton Association: This association occurs on broad rolling ridges parallel to the coast and consists of excessively well-drained to moderately well-drained loamy coarse sands and fine sandy loams that have a subsoil of sandy clay over a hardpan. Salinas-Corralitos Association: This association consists of moderately well-drained to somewhat excessively drained clays, clay loams, and loamy sands on alluvial fans, and occurs on coastal plains. Cieneba-Fallbrook Association (Very Rocky): This association is composed of soils that developed in material weathered in-place from decomposed tonalite or granodiorite and generally occurs in the foothills. Exchequer-San Miguel Association: This association consists of rocky, well-drained silt loams over metavolcanic rock, developed from hard metavolcanic rock, and generally occurs in the foothills. Diablo-Altamont Association: Well-drained clays are the major characteristic of this association, formed from marine sandstone, shale and breccia. This association occurs in the rolling uplands of the coastal plains. 4.8 Geology/Soils Page 4.8-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Diablo-Las Flores Association: This association consists of soils derived from calcareous and noncalcareous marine sandstone and shale and occurs in the coastal plains. Diablo soils are well- drained, dark-gray clays, while Los Flores soils are moderately well-drained fine sandy loam with a subsoil of sandy clay loam. Las Flores-Huerhuero Association: This association occurs in the coastal plains and is composed of soils that develop in material derived from sandstone or marine sediments. The soils consist of moderately well-drained loamy fine sands to loams that have a subsoil of sandy clay or clay. Faults and Seismic Hazards The San Diego region faces the potential for substantial damage associated with seismic and geologic activity. Earthquake faults occur in and through the urban areas of the region, increasing the potential of earthquake damage to structures and potentially endangering the safety of the area’s inhabitants. Most damage from earthquake activity results from ground movement, causing ground shaking, surface fault rupture, landslides and mudslides, liquefaction, and tectonic subsidence or uplift. Ground shaking is the oscillation or vibration of earth materials and causes the greatest amount of damage during an earthquake. Ground-shaking hazards usually occur in areas underlain by loose, water-saturated, unstable materials. Surface fault rupture results from the intersection of the ground surface with fault displacement. The study area for the DMP Update is not located near a known fault, and Carlsbad is not listed as a city potentially affected by earthquake fault zones (CDC 1997). The nearest known active fault is the northern extension of the Rose Canyon fault, which originates in Mission Bay, drops off into the Pacific Ocean at La Jolla Shores, and then runs north several miles off the coast to Oceanside. Regional fault systems, including the San Jacinto, San Andreas, and Elsinore faults are located to the east and north of Carlsbad. Strong vibratory motion resulting from seismic activity can cause liquefaction and dynamic settlement of soils, such as loose, granular soils. Finer-textured granular soils are more susceptible to liquefaction than coarse-grained types, and soils of uniform grain size are more likely to liquefy than well-graded materials. Most silty clay and clay soils are not adversely affected by vibratory motion. There are limited areas in Carlsbad that are considered potentially subject to liquefaction, including areas west of El Camino Real, land within and adjacent to the lagoons, and areas along the coastline (City of Carlsbad 1994). The city is not located in a mapped Alquist-Priolo fault zone area (CDC 1997). 4.8 Geology/Soils City of Carlsbad Drainage Master Plan Update EIR Page 4.8-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 Mineral Resources Mineral resources within Carlsbad are no longer being extracted and utilized as exploitable natural resources. There are several abandoned oil wells and gravel pit operations within the city limits, as well as two abandoned salt evaporation ponds; one is near the south shore of Buena Vista Lagoon and the other one is north of La Costa Avenue near the eastern perimeter of Batiquitos Lagoon (City of Carlsbad 1994). The only area with mineral resources delineated in the General Plan EIR is located around Calavera Hills/Robertson Ranch, west of Lake Calavera. The remaining mineral resources in the city are not planned for future extraction and the area is designated for urban development in the General Plan. No program level PLDA or non-PLDA components are proposed within an area where mineral resources are known to be present. 4.8.1.2 Project Level Soils There are four soil series that underlay the Agua Hedionda and Calavera creeks within the limits of work: Huerhuero (9 to 15 percent slopes), Salinas clay loam (0 to 2 percent slopes and 2 to 9 percent slopes), Tujunga (0 to 5 percent slopes), and Riverwash (USDA 1973). The Huerhuero loam soil series consists of moderately well-drained loams that have clay subsoil and occur along Calavera Creek, at the north end of Cannon Road. The Huerhuero soil series contains clay loam components, which are considered an expansive soil type, and have high shrink-swell behavior (USDA 1973). The eastern portion of Agua Hedionda Creek is underlain by Salinas clay loam, which consists of well-drained and moderately well-drained clay loams. The Salinas series has moderate shrink-swell behavior, and Tujunga sand and Riverwash, found along the creeks, have low shrink-swell behavior and are not considered expansive soil types. The presence of shallow groundwater and the relatively granulated nature of the soils underlying the site create a moderate potential for liquefaction and seismically induced settlement (Ninyo & Moore 2004). Faults and Seismic Hazards The nearest known active fault to the proposed project boundary area is the northern extension of the Rose Canyon fault located approximately 7 miles to the west offshore, as described above. A 4.8 Geology/Soils Page 4.8-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 geotechnical evaluation was prepared for the project to determine the geotechnical conditions of the proposed DMP Update site and provide recommendations for design and earthwork construction measures for the project (Ninyo & Moore 2004). The investigation found no evidence of faulting on the site. Mineral Resources Mineral resources are not known to occur within the proposed work area. No locally important mineral resource recovery sites have been identified within the proposed work area (City of Carlsbad 1994). 4.8.2 Significance Criteria The DMP Update would result in potentially significant impacts to geology or soils if it would: • expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving: o rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault, o strong seismic ground shaking, o seismic-related ground failure, including liquefaction, or o landslides; • result in substantial soil erosion or the loss of topsoil; • be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse; or • be located on expansive soils, as defined in the 1997 Uniform Building Code, creating substantial risks to life or property; or • result in the loss of availability of a locally important mineral resource. 4.8 Geology/Soils City of Carlsbad Drainage Master Plan Update EIR Page 4.8-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.8.3 Impact Analysis 4.8.3.1 Program Level Soils Impacts associated with the proposed DMP Update project components that would involve excavation, grading, or construction of new structures could include encountering unstable soil and rock conditions and exposure of oversize rock material during grading. The specific soil types and rock formations impacted by each DMP Update component are unknown at this time, as site-specific geotechnical analyses were not performed for individual components. Construction of proposed DMP Update components could result in potential hazards resulting from expansive or unstable soils and rock conditions. A geotechnical investigation would be required prior to construction of individual projects involving excavation, grading, or construction of new structures, to determine if there are expansive soils or rock formations within the proposed construction area, that would require special remediation measures. Following a site-specific geotechnical evaluation for applicable projects, additional information regarding content, expansiveness, stability, potential for subsidence, and compactibility would be determined during planning and design of individual project components. Appropriate remediation would be incorporated into project design to minimize impacts associated with soils. Potential impacts would be less than significant. During the construction of proposed project components, erosion could be accelerated, which could undermine slopes, create siltation of surface waters, and expose and damage underground facilities. As described in Table 3-6, all construction would be performed in accordance with the requirements of the City’s Grading Ordinance (Municipal Code Title 15), which requires the control of erosion during construction and the stabilization of all disturbed surfaces upon completion of construction (City of Carlsbad 1994). Thus, the proposed projects would not result in substantial soil erosion or substantial losses of topsoil. Potential impacts would be less than significant. Faults and Seismic Hazards The study area is located within seismically active San Diego County. However, the proposed DMP Update components would not traverse any known faults within the county. The proposed DMP Update components may be subject to local seismically induced secondary effects related to liquefaction, lateral spreading, local subsidence of soil, and vibration damage. Geotechnical 4.8 Geology/Soils Page 4.8-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 investigations would be required prior to design of each component to identify impacts related to faults and seismic hazards and develop appropriate remediation. Additionally, the requirements of the City Building Code (Carlsbad Municipal Code, Title 18) and the Uniform Building Code requirements would be incorporated into project component design to minimize the threat of damage to structures associated with seismic instability, subsidence, liquefaction, and stability, which would minimize impacts related to seismic hazards. Potential impacts would be less than significant. Mineral Resources Extraction of mineral resources is not proposed as part of the project. The South Coast Materials Company Carlsbad Quarry is located immediately south of the intersection of SR 78 and College Boulevard approximately 0.75 mile away from the nearest proposed project component (DMP Update component AFB). Extraction operations at the quarry have ceased. There would be no impacts to the known aggregate resources associated with the quarry. There are no mineral resources recovery sites designated within the City’s General Plan (City of Carlsbad 1994). Therefore, no impacts related to the loss of availability of a locally important mineral resource recovery site are anticipated from implementation of proposed DMP Update project components. 4.8.3.2 Operation and Maintenance Operation and maintenance activities would occur in existing or proposed drainage facilities and would not involve the construction of new structures. Assuming a site-specific geotechnical analysis would be conducted for proposed PLDA and non-PLDA components and site-specific remediation measures would be incorporated into facility project design, no additional impacts due to soils or seismic activity are anticipated to occur from routine operation and maintenance of built facilities. During some operation and maintenance activities within natural channels, erosion could be accelerated, which could undermine slopes, create siltation of surface waters, and expose and damage underground facilities. As described in Table 3-6, all operation and maintenance would be performed in accordance with the requirements of the City’s Grading Ordinance (Municipal Code Title 15), which requires the control of erosion during construction and the stabilization of all disturbed surfaces upon completion of construction (City of Carlsbad 1986). Due to conformance with the City’s Grading Ordinance, it is not anticipated that the proposed project would result in substantial soil erosion or significant losses of topsoil. Potential impacts would be less than significant. 4.8 Geology/Soils City of Carlsbad Drainage Master Plan Update EIR Page 4.8-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.8.3.3 Project Level This analysis of impacts to geology and soils applies to proposed project level PLDA and non- PLDA project components B and BN. Soils As described in Chapter 3.0 (Project Description), the project involves slope stabilization and enhancement along the creeks to address existing erosion problems. Additionally, the long-term maintenance plan involves periodic inspections and repair of eroded slopes. Providing that construction, dredging, and maintenance activities conform to the erosion control requirements of the City, substantial erosion and loss of topsoil are not anticipated. The proposed drainage improvements in Agua Hedionda and Calavera creeks would not involve any new septic tanks or alternative waste disposal systems. However, the project would involve bank and channel excavation and installation of drop structures, drains, and an access road where expansive soils potentially occur. Design of the project components would incorporate BMPs and erosion-prevention measures to address issues related to expansive soils and stabilize the banks of the creeks, including: • incorporating standards from current seismic design code; • using slope stabilization material, such as Vmax; • for slopes higher than 12 feet, retaining 2:1 (H:V) side slope design for slope stability; • planting a combination of shallow and deep-rooted vegetation to provide slope stability; • performing fill placement (if needed) in accordance with the typical earthwork guidelines (Ninyo & Moore 2004); • engineering surface drainage away from the top of slopes and maintaining drainage features such as berms, swales, collectors, pipes, and energy dissipaters; and • implementating the long-term maintenance plan (Appendix B), including inspection and repair of the channel banks. Overall, potential impacts to soils would be less than significant. 4.8 Geology/Soils Page 4.8-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Faults and Seismic Hazards A geotechnical evaluation found no evidence of faulting within the project limits (Ninyo & Moore 2004). Therefore, there would be no substantial adverse effects due to a fault rupture from the proposed components. The project area could experience seismic ground shaking due to the nearest known active fault, Rose Canyon fault (Ninyo & Moore 2004). However, the requirements of the City Building Code (Carlsbad Municipal Code Section 18) and the 2001 Uniform Building Code would be implemented as part of the project components design to minimize the threat of construction damage associated with seismic activity. The presence of shallow groundwater and the relatively granulated nature of the soils underlying the site create a moderate potential for liquefaction and seismically induced settlement (Ninyo & Moore 2004). Catastrophic ground failure is not considered likely as a result of development in the area. The proposed DMP Update area is not located in a potential landslide zone. The proposed DMP Update would not increase human exposure to seismic ground failure beyond existing conditions. Based on the relatively flat topography, project implementation would not increase the potential for landslides or instability. Therefore, it is not anticipated that people or buildings would be exposed to landslides resulting from implementation of the project components. Potential impacts related to faults and seismic hazards would be less than significant. Mineral Resources Project components B and BN would be located almost 2 miles from the South Coast Materials Company Carlsbad Quarry, which is no longer in operation. As noted in the program level analysis, no mineral resources recovery sites are designated within the city, and no impacts related to loss of availability of a locally important mineral resource recovery site are anticipated. 4.8.4 Significance of Impacts 4.8.4.1 Program Level Implementation of program level DMP Update components is not anticipated to result in direct or indirect potentially significant short- or long-term impacts related to geology/soils. 4.8.4.2 Operation and Maintenance No direct or indirect short- or long-term potentially significant impaacts to geology/soils are anticipated as a result of operation and maintenance activities. 4.8 Geology/Soils City of Carlsbad Drainage Master Plan Update EIR Page 4.8-9 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.8.4.3 Project Level Implementation of project level DMP Update components are not anticipated to result in direct or indirect potentially significant short- or long-term impacts related to geology/soils. 4.8.5 Mitigation Measures 4.8.5.1 Program Level No potentially significant impacts were identified for program level DMP Update components; therefore, no mitigation would be required. 4.8.5.2 Operation and Maintenance No potentially significant impacts were identified for operation and maintenance activities; therefore, no mitigation would be required. 4.8.5.3 Project Level No potentially significant impacts were identified for project level DMP Update components; therefore, no mitigation would be required. 4.8 Geology/Soils Page 4.8-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.9 HYDROLOGY/WATER QUALITY This section addresses existing hydrology and water quality in Carlsbad, outlines applicable regulatory programs designed to manage water quality within the city, and discusses the potential impacts implementation of the DMP Update project components could have on local water quality and hydrology. 4.9.1 Existing Conditions 4.9.1.1 Regional Climatic Conditions and Precipitation Climatic conditions in the Carlsbad area are consistent with the semiarid climate and temperature conditions predominant in San Diego County. Average annual temperature is 59.2 °F; average July/August high temperature is 72.9°F; and average January low temperature is 42.6°F. The predominant rainfall season is from October through March. Mean annual precipitation within Carlsbad is approximately 9 to 14 inches annually, with little variation over the area in terms of short-term rainfall intensity, duration, and frequency. 4.9.1.2 General Surface Hydrology Carlsbad is located within the CHU No. 904.00. The CHU encompasses approximately 210 square miles and includes portions of eight jurisdictional areas: Carlsbad, Encinitas, Escondido, Oceanside, San Marcos, Solana Beach, Vista, and the County of San Diego. There are six individual watersheds or Hydrologic Areas within the Carlsbad Watershed: Loma Alta, Buena Vista Creek, Agua Hedionda, Encinas, San Marcos Creek, and Escondido Creek. Carlsbad’s jurisdiction extends over portions of four of the watersheds: Buena Vista Creek, Agua Hedionda, Encinas, and San Marcos Creek. Four major coastal lagoons exist within the CHU: Buena Vista, Agua Hedionda, Batiquitos, and San Elijo. Agua Hedionda and Batiquitos lagoons occur entirely with the City’s jurisdictional boundary, as well as portions of Buena Vista Lagoon. Carlsbad is divided into four major watersheds: the Buena Vista Creek Watershed, the Agua Hedionda Creek Watershed, the Encinas Creek Watershed, and the Batiquitos Lagoon Watershed. Three of the listed watersheds terminate in coastal lagoons that support a variety of flora and fauna. The Encinas Creek Watershed is the only one among the four listed watersheds that discharges directly to the Pacific Ocean. Watershed boundaries correspond roughly to the project drainage basins (Basins A, B, C, and D), as discussed in Chapter 2.0 (Environmental 4.9 Hydrology/Water Quality Page 4.9-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Setting). Figure 1-2 in Chapter 1.0 (Introduction) provides a map with the city limits, basin boundaries, and the main waters and blue-line streams for each basin. 4.9.1.3 Regulatory Authority There are various regulatory agencies responsible for overseeing water quality, flooding, and hydrology issues within the State of California. Approval of projects with the potential to impact water quality, flood protection, or hydrology requires consultation with several agencies, as well as consistency with the rules and regulations of each agency. Clean Water Act The CWA is the primary federal statute governing the protection of water quality and was established to provide a comprehensive program to protect the nation’s surface waters. The CWA consists of the Federal Water Pollution Prevention and Control Act, passed in 1948 and subsequent amendments of 1972 and 1987. The Water Pollution Prevention and Control Act required the USEPA to establish nationwide effluent standards on an industry-by-industry basis. The 1972 Amendment established the NPDES. Section 303 of the CWA requires states to adopt water quality standards for all surface waters of the U.S. Where multiple uses exist, water quality standards must protect the most sensitive use. Water quality standards are typically numeric, although narrative criteria based on bio-monitoring methods may be employed where numerical standards cannot be established or where they are needed to supplement numerical standards. As a result of the reauthorization of the CWA in 1987, Sections 402(p) through 405 were added. One of the results of the new sections was the creation of the NPDES permit program, which is discussed later in this section. Also, as discussed in Section 4.10 (Biological Resources), the Section 404 program regulating discharges into waters of the U.S. was established by the CWA. Porter-Cologne Act The Porter-Cologne Water Quality Control Act (California Water Code Section 13000 et seq.) is California’s statutory authority for the protection of water quality. Under the Porter-Cologne Act, the responsibilities for protecting water quality in California belong to the State Water Resources Control Board (SWRCB) and the nine subsidiary RWQCBs. The SWRCB and the subsidiary RWQCBs must adopt water quality policies, plans, and objectives to protect the State’s waters for use and enjoyment by the people of California. Basin Plans are the regional water quality control plans required by both the CWA and the Porter-Cologne Act in which 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 beneficial uses, water quality objectives, and implementation programs are established for each of the nine regions in California. State Water Resources Control Board and Regional Water Quality Control Boards The SWRCB and nine RWQCBs are responsible for ensuring implementation and compliance with the provisions of the federal CWA and California’s Porter-Cologne Water Quality Control Act. Along with the SWRCB and RWQCBs, water quality protection is the responsibility of numerous water supply and wastewater management agencies, as well as city and county governments, and requires the coordinated efforts of these various entities. Carlsbad is situated within the jurisdiction of the San Diego RWQCB (Region 9). The San Diego RWQCB has the authority to implement water quality protection standards through the issuance of permits for discharges to water at locations within its jurisdiction. Water quality objectives for waterways in Carlsbad are specified in the Water Quality Control Plan for the San Diego Basin (Basin Plan), as prepared by the San Diego RWQCB. The most recent version of the Basin Plan is dated 1994, which was prepared in compliance with the provisions of the federal CWA and the State Porter-Cologne Water Quality Control Act. National Pollutant Discharge Elimination System The 1972 amendment to the CWA established the NPDES permit program. The NPDES permit program outlined in the CWA contains effluent limitation guidelines, water quality requirements, and permit program requirements for discharges to waters of the U.S. The USEPA has overall responsibility for the NPDES program, but administration of the program in California has been delegated to the SWRCB and the nine RWQCBs. The 1987 amendments to the CWA established a framework for regulating discharges under the NPDES program and, in 1990, the USEPA promulgated regulations for permitting storm water discharges from industrial sites, including construction sites that disturb 5 acres or more, and from municipal separate storm sewer systems (MS4s) serving a population of 100,000 people or more. The November 16, 1990, regulations, known as the Phase I regulations (Title 55 FR 47990), rely on NPDES permit coverage to address storm water runoff from (1) operators of medium4 and large5 MS4s, (2) construction activity disturbing 5 acres of land or greater, and (3) 10 categories of industrial activity. 4 An incorporated place or county with a population of 100,000 to 249,999. 4.9 Hydrology/Water Quality Page 4.9-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 On December 8, 1999, the USEPA promulgated regulations known as Phase II. The regulations set forth in the Storm Water Phase II Final Rule (Title 64 FR 68722) require permits for discharges from operators of small6 MS4s and from construction sites disturbing at least 1 acre of land. Phase II is intended to further reduce adverse impacts to water quality in receiving waters and aquatic habitats by instituting controls on the unregulated sources of storm water discharges that have the greatest likelihood of continued environmental degradation. The goal of the NPDES non-point source regulations is to improve the quality of storm water discharged to receiving waters to the “maximum extent practicable” through the use of BMPs. The focus of the Phase II program is the implementation of the following six minimum control measures: public education and outreach, public participation and involvement, illicit discharge detection and elimination, construction site runoff control, postconstruction runoff control, and pollution prevention and good housekeeping. Under Phase II regulations in California, small MS4s are covered under the SWRCB Water Quality Order No. 2003-0005-DWQ, NPDES General Permit No. CAS000004 (Small MS4 Permit). Construction projects disturbing at least 1 acre of land are covered under the General Construction Permit: SWRCB Water Quality Order No. 99-08-DWQ, NPDES General Permit No. CAS000002 (SWRCB 2002). Compliance with the NPDES General Construction Permit (General Permit No. CAS000002) requires that any construction activity affecting 1 acre or more obtain a General Construction Activity Storm Water Permit. Permit applicants are required to submit a Notice of Intent (NOI) to the SWRCB and to prepare a Storm Water Pollution Prevention Plan (SWPPP). The SWPPP identifies BMPs that must be implemented to reduce construction effects on receiving water quality. The BMPs identified are directed at implementing both sediment and erosion control measures and other measures to control potential chemical contaminants. Examples of construction BMPs identified in SWPPPs include using temporary mulching, seeding, or other stabilization measures to protect uncovered soils; storing materials and equipment to ensure that spills or leaks cannot enter the storm drain system or surface water; developing and implementing a spill prevention and cleanup plan; installing traps, filters, or other devices at drop inlets to prevent contaminants from entering storm drains; and using barriers, such as straw wattles or silt fencing, to minimize the amount of uncontrolled runoff that could enter drains or surface water. 5 An incorporated place or country with a population of 250,000 or greater. 6 An MS4 that is not permitted under the municipal Phase I regulations, and which is “owned or operated by the United States, a state, city, town, parish, district, association, or other public body (created by or pursuant to state law) having jurisdiction over disposal of sewage, industrial wastes, storm water, or other wastes” (40 CFR Section 122.26(6)(16)). 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 Storm Water Municipal Permit Carlsbad and other MS4s within the San Diego region were required to obtain coverage under NPDES. The NPDES program regulates storm water discharges from such municipalities under the municipal permit program. The County of San Diego, the 18 cities within San Diego County, the Port of San Diego, and more recently the San Diego Regional Airport Authority operate as copermittees under a single Municipal Permit, the San Diego Municipal Storm Water Permit (Order 2001-01), NPDES No. CAS0108758 (Municipal Permit), issued in 2001. The Municipal Permit expired in February 21, 2006; however, Tentative Order No. R9-2006-0011 for the Revised Municipal Permit has been issued. The Municipal Permit requires each copermittee to prepare guidance documents for storm water management, including the SUSMP, JURMP, and Watershed Urban Runoff Management Program (WURMP). The SUSMP is a guidance document that defines the local requirements that projects must comply with for storm water management and the requirements are incorporated into the local municipal code. The JURMP is the City’s associated management document. The City’s SUSMP and JURMP define the requirements for private and public projects to comply with storm water regulations. Carlsbad is also covered by the WURMP for the CHU, which includes seven other local jurisdictions (City of Carlsbad et al. 2003). The WURMP defines the watershed level goals and the proposed strategy for managing water quality within the CHU. 4.9.1.4 Program Level Hydrology The following provides a description of the four watersheds and their relationship to the basin areas identified for the proposed DMP Update. Buena Vista Creek Watershed (Basin A) The Buena Vista Creek Watershed drains a 9-mile-long, 2-mile-wide area encompassing approximately 23 square miles (14,437 acres) (CWN 2006) and ultimately discharges out into Buena Vista Lagoon and into the Pacific Ocean. Buena Vista Creek traverses through the northwestern portion of Carlsbad and eventually discharges into man-made Buena Vista Lagoon. A 50-foot weir structure that is barely visible when the lagoon is at normal levels (BVLF 2006) controls water level by preventing water from flowing westward towards the Pacific Ocean, thus maintaining a minimum water level in the lagoon. 4.9 Hydrology/Water Quality Page 4.9-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Approximately 3.5 square miles (2,270 acres) of this watershed is within Basin A. Basin A encompasses all areas in the city that drain into the Pacific Ocean via the Buena Vista Creek and the Buena Vista Lagoon. Buena Vista Creek originates in Vista. Basin A elevations range from sea level to 450 feet, with a few canyons located in the eastern portion of the basin. The western portion of the basin is predominantly flat coastal plain. Agua Hedionda Creek Watershed (Basin B) The Agua Hedionda Creek Watershed drains an area measuring approximately 29 square miles (18,837 acres) (CWN 2006) and ultimately discharges into Agua Hedionda Lagoon. Agua Hedionda Creek originates south of the San Marcos Mountains and merges with Buena Creek. After merging with Buena Creek, Agua Hedionda Creek runs approximately 6 miles before reaching Agua Hedionda Lagoon. In addition, the basin includes Lake Calavera and Squires Reservoir, which are located on the eastern edge of the basin. Calavera Creek, located approximately 1.4 miles upstream from Agua Hedionda Lagoon, originates from Lake Calavera and discharges into Agua Hedionda Creek. Water in the Squires Reservoir is treated for potable uses by city residents (CWN 2006). Approximately 14.6 square miles (9,340 acres) of this watershed is within Basin B. Basin B elevations range from sea level to 582 feet with steep hillsides east of I-5. Basin B includes the area of the city that drains to Agua Hedionda Creek and Agua Hedionda Lagoon. Intermittent streams are located in low areas that feed the perennial Agua Hedionda Creek. Encinas Creek Watershed (Basin C) The Encinas Creek Watershed covers an area of approximately 5 square miles (3,434 acres) (CWN 2006) and runoff is discharged into Encinas Creek prior to reaching the Pacific Ocean. Encina Creek is located at the center of the watershed and serves as the main collector for storm water runoff. Encinas Creek originates approximately 3,000 feet east of El Camino Real in a small drainage behind an industrial park and flows west to the Pacific Ocean parallel to Palomar Airport Road. Encinas Creek does not end in a lagoon but flows directly into the Pacific Ocean after crossing I-5 and Carlsbad Boulevard (CWN 2006). Approximately 4 square miles (2,580 acres) of this watershed is within Basin C. Topographically, Basin C has more gradual elevation change than the other basins, starting from sea level to a peak elevation of 410 feet. This basin encompasses the area of Carlsbad that drains into Encinas Creek. 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 Batiquitos Lagoon Watershed (Basin D) The Batiquitos Lagoon Watershed encompasses 56 square miles (35,840 acres) (CWN 2006) and includes two major drainage conveyances, San Marcos Creek and Encinitas Creek, which ultimately drain into Batiquitos Lagoon. San Marcos Creek originates in the coastal mountain range northeast of San Marcos, while Encinitas Creek originates in the mountains southwest of San Marcos. The capacity of the lagoon allows it to provide considerable storage of storm water before discharging to the Pacific Ocean. Approximately 17 square miles (10,907 acres) of this watershed is categorized as Basin D within Carlsbad. Basin D elevations range from sea level to 944 feet with numerous steep ravines located in the eastern portion of the basin forming various natural drainage patterns that produce intermittent streams. Basin D includes the portion of the city that drains to Batiquitos Lagoon and its tributaries. Drainage Surface water in Carlsbad drains through one of the four watersheds identified above. In addition to natural watercourses, drainage in the region has been altered by development and associated storm water infrastructure. Regional drainage currently consists of a combination of soft-bottomed natural watercourses and engineered infrastructure projects. The DMP Update presents existing and proposed projects to improve storm water drainage within Carlsbad. Soils The Soil Survey of San Diego County provides a standard classification of hydrologic soil groups, which establishes the expected potential of each soil type for generating runoff across the soil surfaces. The hydrologic soil group classifications are from A to D, with D representing soils that would generate greater runoff. As described below, soil types vary within each basin. For a discussion of the general soil associations, refer to Section 4.8 (Geology/Soils). Basin A: Multiple hydrologic soil groups are present in Basin A. The eastern portion of the basin is underlain by a combination of Groups C and D, while the western portion of the basin contains a combination of Groups A and C. 4.9 Hydrology/Water Quality Page 4.9-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Basin B: Group A soils are mainly present in the western coastal plain of this basin, while Group B soils are found in the eastern portion of the basin where Agua Hedionda Creek flows into Carlsbad from Vista. Group C and Group D soils are found in the eastern portion of the watershed. Basin C: Existing soil types within this basin include Groups A and D. Group A soils are located in the coastal plain, while Group D soils can be found predominately east of I-5. A small sliver of Group B soils is located along Encinas Creek. Basin D: Soil types within Basin D are mainly Group A in the western portion of the basin and in the streambeds of the creeks/ephemeral tributaries. Some drainage areas contain Group C soils, while the eastern slopes are primarily made up of Group D soils. 100-Year Floodplain The Federal Emergency Management Agency (FEMA) prepares Flood Insurance Rate Maps (FIRMs) that indicate potential flood areas, based upon a 100-year storm and a 500-year event. A 100-year storm is a storm that statistically would occur once in a 100-year period. This is the standard used to determine areas of flooding for the purposes of flood insurance programs managed by FEMA, and it has become the standard for the evaluation of potential flooding impacts. Tables 4.9-1 and 4.9-2 summarize the program level PLDA and non-PLDA components proposed in the DMP Update that would be located within the 100-year floodplain, 500-year floodplain, and/or are within or adjacent to drainage channels. Staging areas are not anticipated to be located within the 100-year floodplain. Water Quality Water Quality Standards The CHU is classified as having numerous beneficial uses, including municipal water supply; agriculture; industrial; contact and noncontact recreation; warm freshwater habitat; wildlife habitat; and rare, threatened, or endangered species. Section 303(d) of the federal CWA requires states to identify waterbodies that do not meet water quality standards and are not supporting their beneficial uses. There are two waterbodies and two watercourses with 303(d) listings in the CHU. These are summarized below. 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-9 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.9-1 Floodplains and Drainage Channels within or adjacent to Proposed Program Level DMP Update PLDA Project Components Project Component ID Project Name 100-year Floodplain 500-year Floodplain Drainage Channel Basin A AAA Jefferson Street Drainage Project AAAA Madison Street Drainage Project AC Highland Drive Drainage Project X X AFA Hidden Valley Drainage Restoration and Enhancement Project X X X AFB North Calavera Hills Drainage Restoration and Enhancement Project X Basin B BB-1 Washington Street Drainage Improvements, Phase I BB-2 Washington Street Drainage Improvements, Phase II BCA Park Drive/ Tamarack Avenue Drainage Project BCB Magnolia Avenue Drainage Project BCC Chestnut Avenue Drainage Project BF1 Kelly Drive Water Quality Basin Project X BFA Country Store Storm Drain Project BFB-L El Camino Real Drainage Project, Phase II BFB-U El Camino Real Drainage Project, Phase I BJ-1 Rancho Carlsbad Sedimentation Basin Project X X BJB College Boulevard Sedimentation Basin Structural Improvements Project X X BL-L College Boulevard Drainage Project Phase V- Downstream Portion X BL-U College Boulevard Drainage Project Phase IV- Upstream Portion X X BM Cantarini Box Culvert Project BNB Calavera Creek Flood Control Improvement Phase II BP Melrose Flood Retention Facility X BQ Sunny Creek Road Restoration and Enhancement Project X BR Cantarini and Holly Springs Development Basin C C1 Carlsbad Boulevard South Drainage Improvements X C2 Paseo Del Norte Drainage Improvements CA Avenida Encinas Drainage Improvements Basin D DBA Poinsettia Village Drainage Improvements DBB Avenida Encinas Drainage Project DFA Batiquitos Lagoon Retention/ Detention Basin Project DH Altiva Place Restoration and Enhancement Project X DQB La Costa Town Center Drainage Improvements Project DZ Poinsettia Lane Bridge Project 4.9 Hydrology/Water Quality Page 4.9-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.9-2 Floodplains and Drainage Channels within or adjacent to Proposed Program Level DMP Update Non-PLDA/CIP Project Components Project Component ID Project Name 100-year Floodplain 500-year Floodplain Drainage Channel Basin A Non-PLDA Project Components No specific non-PLDA components have been identified in Basin A at this time. CIP Project Components A-CIP-1 Miscellaneous Road Subdrains (Project Number 3681) A-CIP-2 Cynthia Lane Storm Drain Project; Cynthia Lane near I-5 A-CIP-3 Carlsbad Boulevard Storm Drain Replacement Project; between the SDNR track and Carlsbad Boulevard A-CIP-4 Ridgecrest Drainage Improvements Project; Ridgecrest Drive Basin B Non-PLDA Project Components BAA Cannon Road Drainage Improvements X BE South of Van Allan Way on south side of Agua Hedionda Creek X X BEA Begins northeast of Faraday Avenue and extends southwest to the south side of Agua Hedionda Creek X X BJ-2 Rancho Carlsbad Detention Basin Project X X BL-L Bridge over Agua Hedionda Creek at College Boulevard CIP Project Components B-CIP-1 and B-CIP-2 Miscellaneous Road Subdrains (Project Number 3681) B-CIP-3 Highland Drive Drainage Improvements Project; Highland Drive between Pine Avenue and Basswood Avenue B-CIP-4 Kelly Drive Drainage Improvements; Kelly Drive east of Hillside Drive Basin C Non-PLDA Project Components C Encinas Creek Restoration and Enhancement Project X CIP Project Components No specific CIP projects have been identified in Basin C at this time. Basin D Non-PLDA Project Components DFA Northwest of the intersection of La Costa Avenue and El Camino Real DM Between Poinsettia Lane and Alga Road, on the west side of Almaden Lane X X CIP Project Components D-CIP-1 through D-CIP-6 Miscellaneous Road Subdrains (Project Number 3681) 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-11 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.9-2. Floodplains and Drainage Channels within or adjacent to Proposed Program Level DMP Update Non-PLDA/CIP Project Components (Continued) Project Component ID Project Name 100-year Floodplain 500-year Floodplain Drainage Channel D-CIP-7 La Costa Avenue Storm Drain Replacement Project; La Costa Avenue between El Camino Real and Viejo Castilla Way X D-CIP-8 Gabbiano Lane Storm Drain Modification; south of Gabbiano Lane near Batiquitos Lagoon D-CIP-9 Calle Gavanzo Subsurface Drainage Improvements; west side of Calle Gavanzo D-CIP-10 Romeria Drainage Improvements Project; Romeria Street • Agua Hedionda Lagoon is listed as limited for sedimentation/siltation and bacteria indicators. • Buena Vista Lagoon is listed as limited for nutrients, sedimentation/siltation, and bacteria indicators. • Agua Hedionda Creek is listed as limited for total dissolved solids. The Pacific Ocean coastal shoreline within Buena Vista Creek Hydrologic Area is listed for bacteria indicators. Urban Runoff Quality Constituents found in urban runoff vary during a storm event, from event to event within a given area, and from area to area within a given watershed. Variances can be the result of differences in rainfall intensity and occurrence, geographic features, and the land use of the area, as well as vehicle traffic and the percentage of impervious surface. Furthermore, sediment runoff from construction sites without adequate erosion control measures can contribute sediments, pesticides, fertilizers, and other pollutants to receiving waters. In the Carlsbad area, the natural weather pattern consists of a dry period from May to September, and a wet season from October to March. During the seasonal dry period, pollutants contributed by vehicle exhaust, vehicle and tire wear, spills, and atmospheric fallout accumulate within the watershed. Precipitation during the early portion of the wet season displaces these pollutants into surface runoff, which can result in elevated pollutant concentrations in initial wet weather runoff. Concentrations of pollutants present in dry weather runoff are typically lower than 4.9 Hydrology/Water Quality Page 4.9-12 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 concentrations present in wet weather runoff. Some sources of constituent pollutants in dry weather runoff include commercial and domestic irrigation, general wash-off, groundwater infiltration, and illegal discharges. 4.9.1.5 Project Level There are two watercourses within the Agua Hedionda project area (project components B and BN): Agua Hedionda Creek and Calavera Creek. Agua Hedionda Creek and Calavera Creek is are listed as having the following beneficial uses: municipal water supply, agriculture, industrial, contact and noncontact recreation, warm freshwater habitat, and wildlife habitat. Calavera Creek is not listed with beneficial uses in the current Basin Plan. (RWQCB 1994). Agua Hedionda Creek is a 303(d) listed water body and has been designated as impaired for total dissolved solids. The WURMP identifies several constituents of concern for Agua Hedionda Creek, including sedimentation, eutrophication, nutrients, general physiochemical characteristics, and pathogens (City of Carlsbad et al. 2003). In addition, Agua Hedionda Lagoon (the ultimate receiving water body) has been designated as limited for sedimentation/siltation and bacteria indicators. 4.9.2 Significance Criteria Proposed DMP Update project components would have a potentially significant impact on hydrology and water quality if they would: • violate federal, state, or local water quality standards or waste discharge requirements; • alter the existing drainage pattern of flow of the area, including through the alteration of the course of a stream or river, in a manner that would result in adverse impacts from erosion, siltation, or flooding on- or off-site; • create or contribute runoff water that would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff; • otherwise adversely impact water quality; • place housing or other structures within a 100-year flood hazard area as mapped on a Federal Flood Hazard Boundary or FIRM or other flood delineation map, that would impede or redirect flows; or 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-13 04080135 Carlsbad DMP EIR.doc 12/11/2007 • expose people or structures to a significant risk of loss, injury, or death involving flooding. 4.9.3 Impact Analysis Impacts to water quality were evaluated qualitatively by assessing proposed long-term activities and maintenance requirements for the components proposed in the DMP Update. The proposed projects may result in a temporary degradation of storm water quality during construction and the operation and maintenance of the proposed infrastructure changes would result in alterations to surface runoff management during a storm event. However, implementation of the proposed DMP Update at the program and project levels would serve to indirectly improve storm water quality in the city boundaries. The DMP Update does not propose wide-scale channelization of natural streams. The majority of the proposed DMP Update components involve improvements to existing facilities or installation of drainage features in developed areas (i.e., roads and right- of-ways; existing commercial, industrial, or residential areas). The proposed drainage improvements would reduce flooding potential, decrease erosion and sedimentation, and enhance storm water flows within the city. In addition, all proposed drainage facilities and infrastructure would comply with the City’s Standard Design Criteria to ensure they are properly sized to handle 100-year flood conditions. Therefore, the proposed DMP Update improvements would indirectly result in positive effects on the long-term management of storm water flows in the region. 4.9.3.1 Program Level Construction Activities Land-disturbing construction activities associated with implementation of the proposed DMP Update, such as grading and excavation and the construction of infrastructure, could lead to temporary construction phase impacts. Construction activities involving soil disturbance, excavation, cutting/filling, stockpiling, and grading could potentially impact receiving water quality. During a storm event, the sediment load of surface runoff flowing over disturbed soils increases, resulting in additional erosion of the site surface. There is also the potential that construction materials such as asphalt, concrete, and equipment fluids could be exposed to rainfall, which would result in contaminated surface runoff and adverse impacts to receiving water quality. 4.9 Hydrology/Water Quality Page 4.9-14 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Anticipated impacts also include the potential for localized alteration of drainage patterns. These alterations may result in temporarily exceeding the capacity of storm water facilities if substantial drainage is rerouted. Temporary ponding and/or flooding could also result from such activities, from temporary alterations of the drainage system (reducing its capacity of carrying runoff), or from the temporary creation of a sump condition due to grading. Alterations may temporarily result in erosion and siltation if flows are substantially increased or routed to facilities or channels without capacity to carry the flow. As discussed above, construction of any project (greater than or equal to 1 acre) requires submission of an NOI to the SWRCB and preparation of a SWPPP to comply with the requirements of the NPDES General Construction Permit. BMPs identified in the SWPPP help reduce impacts related to construction activities and postconstruction activities on storm water quality. In addition, under the San Diego County Municipal Permit, compliance with the City’s storm water management requirements includes preparation of a Water Quality Technical Report (WQTR), which would minimize any impact of proposed projects on storm water quality, regardless of project size. The requirement for preparation of appropriate storm water management documents has been included in the design features of the project. Implementation of appropriate BMPs defined in these documents including, but not limited to, those summarized below, would minimize impacts to water quality by controlling runoff and by ensuring that the quality of storm water flows meets the applicable requirements. Consequently, any short-term impacts resulting from alterations of drainage and hydrology during construction would be less than significant. Erosion would be controlled through use of the following types of BMPs, which would be incorporated into the appropriate project-specific SWPPP or WQTR, as required in Table 3-6. BMP designations are based on those used by the California Department of Transportation Storm Water Quality Handbooks, Construction Site BMPs Manual (Caltrans 2000) and the California Stormwater Quality Association Construction BMP Handbook (2004): • Scheduling (SS-1): Proper scheduling assists in identifying ways to minimize disturbed areas, which allows for a reduction in the active project area requiring protection and also minimizes the length of time disturbed soils are exposed to erosive processes. • Preservation of Existing Vegetation (SS-2): Preservation of existing vegetation to the maximum extent practicable facilitates protection of surfaces from erosion and can also 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-15 04080135 Carlsbad DMP EIR.doc 12/11/2007 provide sediment control benefits. Sensitive areas should also be clearly identified and protected. • Hydraulic Mulch (SS-3), Straw Mulch (SS-6), and Wood Mulching (SS-8): The use of various mulches is a temporary soil stabilization method that can be used on surfaces with little or no slope. • Geotextiles, Plastic Covers, and Erosion Control Blankets/Mats (SS-7): These erosion control methods can be used on flat or, usually, sloped surfaces, channels, and stockpiles. • Stabilized Construction Entrance/Exit (TC-1): A graveled area or pad located at points where vehicles enter and leave a construction site can be built. This BMP provides a buffer area where vehicles can drop their mud and sediment to avoid transporting it onto public roads, to control erosion from surface runoff, and to help control dust. • Runoff Control Measures (SS-9, SS-10 and SC-10): These include graded surfaces to redirect sheet flow, diversion dikes or berms that force sheet flow around a protected area, and storm water conveyances (swales, channels, gutters, drains, sewers) that intercept, collect, and redirect runoff. Diversions can be either temporary or permanent in nature. Temporary diversions include excavation of a channel along with placement of the spoil in a dike on the downgradient side of the channel, and placement of gravel in a ridge below an excavated swale. Permanent diversions are used to divide a site into specific drainage areas, should be sized to capture and carry a specific magnitude of storm event, and should be constructed of more permanent materials. A water bar is a specific kind of runoff diversion that is constructed diagonally at intervals across a linear sloping surface such as a road or right-of-way that is subject to erosion. Water bars are meant to interrupt accumulation of erosive volumes of water through their periodic placement down the slope, and divert the resulting segments of flow into adjacent undisturbed areas for dissipation. • Silt Fence (SC-1): A temporary sediment barrier consisting of fabric, designed to retain sediment from small disturbed areas by reducing the velocity of sheet flows. • Gravel Bag Berm (SC-6) and Sand/Gravel Bag Barrier (SC-8): A temporary sediment barrier consisting of gravel-filled fabric bags, designed to retain sediment from small disturbed areas by reducing the velocity of sheet flows. 4.9 Hydrology/Water Quality Page 4.9-16 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 • Desilting Basin (SC-2) and Sediment Trap (SC-3): Construction of temporary detention structures to facilitate the removal of sediment from waters. The devices provide time for sediment particles to settle out of the water before runoff is discharged. • Storm Drain Inlet Protection (SC-10): Inlet protection consists of devices that detain or filter sediment-laden runoff to facilitate the removal of sediment from waters prior to discharge. Secondary concerns include potential pollutants from inappropriate material storage and handling procedures and non-storm water discharges. These would be addressed through the following types of BMPs, which would be incorporated into the appropriate project-specific SWPPP or WQTR, as required in Table 3-6: • Material Delivery and Storage (WM-1): Provide covered storage for materials, especially toxic or hazardous materials, to prevent exposure to storm water. Toxic or hazardous materials should also be stored and transferred on impervious surfaces that will provide secondary containment for spills. Vehicles and equipment used for material delivery and storage, as well as contractor vehicles, should be parked in designated areas. • Spill Prevention and Control (WM-4): Ensure that spills and releases of materials are cleaned up immediately and thoroughly. Ensure that appropriate spill response equipment, preferably spill kits preloaded with absorbents in an overpack drum, are provided at convenient locations throughout the site. Spent absorbent material must be managed and disposed of in accordance with applicable regulations. In particular, absorbents used to clean up spills of hazardous materials or waste must be managed as hazardous waste unless characterized as nonhazardous. • Solid Waste Management (WM-5): Provide a sufficient number of conveniently located trash and scrap receptacles to promote proper disposal of solid wastes. Ensure that the receptacles are provided with lids or covers to prevent windblown litter. • Hazardous Waste Management (WM-6): Provide a sufficient number of proper receptacles to promote proper disposal of hazardous wastes. • Concrete Waste Management (WM-8): Excess concrete should be disposed of in specific concrete washout facilities. 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-17 04080135 Carlsbad DMP EIR.doc 12/11/2007 • Sanitary/Septic Waste Management (WM-9): Sanitary and septic waste facilities should be located away from drainage courses and traffic areas. The facilities should be maintained regularly. • Street Sweeping and Vacuuming (SC-7): Perform regular street cleaning at entrance/exit points to the construction site and within the construction site as necessary. • Vehicle and Equipment Cleaning (NS-8): Clean vehicles and equipment that regularly enter and leave the construction site. • Vehicle and Equipment Fueling (NS-9): Fuel vehicles and equipment off-site whenever possible. If off-site fueling is not practical, establish a designated on-site fueling area with proper containment and spill cleanup materials. • Vehicle and Equipment Maintenance (NS-10): Use off-site maintenance facilities whenever possible. Any on-site maintenance areas must be protected from storm water runoff and runon. 4.9.3.2 Operation and Maintenance Temporary construction-related impacts to water quality, such as non-storm water discharges, illicit connections to the storm drainage system, accidental spills, and other operational impacts associated with operation and maintenance activities, would be minimized through implementation of the spill contingency plan and construction measures identified in Table 3-6, including a SWPPP or WQTR, as appropriate. Operation and maintenance activities would occur in existing or proposed drainage facilities. Operation and maintenance of the City’s drainage system with the proposed DMP Update upgrades would improve storm water flow in the region. Operation and maintenance activities would allow drainage facilities to continue to provide adequate flood protection, storm water quality control, and storm flow conveyance. Overall, potential impacts to hydrology/water quality from operation and maintenance activities would be less than significant. 4.9.3.3 Project Level Implementation of the drainage improvements in Agua Hedionda and Calavera creeks (components B and BN) would modify the existing watercourses, through channel widening, and removal of accumulated sediment, to return the channels to conditions similar to the original 4.9 Hydrology/Water Quality Page 4.9-18 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 design contours, thereby restoring capacity in the channels and reducing the potential for flooding of the adjacent Rancho Carlsbad residential community. No changes to land use are proposed as a part of the project. The minor alterations in the watercourses and ongoing maintenance would result in modifications to surface runoff management and potential construction and maintenance period impacts to water quality. The proposed DMP Update project level components B and BN involve dredging and construction activities that could potentially degrade water quality in the creeks. To avoid and minimize impacts to water quality, project components B and BN would be required to incorporate BMPs into the project design, which would be part of the project’s SWPPP, as specified in Table 3-6. Construction BMPs would be specifically developed to control the effects of dredging and other construction-related project activities, including bridge modifications and equipment operation and maintenance, to regulate in-stream disturbances. In- stream water quality controls, as well as upland construction site BMPs, would be implemented in compliance with resource agency permit requirements to avoid or minimize potential water quality impacts. In addition to the project design features/methods and construction measures identified in Table 3-6, BMPs that would be implemented as part of the project SWPPP during dredging and construction activities could also include, but not be limited to: • gravel-bag check dam structures to create stilling pools for capturing sediment and controlling turbidity downstream of the project limits; • flocculant logs to promote the settling of suspended silt particles in stilling pools; • creation of a diversion channel to protect active stream flow from water quality impacts associated with in-stream construction activities; • desilting basin upstream of project limits to promote sediment settling and capture prior to flow coming in contact with the gravel-bag check dams downstream. (The desilting basin would remain as a permanent project BMP to allow for periodic removal of accumulated sediment as part of project maintenance. Refer to the maintenance plan included in Appendix B.); • access roadways along sides of channel bottoms to allow the dredging excavator and dump trucks to travel the length of the creek without disturbing water quality; • stream crossings with a water quality bypass underneath the access route, such as a steel pipe covered with creekbed sand; and 4.9 Hydrology/Water Quality City of Carlsbad Drainage Master Plan Update EIR Page 4.9-19 04080135 Carlsbad DMP EIR.doc 12/11/2007 • turbidity compliance monitoring, including collection of water samples within the active flow to measure turbidity onshore, measurement of creek velocity at the point of measurement, and recording of visual observations. The proposed dredging and improvements to Agua Hedionda and Calavera creeks would improve flood control within the creeks and alleviate or partially alleviate residences from inundation during a 100-year flood event. A beneficial impact of the proposed project would be a reduced 100-year floodplain within the project area. This change to the 100-year floodplain would require modifications to existing FIRMs. Modifications to existing FIRMs would be a separate action under FEMA requiring a CLOMR and LOMR to remove property from a Special Flood Hazard Area. 4.9.4 Significance of Impacts 4.9.4.1 Program Level Potential short-term impacts to storm water quality, including potential discharges to 303(d) listed waterbodies, would be considered less than significant during construction. Long-term postconstruction impacts would be beneficial to hydrology, drainage capacity, and water quality in Carlsbad overall. 4.9.4.2 Operation and Maintenance Potential short-term impacts to storm water quality would be considered less than significant during construction. Overall, long-term postconstruction impacts would be beneficial to storm water conveyance and water quality throughout Carlsbad. 4.9.4.3 Project Level Potential short-term impacts to storm water quality would be considered less than significant during construction. Long-term postconstruction impacts would be beneficial to hydrology, drainage capacity, and water quality in Basin B. 4.9 Hydrology/Water Quality Page 4.9-20 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.9.5 Mitigation Measures 4.9.5.1 Program Level Potential hydrology/water quality impacts from implementation of proposed program level DMP Update components would be less than significant; therefore, no mitigation would be required. 4.9.5.2 Operation and Maintenance Potential impacts from proposed operation and maintenance activities would be less than significant; therefore, no mitigation would be required. 4.9.5.3 Project Level Potential hydrology/water quality impacts from project level DMP Update components would be less than significant; therefore, no mitigation would be required. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.10 BIOLOGICAL RESOURCES This section describes the flora and fauna within the Carlsbad DMP study area. Biological resources are discussed in terms of vegetation types, wildlife habitat, and species known to occur within the study area. The program level analysis is based on existing available data such as, the National Wetland Inventory, California Natural Diversity Database (CNDDB), and preserve planning boundaries as established in the Carlsbad HMP. For the program level analysis, vegetation communities were mapped using current data obtained from SANGIS, with data dates ranging from 1995 to 2006, depending on updates to specific vegetation polygons. Therefore, vegetation mapping may not necessarily reflect existing conditions at a specific project component location (i.e., some areas classified by a specific vegetation community may now be developed or disturbed). Vegetation mapping for specific program level DMP Update components would be confirmed during subsequent project level environmental review. No focused or protocol-level surveys were conducted for the program level DMP components due to the time-sensitive nature of such surveys, which would have reduced their applicability during project design of future planned components. Project level analysis for Agua Hedionda and Calavera creeks (i.e., project components B and BN) included a general biological survey for both plant and wildlife species. A wetland delineation was completed in January 2007 for the Agua Hedionda and Calavera creeks (EDAW 2007). In addition, a rare plant survey was also conducted in August 2005 (EDAW 2005). Surveys for the federally listed least Bell’s vireo (Vireo bellii pusillus) and southwestern willow flycatcher (Empidonax traillii extimus) were conducted during the spring (2005) breeding season (RECON 2005). Surveys for the federally listed light-footed clapper rail (Rallus longirostris levipes) were conducted in spring of 2006 (Konecny Biological Services 2006). Supplemental information was also obtained from the Biological Technical Report for the Rancho Carlsbad Channel Maintenance Project (RECON 2002). These biological reports related to the project level analysis for project components B and BN are included in Appendix D of this EIR. 4.10.1 Existing Conditions 4.10.1.1 Program Level Vegetation communities within Carlsbad are generally described below. Figures 4.10-1 through 4.10-4 illustrate generalized vegetation types located within each DMP Update basin. With the exception of the Buena Vista Lagoon, the majority of the central and western portions of Basin A are characterized with disturbed and developed habitat. Isolated patches of agriculture, coastal sage scrub, and grassland also exist within the basin. The eastern portion of Basin A has larger, 4.10 Biological Resources Page 4.10-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 denser areas of grassland, coastal sage scrub, chaparral, and riparian and wetland vegetation. Basin B is largely disturbed/developed in the western portion, with denser upland vegetation communities (i.e., chaparral, grassland, coastal sage scrub, and woodland) in the eastern portion of the basin. Wetland and riparian vegetation communities are primarily located within and adjacent to Agua Hedionda Lagoon and its tributary creeks. Most of Basin C is disturbed/developed, with some upland vegetation communities located in the central portion and wetland and riparian vegetation along Encinas Creek. Basin D is includes large areas of disturbed/ habitat and developed areas throughout the basin, with upland vegetation communities in the northern and eastern portions and wetland and riparian communities within and adjacent to Batiquitos Lagoon and its tributary creeks. Below is a description of each habitat type. The approximate acreages for vegetation communities within Carlsbad are provided in Table 4.10-1. Table 4.10-1 Vegetation Community Acreages in Carlsbad by Basin Vegetation Community Basin A (acres) Basin B (acres) Basin C (acres) Basin D (acres) Agriculture 12 1021 102 701 Chaparral 20 436 42 499 Coastal sage scrub 115 1577 204 1451 Disturbed 119 483 161 562 Eucalyptus woodland 105 27 9 117 Grassland 194 604 184 820 Marsh, estuarine, freshwater and other wetlands 167 516 43 630 Oak woodland 0 15 1 14 Open water (not including lagoons) 0 1 0 7 Riparian scrub, woodland, and forest 89 294 22 198 Southern maritime chaparral 0 99 19 334 Urban/disturbed 1441 4253 1786 5553 Riparian and Wetland Communities Riparian communities occur along stream courses and drainages and are floristically and structurally distinct from the adjacent upland communities. Riparian communities may be floristically similar to each other but may differ sufficiently in structure to warrant different COLLEGE BLVDE L C A M IN O R E A L E L C A M INO R E ALCARLSBAD VILLAGE DRMARRON RDTAMARACK AVEC A R L S B A D B L V DCARLSBAD VILLAGE DRAAAAAAAAFAACACAFBA-CIP-2A-CIP-3A-CIP-1A-CIP-4U N K N O W N !"^$BASIN BBASIN AA©BUENA VISTA LAGOONUNKNOWNBUENA VISTA CREEKBUENA VISTA CREEKBUENA VISTA LAGOONLAKE CALAVERACity of Carlsbad Drainage Master Plan Update EIRFigure 4.10-1VegetationTypesBasin ASource: City of Carlsbad 2005; SANDAG/SanGIS 1995-2006Page x-xxPath: P:\2004\04080135 Carlsbad Drainage Master Plan\5GIS\Mxd\PEIR\BIO\A_Basin_Vegetation.mxd, 04/30/07, marraccinibPLDA Project ComponentNon-PLDA Project ComponentBasin BoundaryWater BodiesUSGS Blue Line StreamsVegetation TypeAgricultureChaparralCoastal Sage ScrubDisturbed/DevelopedGrasslandRiparianWetlandOceansidePacific Ocean1,600 0 1,600800FeetScale: 1:19,200; 1 inch = 1,600 feetILEGEND 4.10 Biological Resources Page 4.10-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. B-CIP-4B-CIP-3B-CIP-1B-CIP-2BEBNBBN!BFB-LBB-1BBFABQBJBBB-2BPBEABAABF1BJ-1BL-U!BFB-UBCBBCCBCABL-LBRBM!BJ-2MELROSE D R MINO REALEL CAMINO REALCOLLEGE BLVDFARADAY AVMARRON RDCAMVIDA ROBLECANNON RDC A R L S B A D B L V D PALOMAR AIRPORT RDC O L L E G E B L V D TAMARACK AVE!"^$BASIN ABASIN BBASIN CBASIN DAGUA HEDIONDA LAGOONBUENA VISTA LAGOONSQUIRES DAMLAKECALAVERAAGUA HEDIONDA CREEKAGUA HEDIONDA CREEKCALAVERA CREEKCity of Carlsbad Drainage Master Plan Update EIRFigure 4.10-2Vegetation TypesBasin BSource: City of Carlsbad 2005; SANDAG/SANGIS 1995-2006 Page x-xxBasin BoundaryPLDA Project ComponentNon-PLDA Project ComponentDual Status (PLDA/Non-PLDA)Water BodiesUSGS Blue Line StreamsVegetation TypesAgricultureChaparralCoastal Sage ScrubDisturbed/DevelopedGrasslandRiparianWetlandWoodlandPath: P:\2004\04080135 Carlsbad Drainage Master Plan\5GIS\Mxd\PEIR\BIO\B_Basin_Vegetation.mxd, 11/04/07, augellopPacific OceanOceansideOceansideVista0.500.50.25MilesScale: 1:33,000; 1 inch = 2,750 feetILEGEND 4.10 Biological Resources Page 4.10-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. CCAC2C1COLLEGE BLVDALGA R DFARADAY AVEL CAMINO REAL POINSETTIA LNALGA RDPALOMAR AIRPORT RDCANNON RDC A R L S B A D B L V DCAM VIDA ROBLE!"^$BASIN CBASIN BBASIN DCity of Carlsbad Drainage Master Plan Update EIRFigure 4.10-3Vegetation TypesBasin CSource: City of Carlsbad 2005; SANDAG/SANGIS 1995-2006Page x-xxPLDA Project ComponentNon-PLDA Project ComponentBasin BoundaryUSGS Blue Line StreamsVegetation TypesAgricultureChaparralCoastal Sage ScrubDisturbed/DevelopedGrasslandRiparianWetlandWoodlandPacific OceanENCINAS CREEKPath: P:\2004\04080135 Carlsbad Drainage Master Plan\5GIS\Mxd\PEIR\BIO\C_Basin_Vegetation.mxd, 04/30/07, marraccinib1,600 0 1,600800FeetScale: 1:19,200; 1 inch = 1,600 feetILEGEND 4.10 Biological Resources Page 4.10-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. D-CIP-7D-CIP-4D-CIP-6D-CIP-9D-CIP-10D-CIP-2D-CIP-8D-CIP-1D-CIP-3D-CIP-5DHDQBDMDBBDFADBADZCOLLEGE BLVDM EL R O S E D R CARRILLO WYLA COSTA AVEPOINSETTIA LNC A R L S B A D B L V DALGA RDCAM VIDA ROBLEPALOMAR AIRPORT RDRANCHO SANTA FE RDE L C A M IN O R E A L !"^$BASIN DBASIN BBASIN CSAN MARCOS CREEKENCINITAS CREEKBATIQUITOS LAGOONCity of Carlsbad Drainage Master Plan Update EIRFigure 4.10-4Vegetation TypesBasin DSource: City of Carlsbad 2005; SANDAG/SANGIS 1995-2006Page x-xxPath: P:\2004\04080135 Carlsbad Drainage Master Plan\5GIS\Mxd\PEIR\BIO\D_Basin_Vegetation.mxd, 05/08/07, marraccinibPLDA Project ComponentNon-PLDA Project ComponentDual Status (PLDA/Non-PLDA)Basin BoundaryWater BodiesUSGS Blue Line StreamsVegetation TypesAgricultureChaparralCoastal Sage ScrubDisturbed/DevelopedGrasslandRiparianWetlandWoodlandPacific OceanEncinitasSan Marcos3,500 0 3,5001,750FeetScale: 1:42,000; 1 inch = 3,500 feetILEGEND 4.10 Biological Resources Page 4.10-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-11 04080135 Carlsbad DMP EIR.doc 12/11/2007 classifications (e.g., forests, woodlands, and scrub). Most riparian species are restricted to areas of a high water table (e.g., drainages) and require moist, bare mineral soils for germination and establishment, much like the conditions following periodic flooding (Holland 1986). Wetlands serve many functions, including flood and sediment control, habitat for rare and common species, corridors for wildlife movement, and control of water quality and erosion. The value of riparian and wetland communities, combined with their loss and degradation, has resulted in the need to protect these communities. Riparian communities within the Carlsbad study area include riparian scrub, mulefat scrub, southern willow scrub, riparian woodland, southern coast live oak riparian woodland, and sycamore alluvial woodland. Wetland communities in Carlsbad are focused within and adjacent to the coastal lagoons, as well as their tributaries. They include cismontane alkali marsh, coastal and valley freshwater marsh, disturbed wetlands, and southern coastal salt marsh. The following riparian and wetland communities are located within Carlsbad. Riparian Scrub, Woodland, and Forest Riparian scrub varies from a dense, broad-leafed, winter-deciduous association dominated by several species of willow to an herbaceous scrub dominated by mulefat (Baccharis salicifolia). Riparian scrub is an inclusive term for several riparian, shrub-dominated communities such as southern willow scrub, mulefat scrub, and tamarisk scrub. Riparian scrub is designated sensitive habitat by the CDFG (City of Carlsbad 2004). Mulefat scrub is a riparian shrub community strongly dominated by mulefat, in association with several willow species (Salix spp.). Mulefat-dominated scrub occurs along intermittent streams with fairly coarse substrates and moderately deep water tables. Understory vegetation is usually composed of nonnative, weedy species or is lacking altogether. This community is maintained by frequent flooding and, in the absence of periodic flooding, may develop into cottonwood- or sycamore-dominated riparian communities. Southern willow scrub is a dense, broad-leaved, winter-deciduous riparian thicket dominated by several species of willows (Salix spp.) in association with mulefat. Scattered individuals of cottonwood (Populus spp.) and western sycamore (Platanus racemosa) may exist as canopy emergents. This is an early seral community that requires periodic flooding for its maintenance. In the absence of periodic flooding, this community develops into riparian woodland or forest. Southern willow scrub is designated sensitive habitat by the CDFG (City of Carlsbad 2004). 4.10 Biological Resources Page 4.10-12 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Riparian woodland is a tall, winter-deciduous riparian association, with western sycamore as the indicator species; however, other riparian tree species, such as willow, white alder (Alnus rhombifolia), and cottonwood, can also be present. This association occupies broader drainages or floodplains of permanent streams and rarely forms closed canopies. Often it may appear as a stand of scattered trees within a matrix of willows, mulefat, mugwort (Artemisia douglasiana), stinging nettle (Urtica dioica ssp. holosericea), and other shrubby species. The understory component is composed primarily of forbs and nonnative grasses, with shrub species accounting for only a small portion of the cover. A riparian forest is the forested area of land adjacent to a stream, river, lake, bay, or marsh. Riparian forests form the transition between the aquatic and the terrestrial environment. Riparian forest differs from riparian woodland in that forest typically has a denser, more closed canopy than woodland. Southern cottonwood-willow riparian forest is an open or closed canopy forest that is generally greater than 6 m (20 ft) high and occupies relatively broad drainages and floodplains supporting perenially wet streams. This community is dominated by mature individuals of winter deciduous trees, including Fremont's cottonwood (Populus fremontii var. fremontii) and several species of willows, and often has a dense understory of shrubby willows, mulefat, and mugwort. The dominant species require moist, bare mineral soil for germination and establishment, provided after floodwaters recede. A willow riparian forest is a community consisting of streamside vegetation similar to a southern cottonwood-willow riparian forest; however, the habitat is absent of cottonwood species and dominated by willow (Salix sp.). Disturbed riparian forest includes stands of this habitat that have reduced cover due to clearing, off- road vehicle activity, and invasion by exotic species such as giant reed (Arundo donax), tamarisk (Tamarix spp.), pepper-tree (Schinus spp.), and eucalyptus (Eucalyptus spp.), among others. Southern Coast Live Oak Riparian Woodland Southern coast live oak riparian woodland is an open to dense evergreen riparian forest that is dominated by coast live oak (Quercus agrifolia). Structurally, this habitat generally consists of western sycamores, cottonwoods, and willows at the channel margins, bordered by coast live oak at slightly higher elevations. Young willows and cottonwoods, mulefat, San Diego sagewort (Artemisia palmeri), and various riparian herbaceous species dominate the understory. Vegetation 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-13 04080135 Carlsbad DMP EIR.doc 12/11/2007 within the channel may include sedges (Cyperus sp.), yerba mansa (Anemopsis californica), and scattered patches of cattails (Tupha spp.). Shrub species in the outer edges of this association may include toyon (Heteromeles arbutifolia), California wild rose (Rosa californica), desert elderberry (Sambucus mexicana), California blackberry (Rubus ursinus), and poison oak (Toxicodendron diversilobum), while typical herbaceous understory species include Douglas mugwort (Artemisia douglasiana) and eucrypta (Eucrypta chrysanthemifolia), among others. Sycamore Alluvial Woodland Sycamore alluvial woodland is an open, winter-deciduous broad-leaved riparian habitat dominated almost exclusively with western sycamore. Interspersed in the subcanopy are typically elderberry and mulefat and occasional islands of coastal sage scrub species. The understory of the sycamore alluvial woodland is often composed of nonnative grasses. This habitat usually occurs in intermittent stream channels with a cobbly substrate. Cismontane Alkali Marsh Cismontane alkali marsh is a community dominated by perennial, emergent monocots that grow in either standing water, or in soils that are saturated during most or all of the year. High evaporation rates combined with low flow levels of fresh water create high saline conditions, which are particularly prevalent during the summer months. This community occurs along ephemeral streams and floodplains. Common species include yerba mansa, coastal saltgrass (Distichlis spicata var. stricta), cattails, spiny rush (Juncus acutus ssp. leopoldii), Mexican rush (Juncus mexicanus), and San Diego marsh elder (Iva hayesiana). Coastal and Valley Freshwater Marsh Coastal and valley freshwater marsh is a community dominated by perennial, emergent monocots, which grow in standing fresh water. This community occurs around lagoons and river mouths along the coast. It can also commonly be found along streamsides, often in association with riparian forest. Common species within this community include cattails, bulrush (Scirpus spp.), umbrella sedge (Cyperus spp.), sedge, and spike sedge (Eleocharis spp.). Disturbed Wetlands Sites classified as disturbed wetlands generally have hydric soils and/or wetland indicator plant species, including nonnative plants. Disturbed wetlands are communities that are dominated by 4.10 Biological Resources Page 4.10-14 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 exotic wetland species. These species have invaded sites that had been previously disturbed or are periodically disturbed. This perturbation regime has resulted in the displacement of native wetland species and the subsequent colonization of these areas by exotics, such as giant reed (Arundo donax), tamarisk (Tamarix spp.), and cocklebur (Xanthium strumarium var. canadense). Southern Coastal Salt Marsh Southern coastal salt marsh is an association of herbaceous and sub-shrub, salt-tolerant species that form a moderate to dense cover. Coastal salt marsh plants are distributed along distinct zones depending upon environmental factors such as frequency and length of tidal inundation, salinity levels, and nutrient status. This association is usually segregated horizontally, with cord grass (Spartina foliosa) nearest open water; dwarf glasswort (Salicornia bigelovii), woody glasswort (Salicornia virginica), and American saltwort (Batis maritima) at mid-littoral levels; and a richer mixture of species, including alkali-heath, sea-blite, and/or Parish’s glasswort (Salicornia subterminalis) at higher elevations. Other characteristic species include coastal saltgrass, alkali- weed (Cressa truxillensis var. vallicola), and fleshy jaumea (Jaumea carnosa). Southern coastal salt marsh occurs at the margins of bays, lagoons, and estuaries along the coast from around Point Conception to the Mexican border. Potential inclusions within southern coastal salt marsh are saltpan, open water, and disturbed wetland. Southern coastal salt marsh is designated sensitive habitat by the CDFG (City of Carlsbad 2004). Upland Communities Scrub Several scrub communities exist in Carlsbad, including Diegan coastal sage scrub, maritime succulent scrub, and coastal sage-chaparral scrub. Diegan coastal sage scrub is composed of low, soft-woody sub-shrubs and occurs on xeric sites with shallow soils or on dry sites, such as steep, south-facing slopes or clay-rich soils that are slow to release stored water. California sagebrush (Artemisia californica) is prevalent in this community, but it often occurs with various codominant species. There are several recognized sub-associations of Diegan coastal sage scrub based upon the dominant species. Typical Diegan coastal sage scrub dominants include California sagebrush, flat-top buckwheat (Eriogonum fasciculatum), laurel sumac (Malosma laurina), black sage (Salvia mellifera), lemonade berry (Rhus integrifolia), and California sunflower (Encelia californica). 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-15 04080135 Carlsbad DMP EIR.doc 12/11/2007 Maritime succulent scrub is confined to thin, rocky, or sandy soils on dry, south-facing slopes along coastal areas. This community is a low, open vegetation type with a poorly developed understory. The dominant shrub species in this community include some of the coastal sage scrub dominants, as well as a number of cacti and other succulent species. Typical shrub and sub-shrub species include California sagebrush, California copperleaf (Acalypha californica), Shaw’s agave (Agave shawii), California sunflower, and cliff spurge (Euphorbia misera). Cacti include velvet cactus (Bergerocactus emoryi), coast barrel cactus (Ferocactus viridescens), coastal prickly pear (Opuntia littoralis), and coastal cholla (Opuntia prolifera). Stands of the shrub species jojoba (Simmondsia chinensis) can be found in this community type. Coastal sage-chaparral scrub reflects the ecotone between coastal sage scrub and chaparral communities. Species characteristic of each community such as California sagebrush, black sage, Ceanothus spp., and chamise (Adenostoma fasciculatum) occur here. Coastal sage-chaparral scrub is generally considered sensitive and is regulated similarly to coastal sage scrub. Chaparral Chaparral communities found in Carlsbad include chamise chaparral, scrub oak chaparral, southern maritime chaparral, and southern mixed chaparral. Chaparral communities are shrub- dominated communities characterized by evergreen species with small, cutinized leaves, and a root system consisting of tap roots and shallow lateral roots. It is typically composed of broad- leaved, sclerophyllous shrubs, although species composition varies considerably with location. Chamise chaparral is dominated, sometimes exclusively, by chamise. This community tends to occur most frequently on ridgelines and flat mesas, though slopes will also support chamise chaparral. The community is composed of more than 50 percent cover of chamise and tends to be of lower stature and density than many other chaparral communities (e.g., southern mixed chaparral). Though the floristic diversity of this community is often relatively low, other component species include mission manzanita (Xylococcus bicolor), black sage, our Lord’s candle (Yucca whipplei), and coast spice bush (Cneoridium dumosum). Scrub oak chaparral is a dense, tall community dominated by scrub oak (Quercus berberidifolia) in association with mountain mahogany (Cercocarpus betuloides). This community occurs on sites that are more mesic than other chaparral, and on soils that are too shallow or xeric for oak woodland communities. Interior live oak (Quercus wislizenii var. frutescens), toyon, deer brush (Ceanothus integerrimus), chaparral whitethorn (Ceanothus leucodermis), 4.10 Biological Resources Page 4.10-16 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Eastwood manzanita (Arctostaphylos glandulosa), and poison oak are all associates within this community (Holland 1986). Southern maritime chaparral is a low, relatively open chaparral characterized by such species as wart-stemmed ceanothus (Ceanothus verrucosus), Del Mar manzanita (Arctostaphylos glandulosa ssp. crassifolia), summer-holly (Comarostaphylis diversifolia ssp. diversifolia), Del Mar sand aster (Corethrogyne filaginifoila var. linifolia), and sea dahlia (Coreopsis maritima), among others. Other species that commonly occur in this habitat are chamise, mission manzanita, and toyon. Southern maritime chaparral is designated sensitive habitat by the CDFG. Southern mixed chaparral is a diverse mixture of sclerophyllous shrubs. The community structure of southern mixed chaparral is more complex than other chaparral communities, having a greater canopy height and higher cover values. Southern mixed chaparral typically occurs on north-facing slopes where microenvironmental conditions are more mesic. Chamise, mission manzanita, scrub oak, and the blue colored lilacs (e.g., Ceanothus tomentosus, C. leucodermis) are the most widespread species, with other species becoming locally important. Woodland Upland woodland habitats in Carlsbad include coast live oak woodland and eucalyptus woodland. Coast live oak woodland is an open to dense tree community with coast live oak the dominant overstory species with Engelmann oak (Quercus engelmannii) as an occasional associate. This community can occur on mesic north-facing slopes and in canyon bottoms. The shrub understory of this community is well developed in undisturbed sites and may include Mexican elderberry (Sambucus mexicana), gooseberry (Ribes spp.), poison oak, and toyon. An herbaceous stratum is usually present including miner’s lettuce (Claytonia perfoliata var. perfoliata), chickweed (Stellaria media), and nonnative grasses. Eucalyptus woodland is a community dominated by nonnative eucalyptus trees. This community can provide habitat for nesting raptors and other birds or roosting bats. Grassland Grassland communities present in Carlsbad include native and nonnative grassland. Native grasslands are communities dominated by perennial bunchgrasses such as needlegrass (Nasella spp. and Achnatherum spp.), plumed beardgrass (Bothriochloa barbinodis), wild rye (Elymus spp.), and deergrass (Muhlenbergia spp.) (Beauchamp 1986). Valley needlegrass grassland is 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-17 04080135 Carlsbad DMP EIR.doc 12/11/2007 characterized by a relatively low (>10 percent) to dense herbaceous cover of the perennial, tussock-forming species, purple needlegrass (Nasella pulchra). Native and introduced annuals occur between the needlegrass, often actually exceeding the bunchgrass in cover. This association generally occurs on fine-textured clay soils that are moist or wet in winter, but very dry in summer. In addition to purple needlegrass, indicator species include blue-eyed grass (Sisyrinchium bellum), mariposa lily (Calochortus splendens), and clarkia (Clarkia spp.), among others. Annual and perennial forbs such as common golden stars (Bloomeria crocea ssp. crocea), and California blue-eyed grass (Sisyrinchium bellum) may also be present. Nonnative grassland generally occurs on fine-textured loam or clay soils that are moist, or even waterlogged, during the winter rainy season and very dry during the summer and fall. It is characterized by a dense to sparse cover of annual grasses, often with native and nonnative annual forbs. This habitat is a disturbance-related community most often found in old fields or openings in native scrub habitats. Typical grasses within the region include wild oat, soft chess (Bromus mollis), red brome (Bromus rubens), ripgutgrass (Bromus diandrus), and foxtail fescue (Vulpia megalura). Characteristic forbs include red-stem filaree (Erodium cicutarium), mustard (Brassica spp.), tarweed (Hemizonia spp.), California goldfields (Lasthenia chrysostoma), and owl’s clover (Orthocarpus purpurascens). Plant and Wildlife Species There are over 300 species of plants, 200 species of birds, 25 species of reptiles and amphibians, 20 species of mammals, 44 species of fish, 45 species of butterflies, and several thousand species of terrestrial and aquatic invertebrates populations within Carlsbad (EIR Carlsbad General Plan Update 1994). Sensitive plant species are those that are federally listed by the USFWS (1998), are state-listed or considered sensitive by the CDFG (2001a, 2001b), or are a “covered species”7 per the HMP (City of Carlsbad 2004). Sensitive wildlife species are those listed as threatened or endangered, proposed for listing, or candidates for listing by the USFWS (1998); are considered sensitive by the CDFG (2001c), or are a “covered species” under the HMP (City of Carlsbad 2004). Table 4.10-2 lists the sensitive plant and wildlife species that occur in each basin area, while Table 4.10-3 lists the sensitive plant and wildlife species by general habitat. See Appendix D for a definition of terms for these listed plant and wildlife species found in Carlsbad. 7 “Covered species” are plant and wildlife species identified in the City’s HMP as species for which take authorizations have been granted (City of Carlsbad 2004). 4.10 Biological Resources Page 4.10-18 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-2 Sensitive Plant and Wildlife Species Found in Carlsbad by Basin Common Name Scientific Name Status Designation1 Basin A Basin B Basin C Basin D Plant Blochman’s dudleya Dudleya blochmaniae ssp. Blochmaniae CNPS List 1B HMP: covered √ √ California adolphia Adolphia californica CNPS List 2 √ √ √ California Orcutt grass Orcuttia californica FE; SE √ √ Cliff spurge Euphorbia misera HMP: covered √ Del Mar manzanita Arctotaphylos glandulosa ssp. crassifolia FE; CNPS List 1B HMP: covered, narrow/endemic √ √ √ Del Mar Mesa sand aster Corethrogyne filaginifolia var. linifolia CNPS List 1B HMP: covered, narrow/endemic √ Encinitas baccharis Baccharis vanessae FT; SE; CNPS List 1B; HMP: covered, narrow/endemic √ Little mousetail Myosurus minimus apus HMP: covered, narrow/endemic √ Nuttall’s lotus Lotus nuttallianus HMP: covered √ Nuttall’s scrub oak Quercus dumosa CNPS List 1B HMP: covered √ √ Orcutt’s brodiaea Brodiaea orcuttii CNPS List 1B HMP: covered √ San Diego button-celery Eryngium aristulatum var. parishii FE; SE √ √ San Diego goldenstar Muilla clevlandii CNPS List 1B HMP: covered, narrow/endemic √ San Diego marsh-elder Iva hayesiana HMP: covered √ San Diego thorn-mint Acanthomintha ilicifolia FT; SE HMP: covered, narrow/endemic √ √ √ Spreading navarretia Navarretia fossalis FT; HMP: covered √ √ Sticky dudleya Dudleya viscida CNPS List 1B HMP: covered √ √ Summer holly Comarostaphylis diversifolia ssp. planifolia CNPS List 1B HMP: covered √ √ √ Thread-leaved brodiaea Brodiaea filifolia FT; SE; CNPS List 1B; HMP: covered, narrow/endemic √ √ √ Wart-stemmed ceanothus Ceanothus verrucosus CNPS List 2; HMP: covered √ √ √ Wildlife Belding’s savannah sparrow Passerculus sandwichensis belding SE √ √ √ 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-19 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-2. Sensitive Plant and Wildlife Species Found in Carlsbad by Basin (Continued) Common Name Scientific Name Status Designation1 Basin A Basin B Basin C Basin D California horned lark Eremophila alpestris actia CDFG: Species of Special Concern √ California least tern Sterna antillarum browni SE; FE √ √ √ Coast (San Diego) horned lizard Phrynosoma coronatum blainvillii CDFG: Species of Special Concern √ √ √ Coastal cactus wren Campylorhynchus brunneicapillus sandiegensis CDFG: Species of Special Concern √ √ Coastal California gnatcatcher Polioptila californica californica FT; CDFG: Species of Special Concern HMP: covered √ √ √ √ Dulzura pocket mouse Chaetodipus californicus femoralis CDFG: Species of Special Concern √ Least Bell’s vireo Vireo bellii pusillus FE; SE √ √ √ Light-footed clapper rail Rallus longirostris levipes FE; SE √ √ √ Northwestern San Diego pocket mouse Chaetodipus fallax fallax CDFG: Species of Special Concern √ Orange-throated whiptail Aspidoscelis (Cnemidophorus) hyperythra beldingi CDFG: Species of Special Concern √ √ Riverside fairy shrimp Streptocephalus woottoni FE √ San Diego black-tailed jackrabbit Lepus californicus bennettii CDFG: Species of Special Concern √ √ San Diego desert woodrat Neotoma lepida CDFG: Species of Special Concern √ √ √ Southern California rufous- crowned sparrow Aimophila ruficeps CDFG: Species of Special Concern √ √ √ Southwestern willow flycatcher Empidonax traillii extimus FE; SE √ Tidewater goby Eucyclogobius newberryi FE; CDFG: Species of Special Concern √ √ Two-striped garter snake Thamnophis hammondii CDFG: Species of Special Concern √ Western snowy plover Charadrius alexandrinus nivosus FT √ √ √ White-faced ibis Plegadis chihi CDFG: Species of Special Concern √ √ White-tailed kite Elanus leucurus CDFG: fully protected √ √ Yellow warbler Dendroica petechia CDFG: Species of Special Concern; HMP: covered √ √ Yellow-breasted chat Icteria virens CDFG: Species of Special Concern; HMP: covered √ √ 1 Sensitivity Status Code: USFWS = U.S. Fish and Wildlife Service 4.10 Biological Resources Page 4.10-20 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-2. Sensitive Plant and Wildlife Species Found in Carlsbad by Basin (Continued) FE = Federally listed endangered FT = Federally listed threatened CDFG = California Department of Fish and Game SE = State listed endangered Species of Special Concern: species that because of declining population levels, limited ranges, and/or continuing threats have been made vulnerable to extinction Fully Protected: species that may not be taken or possessed without a permit from Fish and Game Commission CNPS = California Native Plant Society 1B: plants rare, threatened, or endangered in California or elsewhere 2: plants rare, threatened, or endangered in California, but more common elsewhere HMP = Habitat Management Plan Covered: species that will be covered under the take authorization for the HMP Narrow/Endemic: native species with restricted geographic distributions, soil affinities, and/or habitats and have important populations within the HMP area, such that a substantial loss of these populations or habitats might jeopardize the continued existence or recovery of that species Source: CDFG 2001a, City of Carlsbad 2004 Table 4.10-3 Sensitive Plant and Wildlife Species by General Habitat Type Species Habitat Type Common Name Scientific Name Wetland Coastal Coastal Sage Scrub Chaparral Woodland Riparian Grassland Vernal Pool River/ Estuary Plant Blochman’s Dudleya Dudleya blochmaniae ssp. blochmaniae √ √ √ California adolphia Adolphia californica √ √ √ California Orcutt grass Orcuttia californica √ Cliff spurge Euphorbia misera √ Coast woolly-heads Nemacaulis denudata var. denudate √ Del Mar Manzanita Arctotaphylos glandulosa ssp. crassifolia √ Del Mar Mesa sand aster Corethrogyne filaginifolia var. linifolia √ √ Encinitas baccharis Baccharis vanessae √ Little mousetail Myosurus minimus apus √ Nuttall’s lotus Lotus nuttallianus √ √ Nuttall’s scrub oak Quercus dumosa √ √ Orcutt’s brodiaea Brodiaea orcuttii √ √ √ √ San Diego button-celery Eryngium aristulatum var. parishii √ San Diego goldenstar Muilla clevlandii √ √ √ √ San Diego marsh-elder Iva hayesiana √ 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-21 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-3. Sensitive Plant and Wildlife Species by General Habitat Type (Continued) Species Habitat Type Common Name Scientific Name Wetland Coastal Coastal Sage Scrub Chaparral Woodland Riparian Grassland Vernal Pool River/ Estuary San Diego thorn-mint Acanthomintha ilicifolia √ √ √ √ Spreading navarretia Navarretia fossalis √ Sticky dudleya Dudleya viscida √ √ Summer holly Comarostaphylis diversifolia ssp. planifolia √ Thread-leaved brodiaea Brodiaea filifolia √ √ √ √ √ Wart-stemmed ceanothus Ceanothus verrucosus √ Wildlife Belding’s savannah sparrow Passerculus sandwichensis belding √ California horned lark Eremophila alpestris actia √ √ California least tern Sterna antillarum browni √ √ Coast (San Diego) horned lizard Phrynosoma coronatum blainvillii √ √ √ Coastal cactus wren Campylorhynchus brunneicapillus sandiegensis √ Coastal California gnatcatcher Polioptila californica californica √ Dulzura pocket mouse Chaetodipus californicus femoralis √ √ Least Bell’s vireo Vireo bellii pusillus √ Light-footed clapper rail Rallus longirostris levipes √ √ Northwestern San Diego pocket mouse Chaetodipus fallax fallax √ √ √ Orange-throated whiptail Aspidoscelis (Cnemidophorus) hyperythra beldingi √ √ Riverside fairy shrimp Streptocephalus woottoni √ San Diego black-tailed jackrabbit Lepus californicus bennettii √ √ √ San Diego desert woodrat Neotoma lepida √ √ Southern California rufous- crowned sparrow Aimophila ruficeps √ Southwestern willow flycatcher Empidonax traillii extimus √ Tidewater goby Eucyclogobius newberryi √ √ Two-striped garter snake Thamnophis hammondii √ √ Western snowy plover Charadrius alexandrinus nivosus √ White-faced ibis Plegadis chihi √ √ 4.10 Biological Resources Page 4.10-22 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-3. Sensitive Plant and Wildlife Species by General Habitat Type (Continued) Species Habitat Type Common Name Scientific Name Wetland Coastal Coastal Sage Scrub Chaparral Woodland Riparian Grassland Vernal Pool River/ Estuary White-tailed kite Elanus leucurus √ √ √ Yellow warbler Dendroica petechia √ Yellow-breasted chat Icteria virens √ Source: CDFG 2001a Wildlife Movement Corridors In an urban context, a wildlife corridor can be defined as a linear landscape feature of sufficient width and buffer to allow wildlife movement between two patches of comparatively undisturbed habitat, or between a patch of habitat and some vital resources. The USFWS defines regional corridors as those linking two or more large areas of natural open space, and local corridors as those allowing resident wildlife to access critical resources (food, cover, and water) in a smaller area that might otherwise be isolated by urban development. Wildlife corridors are essential in geographically diverse settings, and especially in urban settings, for the sustenance of healthy and genetically diverse wildlife communities. At a minimum, they promote colonization of habitat and genetic variability by connecting fragments of like habitat, and they help sustain individual species distributed in and among habitat fragments. Habitat fragments, by definition, are separated by otherwise foreign or inhospitable habitats, such as urban/suburban tracts. Isolation of populations can have many harmful effects and may contribute significantly to local species extinction. A viable wildlife corridor consists of more than a path between habitat areas. To provide food and cover for transient species as well as resident populations of less mobile species, a wildlife corridor must also include pockets of vegetation. Wildlife corridors within Carlsbad are defined as linkages within the HMP focused planning areas. These areas are known as Core Areas. As a component of the HMP preserve system, linkages of conserved habitat have been established to provide connectivity between the Core Areas and to natural communities within the region (City of Carlsbad 2004). Core Areas within the focused planning areas as they relate to the program level DMP components are shown in 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-23 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-4. These Core Areas and linkages consist of blocks of habitat that are sufficiently large to reliably support breeding populations of species, or that are large and intact enough to form ecologically functional areas for preserve design. Table 4.10-4 Wildlife Corridors (Linkages) in the HMP Core Areas Core Areas/Linkages Basin A Basin B Basin C Basin D Core Area 1: Northwest section of Carlsbad, dominated by open water and riparian habitats. Functions as corridor for birds and mammals. √ Core Area 2 (Link A): Supports riparian scrub and freshwater marsh habitats. Critical area for gnatcatchers; corridor for birds, mammals, coyote and bobcat. √ Core Area 3 (Links B and C): Supports grassland and coastal sage scrub; corridor for birds and mammals. √ Core Area 4 (Links B and C): Small fragments of coastal sage scrub, grassland, and chaparral. Critical vegetation includes salt marsh, freshwater marsh. Corridor for birds and mammals across this large, open area. √ Core Area 5 (Link D): Coastal sage scrub, chaparral, grassland, and riparian habitats. Linkage is probably a moderately effective corridor for birds and mammals. √ Core Area 6 (Links E and F): contains southern maritime chaparral, grassland, vernal pools, coastal sage scrub, chaparral, open water, disturbed wetland, oak woodland, eucalyptus woodland, and riparian forest. Narrow north- south canyons vegetated with coastal sage effective for dispersing gnatcatcher and other birds and mammals. √ √ Core Area 7 (Link E): Contains large areas of coastal sage scrub, grassland, riparian scrub, and chaparral. This is an effective regional landscape linkage for a wide range of species. √ Core Area 8: Includes Batiquitos Lagoon and critical populations of Nuttall’s lotus, salt marsh skipper butterfly, white faced-ibis, light-footed clapper rail, western snowy plover, California least tern, and Belding’s Savannah sparrow; critical foraging area for American peregrine falcon and California brown pelican. √ Source: City of Carlsbad 2004 4.10 Biological Resources Page 4.10-24 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Applicable Plans and Policies Carlsbad Habitat Management Plan The State of California implemented the NCCP Program, which is aimed at conserving and ensuring the biological integrity of entire communities while accommodating economic development. With the initiating of the NCCP Program in 1991, formal regional planning for biological resources protection has become widespread and important in southern California. Regional conservation planning efforts in Carlsbad have been conducted in accordance with the NCCP Program of 1991. In November 2004, the City adopted a HMP. The overall goal of the HMP is to contribute to regional biodiversity and the viability of rare, unique or sensitive biological resources throughout Carlsbad. The HMP includes conservation goals and measures to avoid, minimize, and mitigate impacts to covered species on a project basis, including measures that apply to drainage infrastructure projects. The HMP goals and measures are applied citywide to all public and private projects regardless of whether projects are located within or outside of the preserve system. Information about the specific mitigation measures for HMP-covered species is included in Appendix C of the Carlsbad HMP. City public facility and improvement projects, such as those included in the DMP Update, are required to provide mitigation based on the ratios shown in Table 4.10-5. These mitigation ratios apply whether a project is located inside or outside the preserve system. For Type D habitats (unoccupied coastal sage scrub, coastal sage/chaparral mix, chaparral), Type E habitats (annual, nonnative grasslands) and Type F habitats (disturbed lands, eucalyptus, agricultural lands) as identified in Table 4.10-5, mitigation fees can be paid in lieu of off-site mitigation as determined by the City Council. City projects are able to use the future Lake Calavera Mitigation Bank for impacts to Type D, E, and F habitats. The HMP also contains standards applicable to development in the Coastal Zone (Section D.7, Conservation Strategy). These standards repeat many of the policies and provisions of the LCP, which is discussed below. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-25 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-5 Mitigation Ratios for Impacts to HMP Habitats Habitat Group and Type Mitigation Ratio/ Requirement by Type of Impacted Habitat A. Coastal salt marsh, alkali marsh, freshwater marsh, estuarine, salt pan/mudflats, riparian forest, riparian woodland, riparian scrub, vernal pools, disturbed wetlands, flood channel, fresh water Engelmann oak woodland, coast live oak woodland 1 No net loss goal (mitigation ratio varies by type of replacement habitat) B. Beach, southern coastal bluff scrub, maritime succulent scrub, southern maritime chaparral, native grassland 3:1 2 C. Gnatcatcher – Occupied coastal sage scrub 2:1 3 D. Unoccupied coastal sage scrub, coastal sage/chaparral mix, chaparral (excluding southern maritime chaparral) 1:1 4,5 E. Annual (nonnative) grassland 0.5:1 4,5 F. Disturbed lands, eucalyptus, agricultural lands Mitigation Fee 4,5 1 Group A habitats are associated with wetlands. Impacts to these habitat types are subject to review under Section 404 of the federal Clean Water Act or Section 1600 of the California Fish and Game Code. 2 It is assumed that all habitats in Type B will be included in the proposed preserve system. Small, isolated patches of low quality southern maritime chaparral may be located outside a preserve area and maximum avoidance and on-site conservation is preferred. 3 Maximum avoidance and on-site conservation of Group C habitat are encouraged. 4 Off-site mitigation for habitat in this group that is not conserved or mitigated on-site shall pay a per acre in lieu mitigation fee in an amount to be determined by the City Council. This fee is discussed in more detail in Section E of the Plan. 5 City projects that impact Type D, E, and F habitats will not pay the fee and will mitigate at the Lake Calavera Mitigation Bank. These projects may mitigate out-of-kind because the objective is to build the preserve system by combining small mitigation requirements into a larger, contiguous area. City projects that impact Type A, B, and C habitats must mitigate in-kind at the ratios stated above. Local Coastal Program The City’s LCP designates five planning areas, or “segments,” within the Coastal Zone (Mello I, Mello II, West Batiquitos Lagoon/Sammis Properties, East Batiquitos Lagoon/Hunt Properties, and Agua Hedionda Lagoon), and includes policies applicable to drainage improvements in these segments. The purpose of the LCP is to provide policies and provisions that protect the City’s resources within the Coastal Zone, including sensitive habitats. The 1994 MDSQMP is incorporated as part of the City’s LCP (Carlsbad Municipal Code Title 21, Zoning, Chapter 21.203 Coastal Resource Protection Overlay Zone). Overall, the LCP requires storm drainage facilities in developed areas to be improved and enlarged according to the City’s existing 1994 MDSQMP (City of Carlsbad 1996). Thus, it is the intent of the LCP to allow implementation of drainage projects that are part of the City’s drainage master planning program. 4.10 Biological Resources Page 4.10-26 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 The LCP includes specific policies to protect sensitive species and habitats within the planning segments of the Coastal Zone. In general, the LCP requires that there shall be no net loss of sensitive habitats, such as coastal sage, scrub, maritime succulent scrub, southern maritime chaparral, southern mixed chapparal, native grassland, oak woodland, riparian habitats, wetlands, and bluff tops (as applicable to the LCP segments). It should be noted that the LCP specifically states that no impacts to wetlands shall occur in the Coastal Zone, with several exceptions, pursuant to California Public Resources Code Section 30233. Per LCP Mello II Policy 3-1.7(a), for example, impacts to wetlands shall only be permitted where there is no feasible less environmentally damaging alternative and where feasible mitigation measures have been provided to minimize adverse environmental effects, and shall be limited to specific instances, including incidental public service purposes (3-1.7(a)(5)). The LCP states that the City’s HMP was developed to implement and be consistent with all of the provisions of the LCP (as amended). As discussed above, Section D.7 of the HMP repeats many of the LCP policies related to sensitive habitats. The mitigation ratios in the HMP are consistent with the ratios included in the LCP (e.g., 3:1 for riparian habitat). Projects proposed within the various LCP planning areas must adhere to the policies, provisions, and mitigation requirements specified in the LCP for potential impacts to sensitive habitats. The City’s Coastal Zone also contains a sixth planning area or segment that encompasses the Village Redevelopment Area. The LCP for this segment is the Carlsbad Village Redevelopment Master Plan and Design Manual. The Village area is mostly developed and lacking in sensitive habitat. The Master Plan and Design Manual does not contain goals or policies related to drainage infrastructure, storm water conveyance, or biological resources. 4.10.1.2 Project Level Vegetation Communities Vegetation types within the project boundary for Agua Hedionda and Calavera creeks (project components B and BN) are shown in Figures 4.10-5a through 4.10-5e and described below. Acreage information inside the project area is provided in Table 4.10-6. The study area used for the vegetation surveys is larger than the project area and encompasses a 500-foot buffer along Agua Hedionda Creek to the west of Cannon Road Bridge, which was established to determine if sensitive species occur within the environmentally sensitive area west of the project area. Refer to the wetland delineation report for more detail on the vegetation survey (Appendix B). Page x-xxRemove and ReplaceOverside DrainRemove and ReplaceOverside DrainORNPermanentDrop StructuresCHAORNORNORNORNDEVDEVCalavera CreekAgua Hedionda CreekCHARemove and ReplaceOrnamental WallORNORNCHADEVCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-5aVegetation Communities withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Veg_Calavera1.mxd, 05/08/07, marraccinib70 0 7035 FeetProject AreaMaintenance Access RoadStaging AreaDrainage EasementVegetation CommunitiesCHA: Unvegetated ChannelORN: Ornamental vegetationDEV: DevelopedILEGEND 4.10 Biological Resources Page 4.10-28 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxORNORNORNORNORNCHACHAORNCHARemove and ReplaceOverside DrainSlope TreatmentRemove Concrete andAdd VMAXRemove Concrete Apronsand Install PermanentDrop StructuresPermanentDrop StructureRemove ConcreteReplace with VMAXDEVDEVCalavera CreekORNEWCHADEVORNCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-5bVegetation Communities withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Veg_Calavera2.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaStaging AreaVegetation CommunitiesEW: Eucalyptus WoodlandCHA: Unvegetated ChannelORN: Ornamental vegetationDEV: DevelopedILEGEND 4.10 Biological Resources Page 4.10-30 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxAgua Hedionda CreekRemove and ReplaceOverside DrainRemove and ReplaceOverside DrainORNCHAORNORNDEVSCWRFDEVDEVCHAORNORNCHADEVSCWRFD-CSSDEVSWSDEVORNSWSCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-5cVegetation Communities withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Veg_AguaHedionda1.mxd, 05/08/07, marraccinib7007035 FeetProject AreaMaintenance Access RoadStaging AreaDrainage EasementVegetation CommunitiesCHA: Unvegetated ChannelD-CSS: Disturbed coastal sage scrubSCWRF: Willow riparian forestSWS: Southern willow scrubDEV: DevelopedORN: Ornamental vegetationILEGENDEl Camino RealCannon Rd 4.10 Biological Resources Page 4.10-32 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxORNRemove and ReplaceOverside DrainRemove and ReplaceOverside DrainDEVAgua Hedionda CreekORNDEVORNCHACity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-5dVegetation Communities withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Veg_AguaHedionda2.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaDrainage EasementVegetation CommunitiesCHA: Unvegetated ChannelORN: Ornamental vegetationDEV: DevelopedILEGEND 4.10 Biological Resources Page 4.10-34 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxRemove and ReplaceExisting CulvertPermanentDrop StructuresORNORNORNORNDEVRetaining WallRemovalCHARemove and ReplaceSide Drain (18" PVC)City of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-5eVegetation Communities withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Veg_AguaHedionda3.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaVegetation CommunitiesCHA: Unvegetated ChannelORN: Ornamental vegetationDEV: DevelopedILEGEND 4.10 Biological Resources Page 4.10-36 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-37 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-6 Project Area Vegetation Communities Vegetation Community Proposed Project Area (acres) Developed 0.10 Nonnative Vegetation/Ornamental 5.801 Unvegetated Channel 3.35 Willow Riparian Forest 0.53 Southern Willow Scrub 0.03 Total 9.81 1 Nonnative/Ornamental vegetation includes the ornamental vegetation within the CDFG jurisdictional areas along the banks of the creek slopes (1.50 acres). This community does not include nonnative grassland or coastal sage scrub habitat. Unvegetated Channel Unvegetated channels are typically found within ephemeral drainages in southern California, where periodic high flows from seasonal storm events prevent the establishment of vegetation. Both Agua Hedionda and Calavera creeks consist of primarily unvegetated channels. Agua Hedionda Creek is characterized by an unvegetated channel, upstream of the El Camino Real Bridge, composed of a series of sandbars among the meandering active channel. Vegetation cover is extremely sparse, generally less than 10 percent. The scattered vegetation is dominated by very low-growing herbaceous vegetation. Calavera Creek is characterized by a very narrow channel and steep banks. The narrow channel located north of and adjacent to the Rancho Carlsbad residential community upstream of the El Camino Real Bridge is also primarily unvegetated. Vegetation identified sparsely within Calavera Creek includes nonnative herbaceous species such as water speedwell (Veronica anagalis-aquatica), dallies grass (Paspalus dilatatum), and green algae. Nonnative/Ornamental Vegetation The nonnative/ornamental vegetation community consists of nonnative plant species typically used in residential or commercial landscape settings. Ornamental vegetation dominates the banks of Agua Hedionda Creek and Calavera Creek within the Rancho Carlsbad residential community upstream of the El Camino Real Bridge. Much of the vegetation on the slopes of the creek is nonnative ornamentals, though several mature sycamores are interspersed along the banks. Though the vegetation within Calavera Creek is routinely cleared, it is assumed that even in the absence of this activity the vegetation would still be dominated by nonnative species. This is due to the high amounts of ornamentals planted on the banks, the narrow channel, the adjacent upland areas that are developed or support nonnative vegetation, and concrete slabs from previous channelization. 4.10 Biological Resources Page 4.10-38 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Southern Willow Scrub/Willow Riparian Forest Agua Hedionda Creek between the El Camino Real Bridge and the Cannon Road Bridge consists of vegetated channel. Vegetation communities within that reach of Agua Hedionda Creek include southern willow scrub and willow riparian forest. The location of the proposed access road on the south side of Agua Hedionda Creek, which provides access to the channel bottom between the bridges, has also been characterized as willow riparian forest. Developed Area Developed Area refers primarily to dirt or gravel roads and other structural features. Developed Area includes an existing small paved road adjacent to the south bank of Agua Hedionda Creek, downstream of El Camino Real Bridge, which will be used for a staging area and structural features within the project area (downdrains, concrete areas). Jurisdictional Areas Section 404 of the CWA (33 USC § 1251 – 1387), as amended in 1977 and 1984, is the primary statute regulating activities in jurisdictional waters. Section 404 prohibits the discharge of dredged or fill material into “waters of the U.S.” without a permit from the USACE. Waters of U.S. encompass both wetland and nonwetland aquatic habitats, such as streams, rivers, lakes, ponds, bays, and oceans. Under Sections 1600-1616 of the California Fish and Game Code, the CDFG regulates activities that would alter the flow, bed, channel, or bank of streams and lakes. The limits of CDFG jurisdiction are defined in the code as the “bed, channel or bank of any river, stream or lake designated by the department in which there is at any time an existing fish or wildlife resource or from which these resources derive benefit.” In addition, the RWQCB may take jurisdiction of waters of the U.S. or waters of the state under the CWA Section 401. Section 401 of the CWA requires certification from the local RWQCB that a proposed project is in compliance with established water quality standards. Jurisdictional areas for the project have been identified pursuant to CWA Section 404, CWA Section 401, and Section 1600 of the California Fish and Game Code. A jurisdictional delineation was conducted in 2007 for the project area and is included in Appendix D (EDAW 2007). During the update, potential jurisdictional areas in the project area were found to include unvegetated channel, southern willow scrub, willow riparian forest, and disturbed (ornamental) riparian function areas. Table 4.10-7 identifies the federal and state jurisdictional extent within the project area. Figures 4.10-6a through 4.10-6e illustrate the jurisdictional areas. Page x-xxRemove and ReplaceOverside DrainRemove and ReplaceOverside DrainPermanentDrop StructuresCalavera CreekAgua Hedionda CreekRemove and ReplaceOrnamental WallCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-6aJurisdictional Areas withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Wet_Calavera1.mxd, 05/08/07, marraccinib7007035 FeetProject AreaUSACE Jurisdictional AreaCDFG Jurisdictional AreaMaintenance Access RoadStaging AreaDrainage EasementILEGEND 4.10 Biological Resources Page 4.10-40 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxRemove and ReplaceOverside DrainSlope TreatmentRemove Concrete andAdd VMAXRemove Concrete Apronsand Install PermanentDrop StructuresPermanent Drop StructureRemove ConcreteReplace with VMAXCalavera CreekCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-6bJurisdictional Areas withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Wet_Calavera2.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaStaging AreaUSACE Jurisdictional AreaCDFG Jurisdictional AreaILEGEND 4.10 Biological Resources Page 4.10-42 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxAgua Hedionda CreekRemove and ReplaceOverside DrainRemove and ReplaceOverside DrainCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-6cJurisdictional Areas withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Wet_AguaHedionda1.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaMaintenance Access RoadStaging AreaDrainage EasementUSACE Jurisdictional AreaCDFG Jurisdictional AreaILEGENDEl Camino RealCannon Rd 4.10 Biological Resources Page 4.10-44 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxRemove and ReplaceOverside DrainRemove and ReplaceOverside DrainAgua Hedionda CreekDEVCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-6dJurisdictional Areas withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Wet_AguaHedionda2.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaDrainage EasementUSACE Jurisdictional AreaCDFG Jurisdictional AreaILEGEND 4.10 Biological Resources Page 4.10-46 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. Page x-xxRemove and ReplaceExisting CulvertPermanentDrop StructuresRetaining WallRemovalRemove and ReplaceSide Drain (18" PVC)Agua Hedionda CreekCity of Carlsbad Drainage Master Plan Update EIRSource: Brown and Caldwell, 2006; SanGIS 2006; AirPhotoUSA 2006Scale: 1:840; 1 inch = 70 feetFigure 4.10-6eJurisdictional Areas withinAgua Hedionda and Calavera Creeks Project BoundaryPath: P:\2005\05080103 Agua Hedionda-Calavera Creek Project\5GIS\Mxd\EIR\Wet_AguaHedionda3.mxd, 04/30/07, marraccinib70 0 7035 FeetProject AreaUSACE Jurisdictional AreaCDFG Jurisdictional AreaILEGEND 4.10 Biological Resources Page 4.10-48 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-49 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-7 USACE and CDFG Jurisdictional Area within Project Area Feature USACE Jurisdictional Area (Area in Coastal Zone) 1 CDFG Jurisdictional Area2 (Area in Coastal Zone) Agua Hedionda Creek 3.73 (0.74) 5.17 (1.55) Calavera Creek 0.17 0.24 Total Area (acres) 3.90 (0.74)3 5.41 (1.55)4 1 Quantifies the area of Agua Hedionda Creek within the Coastal Zone boundary (southwest of El Camino Real and east of Cannon Road). Calavera Creek is not within the Coastal Zone. 2 Encompasses USACE jurisdictional area. 3 The total USACE jurisdictional area includes 3.35 acres of unvegetated channel, 0.03 acre of southern willow scrub, and 0.52 acre of willow riparian forest, all considered permanent impacts. 4 The CDFG jurisdictional area includes an additional 0.01 acre of impacts to willow riparian forest (access road) and 1.50 acres of nonnative/ornamental vegetation along the banks of the slopes of both creeks. Sensitive Plants The study area for Agua Hedionda and Calavera Creeks was surveyed in August 2005 for the presence of sensitive and rare plant species (refer to Appendix D). Rare plant species were not observed during the survey. No rare plant species are expected to occur within the study area given its relatively disturbed condition and long history of periodic disturbances. Additionally, rare plant species within or along Agua Hedionda Creek were not detected during the wetland delineation in 2002 (RECON 2002). Sensitive Wildlife Focused surveys were conducted within the study area for Agua Hedionda and Calavera Creek for light-footed clapper rail (Rallus longirostris levipes) in spring 2006, and for least bell’s vireo (Vireo bellii pusillus) and southwestern willow flycatcher (Empidonax traillii extimus) in 2005. The study area encompassed a 500-foot buffer area to include adjacent sensitive habitat downstream of the project area. During the 2005 protocol surveys for least Bell’s vireo and southwestern willow flycatcher, a total of 26 wildlife species were observed within the study area including 1 amphibian, 1 reptile, 22 birds, and 2 mammals. An additional 14 species (3 amphibians, 4 reptiles, 3 birds, and 4 mammals) have the potential to occur within the project vicinity (Refer to Appendix D, Supplemental Biological Resources Information). No aquatic species (i.e., fish) were observed or detected during surveys of the project area. According to the CNDDB database, no special status aquatic species have the potential to occur within the project vicinity. 4.10 Biological Resources Page 4.10-50 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Light-footed Clapper Rail The light-footed clapper rail is listed as an endangered species by the USFWS and CDFG. Surveys for the light-footed clapper rail were conducted by wildlife biologist John Konecny, following methodology formulated by Konecny Biological Services (KBS) in consultation with light-footed clapper rail principal investigator Richard Zembal, and approved by the USFWS. This activity is authorized by Konecny Biological Services’ USFWS section 10(a) permit number TE837308-3 and a CDFG Memorandum of Understanding. Five focused light-footed clapper rail surveys were conducted at least 7 days apart between February 13 and March 14, 2006. Dusk surveys were conducted on February 13, March 7, and March 14, 2006. Dawn surveys were conducted on February 20 and February 27, 2006. Each dawn and dusk survey lasted approximately 2 hours. Dawn surveys were conducted from pre-dawn to no later than 2 hours after sunrise. Dusk surveys were conducted between sunset and no more than 2 hours prior to sunset. Two pairs of light-footed clapper rails were detected in the freshwater marsh downstream (west) of the Cannon Road Bridge (see Figure 2 in Light-footed Clapper Rail Survey Report, Appendix D). No light-footed clapper rails were detected between the El Camino Real Bridge and the Cannon Road Bridge. One light-footed clapper rail was initially detected on February 13, near the eucalyptus grove immediately west of the Cannon Road Bridge and south of El Camino Real. No light-footed clapper rails were detected on the morning of February 20. Two pairs of “dueting” light-footed clapper rails were detected the morning of February 27 downstream (west) of the Cannon Road Bridge, and subsequently relocated during the dusk surveys of March 7 and 14. The results of the focused surveys and presence of the light-footed clapper rails indicate that the light-footed clapper rail occupies the sensitive habitat adjacent to the project area. No light- footed clapper rails were detected within the project area (i.e., upstream of Cannon Road Bridge and Rancho Carlsbad residential community). Least Bell’s Vireo Focused surveys for least Bell’s vireo were conducted according to USFWS survey guidelines (USFWS 2001), which required eight surveys at least 10 days apart between April 1 and July 31, 2005. Surveys were conducted by walking meandering transects throughout and adjacent to areas of suitable least Bell’s vireo habitat (RECON 2005). Two least Bell’s vireo were detected within the southern willow scrub along Agua Hedionda Creek west of the intersection of El 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-51 04080135 Carlsbad DMP EIR.doc 12/11/2007 Camino Real and Cannon Road, outside the project area approximately 300 feet downstream of the Cannon Road Bridge (refer to Figure 4 in Post-survey Letter Report, Appendix D). Southwestern Willow Flycatcher Focused surveys for southwestern willow flycatcher were conducted under USFWS permit number TE-811615 according to USFWS survey guidelines (USFWS 2000), which requires five surveys. One survey was conducted in each of the two periods from May 15 through May 31 and from June 1 through June 21, 2005. Three surveys were conducted between June 22 and July 17, 2005, with at least 5 days separating consecutive surveys. Surveys were conducted by walking meandering transects throughout and adjacent to areas of suitable southwestern willow flycatcher habitat (RECON 2005). One southwestern willow flycatcher was detected within the southern willow scrub along Agua Hedionda Creek, west of the intersection of El Camino Real and Cannon Road, outside the project area approximately 300 feet downstream of the Cannon Road Bridge (Figure 4, Post- survey Letter Report, Appendix D). The southwestern willow flycatcher was detected during the first of the five focused surveys and was not seen during any of the subsequent surveys, indicating the individual migrating. Wildlife Species During the focused surveys conducted in 2005, two California species of special concern, yellow warbler (Dendroica petechia) and yellow-breasted chat (Icteria virens auricollis), were detected in the survey area, downstream (west) of Cannon Road Bridge. A white-tailed kite (Elanus leucurus), a California fully protected species, was also observed downstream of the project area. Birds commonly observed in the riparian areas during the surveys for least Bell’s vireo and southwestern willow flycatcher included western scrub-jay (Aphelocoma californica), wrentit (Chamaea fasciata henshawi), lesser goldfinch (Carduelis psaltria hesperophilus), Pacific slope flycatcher (Empidonax difficilis), Anna’s hummingbird (Calypte anna), bushtit (Psaltriparus minimus), orange-crowned warbler (Vermivora celata), common yellowthroat (Geothlypis trichas), spotted towhee (Pipilo maculatus), European starling (Sturnus vulgaris), and Nuttall’s woodpecker (Picoides nuttallii). Two brown-headed cowbirds (Molothrus ater) were detected on-site within the southern willow scrub along Agua Hedionda Creek south of Cannon Road and west of El Camino Real. 4.10 Biological Resources Page 4.10-52 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Mature trees along the banks of the creeks provide habitat for roosting, nesting, and foraging for a variety of raptor species. Although no nests were observed during the focused surveys or general biological surveys, the following species have the potential to nest within these areas: red-shouldered hawk (Buteo lineatus), white-tailed kite (Elanus leucurus), Cooper’s hawk (Accipiter cooperii), sharp-shinned hawk (Accipiter striatus velox), and red-tailed hawk (Buteo jamaicensis). Agua Hedionda Creek functions as a moderate quality movement corridor for numerous wildlife species such as birds, coyotes, skunks, opossums, and raccoons. The creek links open space areas located upstream to Agua Hedionda Lagoon and provides road crossing for wildlife at El Camino Real and Cannon Road via bridge undercrossings. Although Calavera Creek may provide an additional local corridor for wildlife movement, the channel is narrow and close to residences; therefore, it is considered a low quality wildlife corridor. Applicable Plans and Regulations Carlsbad Habitat Management Plan The portion of Agua Hedionda Creek, between Cannon Road and El Camino Real bridges, is within the HMP Core Area 4 Focused Planning Area. The eastern portion of this area is identified as an Existing Hardline Preserve area (see Figure 4.1-5, Land Use), but a detailed examination of the easement creating the conservation area revealed that the channel is not actually included within that designated Existing Hardline Preserve Area (Irrevocable Offer to Dedicate Open-space Easement and Declaration of Restrictions No. 1994-0488749, dated August 11, 1994). The western half of this area is designated as a “development area” in the HMP. Local Coastal Program Improvements within Agua Hedionda Creek, downstream of El Camino Real Bridge, are within the Coastal Zone and are therefore subject to the LCP policies for Segment Mello II. Segment Mello II of the LCP specifically requires that drainage improvements in undeveloped upstream areas of the Coastal Zone be installed prior to development. Applicable LCP biological resource policies for DMP Update projects within Segment Mello II are summarized below: • Policy 3-1.2: Environmentally Sensitive Habitat areas. Environmentally sensitive areas shall be protected against any significant disruption of habitat values. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-53 04080135 Carlsbad DMP EIR.doc 12/11/2007 • Policy 3-1.7: Wetlands. No impacts to wetlands are permitted, except dredging for specific circumstances including, but not limited to, such projects for incidental public service purposes and restoration purposes. Dredging would be conducted in accordance with other applicable provisions of this division, where there is no feasible less environmentally damaging alternative, where feasible mitigation measures have been provided to minimize adverse environmental effects, and limited to specific instances, including incidental public service purposes (3-1.7(a)(5)). In addition to the other provisions of this section, dredging and spoils disposal shall be planned and carried out to avoid significant disruption to marine and wildlife habitats and water circulation Dredge spoils suitable for beach replenishment should be transported for such purposes (3-1.7(b). Dredging in existing estuaries and wetlands shall maintain or enhance the functional capacity of the wetland or estuary (3-1.7(c). • Policy 3-1.8: Wetland Mitigation Requirements. If impacts to a wetland are allowed consistent with Policy 3-1.7, mitigation shall be provided at a ratio of 3:1 for riparian impacts and 4:1 for saltwater or freshwater wetland or marsh impacts. • Policy 3-12: Buffer Zones. A 100-foot buffer zone must be maintained between all identified preserved wetland areas and developed areas (unless the applicant demonstrates that a buffer of lesser width will protect the identified resources, based on site-specific information). No development, grading, or alterations, including clearing of vegetation, shall occur in the buffer area. • Policy 4-4: Removal of Natural Vegetation. When earth changes and vegetation removal are required, the area and duration of exposure must be minimized. • Policy 4-5: Soil erosion control practices shall be used against “onsite” soil erosion. These include keeping soil covered with temporary or permanent vegetation or with mulch materials, special grading procedures, diversion structures to divert surface runoff from exposed soils, and grade stabilization structures to control surface runoff. • Policy 4-6: Apply “sediment control” practices as a perimeter protection to prevent offsite drainage. Preventing sediment from leaving the site should be accomplished by such methods as diversion ditches, sediment traps, vegetation filters, and sediment basins. Prevention erosion is of course the most effective way to control sediment runoff. 4.10 Biological Resources Page 4.10-54 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Carlsbad Opportunistic Beach Fill Program The Carlsbad Opportunistic Beach Fill Program was developed to contribute to renourishment of the Oceanside Littoral Cell, improve protection to coastal structures and enhance beach recreational opportunities in the City, and to provide on-going maintenance of beach nourishment projects associated with regional beach-fill efforts. The intent of the program is to take advantage of opportunistic beach fill sources in the region for beneficial reuse to achieve multi-use benefits associated with beach nourishment (Moffatt & Nichol 2000b). The program specifies criteria for suitability of materials for beach fill, appropriate placement volumes based on substrate characteristics and seasonal considerations, and guidelines for sand placement. If the City decides to pursue disposal of dredge materials at the South Carlsbad receiver site (discussed as Option 1 in Section 3.4.3 of the Project Description) the action would be subject to criteria and guidelines specified in the Opportunistic Beach Fill Program EIA/MND (City of Carlsbad 2006). 4.10.2 Significance Criteria A potentially significant impact would occur to biological resources if implementation of the proposed DMP Update components would: • have an adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the USFWS or CDFG; • have an adverse effect on any riparian, aquatic, or wetland habitat or other sensitive natural community identified in local or regional plans, policies, or regulations, or by the USFWS or CDFG; • have an adverse effect on federally protected wetlands as defined by Section 404 of the CWA (including but not limited to marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means; • interfere with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites; or • conflict with local policies or ordinances (i.e., Carlsbad HMP and LCP) protecting biological resources. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-55 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.10.3 Impact Analysis 4.10.3.1 Program Level Each of the proposed PLDA and non-PLDA project components has the potential to directly impact sensitive species and habitats through vegetation removal associated with construction of the drainage facility improvements. Direct permanent impacts include the potential alteration of natural creeks, while temporary impacts include staging areas that would be revegetated following construction of the projects. Project-related temporary impacts also include increases in noise and fugitive dust emissions associated with the construction activities. Potential impacts to biological resources within the study area are described below for DMP Update components (PLDA and non-PLDA). Impacts to Sensitive Species and Habitat DMP Update components could directly impact chaparral, coastal sage scrub, grassland, riparian, and wetland, and woodland habitat and their associated sensitive species. Table 4.10-8 provides a list of vegetation types potentially affected by PLDA project components, while Table 4.10-9 includes a list of vegetation types potentially affected by non-PLDA components. The information in Table 4.10-3 shows a list of sensitive plant species found in each habitat type. Focused and protocol-level surveys for sensitive plant species were not conducted for this program level analysis. Potential impacts to sensitive plant species during construction of DMP Update components may occur if these resources are present. Short-term construction-related impacts would be minimized through the project design features/methods and construction measures identified in Table 3-6. Potential indirect impacts to sensitive plant species adjacent to construction activities from unauthorized human trespass, sedimentation, and exotic plant introduction would also be minimized with implementation of the project design features/methods and construction practices included in Table 3-6. Permanent significant impacts could include crushing or removal of sensitive plants during project implementation. The loss of state sensitive listed plant species is considered a significant impact. At a regional level, loss of sensitive plant species would contribute to a cumulative impact. 4.10 Biological Resources Page 4.10-56 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-8 Impacts to Vegetation Types from PLDA Project Components Project Component ID Project Name Vegetation Type Impacted AAA Jefferson Street Drainage Project Disturbed/Developed AAAA Madison Street Drainage Project Disturbed/Developed AC Highland Drive Drainage Project Disturbed/Developed AFA Hidden Valley Drainage Restoration and Enhancement Project Riparian, Wetland, Coastal Sage Scrub AFB North Calavera Hills Drainage Restoration and Enhancement Project Riparian, Wetland, Coastal Sage Scrub, Grassland BB-1 Washington Street Drainage Improvements, Phase I Disturbed/Developed BB-2 Washington Street Drainage Improvements, Phase II Disturbed/Developed BCA Park Drive/ Tamarack Avenue Drainage Project Disturbed/Developed BCB Magnolia Avenue Drainage Project Disturbed/Developed BCC Chestnut Avenue Drainage Project Disturbed/Developed BFB-L El Camino Real Drainage Project, Phase II Agriculture, Riparian BFB-U El Camino Real Drainage Project, Phase I Wetland BF1 Kelly Drive Water Quality Basin Project Wetland, Coastal Sage Scrub BFA Country Store Storm Drain Project Disturbed/Developed BJ-1 Rancho Carlsbad Sedimentation Basin Project Agriculture, Riparian BJB College Boulevard Sedimentation Basin Structural Improvements Project Agriculture, Riparian BL-L College Boulevard Drainage Project Phase V- Downstream Portion Coastal Sage Scrub, Grassland BL-U College Boulevard Drainage Project Phase IV- Upstream Portion Riparian BM Cantarini Box Culvert Project Wetland, Coastal Sage Scrub BNB Calavera Creek Flood Control Improvement Phase II Grassland BP Melrose Flood Retention Facility Riparian, Coastal Sage Scrub BQ Sunny Creek Road Restoration and Enhancement Project Riparian, Coastal Sage Scrub, Chaparral BR Cantarini and Holly Springs Development Disturbed/Developed C1 Carlsbad Boulevard South Drainage Improvements Disturbed/Developed C2 Paseo Del Norte Drainage Improvements Riparian, Wetland CA Avenida Encinas Drainage Improvements Disturbed/Developed DBA Poinsettia Village Drainage Improvements Disturbed/Developed DBB Avenida Encinas Drainage Project Disturbed/Developed DFA Batiquitos Lagoon Retention/ Detention Basin Project Disturbed/Developed DH Altiva Place Restoration and Enhancement Project Coastal Sage Scrub DQB La Costa Town Center Drainage Improvements Project Coastal Sage Scrub, Grassland DZ Poinsettia Lane Bridge Project Chaparral 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-57 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.10-9 Impacts to Vegetation Types from Non-PLDA Project Components Project Component ID Project Location Vegetation Type Impacted Basin A Non-PLDA Projects No specific non-PLDA components have been identified in Basin A at this time. CIP Project Components A-CIP-1 Miscellaneous Road Subdrains (Project Number 3681) Disturbed/Developed A-CIP-2 Cynthia Lane Storm Drain Project; Cynthia Lane near I-5 Disturbed/Developed A-CIP-3 Carlsbad Boulevard Storm Drain Replacement Project; between the SDNR track and Carlsbad Boulevard Disturbed/Developed A-CIP-4 Ridgecrest Drainage Improvements Project; Ridgecrest Drive Disturbed/Developed Basin B Non-PLDA Project Components BAA Cannon Road Drainage Improvements Disturbed/Developed BE South of Van Allan Way on south side of Agua Hedionda Creek Riparian, Wetland, Coastal Sage Scrub BEA Begins northeast of Faraday Avenue and extends southwest to the south side of Agua Hedionda Creek Riparian, Coastal Sage Scrub, Grassland BJ-2 Rancho Carlsbad Detention Basin Project Agriculture, Riparian BL-L College Boulevard Drainage Project Phase V- Downstream Portion Riparian CIP Project Components B-CIP-1 and B-CIP-2 Miscellaneous Road Subdrains (Project Number 3681) Disturbed/Developed B-CIP-3 Highland Drive Drainage Improvements Project; Highland Drive between Pine Avenue and Basswood Avenue Disturbed/Developed B-CIP-4 Kelly Drive Drainage Improvements; Kelly Drive east of Hillside Drive Disturbed/Developed Basin C Non-PLDA Project Components C Natural channel extending from southwest corner of Palomar Airport Road and El Camino Real towards Pacific Ocean. Riparian CIP Project Components No specific CIP projects have been identified in Basin C at this time. Basin D Non-PLDA Project Components DFA Northwest of the intersection of La Costa Avenue and El Camino Real Disturbed/Developed DM Between Poinsettia Lane and Alga Road, on the west side of Almaden Lane Riparian, Grassland CIP Project Components D-CIP-1 through D-CIP-6 Miscellaneous Road Subdrains (Project Number 3681) Coastal Sage Scrub, Grassland D-CIP-7 La Costa Avenue Storm Drain Replacement Project; La Costa Avenue between El Camino Real and Viejo Castilla Way Disturbed/Developed D-CIP-8 Gabbiano Lane Storm Drain Modification; south of Gabbiano Lane near Batiquitos Lagoon Disturbed/Developed D-CIP-9 Calle Gavanzo Subsurface Drainage Improvements; west side of Calle Gavanzo Disturbed/Developed D-CIP-10 Romeria Drainage Improvements Project; Romeria Street Coastal Sage Scrub 4.10 Biological Resources Page 4.10-58 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Focused and protocol-level surveys for sensitive wildlife species were not conducted for this program level analysis. However, Table 4.10-3 includes a list of sensitive plant and wildlife species typically found in each habitat type within Carlsbad. Sensitive wildlife associated with each habitat type could be directly impacted through loss or alteration of habitat if they occupy the habitat on-site. However, short-term construction-related impacts would be minimized to levels below significance through the project design features/methods and construction practices identified in Table 3-6. Impacts to sensitive wildlife species are considered to be a significant and cumulative impact and would require adherence to the HMP mitigation measures. Construction-generated noise and disturbance could impact migratory nesting birds and raptors during the breeding season, if these species are present. Construction-generated noise, in excess of 60 dBA, at the edge of California gnatcatcher, southwestern willow flycatcher, or least Bell’s vireo occupied coastal sage scrub or riparian habitat during the breeding season would be a significant construction impact. Potential indirect impacts to sensitive wildlife adjacent to construction activities from fugitive dust, unauthorized human trespass, sedimentation, excess lighting, and exotic plant introduction would be reduced to below levels of significance with implementation of the project design features/methods and construction practices in Table 3-6. Impacts to Riparian, Aquatic, and Wetlands Habitat Short-term construction impacts to riparian, aquatic, and wetland habitats such as the replacement of structural features or the addition of permeable erosion control measures, from DMP Update components would be minimized with the project design features/methods and construction practices identified in Table 3-6. Long-term or permanent impacts, such as the construction of new concrete structures or permanent removal of vegetation, would be significant and cumulative due to the loss of riparian, aquatic, and wetland habitats. In addition, some proposed program level DMP Update components would occur within or adjacent to riparian, aquatic, and wetland habitats within the Coastal Zone. Impacts to these habitats within the Coastal Zone would be considered a potentially significant impact. Impacts to USACE and CDFG Jurisdictional Areas Some DMP Update components may occur within areas under the jurisdiction of the USACE pursuant to Section 404 of the CWA, CDFG pursuant to Section 1600 California Fish and Game Code, and/or the RWQCB pursuant to Section 401 of the CWA. As stated above, long-term or permanent impacts would be significant and cumulative due to the loss of riparian and wetland 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-59 04080135 Carlsbad DMP EIR.doc 12/11/2007 habitats. Should implementation of a component result in impacts to waters of the U.S. or wetlands, mitigation would be required to enhance, create, and/or restore wetlands, at a ratio to be determined by the appropriate resource agencies. Impacts to Wildlife Movement Corridors Construction, dredging, and maintenance activities would temporarily impact existing wildlife movement corridors. However, impacts would be short term and would not be considered significant. Drainage improvements that impede the movement of wildlife within Core Areas and linkages would result in a significant impact. Additionally, substantial clearing of vegetation within an area determined to be a wildlife movement corridor could reduce the amount of vegetated cover for wildlife and would be considered a direct significant impact as well as a regional, cumulative impact (see Chapter 5.0 [Cumulative Impacts]). Consistency with Local Policies or Ordinances Carlsbad Habitat Management Plan Some of the proposed DMP Update components would be located within the HMP preserve boundaries (Tables 4.1-2 and 4.1-3). As required by the City’s HMP, drainage projects within the HMP preserve would be designed and routed to minimize impacts to biological resources (i.e., sensitive species and habitats). However, construction of proposed DMP Update components within or adjacent to existing or proposed HMP preserve areas could result in direct or indirect permanent impacts to sensitive biological resources within the HMP boundaries. Impacts to sensitive biological resources resulting from habitat modification within the HMP preserve would be considered significant. Impacts would be minimized with the incorporation of the project design features/methods and construction practices described in Table 3-6. However, additional mitigation may be required to reduce impacts to a level of less than significant, which is included in Section 4.10.5.1. Prior to construction of specific project components, the design would be reviewed at a project level for consistency with specific HMP goals and policies. It should be noted that consistency with HMP policies from a land use perspective is evaluated in Section 4.1 (Land Use) of this EIR. 4.10 Biological Resources Page 4.10-60 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Local Coastal Program DMP Update projects that would occur in the Coastal Zone are identified in Tables 4.1-2 and 4.1-3. Improvements to the City’s drainage facilities would be conducted for public service purposes (i.e., to maintain adequate flood control within the city). Therefore, DMP Update components that would result in impacts to wetlands would be permitted under LCP Policy 3- 1.7(a)(5). Mitigation to minimize impacts to wetlands is included in Section 4.10.5.1 of this EIR. In addition, each component would incorporate the project design features/methods and construction measures described in Table 3-6 to minimize impacts to the resources within the LCP. However, there is the potential for DMP Update components to impact sensitive habitats within the Coastal Zone, as listed in Tables 4.10-8 and 4.10-9. Mitigation consistent with the policies and provisions of the LCP would be required to reduce impacts to sensitive habitats to a level of less than significant. Specific projects that are located in the Coastal Zone would require project level review for consistency with the California Coastal Act and specific LCP policies and provision prior to issuance of a CDP. The required consistency review and adherence to the conditions identified in the CDPs would ensure that proposed DMP Update components, particularly those located outside of public rights-of-way or property, or in sensitive areas, would be consistent with the LCP. 4.10.3.2 Operations and Maintenance Operation and maintenance activities would require occasional temporary access into vegetated areas adjacent to facilities, as well as unvegetated channels. In addition, activities such as channel and facility maintenance or bridge replacement may require excavation and/or vegetation removal in channel floodways or the potential placement of fill in the form of pillars. Encroachment into sensitive areas due to operation and maintenance activities would be minimized by incorporation of project design features/methods and construction practices identified in Table 3-6; however, impacts may still occur to protected habitats and/or species. Such impacts would be considered potentially significant. 4.10.3.3 Project Level The following analysis is for proposed project level PLDA and non-PLDA project components consisting of dredging and improvements for Agua Hedionda and Calavera creeks (project components B and BN) and long-term maintenance of the creeks. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-61 04080135 Carlsbad DMP EIR.doc 12/11/2007 As discussed in Section 3.0, in March 2006 emergency dredge activities were performed in Agua Hedionda Creek from the east (upgradient) side of the Cannon Road Bridge to just west (approximately 80 feet downgradient) of the Rancho Carlsbad Drive Bridge. The dredge work involved the removal of sediment that had accumulated over decades in the channel bottom, reducing the capacity of the creek. The emergency dredge work was conducted pursuant to emergency permits obtained with the USACE (2006001510KJC), RWQCB (06C-007), and CDFG (1600-2006-0060-R5). These permits outline the anticipated impacts and required mitigation associated with the emergency dredge project. Implementation of the project, however, resulted in fewer impacts than anticipated. The emergency dredge work was contained to the channel bottom between existing toe of slopes of the side slopes and primarily involved impacts to unvegetated channel (waters of the U.S). However, riparian habitat consisting of willow riparian forest and southern willow scrub, between the El Camino Real Bridge and the Cannon Road Bridge, was also removed during the emergency dredge work. No work was conducted in the waters underneath the Cannon Road Bridge. The impacts associated with the emergency dredge project are summarized in Table 4.10-10. Only impacts to jurisdictional areas not impacted by and mitigated for under the emergency dredge project will be described for the Agua Hedionda and Calavera Creeks Improvement Project (B and BN). The impacts for project level components B and BN are identified in Table 4.10-10 in the column titled “Net Permanent Project Impacts.” Table 4.10-10 Net Impact Acreages from Dredging and Improvements of Agua Hedionda and Calavera Creeks Vegetation Community Proposed Project Impacts (Permanent) Proposed Project Impacts (Temporary) Previously Mitigated Emergency Dredge Impacts Net Permanent Project Impacts Developed 0.02 0.08 0.00 0.10 Nonnative Vegetation/ Ornamental (includes staging areas) 1.561 4.24 0.00 5.80 Unvegetated Channel 3.35 0.00 3.06 0.29 Willow Riparian Forest 0.53 0.00 0.45 0.08 Southern Willow Scrub 0.03 0.00 0.03 0.00 Total 5.49 4.32 3.54 6.27 1 Nonnative/ornamental vegetation includes the ornamental vegetation within the CDFG jurisdictional areas along the banks of the creek slopes (1.50 acres). 4.10 Biological Resources Page 4.10-62 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Impacts to Sensitive Species and Habitat No federally or state-listed endangered or threatened plant species were observed during the recent surveys within the project limits; therefore, project level DMP Update components would not directly impact sensitive plant species. No sensitive plant species would be indirectly impacted from proposed construction or operations and maintenance activities, as no sensitive species are anticipated to occur adjacent to the project footprint. Direct mortality would occur to several amphibian, and reptile species, including pacific tree frog, western fence lizard, and side-blotched lizard. These impacts would occur from disturbance of riparian habitats and the unvegetated channel. There is also a potential for direct mortality of other species that inhabit riparian and upland habitats if impacts occur during any of the various breeding seasons of these species, when they are less likely to disperse away from any construction activity. Direct impacts to nonsensitive wildlife species are considered adverse but not significant. Potential impacts would occur to wildlife species that are dependent on aquatic habitat. Flows through Agua Hedionda and Calavera creeks are perennial. The unvegetated channels are not known to support sensitive aquatic species. Due to the frequency of disturbance (i.e., floods and periodic vegetation clearing), the potential for sensitive aquatic species is low. However, non- sensitive aquatic species are known to occur within Calavera Creek. The potential presence of non-sensitive aquatic species may result in a temporary impact to aquatic species during dredging and construction activities within the creeks due to habitat removal and disturbance. This impact would be adverse but not significant since disturbances within the channel beds would be minimized once construction is completed. The proposed channel widening would maintain the earthen soft bottom channels, promoting restoration of aquatic habitat within the channel. No federal and state-listed wildlife species were observed within the project area. However, sensitive wildlife species were detected in the adjacent 500-foot buffer area, downstream of Cannon Road Bridge. Due to the potential for presence of least Bell’s vireo, southwestern willow flycatcher, and light-footed clapper rail in the project vicinity (defined as all suitable habitat within 500 feet of the limits of project activities), the proposed activities in Agua Hedionda Creek have the potential to result in indirect impacts to these sensitive biological resources. An increase in the ambient noise levels during construction and maintenance activities has the potential to affect the nesting success of sensitive riparian bird species if activities are conducted during the breeding season. Avoidance measures as described in Table 3-6 and mitigation measures would be 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-63 04080135 Carlsbad DMP EIR.doc 12/11/2007 implemented during project activities to minimize impacts. Indirect noise impacts from dredging activities would be incrementally significant within the study area. Indirect impacts to wildlife species during construction and maintenance activities would occur through loss of foraging habitat and protective cover due to project-related disturbance of vegetation communities. The wildlife species typically affected by these indirect impacts would be bird and mammal species occurring within the study area. These short-term indirect impacts are considered adverse but not significant since mature specimen trees on the channel banks would be preserved to the extent feasible during dredging activities. Upon completion of dredging and improvements, vegetation cover would be restored to the extent practicable to maintain drainage capacity within the creeks, consistent with the long-term maintenance plan (Appendix B). The potential exists for nesting raptors to occur in the trees along the banks of the creek during the migratory breeding season (February 1 through August 31). Implementation of the design features/methods in Table 3-6 and mitigation measures would reduce this potential impact to less than significant. Impacts to Riparian, Aquatic, and Wetlands Habitat Table 4.10-10 quantifies potential habitat impacts within the project boundaries as a result of dredging and improvements in Agua Hedionda and Calavera creeks. As shown in Table 4.10-10, the proposed dredging and improvements for Agua Hedionda and Calavera Creeks would directly and permanently impact unvegetated channel, willow riparian forest, southern willow scrub, and nonnative/ornamental vegetation on channel slopes within the creeks. Permanent impacts would also occur to willow riparian forest as a result of an access road on the south side of Agua Hedionda Creek west of El Camino Real. Temporary impacts would occur to nonnative/ornamental vegetation at the staging area north of Calavera Creek. The access road located on the north side of the confluence of Agua Hedionda and Calavera creeks and the staging area adjacent to the southern access road near the bridges would only impact developed area. Impacts to the willow riparian forest and southern willow scrub are considered significant, as these riparian and wetland communities have some habitat value due to inherent importance and historic loss of these habitat types. Impacts to the unvegetated channel would be considered adverse, but not significant as the losses of functions and values for sediment transport and groundwater 4.10 Biological Resources Page 4.10-64 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 recharge from the creeks are relatively minor, and this habitat type does not have the potential to support sensitive vegetation communities. Impacts to nonnative/ornamental vegetation and developed areas are not considered significant. Impacts within the channel are considered permanent due to disturbance of the creekbed during dredging and construction activities and the need for routine maintenance following initial dredging operations. However, since sediment removal would not permanently degrade or destroy jurisdictional waters and if impacted wetlands were either restored or mitigated, there would be no net loss of channel. It is anticipated that a net gain in jurisdictional waters would result from the project due to channel widening at the confluence of Agua Hedionda Creek and Calavera Creek. Impacts to USACE and CDFG Jurisdictional Areas Table 4.10-10 identifies the quantity of USACE and CDFG jurisdictional area within the project area. All jurisdictional area within the project area will be impacted by the dredging and improvements in Agua Hedionda and Calavera creeks. In addition, ongoing channel maintenance activities will occur within the project area; therefore, impacts to jurisdictional area are being classified as primarily permanent impacts. As shown in Table 4.10-10, impacts associated with the emergency dredge project will be mitigated as part of the environmental permits for that project and therefore reduce the net impacts requiring mitigation for the proposed project. Short-term construction impacts within the Coastal Zone and adjacent HMP habitats would be minimized with implementation of the project design features/methods and construction measures identified in Table 3-6. The loss of 0.08 acre of wetland and riparian habitat, including loss of habitat within the Coastal Zone boundary, is considered a significant impact at the local and level (see Chapter 5.0 [Cumulative Impacts]). Impacts to Wildlife Movement Corridors Agua Hedionda and Calavera creeks function as moderate quality wildlife movement corridors for species such as birds, coyotes, skunks, opossums, and raccoons. The creeks also link open space areas located upstream of Rancho Carlsbad to downstream habitat, including Agua Hedionda Lagoon. Construction, dredging, and occasional maintenance activities within the creeks (as described in the long-term maintenance plan included in Appendix B) would temporarily impact existing wildlife movement along and through the creek. Clearing of vegetation along the creek banks and within the westernmost portion of the project between the Cannon Road and El Camino Real bridges could potentially result in temporary wildlife corridor impacts by reducing the amount 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-65 04080135 Carlsbad DMP EIR.doc 12/11/2007 of vegetated cover for wildlife. However, wildlife corridor movement is not lost and the temporary impacts are not considered significant. Upon completion of dredging and improvement activities, no permanent impacts to wildlife corridor movements along the creeks would occur. Consistency with Local Policies or Ordinances Carlsbad Habitat Management Plan The HMP establishes a conservation goal for Core Area 4 of no net loss of wetland and riparian habitat (HMP Section D.7, Standard 7-8). The project would result in the loss of wetland and riparian habitat in Core Area 4 as a result of vegetation clearing for dredging and construction in the area downstream of the El Camino Real Bridge (upgradient or east of the Cannon Road Bridge). This would result in a significant and cumulative impact since this would contribute to the regional loss of wetland and riparian habitat. Agua Hedionda Creek is also referenced in Section G of the HMP, “Take Authorization and Assurances, and Provisions for Unforeseen Circumstances.” Section G.3, Item 2 states “For the purpose of defining Changed Circumstance, Flood is defined as natural rain runoff events occurring within and causing damage to HMP preserve floodplains associated with the City’s four watersheds … Agua Hedionda …and their associated creeks and tributaries, at less than 50- year levels …” This section is mostly concerned with damage to the preserve areas as a result of flooding. The removal of sediment and/or debris is included as an acceptable maintenance activity following flood events. The project is therefore consistent with this goal. The HMP adjacency standards include management recommendations for erosion control (Section F.3.B). The proposed dredging and improvements in Agua Hedionda and Calavera creeks (project components B and BN) would be required to incorporate BMPs into the project design as part of the project’s SWPPP, including sediment and erosion control measures. These measures are described in more detail in Section 4.9 (Hydrology/Water Quality). The long-term maintenance plan for the dredging and improvements project in Agua Hedionda and Calavera creeks also includes BMPs for long-term erosion control. Although Agua Hedionda and Calavera creeks within the project area are not within an Existing HMP Hardline Preserve, the mitigation plan would be consistent with the HMP’s recommendations for Habitat Restoration and Revegetation (Section F.2.A) and the Landscaping Restrictions (Section F.3.C), as applicable. Therefore, proposed project components B and BN would be consistent with the applicable preserve management goals in Section F of the HMP. 4.10 Biological Resources Page 4.10-66 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Appendix B-3 of the HMP includes a list of “City Projects Covered by Proposed City-Lands Mitigation Bank.” Under the “Drainage Projects” category, the table lists “Future projects needed to complete the Master Drainage and Storm Water Quality Management Plan [DMP] inclusive of, but not limited to the following projects.” Channel enhancement in Agua Hedionda Creek is listed as one of the projects meeting these criteria. While the City is early in the process of establishing the Lake Calavera Mitigation Bank, the HMP contemplates providing mitigation for drainage projects in the mitigation bank and specifically identifies Agua Hedionda Creek as a potential project. Local Coastal Program The portion of Agua Hedionda Creek downstream of El Camino Real Bridge is located within the Coastal Zone and is part of the City’s LCP Mello II planning area. The proposed work is subject to the policies and requirements established in the LCP for Mello II. LCP Policy 3-1.7(a)(5) permits impacts to wetlands for dredging required for public service purposes. Implementation of the dredging and improvements in Agua Hedionda and Calavera creeks would provide a necessary public service by improving protection from a 100-year flood event for Rancho Carlsbad residents. The purpose of the project is to restore the 100-year flood capacity in creeks. Removal of accumulated sediment in the Coastal Zone area between the El Camino and Cannon Road bridges is imperative to provide flood protection and restore the 100-year flood capacity. There is no feasible alternative to dredging the area between the bridges that would provide flood protection to Rancho Carlsbad to the extent feasible and restore 100-year flood capacity in the creeks. Therefore, DMP Update components B and BN would be permitted to impact wetlands within the Coastal Zone under LCP Policy 3-1.7(a)(5). Additionally, as required by Policy 3-1.7(a), mitigation would be implemented to reduce impacts to the wetlands within the Coastal Zone to a level of less than significant (refer to Section 4.10.5.3). As discussed in Section 4.1.3.3 of the Land Use section, the portion of Agua Hedionda Creek within the LCP is not part of the City’s HMP Hardline Preserve. Therefore, this portion of the creek is not identified as a preserved wetland. Additionally, the intent of Policy 3-1.7 is to provide protection to wetland areas from adjacent development projects and does not explicitly apply to projects within a wetland. Further, dredging within the portion of Agua Hedionda Creek within the Coastal Zone is permitted per LCP Policy 3-1.7(a)(5). For these reasons, Policy 3-1.12, which establishes buffers between preserved habitat and development, is not applicable to the proposed project. LCP Policy 4.7 permits the improvements in Agua Hedionda and 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-67 04080135 Carlsbad DMP EIR.doc 12/11/2007 Calavera creeks because the creeks are considered storm drainage facilities. Further, Policy 47 (f) states “adopt the provisions of the Master Drainage Plan to ameliorate flood and drainage hazards within the [Mello II] planning area.” LCP Policy 4-4 discourages removal of natural vegetation. The majority of the vegetation that would be removed during the proposed dredging and improvements in Agua Hedionda and Calavera creeks would be nonnative or ornamental vegetation, as shown in Table 4.10-10. The majority of the nonnative and ornamental vegetation within the project area occurs outside of the Coastal Zone (i.e., north of El Camino Real). Additionally, on-site mitigation could potentially occur on the creek banks, where feasible, to restore natural vegetation in place of existing exotic or ornamental vegetation. The long-term maintenance plan would promote the growth of native vegetation on the creek bank where appropriate and discourage establishment of invasive exotic, nonnative, and ornamental vegetation via maintenance activities. The wetland and riparian habitat between El Camino Real and Cannon Road bridges would be permanently impacted due to dredging and long-term maintenance activities, as shown in Table 4.10-10, which would conflict with Policy 3-1.2 to protect environmentally sensitive habitat. This removal, however, is necessary to maintain flood control, a recognized public service purpose that is valid for dredging, per Policy 3-1.7. Mitigation would be required for impacts to these wetlands within the Coastal Zone, consistent with the provisions and policies of the LCP. The proposed dredging and improvements in Agua Hedionda and Calavera creeks (project components B and BN) would be required to incorporate BMPs into the project design as part of the project’s SWPPP, as discussed above under the HMP consistency analysis. In addition, the long-term maintenance plan for the creeks would include BMPs for long-term erosion and sediment control (refer to Appendix B for more detail). With implementation of the project’s SWPPP and long-term maintenance plan, project components B and BN would be consistent with requirements of LCP policies 4-5 (erosion control) and 4-6 (sediment control). City of Carlsbad Opportunistic Beach Fill Program As described under Option 1 in Section 3.4.3 of the Project Description, should the City decide to pursue disposal of dredge materials at the South Carlsbad beach replenishment site, use of sediment dredged from Agua Hedionda and Calavera creeks would be in conformance with the City of Carlsbad Opportunistic Beach Fill Program (City of Carlsbad 2006). The proposed volume of dredge material is within the guidelines for Tier 1 sediment testing based on use of existing data. Available sediment analysis of the upper 2 feet of Agua Hedionda Creek indicates 4.10 Biological Resources Page 4.10-68 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 the material is mainly sand (> 75% sand content) with low contaminant concentrations (Ninyo & Moore 2006). 4.10.4 Significance of Impacts 4.10.4.1 Program Level At the program level, implementation of the proposed PLDA and non-PLDA project components would result in the following potentially significant impacts as addressed in the previous impact analysis: • Per the City’s HMP, implementation of proposed DMP Update components could result in long-term impacts if sensitive species or habitats are permanently destroyed or degraded. This would also result in a cumulative impact to biological resources. (Bio-1) • Long-term or permanent impacts could result from loss of sensitive habitats within the Coastal Zone. This would contribute to the regional loss of sensitive habitats, resulting in a cumulative impact. (Bio-2) • The loss of state and/or federally listed plant species is considered a significant impact. The loss of sensitive plant species at a regional level would contribute to a cumulative impact. (Bio-3) • Drainage facility improvements that result in substantial vegetation clearing or impede wildlife movement within Core Areas and linkages would result in a significant impact. (Bio-4) 4.10.4.2 Operations and Maintenance Operations and maintenance activities could result in potentially significant impacts similar to those addressed above in the impact analysis for PLDA and non-PLDA components (see Bio-1 through Bio-4). 4.10.4.3 Project Level At the project level, implementation of the proposed PLDA and non-PLDA project components would result in the following potentially significant impacts as addressed in the previous impact analysis: 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-69 04080135 Carlsbad DMP EIR.doc 12/11/2007 • The loss of 0.08 acres of willow riparian forest is considered a significant and cumulative impact and requires compensatory mitigation (i.e., creation, restoration, and/or replacement of in-kind habitat). (Bio-5) • Loss of wetland and riparian habitat within the Coastal Zone is considered a significant and cumulative impact. (Bio-6) • Proposed dredging and improvements within Agua Hedionda Creek (area adjacent to Cannon Road Bridge) have the potential to result in significant indirect impacts to least Bell’s vireo, southwestern willow flycatcher, and light-footed clapper rail. (Bio-7) 4.10.5 Mitigation Measures 4.10.5.1 Program Level Implementation of the mitigation measures Bio 1-a through Bio 1-d would be required for DMP components that would impact sensitive HMP habitats and would reduce direct and cumulative impacts to below a level of significance. Note that the descriptions of Type A through F habitats are per Table 11 of the HMP. Avoidance and on-site mitigation are the priority. Future project level environmental review for DMP Update components that would impact biological resources would be provided to the Wildlife Agencies for review to verify consistency with the City’s HMP. Bio-1a For impacts to Type A habitats (coastal salt marsh, alkali marsh, freshwater marsh, estuarine, salt pan/mudflats, riparian forest, riparian woodland, riparian scrub, disturbed wetlands, flood channel, fresh water, Engelmann oak woodland, coast live oak woodland) a goal of no net loss of habitat value or function shall be met. Habitat replacement ratios and the specific location of mitigation lands shall be determined in consultation with the USFWS, USACE, and CDFG as appropriate in accordance with the requirements of the federal CWA, federal wetland policies, and the California Fish and Game Code. All mitigation lands for impacts to riparian and wetland habitats shall be in the City or MHCP plan area, at a ratio to be determined by the applicable resource agencies at the time of project permitting. Bio-1b Impacts to Type B habitats (beach, southern coastal bluff scrub, maritime succulent scrub, southern maritime chaparral, native grass) shall be mitigated at a 3:1 ratio, or at an appropriate ratio based on habitat quality and quantity as 4.10 Biological Resources Page 4.10-70 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 determined in coordination with the applicable resource agencies at the time of project permitting. Bio-1c Impacts to Type C habitats (California gnatcatcher-occupied coastal sage scrub) shall be mitigated at a 2:1 ratio, or at an appropriate ratio based on habitat quality and quantity as determined in coordination with the applicable resource agencies at the time of project permitting. Bio-1d Impacts to Type D (unoccupied coastal sage scrub, coastal sage/chaparral mix, chaparral), Type E (annual, nonnative grassland), and Type F (disturbed lands, eucalyptus, agricultural lands) habitats are not subject to the fee payment. Instead, these types of impacts will be mitigated at the Lake Calavera Mitigation Bank, per the ratios included in HMP Table 11. An appropriate mitigation ratio would be determined based on habitat quality and quantity as determined in coordination with the applicable resource agencies at the time of project permitting. Implementation of mitigation measures Bio-1e through Bio-1g shall be required for DMP components that would result in indirect impacts to coastal California gnatcatcher, within 150 m (500 ft) of the proposed project footprint, from construction-generated noise and would reduce impacts to below a level of significance: Bio-1e Prior to the first preconstruction meeting for each project component, the City shall verify that the following statement is included in the construction specifications: No clearing, grubbing, grading, or other construction activities within or adjacent to the HMP occupied gnatcatcher habitat shall occur between March 1 and August 15, the breeding season of tthe coastal California gnatcatcher, he gnatcatcher. No clearing, grubbing, grading, or other construction activities within or adjacent to unoccupied habitat shall occur between March 1 and August 15, until the following requirements (requirements in Bio-1f and Bio- 1g) have been met to the satisfaction of the City: Bio-1f A qualified Biologist (possessing a valid Endangered Species Act Section 10(a)(1)(a) Recovery Permit) shall survey appropriate habitat areas subject to construction noise levels exceeding 60 dBA Leq for the presence of gnatcatcher. Gnatcatcher surveys shall be conducted pursuant to USFWS protocol survey guidelines a minimum of 4 weeks (within the breeding season) prior to 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-71 04080135 Carlsbad DMP EIR.doc 12/11/2007 commencement of construction. If gnatcatchers are present, then the following conditions must be met: • Between March 1 and August 15, no construction activities shall occur within any portion of the site where such activities would result in noise levels exceeding 60 dBA Leq at the edge of occupied gnatcatcher habitat. An analysis concluding that construction-generated noise would not exceed 60 dBA Leq at the edge of occupied habitat must be completed by a qualified Acoustician (possessing current noise engineer license or registration, with experience monitoring noise levels for listed wildlife species) and approved by the City at least 2 weeks prior to commencement of construction activities; OR • At least 2 weeks prior to commencement of construction activities, and under the direction of a qualified Acoustician, noise attenuation measures (e.g., berms, walls) shall be implemented to ensure that construction- generated noise will not exceed 60 dBA Leq at the edge of occupied gnatcatcher habitat. Concurrent with commencement of construction activities and with implementation of necessary noise attenuation measures, noise monitoring8 shall be conducted at the edge of occupied habitat to ensure that construction-generated noise does not exceed 60 dBA Leq. If the noise attenuation measures implemented are determined to be inadequate by the qualified Acoustician or Biologist, then the associated construction activities shall cease until such time that adequate noise attenuation is achieved or until the end of the breeding season (August 15). Bio-1g If gnatcatchers are not detected during the preconstruction survey within areas that would be subject to construction noise levels exceeding 60 dBA Leq, the qualified Biologist shall submit substantial evidence to the City and applicable regulatory agencies demonstrating whether noise attenuation measures (e.g., berms, walls) are necessary between March 1 and August 15 as follows: 8 Noise monitoring shall continue at least twice weekly on varying days, or more frequently depending on the construction activity, to verify that noise levels at the edge of occupied habitat are maintained below 60 dBA Leq or to the ambient noise level if it already exceeds 60 dBA Leq. If not, other measures shall be implemented in consultation with the Biologist and the City, as necessary, to reduce construction-generated noise levels to below 60 dBA Leq or to the ambient noise level if it already exceeds 60 dBA Leq. Such measures may include, but are not limited to, limitations on the placement of construction equipment and the simultaneous use of equipment. 4.10 Biological Resources Page 4.10-72 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 • If this evidence indicates the potential is high for gnatcatcher to be present based on historical records or site conditions, then measure Bio-1f shall be adhered to as specified above. • If this evidence concludes that no impacts to this species are anticipated, no mitigation measures will be necessary. Implementation of mitigation measures Bio-1h through Bio-1j shall be required for DMP components that result in indirect impacts to the least Bell’s vireo, within 150 m (500 ft) of the proposed project footprint, from construction-generated noise and would reduce impacts to below a level of significance: Bio-1h Prior to the first preconstruction meeting for each project component, the City shall verify that the following statement is included in the construction specifications: No clearing, grubbing, grading, or other construction activities within or adjacent to potential least Bell’s vireo habitat shall occur between March 15 and September 15 (least Bell’s vireo breeding season) in occupied least Bell’s vireo habitat. No clearing, grubbing, grading, or other construction activities within or adjacent to unoccupied least Bell’s vireo habitat shall occur between March 15 and September 15 until the following requirements (in Bio-1i and Bio-1j) have been met to the satisfaction of the City. Bio-1i A qualified Biologist shall survey those wetland areas that would be subject to construction noise levels exceeding 60 dBA Leq for the presence of least Bell’s vireo. Least Bell’s vireo surveys shall be conducted a minimum of 8 weeks (within the breeding season) prior to commencement of construction. If least Bell’s vireos are present, then the following conditions must be met: • Between March 15 and September 15, no construction activities shall occur within any portion of the site where such activities would result in noise levels exceeding 60 dBA Leq at the edge of occupied least Bell’s vireo habitat. An analysis showing that construction-generated noise would not exceed 60 dBA Leq at the edge of occupied habitat must be completed by a qualified Acoustician (possessing current noise engineer license or registration), with experience monitoring noise levels for listed wildlife species) and approved by the City at least 2 weeks prior to commencement of construction activities; OR 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-73 04080135 Carlsbad DMP EIR.doc 12/11/2007 • At least 2 weeks prior to commencement of construction activities, and under the direction of a qualified Acoustician, noise attenuation measures (e.g., berms, walls) shall be implemented to ensure that construction- generated noise would not exceed 60 dBA Leq at the edge of occupied least Bell’s vireo habitat. Concurrent with commencement of construction activities and with implementation of necessary noise attenuation measures, noise monitoring1 shall be conducted at the edge of occupied habitat to ensure that construction-generated noise does not exceed 60 dBA Leq. If the noise attenuation measures implemented are determined to be inadequate by the qualified Acoustician or Biologist, then the associated construction activities shall cease until such time that adequate noise attenuation is achieved or until the end of the breeding season (September 16). Bio-1j If least Bell’s vireos are not detected during the preconstruction survey within areas of potential habitat that would be subject to construction noise levels exceeding 60 dBA Leq, the qualified Biologist shall provide evidence to the City and applicable regulatory agencies demonstrating whether noise attenuation measures (e.g., berms, walls) are necessary between March 15 and September 15 as follows: • If this evidence indicates the potential is high for least Bell’s vireo to be present based on historical records or site conditions, then condition 1i shall be adhered to as specified above. • If this evidence concludes that no impacts to this species are anticipated, no mitigation measures would be necessary. Implementation of mitigation measures Bio-1k through Bio-1m shall be required for DMP components that would result in indirect impacts to the southwestern willow flycatcher, within 150 m (500 ft) of the proposed project footprint, from construction-generated noise and would reduce impacts to below a level of significance: Bio-1k Prior to the first preconstruction meeting for each phase of the project component, the City shall verify that the following statement is included in the construction specifications: No clearing, grubbing, grading, or other construction activities within or adjacent to potentialshall occur within occupied southwestern willow flycatcher habitat shall occur between May 1 and September 1 (southwestern 4.10 Biological Resources Page 4.10-74 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 willow flycatcher breeding season)). No clearing, grubbing, grading, or other construction activities within or adjacent to unoccupied southwestern willow flycatcher habitat shall occur between May 1 and September 1 until the requirements in Bio-1l and Bio-1m have been met to the satisfaction of the City. Bio-1l A qualified Biologist shall survey those wetland areas that would be subject to construction noise levels exceeding 60 dBA Leq for the presence of southwestern willow flycatcher. Southwestern willow flycatcher surveys shall be conducted pursuant to USFWS protocol survey guidelines a minimum of 6 weeks (within the breeding season) prior to commencement of construction. If southwestern willow flycatchers are present, then the following conditions must be met: • Between May 1 and September 1, no construction activities shall occur within any portion of the site where such activities would result in noise levels exceeding 60 dBA Leq at the edge of occupied southwestern willow flycatcher habitat. An analysis showing that construction-generated noise would not exceed 60 dBA Leq at the edge of occupied habitat must be completed by a qualified Acoustician (possessing current noise engineer license or registration, with experience monitoring noise levels for listed wildlife species) and approved by the City at least 2 weeks prior to commencement of construction activities; OR • At least 2 weeks prior to commencement of construction activities, and under the direction of a qualified Acoustician, noise attenuation measures (e.g., berms, walls) shall be implemented to ensure that construction- generated noise would not exceed 60 dBA Leq at the edge of occupied southwestern willow flycatcher habitat. Concurrent with commencement of construction activities and with implementation of necessary noise attenuation measures, noise monitoring1 shall be conducted at the edge of occupied habitat to ensure that construction-generated noise does not exceed 60 dBA Leq. If the noise attenuation measures implemented are determined to be inadequate by the qualified Acoustician or Biologist, then the associated construction activities shall cease until such time that adequate noise attenuation is achieved or until the end of the breeding season (September 2). Bio-1m If southwestern willow flycatchers are not detected during the preconstruction survey within areas of potential habitat that would be subject to construction noise 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-75 04080135 Carlsbad DMP EIR.doc 12/11/2007 levels exceeding 60 dBA Leq, the qualified Biologist shall submit substantial evidence to the City and applicable regulatory agencies demonstrating whether noise attenuation measures (e.g., berms, walls) are necessary between May 1 and September 1 as follows: • If this evidence indicates the potential is high for southwestern willow flycatcher to be present based on historical records or site conditions, then measure Bio-1l shall be adhered to as specified above. • If this evidence concludes that no impacts to this species are anticipated, no mitigation measures would be necessary. Bio-1n To identify the presence/absence of sensitive and/or native fish species within potential aquatic habitat (e.g., freshwater species such as the tidewater goby), the following measures shall be implemented: • Conduct a trapping/netting study; if sensitive native fish are detected, then (1) trapping and translocation of the sensitive fish shall occur, and/or (2) exclusionary trapping shall be placed to prevent sensitive fish species from entering the area of disturbance during in-stream activity. Bio-1o Where required, protocol-level surveys will be conducted for sensitive plant or wildlife species prior to construction of DMP Update components, as determined by the Wildlife Agencies. Bio-2a For DMP components that would result in the loss of sensitive habitats within the Coastal Zone, mitigation shall be required at ratios consistent with requirements of the HMP, including Standards 7-1 through 7-14 of Section D, and the policies and provisions of the LCP. Bio-2b Mitigation ratios shall be consistent with the provisions of the HMP and LCP. For all projects affecting riparian and wetland habitat, habitat replacement ratios and the specific location of mitigation lands shall be determined in consultation with the USFWS, USACE, and CDFG as appropriate in accordance with the requirements of the federal CWA, federal wetland policies, and the California Fish and Game Code. For DMP Update components with unavoidable impacts, the City shall demonstrate that viable wetlands can either be: 1) created at a minimum ration of 1:1 within close proximity of the impact area to replace the wildlife function affected by the project,; or, 2) provide proof that wetland 4.10 Biological Resources Page 4.10-76 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 creation credits at a minimum ratio of 1:1 have been purchased at a Wildlife Agency approved bank. Consistent with the City’s HMP, higher ratios will be required for impacts to high quality wetlands (e.g., occupied by listed or otherwise sensitive species) and for wetlands within the Coastal Zone. For DMP Update components where wetland creation will be necessary, construction shall not be initiated until a viable wetland creation mitigation site with long-term value is identified (and if necessary purchased by the City) and the wetland mitigation plan is approved by the appropriate Resource Agencies. The wetland creation shall not require impacts to sensitive wildlife or vegetation communities. All mitigation lands for impacts to riparian and wetland habitats shall be in the City or MHCP plan area as deemed appropriate by the Wildlife Agencies. Bio-3 As needed, surveys for state and federally listed sensitive plant species shall be conducted to complete a determination of suitable habitat presence prior to implementation of DMP Update components. Surveys shall be conducted at a time when sensitive plant species would be most observable. Bio-4 At the project design stage for the DMP Update components located within key Core Areas and linkages, design measures and restoration efforts shall be required to maintain the viability of the wildlife corridors throughout Carlsbad. 4.10.5.2 Operation and Maintenance Potential impacts to sensitive habitats, including riparian or wetland habitat, or to sensitive plant and/or wildlife species, wildlife migration corridors, and HMP consistency could be mitigated to below a level of significance through the implementation of measures Bio-1 through Bio-4, as summarized above for the program level analysis. 4.10.5.3 Project Level The following mitigation measures would reduce significant and cumulative impacts associated with project level PLDA (B and BN) and non-PLDA (operations and maintenance) components to a level below significance. Bio-5 Mitigation measures listed for Bio-1a and Bio-2a and 2b shall be implemented as applicable to address project-specific vegetation impacts within Agua Hedionda and Calavera creeks. 4.10 Biological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.10-77 04080135 Carlsbad DMP EIR.doc 12/11/2007 Bio-6 The project shall mitigate impacts to wetland and riparian habiat habitat through on- site restoration and/or off-site wetland and riparian habitat creation/restoration/ enhancement at a ratio to be determined in coordination with the applicable resources agencies at the time of permitting, consistent with LCP and HMP policies and provisions, as applicable. If adequate acreage to satisfy mitigation is not available on-site and/or at the Lake Calavera Mitigation Bank, then alternative mitigation credits may be purchased from the North County Mitigation Bank, or other alternative sites deemed acceptable by the resource agencies. Bio-7a If dredging and improvement activities cannot be conducted outside the breeding season for sensitive wildlife species, then prior to commencement of construction activities, a preconstruction survey shall be conducted by a qualified biologist to determine presence/absence of nesting birds. If nesting birds are detected on-site, vegetation removal shall be delayed until the chicks have fledged or the nest has failed. Bio-7b To address potential impacts to the light-footed clapper rail, a qualified biologist shall survey the area and surrounding 500-foot buffer area for light-footed clapper rails prior to implementation of dredging activities. There is no need to survey the area upstream of El Camino Real since this area is void of suitable clapper rail habitat (freshwater marsh). If clapper rails are detected in the project area, they should be flushed, prior to the onset of any vegetation removal. Bio-7c For potential indirect impacts to least Bell’s vireo, mitigation measures Bio 1-h through Bio 1-j shall be implemented, as applicable. Bio-7d For potential indirect impacts to southwestern willow flycatcher, implementation mitigation measures Bio 1-k through Bio 1-m shall be implemented, as applicable. Bio-7e To discourage sensitive bird species from entering active construction areas between El Camino Real and Cannon Road bridges, a physical barrier (construction fence) shall be installed on the downstream side of Cannon Road before dredging or vegetation removal commences. The barrier would be removed once the construction activity has ceased on the south side of El Camino Real. 4.10 Biological Resources Page 4.10-78 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.11 CULTURAL RESOURCES The information presented in this section addresses prehistoric and historic cultural resources for the proposed DMP Update. A records and literature search for the project components located within each drainage basin was conducted. Additionally, archaeologists conducted fieldwork for the Agua Hedionda and Calavera creeks study area (project level components B and BN). It should be noted that the archaeological survey report identifies an upland disposal site, at the northwest intersection of Cannon Road and College Boulevard. This site is no longer a part of the proposed project. 4.11.1 Existing Conditions The prehistoric cultural sequence in northern San Diego County is generally conceived as comprising three basic periods: the Paleoindian, dated prior to 8,000 years ago and manifested by the scraper planes, choppers, scraping tools, crescentics, and leaf-shaped points of the San Dieguito complex; the Archaic, lasting from about 8,000 to 1,500 years ago and manifested by the cobble and core technology of the La Jollan and Pauma complexes; and the Late Prehistoric, lasting from about 1,500 years ago to historic contact and marked by the appearance of ceramics, small arrow points, and cremation burial practices. By the time Spanish colonists began to settle California, Carlsbad was probably within the territories of two cultural groups, historically known as the Luiseño and the Kumeyaay, or Northern Diegueno. The Kumeyaay spoke a Yuman language, differentiating them from the Takic-speaking Luiseño, whose territory was located in northern San Diego County. Agua Hedionda Creek and the San Dieguito River have variously been identified as the border between territories of these two cultural groups. Villages were usually located along major drainages, in valley bottoms, or on the coastal strand, with each family controlling specific gathering areas (Kroeber 1925; Bean and Shipek 1978). Cultural activities within San Diego County between the late 1700s and the present provide a record of Native American, Spanish (1769-1821), Mexican (1821-1848), and American (1848- present) occupation and land use. During the 1860s, small ranches and farms were first established in the project vicinity, but most communities and ranches were not established until the land booms of the 1880s, following completion of the Santa Fe and Southern Pacific railroads. 4.11 Cultural Resources Page 4.11-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.11.1.1 Program Level The following provides a summary of the cultural resources located within or adjacent to currently proposed DMP Update components, as identified by archival research. No field investigations were conducted at the program level as part of this study. This section also identifies those project components that would require additional field investigation during project-specific design. Archival Research The archival search conducted for the DMP Update project area consisted of archaeological and historical records and literature reviews conducted at the South Coastal Information Center (SCIC) at San Diego State University and at the San Diego Museum of Man. The data reviewed included historic maps and National Register of Historic Places (NRHP) and California Register of Historical Resources (CRHR) information for the project area. The records searches are on file at EDAW, San Diego. The area for the program level archival and literature searches for the DMP Update encompassed an approximately 1/4-mile radius around each of the currently proposed project components. Also reviewed was the SCIC’s Directory of Historic Properties data for resources within or adjacent to each of the component locations. Information obtained from these reviews was used to determine if previous cultural resources surveys had been conducted in the project area, what types of resources might be expected, and if any cultural resources had been recorded within proposed project limits. These records searches identified 89 previous investigations that have been conducted partially or entirely within the 1/4-mile records search area. These investigations include EIRs, archaeological testing or surveys, and evaluations of historic structures. The records search identified 160 cultural resources within the 1/4-mile records search area. Of these, 28 are located within or adjacent to DMP Update project components (Table 4.11-1). Information regarding 4 of the latter resources is not available; the remaining 24 are prehistoric archaeological sites. These prehistoric sites include shell scatters, shell and lithic scatters, shell and artifact scatters, habitation sites, an artifact scatter, a cobble hearth, a shell midden, a site with flakes and prehistoric ceramic sherd, and one site that was apparently redeposited as fill. Of these 28 sites, 22 were last recorded prior to 1990, and their current condition is unknown. The records search information, combined with aerial mapping showing which areas of the city have already been developed, indicate project components that may have impacts on known cultural resources in the city. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.11-1 Proposed Program Level DMP Update Components within or adjacent to Cultural Resources Areas1 Resource Number(s) Project Component ID Primary Number (P-37-) Trinomial (CA-SDI-)Museumof Man (SDM-W-)Resource Description Date(s) Recorded CRHR and NRHPEligibility PLDA Project Components Basin A AFA 008914 8914 3030A, B Shell and lithic scatter 1981 Potentially eligible AFB 005651 5651 1539 Marine shell midden 1983 Potentially eligible Basin B BJ-1 015069 15,069 Unknown Unknown Potentially eligible BP 002722 2722 Flakes, one pottery sherd 1973 Potentially eligible Basin C CA 760 760 Shell and fractured rock 1961 Potentially eligible Basin D DH 3475 Shell scatter 1984 Potentially eligible DZ 008195 8195 108 Lithic scatter, projectile point, groundstone, ceramics, prehistoric burial Unknown Potentially eligible Non-PLDA Project Components Basin A A-CIP-4 005213 5213 143/146 Habitation site with hearths, groundstone, flaked stone, tools, debitage, ceramics, bone tools, shell beads, and a midden deposit 1985, 1986 Eligible Basin B BE 008303 8,303 123, 1892 (2730) Shell and midden deposits 1980, 1981, 1986, 1999 Eligible 4.11 Cultural Resources Page 4.11-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.11-1. Proposed Program Level DMP Update Components within or adjacent to Cultural Resources Areas1 (Continued) Project Component ID Resource Number(s) Resource Description Date(s) Recorded CRHR and NRHPEligibility Basin C 010876 10,876 3994 Fill deposit from a shell midden with ceramics 1988 Potentially eligible 4016 Habitation site with shell midden and a lithic scatter 1987 Potentially eligible C 4047A-C Three shell scatters 1989 Potentially eligible Basin D DM 000946 946 149 Shell midden 1961 Potentially eligible D-CIP-4 577 Unknown Unknown Potentially eligible D-CIP-8 012807 12,807 100/2544 Marine shell scatter, fire-affected rock, debitage, groundstone, flaked stone tools 1988 Potentially eligible D-CIP-9 004403 4403 943 Artifact scatter including hammerstones, core fragments, debitage, blades, manos, fire-affected rock, marine shell 1975 Potentially eligible D-CIP-6 004410 4410 951 Midden with shell, flakes, manos, metate fragments, hammerstones, and debitage 1975 Potentially eligible 1 Archival and literature searches encompass an appropriate ¼-mile radius around each of the proposed project components. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.11.1.2 Project Level A records search and field survey were conducted within a 1-mile radius of the proposed DMP Update boundary for the dredging and construction work in Agua Hedionda and Calavera creeks (components B and BN), including proposed staging areas. The following summarizes the archival research and survey results for the project location. A cultural resources survey is included in Appendix E. Confidential information associated with the records search and field survey is on file with the City. Archival Research The records search identified five cultural resource investigations that were conducted within the proposed project boundary. However, these investigations comprise only a limited portion of the project area. The investigations were conducted in association with the Rancho Carlsbad Mobile Home Park Project and proposed realignment of a portion of College Boulevard (Buysse and Smith 1999), Lake Calavera off-site improvements (Gallegos and Strudwick 1991), additions to Rancho Carlsbad (Smith and Gilbert 2004), and development projects associated with Carlsbad Highlands (Hanna 1981), and Kelly Ranch (Ultra Systems, Inc. and Archaeological Associates 1983). Although not included in the records search results, it should be noted that a report of archaeological subsurface investigations conducted at CA-SDI-5353, which may be the “rancheria” recorded by Portola in 1769, has been published in the Pacific Coast Archaeological Society Quarterly (Koerper et al. 1992). Site CA-SDI-5353 is within the 1-mile radius records search area, but outside of the area of potential effect for the proposed project components B and BN. The records search identified 72 archaeological sites within a 1-mile radius of the project. None of these sites are recorded within the project area; the nearest sites are recorded approximately 150 feet north of the project area. Previously recorded sites include temporary campsites, bedrock milling sites, marine shell scatters with associated artifacts, artifact scatters, or historic refuse deposits. Several sites appear to be longer-term prehistoric habitation areas. Evidence of longer-term habitation includes midden deposits, hearths, high densities of artifacts, and/or a variety of artifact types. Archaeologists conducted an archaeological field survey of the Agua Hedionda and Calavera creek banks (components B and BN), and the proposed staging areas. Results of this survey are included in the cultural resources technical report (Appendix E). No cultural resources were found during the survey. Ground visibility was generally good, although it was poor west of 4.11 Cultural Resources Page 4.11-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 El Camino Real due to dense vegetation. The creek channels were found to have been altered through past dredging and landscaping. The proposed staging areas would undergo little ground disturbance. 4.11.2 Significance Criteria The DMP Update would result in potentially significant impacts to cultural resources if it would: • cause a substantial adverse change in the significance of a historical or archaeological resource as defined in Section 15064.5; or • disturb any human remains, including those interred outside of formal cemeteries. 4.11.3 Impact Analysis 4.11.3.1 Program Level PLDA Project Components Ground-disturbing activities within intact native soils, including but not limited to trenching, grading, and dredging, have the potential to impact identified or unknown cultural resources within the project area. Table 4.11-1 above identifies the cultural resources that have been recorded within or adjacent to proposed locations of PLDA components. Recommendations regarding eligibility to the NRHP or CRHR are indicated on one of the site forms (CA-SDI- 5213). The remaining sites are of undetermined significance and are regarded as potentially eligible. None are known to have been evaluated and found not eligible based on current information. Many of the sites were recorded prior to 1990 and their current condition is unknown without field survey. One site (W-173) is reported destroyed, and others may have been destroyed as well due to development within the city. Sites that are recorded adjacent to proposed DMP Update components are included because of uncertainty regarding site locations and boundaries and the inadequacy of survey information due to record age and comprehensiveness. Based on this information, all project components proposed within currently undeveloped areas within the city could result in potential significant impacts to surface cultural resources. Activities that would result in subsurface excavation of native soils, even within developed areas, could also potentially affect cultural deposits if excavation into native soils would occur. Table 4.11-2 outlines the proposed PLDA components that would involve the placement of DMP Update components in undeveloped areas or would result in potential excavation of native soils. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.11-2 Cultural Resources Survey and Monitoring Requirements for Program Level Proposed Plan PLDA Project Components Project Component ID Project Name Potential Impact to SuperficialSurficial Cultural Resources? Potential Impact to Subsurface Cultural Resources? 1 Basin A AAA Jefferson Street Drainage Project No Yes AAAA Madison Street Drainage Project No Yes AC Highland Drive Drainage Project Yes Yes AFA Hidden Valley Drainage Restoration and Enhancement Project Yes Yes AFB North Calavera Hills Drainage Restoration and Enhancement Project Yes Yes Basin B BB-1 Washington Street Drainage Improvements, Phase I No Yes BB-2 Washington Street Drainage Improvements, Phase II No Yes BCA Park Drive/Tamarack Avenue Drainage Project No No BCB Magnolia Avenue Drainage Project No No BCC Chestnut Avenue Drainage Project No No BF1 Kelly Drive Water Quality Basin Project Yes Yes BFA Country Store Storm Drain Project No Yes BFB-L El Camino Real Drainage Project, Phase II Yes To be determined following focused investigation BFB-U El Camino Real Drainage Project, Phase I Yes To be determined following focused investigation BJ-1 Rancho Carlsbad Sedimentation Basin Project Yes Yes BJB College Boulevard Sedimentation Basin Structural Improvements Project No No BL-L College Boulevard Drainage Project Phase V- Downstream Portion Yes Yes BL-U College Boulevard Drainage Project Phase IV- Upstream Portion Yes Yes BM Cantarini Box Culvert Project Yes To be determined following focused investigation 4.11 Cultural Resources Page 4.11-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.11-2. Cultural Resources Survey and Monitoring Requirements for Program Level Proposed Plan PLDA Project Components (Continued) Project Component ID Project Name Potential Impact to SuperficialSurficial Cultural Resources? Potential Impact to Subsurface Cultural Resources? 1 BNB Calavera Creek Flood Control Improvement Phase II Yes Yes BP Melrose Flood Retention Facility Yes Yes BR Cantarini and Holly Springs Development Yes Yes BQ Sunny Creek Road Restoration and Enhancement Project Yes To be determined following focused investigation Basin C C1 Carlsbad Boulevard South Drainage Improvements Yes Yes C2 Paseo Del Norte Drainage Improvements Yes Yes CA Avenida Encinas Drainage Improvements No Yes Basin D DBA Poinsettia Village Drainage Improvements No Yes DBB Avenida Encinas Drainage Project No Yes DFA Batiquitos Lagoon Retention/ Detention Basin Project Yes Yes DH Altiva Place Restoration and Enhancement Project Yes Yes DQB La Costa Town Center Drainage Improvements Project Yes To be determined following focused investigation DZ Poinsettia Lane Bridge Project Yes Yes 1 Proposed project components would potentially impact subsurface cultural resources if the component would involve grading or excavation of undisturbed native soils. Non-PLDA Project Components Ground-disturbing project activities have the potential to impact identified or unknown cultural resources within the project area. Table 4.11-1 identifies the cultural resources that have been recorded within or adjacent to proposed locations of non-PLDA components. Eligibility recommendations are indicated on one of the site forms (CA-SDI-8303). The remaining sites are of undetermined significance and are regarded as potentially eligible. Table 4.11-3 outlines the proposed non-PLDA projects that could result in potentially significant impacts to cultural resources. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-9 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.11-3 Cultural Resources Survey and Monitoring Requirements for Program Level Proposed Non-PLDA/CIP Project Components Project Component ID Project Location Potential Impact to SuperficialSurficial Cultural Resources? Potential Impact to Subsurface Cultural Resources? 1 Basin A A-CIP-1 Miscellaneous Road Subdrains (Project Number 3681) No Yes A-CIP-2 Cynthia Lane Storm Drain Project; Cynthia Lane near I-5 No Yes A-CIP-3 Carlsbad Boulevard Storm Drain Replacement Project; between the SDNR track and Carlsbad Boulevard No Yes A-CIP-4 Ridgecrest Drainage Improvements Project; Ridgecrest Drive No No Basin B BAA Cannon Road Drainage Improvements No Yes BE South of Van Allan Way on south side of Agua Hedionda Creek Yes Yes BEA Begins northeast of Faraday Avenue and extends southwest to the south side of Agua Hedionda Creek Yes Yes BJ-2 Rancho Carlsbad Detention Basin Project Yes Yes BL-L College Boulevard Drainage Project Phase V- Downstream Portion No Yes B-CIP-1 and B-CIP-2 Miscellaneous Road Subdrains (Project Number 3681) No Yes B-CIP-3 Highland Drive Drainage Improvements Project; Highland Drive between Pine Avenue and Basswood Avenue No Yes B-CIP-4 Kelly Drive Drainage Improvements; Kelly Drive east of Hillside Drive No Yes Basin C C Natural channel extending from southwest corner of Palomar Airport Road and El Camino Real towards Pacific Ocean. Yes Yes Basin D DFA Northwest of the intersection of La Costa Avenue and El Camino Real Yes Yes DM Between Poinsettia Lane and Alga Road, on the west side of Almaden Lane Yes To be determined following focused investigation 4.11 Cultural Resources Page 4.11-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 4.11-3. Cultural Resources Survey and Monitoring Requirements for Program Level Proposed Non-PLDA/CIP Project Components (Continued) Project Component ID Project Location Potential Impact to SuperficialSurficial Cultural Resources? Potential Impact to Subsurface Cultural Resources? 1 D-CIP-1 through D-CIP-6 Miscellaneous Road Subdrains (Project Number 3681) No Yes D-CIP-7 La Costa Avenue Storm Drain Replacement Project; La Costa Avenue between El Camino Real and Viejo Castilla Way No Yes D-CIP-8 Gabbiano Lane Storm Drain Modification; south of Gabbiano Lane near Batiquitos Lagoon Yes To be determined following focused investigation D-CIP-9 Calle Gavanzo Subsurface Drainage Improvements; west side of Calle Gavanzo No No D-CIP-10 Romeria Drainage Improvements Project; Romeria Street Yes Yes D-CIP-10 Romeria Drainage Improvements Project; Romeria Street Yes Yes 1 Proposed project components would potentially impact subsurface cultural resources if the component would involve grading or excavation of undisturbed native soils. 4.11.3.2 Operation and Maintenance Ground-disturbing operation and maintenance activities are anticipated to occur only within the limits of previous disturbance and are not anticipated to impact native soils. Therefore, these activities are not expected to affect subsurface cultural resources. Some operation and maintenance activities may involve the temporary construction of access roads required during repair work, however, which could result in surface disturbance of previously undeveloped areas. Each of the proposed components would initially be subject to those project design features/methods listed in Table 3-6, which emphasize the avoidance of previously undisturbed areas to the extent possible. Access roads to existing facilities would be located, when possible, along previously disturbed routes to minimize potential impacts. Changes in access, adjacent development, or other shifts in accessibility may require routing of access roads through previously undisturbed areas, however, which could subsequently result in potentially significant impacts to surface cultural deposits. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-11 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.11.3.3 Project Level PLDA Project Components The proposed drainage improvements to Agua Hedionda and Calavera creeks (PLDA components B and BN) are not expected to affect historical or cultural resources. No historical or cultural resources were identified during the archival research or field survey within the proposed DMP Update area. Although the potential exists for buried cultural deposits in areas adjacent to creek and river beds, none are expected to be encountered during ground-disturbing activities associated with the dredging of Agua Hedionda and Calavera creeks because of the level of previous disturbance in the area. These two creek beds have been subject to previous dredging and mass grading operations during the construction of the Rancho Carlsbad community. The proposed dredging would not extend beyond the limits of disturbance from previous channelization and excavation efforts during creation of the channels and construction of Rancho Carlsbad or dredging efforts during the emergency dredge project. There would be little additional ground disturbance in the already disturbed proposed staging areas. Therefore, impacts to cultural resources are anticipated to be less than significant. Non-PLDA Project Components The long-term maintenance activities in Agua Hedionda and Calavera creeks (non-PLDA components B and BN) would occur within the same project footprint as discussed for the project level work; therefore, no impacts to cultural resources would occur. No cultural resources were identified during the archival research or field survey within the proposed DMP Update Component B and BN area. None are expected to be found during ground-disturbing activities associated with the project or during operation and maintenance activities. Therefore, impacts to cultural resources are anticipated to be less than significant. 4.11.4 Significance of Impacts 4.11.4.1 Program Level Based on the analysis discussed above, the following potentially significant impacts to cultural resources would occur. • For those areas not adequately surveyed, as identified in Tables 4.11-2 and 4.11-3, roads traversing previously undisturbed areas or projects requiring surface disturbance in 4.11 Cultural Resources Page 4.11-12 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 undeveloped areas could potentially lead to significant impacts to surface cultural deposits. (Cult-1) • Ground-disturbing project activities or excavation into intact native soils could potentially impact significant cultural resources that have not yet been discovered. (Cult-2) 4.11.4.2 Operation and Maintenance Roads traversing previously undisturbed areas could potentially lead to significant impacts to surface cultural deposits (Cult-1). No potentially significant impacts to subsurface deposits are anticipated. 4.11.4.3 Project Level Implementation of the project level DMP Update components would not result in direct or indirect potentially significant short- or long-term impacts to cultural resources. 4.11.5 Mitigation Measures 4.11.5.1 Program Level If avoidance is not feasible, and project components would encroach into previously undisturbed areas or intact native soils, the following mitigation measures will be required. Implementation of these measures will reduce potential impacts to cultural resources to below a level of significance. Cult-1 The following mitigation measures will be required if a proposed PLDA or non- PLDA component is located in an undeveloped area that could potentially impact significant cultural deposits, as indicated in Tables 4.11-2 and 4.11-3. In addition, for any operation and maintenance activities that will require temporary construction of an access road through previously undeveloped or undisturbed areas, the following mitigation measures will be required prior to construction. a) Preconstruction Requirements – Prior to the start of construction, a pedestrian survey shall be conducted under the supervision of a qualified archaeologist for previously undisturbed areas that have not been surveyed or adequately surveyed (e.g., the area was surveyed with outdated or non- 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-13 04080135 Carlsbad DMP EIR.doc 12/11/2007 protocol methods). The survey shall be conducted in parallel linear transects spaced no farther than 10 meters apart in undeveloped areas. 1) Cultural resources, if found during the survey, shall be photographed, mapped using a global positioning system (GPS), and recorded on the appropriate California Department of Parks and Recreation forms (DPR Form 523A/B). The forms shall be submitted to the SCIC for the assignment of Primary numbers within 1 week of the survey. 2) Within 1 month of completion of the field survey, a draft letter report or technical report shall be submitted to the City for review, whether the survey is negative or positive. A final report shall be submitted within 6 weeks of receipt of the City’s comments, with a copy submitted to the SCIC for their files. b) If the pedestrian survey is positive, the qualified archaeologist shall conduct an updated archival search, if needed, as well as additional detailed field testing. Local Native American groups shall be contacted for testing of prehistoric cultural resources regarding the project. Where applicable, the City will execute a Pre-Excavation Agreement with the appropriate Native American groups. 1) Prior to the start of field testing, surface artifacts and/or features shall be marked and mapped using a GPS. Testing shall be required if surface artifacts are discovered, and shall include a program of 30-cm- diameter shovel test pits (STPs) to define site boundaries and identify the potential for a substantial subsurface deposit. 2) Based on the results of the STPs, additional measures such as Test Excavation Units or mechanical trenching (for substantial historic sites) would be placed in areas with the potential for a substantial subsurface deposit, as determined by the qualified archeologist. 3) All excavated soils shall be screened through 1/8-inch mesh hardware cloth. On completion of the project the artifact collection, along with copies of the catalogs and the technical report, shall be permanently 4.11 Cultural Resources Page 4.11-14 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 curated at the San Diego Archaeological Center. An updated site record shall be prepared and submitted to the SCIC. 4) Within 3 months of completion of the fieldwork, a draft technical report including evaluations and recommendations shall be prepared and submitted. The final technical report shall be submitted within 6 weeks of receipt of the City’s comments. Cult-2 Monitoring Requirements – Construction monitoring will be required for proposed PLDA or non-PLDA DMP components that involve excavation or grading within undisturbed native soils and could potentially impact subsurface cultural deposits, as indicated in Tables 4.11-2 and 4.11-3. a) Prior to the first preconstruction meeting for the project, the Planning Director (PD) shall verify that the requirements for archaeological monitoring and Native American monitoring, if applicable, have been noted on the appropriate construction documents. The applicant shall retain a qualified archaeologist to verify that a records search has been completed and updated, as necessary, and to implement the monitoring program. At the preconstruction meeting, the archaeologist shall submit to the PD a copy of the site/grading plan that identifies areas to be monitored. b) The qualified archaeologist shall be present full-time during grading/ excavation of native soils with the potential to contain buried cultural features or deposits and shall document activity via the Consultant Monitor Record. Monitoring of trenches shall include mainline, laterals, services and all other appurtenances that impact native soils 1 foot deeper than existing as detailed on the plans or in the contract documents. It is the construction manager’s responsibility to keep the archaeological monitors up-to-date with current plans. c) In the event of a discovery, the archaeologist, or the Principal Investigator (PI) if the monitor is not qualified as a PI, shall divert, direct, or temporarily halt ground-disturbing activities in the area of the discovery to allow for preliminary evaluation of potentially significant archaeological resources. The PI shall also immediately notify the construction manager and the PD of such findings at the time of discovery. 4.11 Cultural Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.11-15 04080135 Carlsbad DMP EIR.doc 12/11/2007 1) The significance of the discovered resources shall be assessed by the PI. For significant archaeological resources, a Research Design and Data Recovery Program shall be prepared and implemented by the qualified archaeologist. The results of the Research Design and Data Recovery Program shall be approved by the City before ground- disturbing activities in the area of discovery shall be allowed to resume. d) If human remains are discovered, work shall halt in that area and procedures set forth in the California Public Resources Code (Sec. 5097.98) and State Health and Safety Code (Sec. 7050.5) shall be implemented. Construction in that area shall not resume until the remains have been evaluated and conveyed to appropriate descendants or reinterred to the satisfaction of the PI. e) The archaeologist shall notify the PD, in writing, of the end date of monitoring. The archaeologist shall be responsible for ensuring that all cultural remains collected are cleaned, catalogued, and permanently curated with an appropriate institution; that a letter of acceptance from the curation institution has been submitted to the Planning Department; that all artifacts are analyzed to identify function and chronology as they relate to the history of the area; that faunal material is identified as to species; and that specialty studies are completed, as appropriate. f) Within 3 months following the completion of monitoring, the Draft Results Report (even if negative) and/or evaluation report, if applicable, which describes the results, analysis, and conclusions of the Archaeological Monitoring Program (with appropriate graphics) shall be submitted to the PD for approval. For significant archaeological resources encountered during monitoring, the Research Design and Data Recovery Program shall be included as part of the Draft Results Report. The qualified archaeologist shall be responsible for recording (on the appropriate State of California Department of Park and Recreation forms-DPR 523 A/B) any significant or potentially significant resources encountered during the Archaeological Monitoring Program, and submitting such forms to the SCIC with the Final Results Report. 4.11 Cultural Resources Page 4.11-16 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.11.5.2 Operation and Maintenance Potentially significant impacts to surface cultural deposits will be mitigated to below a level of significance through the implementation of Cult-1 (as applicable) for any operation and maintenance activities that require the construction of temporary access roads traversing undeveloped or previously undisturbed areas. 4.11.5.3 Project Level No significant impacts to cultural resources have been identified; therefore, no mitigation measures would be required. 4.12 Paleontological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.12-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.12 PALEONTOLOGICAL RESOURCES Paleontological resources represent a limited, nonrenewable, and impact-sensitive scientific and educational resource. As defined in this section, paleontological resources (i.e., fossils) are the remains and/or traces of prehistoric plant and animal life exclusive of man. Fossil remains such as bones, teeth, shells, and leaves are found in the geologic deposits (rock formations) where they were originally buried. Paleontological resources include not only the actual fossil remains, but also the collecting localities and the geologic formations containing those localities. This section identifies geologic formations within Carlsbad, as well as the potential for those formations to contain fossil remains. The information contained in this section is derived from information found in geologic formation mapping and paleontological reports. 4.12.1 Existing Conditions 4.12.1.1 Program Level A wide range of geologic rock formations occur throughout Carlsbad, with varying degrees of sensitivity for paleontological resources. The following discussion addresses those rock formations found within the city that are considered moderately to highly sensitive for paleontological resources. A report describing the paleontological resources in Carlsbad and a paleontological resources reference map are available at the City Planning Department. Unnamed Marine Terrace Deposits The Coastal Plain Province of San Diego County is characterized by a “stair-step” sequence of elevated marine terraces (uplifted sea floors) and associated marine and nonmarine sedimentary covers (Deméré and Walsh 1993). The unnamed marine terrace deposits often consist of a basal nearshore marine stratigraphic unit and an upper nonmarine stratigraphic unit. The basal unit has produced large and diverse assemblages of marine invertebrate fossils such as mollusks, crustaceans, and echinoids as well as sparse remains of marine vertebrates such as sharks, rays, and bony fish. The upper unit has produced sparse remains of terrestrial mammals such as camel, horse, and mammoth. Based on the sedimentary origin of these deposits and the published fossil record, they have been assigned moderate paleontological resource sensitivity. 4.12 Paleontological Resources Page 4.12-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Unnamed River Terrace Deposits Deposits of coarse-grained, gravelly sandstones; pebble and cobble conglomerates; and claystones occur along the margins of many of the larger coastal valleys. The exact age of the deposits is uncertain, but they are related to the Pleistocene climatic events (Deméré and Walsh 1993). Although limited fossil occurrence has resulted from these deposits, remains of “Ice Age” mammals and other important vertebrate remains have been collected from several sites, indicating the potential for significant paleontological resources elsewhere. Thus, a moderate resources sensitivity has been assigned. Santiago Formation Middle Eocene strata in northwestern San Diego County have been generally assigned to the Santiago Formation, with three members (“A,” “B,” and “C”) recognized in the Encinitas- Carlsbad area. Member “B” of the Santiago Formation has produced well-preserved vertebrate fossils, from several localities in Carlsbad and Oceanside, including remains of opossums, insectivores, primates, rodents, brontotheres, rhinoceros, and uintathere (Deméré and Walsh 1993). The mammalian fauna is especially significant as it contains a mosaic of archaic and advanced species, and serves to document an important period in mammal evolutionary history. Member “B” of the Santiago Formation is assigned a high paleontological resource sensitivity based on the recovery of important remains of terrestrial vertebrate fossils. Delmar Formation The Delmar Formation was deposited in lagoonal/estuarine settings during the middle Eocene (Kennedy and Tan 1966). Fossils from the Delmar Formation consist of well-preserved to poorly preserved remains of estuarine invertebrates such as clams, oysters, and snails, as well as estuarine vertebrates, such as sharks and rays. This formation is considered highly sensitive for paleontological resources due to the important remains of terrestrial vertebrate fossils it has produced (Deméré and Walsh 1993). Point Loma Formation The Point Loma Formation was deposited on an ancient sea floor during the late Cretaceous and has produced many well-preserved types of fossil marine invertebrates, such as clams, snails, nautiloids, ammonites, crabs, and sea urchins, as well as marine vertebrates, such as sharks and mosasaurs (Deméré and Walsh 1993). The formation has also produced some remains of 4.12 Paleontological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.12-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 terrestrial plants and armored and duck-billed dinosaurs. As a result of the diverse and well- preserved marine fossils and dinosaur remains produced by the Delmar Formation, it has been assigned a high paleontological sensitivity. Lusardi Formation The Lusardi Formation consists of reddish-brown, poorly sorted, sandy pebble and boulder conglomerates with minor lenses of arkosic sandstone (Deméré and Walsh 1993). Although no identifiable fossils have been recovered from the Lusardi Formation, it has been assigned a moderate paleontological sensitivity due to its unproven resource potential. Undifferentiated Santiago Peak Volcanics Santiago Peak Volcanics are composed primarily of volcanic breccias, with a lesser amount of volcanic tuffs and flows (Deméré and Walsh 1993). The earliest flow-rocks date back to the Cretaceous ages. While the molten origin of the formation generally precludes the possibility of fossil remains, medisedimentary portions of the formation have produced important remains of siliceous microfossils and marine macroinvertebrates, including belemnites and clams. Therefore, the medisedimentary rocks of the Santiago Peak Volcanics have been assigned a high paleontological resources sensitivity, while the remainder of the formation is considered to have marginal sensitivity. 4.12.1.2 Project Level The project area for components B and BN is located on Quaternary Alluvium, which has been assigned a low paleontological resource sensitivity due to the relatively young age (i.e., generally younger than 10,000 years) of the deposits (Deméré and Walsh 1993). 4.12.2 Significance Criteria The DMP Update would result in potentially significant impacts to paleontological resources if it would: • directly or indirectly destroy an identified sensitive paleontological resource or site or an identified sensitive geologic feature. 4.12 Paleontological Resources Page 4.12-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.12.3 Impact Analysis 4.12.3.1 Program Level Proposed DMP Update components may require excavation activities within potential fossil- bearing geologic formations (as identified in Section 4.12.1.1 above), which would be determined during project-specific design. Excavation in such formations could potentially impact significant paleontological resources, particularly within formations considered moderately to highly sensitive for paleontological resources. Project-specific information regarding underlying formations would become available during project design (i.e., through geotechnical analysis required in Table 3-6) prior to grading. Proposed DMP Update project components that involve repairs and/or maintenance of existing facilities would not result in additional impacts to paleontological resources. These areas and associated underlying earth materials have previously been disturbed during construction. While construction of proposed DMP Update components may disturb fossil-bearing geological strata in many locations throughout the city, many proposed components would occur in areas previously disturbed or would be limited to surface disturbance, however, and would not require excavation into intact geological formations. For example, pipelines would generally be constructed in road rights-of-way or existing easements where strata have already been disturbed, so the recovery of intact fossil remains representing unique paleontological information is highly unlikely. Therefore, construction of DMP Update components would result in potentially significant impacts to paleontological resources. 4.12.3.2 Operation and Maintenance Proposed operation and maintenance activities would primarily involve replacement of, or modifications to, existing drainage facilities located in previously disturbed areas and would not result in additional disturbance to paleontological resources or sites or unique geologic features. Therefore, disturbance of unique paleontological resources or sites or unique geologic features is not anticipated during operation and maintenance activities. Potential impacts would be less than significant. 4.12.3.3 Project Level The proposed project boundary for project level DMP Update components B and BN is located on Quaternary alluvial deposits, which have a low to moderate potential to contain 4.12 Paleontological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.12-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 paleontological resources (Deméré and Walsh 1993). Additionally, the creeks were previously dredged and channelized during construction of the Rancho Carlsbad residential community in the late 1960s, as well as during the emergency dredging conducted in March 2006. Dredging activities are intended to excavate material to the original grades in the creeks (to a depth of 4 to 6 feet), only remove debris and sediment that have accumulated in the last few decades, and not extend into previously undisturbed intact geological formations. Therefore, unique paleontological resources or sites or unique geologic features would not likely be destroyed as a result of conducting the proposed dredging and improvements. Potential impacts to paleontological resources are considered less than significant. Further, long-term maintenance of the creeks would be conducted in disturbed areas where dredging and channel improvement have previously occurred and would remove accumulated debris and sediment. Because activities would remove only accumulated debris and sediment, and proposed removal would not extend into previously undisturbed intact geological formations, destruction of unique paleontological resources or sites or unique geologic features is not anticipated as a result of conducting long-term maintenance in the creeks. Potential impacts to paleontological resources are considered less than significant. 4.12.4 Significance of Impacts 4.12.4.1 Program Level For DMP Update components proposed in locations considered to have moderate to high sensitivity for paleontological resources (to be determined during project-specific design), grading and earthwork could disturb potentially unknown fossil remains and the information in the fossils could be lost. Impacts would be considered significant. (Paleo-1) 4.12.4.2 Project Level No direct or indirect significant impacts to paleontological resources are anticipated to occur from proposed project level DMP Update components. 4.12.4.3 Operation and Maintenance No direct or indirect significant impacts to paleontological resources are anticipated to occur from proposed operation and maintenance activities. 4.12 Paleontological Resources Page 4.12-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 4.12.5 Mitigation Measures 4.12.5.1 Program Level The following mitigation measures shall be implemented during construction of PLDA and non- PLDA project components proposed in geologic formations with a moderate to high sensitivity for paleontological resources, including Unnamed Marine Terrace Deposits, Unnamed River Terrace Deposits, Santiago Formation, Del Mar Formation, Point Loma Formation, Lusardi Formation, or Undifferentiated Santiago Peak Volcanics. Determination of the underlying geologic formations shall be determined during project design through existing mapping, project- specific geotechnical investigations, or other appropriate testing methods. Implementation of these measures will reduce impacts to paleontological resources to below a level of significance. Paleo-1 A monitoring program shall be prepared and implemented if excavation into intact geologic formations with moderate to high sensitivity is proposed. Components of such a monitoring program shall include, but not be limited to, the following: a) A qualified paleontological monitor shall be present at a pregrading meeting with the construction contractor and PD of the City Planning Department. The purpose of the meeting will be to consult and coordinate the role of the paleontologist during construction. The paleontological monitor shall have adequate knowledge and experience with fossilized remains likely to be present to identify them in the field. The paleontological monitor shall be adequately experienced to remove paleontological resources for further study. b) The paleontological monitor shall be present during the applicable stages of grading and construction (including trenching), as determined at the pregrading meeting. The paleontological monitor shall have the authority to temporarily direct, divert, or halt grading in the area of an exposed fossil to facilitate evaluation and, if necessary, salvage. At the discretion of the monitor, recovery may include washing and picking of soil samples for microvertebrate bone and teeth. Construction activities in the area of discovery shall resume upon notification by the paleontologist that fossil remains have been recovered. The City shall ensure the contractor is aware of the random nature of fossil occurrences and the possibility of a discovery 4.12 Paleontological Resources City of Carlsbad Drainage Master Plan Update EIR Page 4.12-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 of such scientific and/or educational importance that it might warrant a long-term salvage operation or preservation. All fossils collected shall be donated to a museum with a systematic paleontological collection, such as the San Diego Natural History Museum. The City shall ensure the grading contractor is aware of this provision. Conflicts regarding the role and authority of the monitor shall be resolved by the PD or his/her designee. c) Collected fossils shall be cleaned and/or prepared to a point of identification, and then curated to museum standards (cataloging of locality and specimen data, numbering, identification, labeling) before being deposited in an appropriate public facility (or facilities) that can provide permanent archival storage (so that specimens are available for future scientific study). A report detailing the mitigation and any discoveries shall be prepared and submitted to the City within 3 months following termination of the paleontological monitoring program, even if negative. The report shall include necessary maps, graphics, and fossil lists to adequately document the paleontological monitoring program. 4.12.5.2 Operation and Maintenance No direct or indirect impacts to paleontological resources are anticipated to occur during operation and maintenance activities; therefore, mitigation would not be required. 4.12.5.3 Project Level No direct or indirect impacts to paleontological resources are anticipated to occur as a result of project level DMP Update components; therefore, mitigation would not be required. 4.12 Paleontological Resources Page 4.12-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 CHAPTER 5.0 – CUMULATIVE IMPACTS 5.1 INTRODUCTION CEQA requires an analysis of the reasonably foreseeable cumulative impacts from existing and proposed projects. “Cumulative impacts” are defined as “two or more individual effects which, when considered together, are considerable or which compound or increase other environmental impacts” (CEQA Guidelines Section 15355). The cumulative impacts analysis is a two-part analysis; first, an agency must ask whether the combined impacts of the projects, taken together, will constitute a significant cumulative impact. If this question is answered affirmatively, the agency must ask whether a particular project’s incremental contribution to that impact is cumulatively considerable. This two-step approach is reflected in the CEQA Guidelines, which state that “[w]hen assessing whether a cumulative effect requires an EIR, the lead agency shall consider whether the cumulative impact is significant and whether the effects of the project are cumulatively considerable” (CEQA Guidelines, Section 15064(d)(i)(1)). CEQA Guidelines allow for the preparation of a list of past, present, and reasonably anticipated future projects as a viable method of determining cumulative impacts. Also allowed is the use of projections contained in adopted general plans or related planning documents. The discussion in this section utilizes both approaches. Consistent with CEQA, this discussion is guided by the standards of practicality and reasonableness. When considering the programmatic components of the project, the most appropriate approach to the cumulative analysis is to consider planning-level documents (e.g., regional plans, master plans, Specific Plans, City of Carlsbad General Plan, etc.). Thus, the cumulative study area for the DMP Update is the region and the city at-large. In addition, the cumulative analysis for the DMP Update considers a long-range planning horizon, given implementation of the DMP Update is anticipated in phases or increments over a 30-year planning timeframe. When considering the projects to be implemented in the short term, this EIR considers not only the programmatic documents described above, but also private and public projects anticipated to occur in the near term in Basin B, where the individual drainage improvements (projects components B and BN) would occur. Table 5-1 summarizes the cumulative projects considered for this analysis. Figure 5-1 shows the general locations of the projects included in Table 5-1. This analysis evaluates projects that, 5.0 Cumulative Impacts Page 5-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1 Summary of Cumulative Projects Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review La Costa Town Square Draft EIR 01-02 in progress (not available for public review) X The project involves the construction and operation of a mixed-use project that includes an estimated 302,000-square-foot (sq ft) community shopping center, a 53,000 sq ft cinema, a 30,193 sq ft tenant warehouse, 63 single-family detached residential units, 120 multi-family residential units, and 45 affordable housing multi-family residential units. To be determined. Villages of La Costa Master Plan Final EIR 98-07 October 2001 X The 1,866.4-acre project consists of three major planning areas: (1) The Greens, which encompasses approximately 660.7 acres and is located approximately 2,500 feet south of Palomar Airport Road, east of El Camino Real, north of Alga Road, and west of Unicornio Street; (2) The Ridge, which includes approximately 493.1 acres and is located southeast of El Fuerte Street and Alga Road and northwest of San Marcos Creek; and (3) The Oaks, which encompasses approximately 712.6 acres and is located on both sides of Rancho Santa Fe Road. Significant Unmitigable (Cumulative): • Visual Quality/Aesthetics • Transportation • Noise • Air Quality • Hydrology/Water Quality/Drainage Significant Unmitigable (Direct): • Landform alteration Mitigated to a Less Than Significant Level: • Visual Quality and Aesthetics • Biological Resources • Archaeological Resources • Paleontological Resources • Transportation 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1. Summary of Cumulative Projects (Continued) Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review • Noise • Air Quality • Geology/Soils • Hydrology, Water Quality & Drainage • Public Facilities and Services • Human Health and Safety Hazards Ponto Beachfront Village Vision Plan Draft EIR 05-05 (April 2007) X The Vision Plan designates six distinct character areas (Mixed Use Center, Beachfront Resort, Townhouse Neighborhood, Village Hotel, Live-Work Neighborhood, and Garden Hotel) for development of the 130-acre Ponto area, located south of of Poinsettia Lane, east of the South Carlsbad State Beach and Campground, north of the Batiquitos Lagoon and La Costa Avenue, and west of the San Diego Northern Railroad. To be determined. Alga Norte Community Park Negative Declaration X A 33-acre master planned community park located at the northwest of the intersection of the future alignment of Poinsettia Lane and Alicante Road, and east of El Camino Real. The park will include amenities such as aquatic facilities, a skatepark, half-court basketball, ballfields, and a tot-lot. No significant impacts were identified. The Palomar Forum/Raceway MND December 2001 X A 50-acre industrial park located at the northeast corner of Melrose Dive and Palomar Airport Road. No significant impacts were identified. 5.0 Cumulative Impacts Page 5-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1. Summary of Cumulative Projects (Continued) Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review Bressi Ranch Master Plan Final Program EIR 98-04 July 2002 X This master plan development includes 623 residential units and 2.1 million sq ft of industrial, mixed-use, and commercial property. It is located within Zone 17 of the LFMP at the southeast corner of El Camino Real and Palomar Airport Road. Significant Unmitigable Impacts (Direct and Cumulative): • Air Quality Mitigated to a Less Than Significant Level: • Traffic/Circulation • Air Quality • Noise • Geology/Soils • Biological Resources • Cultural Resources • Visual/Aesthetics/Grading • Public Services and Utilities • Water Quality/Hydrology • Hazardous Materials & Hazards Carlsbad Raceway Business Park MND 2001 X This project consists of 1.5 million sq ft of phased industrial development. Involves a subdivision of 146.3-acre parcel into 25 industrial lots and 3 open space lots. The project is located at Palomar Airport Road and Melrose Drive. Approximately 50 percent (72 acres) of the site is slated for open space. No significant impacts were identified. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1. Summary of Cumulative Projects (Continued) Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review Municipal Golf Course Final EIR June 2000 X An 18-hole championship golf course, which is scheduled to open in 2007. The golf course will be located along the north side of Palomar Airport Road at Hidden Valley Road. Half of the 400-acre course will be preserved for habitat and will help tie together more than 1,000 acres of open space in the central part of the city. Significant Unmitigable Impacts (Cumulative): • Air Quality • Traffic/Circulation Mitigated to a Less Than Significant Level: • Biological Resources • Air Quality • Water Quality/Hydrology • Archeological Resources • Paleontological Resources • Landform Alteration/Grading • Public Services and Utilities Carlsbad Oaks North Specific Plan Final EIR 98-08 October 2002 X A Specific Plan that provides regulations for the development of a 194.5-acre industrial park that includes 23 industrial use lots with some auxiliary commercial uses and the preservation of three open space lots, totaling 219.5 acres. Significant Unmitigable (Cumulative): • Transportation/Traffic • Air Quality Significant Unmitigable (Direct): • Transportation/Traffic • Air Quality • Biological Resources Mitigated to a Less Than Significant Level: • Land Use and Planning • Noise 5.0 Cumulative Impacts Page 5-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1. Summary of Cumulative Projects (Continued) Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review • Geology/Soils • Hazards and Hazardous Materials • Hydrology/Water Quality • Cultural Resources • Paleontological Resources • Public Services and Utilities • Aesthetics Cantarini Ranch/Holly Springs Developments Final EIR 02-02 October 2004 X The project sites are located east of El Camino Real and south of Cannon Road. The project involves the development of residential subdivisions on approximately 276 acres within the LFMP Zone 15. The Cantarini Tentative Map proposed development of 105 single-family units and 80 multi-family units on 156.14 acres would be placed under a conservation easement as permanent open space. The Holly Springs Tentative Map would develop a total of 43 single-family residential lots on 0.5-acre lots over approximately 24.40 acres on the 119.85-acre property. Significant Unmitigable (Cumulative): • Air Quality Mitigated to a Less Than Significant Level: • Biological Resources • Air Quality (Direct) • Noise • Water Quality • Geology/Soils • Hazardous Materials and Hazards • Archaeological Resources • Paleontological Resources Vmax Riprap Removal2 Notice of Exemption X The project involves the removal of the Vmax riprap on the south bank of Calavera Creek across from the weir wall located at the outlet for the existing Basin BJB. The weir wall has caused significant erosion of the channel bank, exposing riprap. The None identified. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1. Summary of Cumulative Projects (Continued) Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review project would also involve stabilization of the channel banks following the riprap removal. Robertson Ranch Master Plan Development Final EIR 03-03 April 2006 X A majority of the 398-acre site is located on the north side of El Camino Real between Tamarack Avenue and Cannon Road; however, the project site also includes 39.7 acres of land north of College Boulevard and 9.5 acres south of Cannon Road directly adjacent to the Rancho Carlsbad residential community. The site is divided into two villages, which include a variety of land uses such as residential uses, commercial uses, an elementary school, a community park, recreational vehicle storage, trails, private recreation areas, water quality treatment facilities and open space. Significant Unmitigable: • Transportation/Circulation • Air Quality Mitigated to a Less Than Significant Level: • Air Quality (short-term construction) • Noise • Biological Resources • Cultural Resources • Geology/Soils • Paleontological Resources • Hazardous Materials and Hazards • Hydrology and Water Quality • Public Services and Utilities • Grading and Aesthetics Calavera Hills Master Plan Phase II, Bridge and Thoroughfare District No. 4, & Detention Basins Final EIR 98-02 January 2002 X The project, located in the northeast quadrant of the city, south of SR 78 and east of El Camino Real, consists of 1,019 acres of urban villages and open space, including 19 residential villages (with over 700 homes) a community park, 2 school sites, 2 community facility sites, as well as areas for environmental mitigation. Significant Unmitigable (Cumulative): • Traffic Circulation Mitigated to a Less Than Significant Level: • Land Use • Landform/Visual Quality • Traffic Circulation • Noise 5.0 Cumulative Impacts Page 5-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Table 5-1. Summary of Cumulative Projects (Continued) Project Name CEQA Documentation Status1 Proposed Approved (Not Yet Under Construction Approved (Under Construction) Completed Project Description Significant Impacts Identified during Environmental Review • Agriculture • Public Facilities • Biological Resources • Archaeology/Cultural Resources • Paleontology • Hydrology • Air Quality • Geology Calavera Dam Modifications Mitigated Negative Declaration (April 2006) X This City project includes upgrade of the outlet structure for Calavera Dam. The new outlet structure and system of valves will allow the lake to be drawn down in anticipation of large storm events, resulting in a lower peak flow out of Lake Calavera. Mitigated to a Less Than Significant Level: • Biological Resources • Cultural Resources • Hydrology/Water Quality Source: City of Carlsbad 2006 and 2007 1 Environmental documents are available for review at the City Planning Department counter. 2 Vmax Riprap Removal is located adjacent to project components B and BN. The cumulative analysis for this project is included in the analysis for project-specific DMP components. No City permits are required for this project. !1 !2 !2 !2 !6 !5 !7 !9 !8 !01 !11 !21!31 !51!41 !3 !4 !8 DM BE C BNB BN ! BFB-U DH DQB BB-1 B CA BFA BQ BJB BB-2 BP BEA BAA BF1 BJ BL-U!BFB-L AAAA BCB AC BCC DBB DFA AAA BCA BL-L AFA AFB AC BM DZ!C2 DBA ! C1 D-CIP-7 B-CIP-4 D-CIP-4 D-CIP-6 D-CIP-9 D-CIP-10 D-CIP-2 D-CIP-5 D-CIP-1 D-CIP-3 B-CIP-1 A-CIP-2 A-CIP-3 A-CIP-1 B-CIP-3 D-CIP-8 A-CIP-4 B-CIP-2 R A N C H O S A N T A F E R D C O L L E GE BLVDMARRON RD ALGA RD LA CO S T A A VEMELROSE DRCARRILLO W Y OLIVENHAIN RD FARADAY AV POINSETTIA L NCARLSBAD BLVDEL CAMI NO REALCANNO N R D TAMARACK AVE PALO M A R A IR P OR T R DCOLL E G E B L V D CARLSBAD VILLAGE DR EL CAMINO REALCARLSBAD BLVDPALOMAR AIRPORT RD Batiquitos Lagoon Agua Hedionda Lagoon Squires Reservoir Lake Calavera B u e n a V i s t a L a g o o n !"^$ !"^$ Buena Vista Creek Calavera CreekAg u a H edionda Creek E n c in as Creek S a n Marc os Cre ek Encinitas Creek Basin A Basin B Basin C Basin D Oceanside Vista Encinitas Ag u a H e dionda Creek ! BJ-2 BJ-1 BR Figure 5-1General Location of Master Planning and Other Related ProjectsCity of Carlsbad Drainage Master Plan Update EIR Path: P:\2004\04080135 Carlsbad Drainage Master Plan\5GIS\Mxd\PEIR\Land_Use\Master Planning_Projects.mxd, 05/08/07, marraccinibSource: AirPhotoUSA 2006; SanGIS 2006; USGS Hydrography 1997 Scale: 1:48,000; 1 inch = 4,000 feetFeet4,000 0 4,0002,000I PLDA Project Component Non-PLDA Project Component Dual Status (PLDA/Non-PLDA) Basin Boundary Water Bodies USGS Blue Line Streams LEGEND !1 La Costa Town Square !2 Villages of La Costa !3 Ponto Beachfront Village !4 Alga Norte Community Park !5 The Palomar Forum/Raceway !6 Bressi Ranch !7 Carlsbad Raceway Business Park !8 Municipal Golf Course !9 Carlsbad Oaks North !01 Cantarini Ranch !11 Holly Springs !21 Vmax Riprap Removal !31 Robertson Ranch Master Plan !41 Calavera Hills !51 Calavera Dam (Throughout southeast quadrant) 5.0 Cumulative Impacts Page 5-10 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-11 04080135 Carlsbad DMP EIR.doc 12/11/2007 considered together with the proposed DMP Update, would result in a cumulatively significant environmental impact. From the time of preparation of this EIR, additional projects related to the DMP Update may be proposed or anticipated within the city, which may also result in potentially significant environmental impacts. The cumulative analysis evaluates the cumulative contribution of the DMP Update to impacts to environmental issue areas for which the DMP Update itself would result in potentially significant impacts. Thus, the analysis addresses the cumulatively considerable impacts of the DMP Update, regardless if additional projects are considered. In addition to the relevant projects identified in Table 5-1, numerous other development projects are occurring or are anticipated to occur throughout the city. The General Plan establishes the maximum intensity of development that can occur within the city (with the exception of additional units granted by the City through density bonuses for affordable housing projects). Implementation of other development projects is anticipated to occur consistent with the City’s General Plan and other relevant planning documents and regulations (e.g., LCP, HMP). The direct, indirect, and cumulative environmental impacts resulting from development citywide are evaluated in the Master EIR for the General Plan Update (City of Carlsbad 1994). The Master EIR identified significant cumulative impacts to transportation/circulation and air quality resulting with implementation of the General Plan Update. This analysis incorporates by reference the environmental impact analysis performed in the Master EIR for the General Plan Update, which is available for review at the City of Carlsbad Planning Department. 5.2 CUMULATIVE IMPACTS ANALYSIS 5.2.1 Program Level The cumulative impacts of the large-scale planning projects identified in Table 5-1, as well as the cumulative impacts identified in the General Plan, are evaluated in conjunction with those of the proposed DMP Update project components. This analysis also takes into consideration the operational and maintenance activities that would occur over the long-term implementation of the DMP Update. 5.2.1.1 Land Use The General Plan establishes the maximum intensity of development that can occur within the city. It is assumed that future development in the city would occur in a manner consistent with the City’s General Plan, Growth Management Plan, and other land use planning documents and 5.0 Cumulative Impacts Page 5-12 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 regulations. However, implementation of the DMP Update would not alter planned land use conditions in the city beyond what is envisioned in the General Plan. For these reasons, the DMP Update would not contribute to cumulative land use impacts in Carlsbad. 5.2.1.2 Agricultural Resources Agriculture is an important and limited resource in the city. The city has several policies that are intended to preserve agricultural lands while planning for the possible future transition of the land to urban uses, as consistent with the City’s General Plan. The General Plan Open Space and Conservation Element intends to secure agricultural lands and promote long-term economic viability of agricultural land uses. However, the projected pattern of development in the city is such that extensive areas generally required for agricultural operation are unlikely to remain available in the long term, and development is likely to occur. The proposed DMP Update components would not involve the conversion of Important Farmlands or existing agricultural uses to nonagricultural uses and would not conflict with any Williamson Act contracts in the city. Therefore the DMP Update would not contribute to cumulative agricultural resource impacts. 5.2.1.3 Visual Resources Carlsbad is a predominantly residential community, with a visual landscape consisting of urban uses, infrastructure, natural areas, hillsides, and coastal views. Cumulatively, development will result in the continued alteration of the visual setting and topography of the area. Local planning policies and development standards, including specific policies related to visual resources and grading, would reduce potential aesthetic impacts of individual projects and developments. Impacts to visual resources are identified for cumulative projects in the city (i.e., Villages of La Costa Master Plan). However, the DMP Update would not result in a substantial change to the visual environment, either individually, or in consideration of the cumulative projects. For this reason, the DMP Update would not contribute considerably to a cumulative visual impact. 5.2.1.4 Transportation/Circulation The DMP Update would result in short-term traffic impacts during construction and maintenance activities. As the project components would be phased over several decades, cumulative short- term construction-related impacts generated in conjunction with other development projects would be minimized through coordination and implementation of traffic control plans at the time of construction with the City Engineering Department. Encroachment permits are required for 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-13 04080135 Carlsbad DMP EIR.doc 12/11/2007 all construction affecting public rights-of-way. This permitting process is the control point for the maximum possible reduction of cumulative short-term traffic impacts and is designed to reduce direct and cumulative impacts to below a level of significance. Although the projects identified in Table 5-1 generate traffic conditions that may be cumulatively significant, the proposed program level DMP Update would not result in permanent contributions to this cumulative baseline. For these reasons, the DMP Update would not contribute considerably to a significant transportation or circulation impact. 5.2.1.5 Air Quality Strategies for the control of both point sources and mobile pollution generation are the responsibility of the SDAPCD. SDAPCD rules and regulations apply uniformly throughout the District and the rest of the SDAB and to all potential sources of pollutant emissions. Thus, air pollution control in the region is applied on a cumulative basis. Development forecasted for the San Diego region will generate increased emission levels from transportation and stationary sources. Planned development projects in Carlsbad (see Table 5-1) would contribute to cumulative short-term air quality impacts due to construction and/or long- term cumulative impacts resulting from increases in traffic. The air quality effects of the DMP Update would be limited to short-term effects. Temporary emissions generated from construction equipment and fugitive dust during construction activities would be minimized by incorporation of the dust control and construction emission control features included in Table 3-6. For these reasons, the DMP Update components would not result in a significant contribution to cumulative air quality impacts. 5.2.1.6 Noise As Carlsbad becomes increasingly urbanized, increases in ambient noise levels resulting in localized effects are inevitable. These increases would be attributed primarily to traffic noise, as roads are constructed to serve new development, and to point sources of noise associated with urban development. The City’s Noise Ordinance and Noise Guidelines Manual are intended to control exposure of residents to excessive or prolonged increases in noise levels. The projects proposed in the DMP Update have the potential to temporarily contribute to the generation of noise during construction and maintenance activities. However, they would not result in any long-term noise effects. Regulation and noise attenuation for other noise sources consistent with the City’s Municipal Code, General Plan, Airport LUCP, and Noise Guidelines Manual would ensure that the cumulative noise impacts in the city are not substantial over the long term. While 5.0 Cumulative Impacts Page 5-14 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 implementation of the DMP Update could temporarily generate noise in localized areas, this contribution to the overall noise environment would not be noticeable. In addition, the recommended mitigation measures contained in Section 4.6 of this EIR would reduce these noise impacts to the extent feasible to ensure localized impacts are minimized. For these reasons, the DMP Update would not result in a significant contribution to cumulative noise impacts. 5.2.1.7 Recreation No direct or indirect impacts to recreational services would occur with implementation of the DMP Update. Additionally, the projects identified in Table 5-1 would not have significant cumulative impacts to recreational services. Therefore, the DMP Update would not contribute to cumulative impacts to recreational services in the city. 5.2.1.8 Geology/Soils Cumulative development in the region would result in an increase in population and development that would be exposed to potential hazardous geological conditions. However, neither the DMP Update nor the cumulative projects identified in Table 5-1 would result in substantial effects related to geology or soils. Geologic conditions in the region would essentially remain the same regardless of implementation of the DMP Update. Therefore, the cumulative contribution to impacts related to geology and soils is considered less than significant. 5.2.1.9 Hydrology and Water Quality Water quality control measures identified in Table 3-6 and project-specific BMPs required in project-specific SWPPPs would minimize sediment loads and downstream erosion resulting from implementation of the DMP Update. In addition, the DMP Update would improve overall long- term water quality and drainage and indirectly improve long-term water quality within the city’s four drainage basins, as described in Section 4.9. The DMP Update would not substantially increase the amount of impervious surfaces and would serve to improve overall flood control and storm water conveyance in the city. In consideration of these effects, the proposed DMP Update would result in cumulatively beneficial effects to water quality, storm water conveyance, and flood control. For these reasons, the project would not significantly contribute to a cumulative hydrology or water quality impact. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-15 04080135 Carlsbad DMP EIR.doc 12/11/2007 5.2.1.10 Biological Resources Historically, impacts to biological resources, such as loss of wetlands, have resulted in permanent loss of sensitive habitats in the city (UCSD 2006). However, the City is participating in the MHCP, which is intended to mitigate for the biological impacts of planned growth through the approval of a streamlined regulatory approach for the issuance of federal and state permits and other authorizations under federal and state law. The end result of the MHCP planning process is to provide a regional conservation plan to mitigate the cumulative biological effects of growth in the region. Carlsbad has developed the HMP within the MHCP framework. Prior to implementation of the mitigation measures recommended in this EIR, the DMP Update would result in potentially significant long-term impacts to biological resources. Impacts to biological resources associated with proposed DMP Update projects would be significant when considered together with other development projects in Carlsbad and the region, due to loss of sensitive habitat. However, the mitigation measures recommended in Section 4.10 of this EIR have been developed consistent with the Carlsbad HMP, which takes a regional and cumulative approach to establishing mitigation requirements. Mitigation would be accomplished through the assessment and mitigation of project-specific impacts as individual components of the DMP Update are implemented, consistent with the Carlsbad HMP. For this reason, although the impacts caused by the DMP Update would contribute to significant biological impacts in the region and would be significant prior to mitigation, implementation of mitigation measures Bio-1 through Bio-8 would reduce these impacts to a less than significant level, both directly and in consideration of the cumulative context. 5.2.1.11 Cultural Resources Many areas within Carlsbad are known to contain cultural resources. As noted in Table 5-1, several of the cumulative projects have been identified as having potential impacts to cultural or archaeological resources. However, these types of impacts are localized and can be addressed through the implementation of feasible mitigation measures. These measures were required for each of the projects listed in Table 5-1, where the potential for cultural resource impacts was present. With the implementation of these measures, the cumulative impacts to cultural resources are considered less than significant. Similarly, potentially significant impacts to cultural resources from proposed DMP Update components would be reduced to a less than significant level with the mitigation measures recommended in Section 4.11. For these reasons, the project would not result in a considerable contribution to a significant cumulative cultural resource impact. 5.0 Cumulative Impacts Page 5-16 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 5.2.1.12 Paleontological Resources Geologic formations within Carlsbad have the potential to contain paleontological resources. As noted in Table 5-1, several of the cumulative projects have been identified as having potential impacts to paleontological resources. However, these types of impacts are localized and can be addressed through the implementation of feasible mitigation measures. These measures were required for each of the projects listed in Table 5-1, where the potential for paleontological impacts was present. With the implementation of these measures, the cumulative impacts to paleontological resources were less than significant. Similarly, potentially significant impacts to paleontological resources from proposed DMP Update components would be reduced to a less than significant level with the mitigation measures recommended in Section 4.11. For these reasons, the project would not result in a considerable contribution to a significant cumulative paleontological resource impact. 5.2.2 Project Level 5.2.2.1 Land Use Consistent with the development envisioned by the General Plan, land uses in Carlsbad will change substantially as development occurs consistent with the City’s development policies. It is assumed that future development in the city is occurring in a manner consistent with the City’s General Plan, Growth Management Plan, and other land use planning documents and regulations. The General Plan establishes the maximum intensity of development that can occur within the city. Therefore, the project level DMP Update components B and BN would not contribute to significant cumulative land use impacts in Carlsbad. 5.2.2.2 Agricultural Resources The proposed dredging and improvements in Agua Hedionda and Calavera creeks (components B and BN) would not involve the conversion of Important Farmlands or existing agricultural uses to nonagricultural uses and would not conflict with any Williamson Act contracts. Therefore, these project components would not contribute to cumulative agricultural resource impacts. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-17 04080135 Carlsbad DMP EIR.doc 12/11/2007 5.2.2.3 Visual Resources Proposed project level DMP components B and BN would potentially result in short-term visual impacts during dredging and grading activities and from equipment setup at upland staging areas or construction vehicles on temporary access roads. However, these impacts would be temporary and localized. Proposed project level DMP components would not result in long-term impacts to scenic vistas or corridors or permanently degrade the visual character of the surrounding area. Following completion of the proposed channel improvements, landscaping opportunities will exist within Agua Hedionda and Calavera creeks. Landscaping of the project site will serve to establish native trees adjacent to the creek banks, resulting in an overall visual improvement within the project area. No permanent impacts to visual resources would occur from implementation of the improvements in Agua Hedionda and Calavera creeks. Although cumulative impacts to visual resources are identified for cumulative projects in the city (i.e., Villages of La Costa Master Plan), project level DMP components would not result in a substantial change to the visual environment. For this reason, the DMP Update would not contribute considerably to a cumulative visual impact. 5.2.2.4 Transportation/Circulation The construction, dredging, and maintenance activities in Agua Hedionda and Calavera creeks (components B and BN) would cause temporary traffic effects, which would be minimized through implementation of the traffic control measures. Potentially significant cumulative traffic circulation impacts could result over the short term if multiple projects were under construction simultaneously and in the same general location (e.g., Robertson Ranch). Cumulative short-term impacts could be minimized through coordination and implementation of traffic control plans at the time of construction with the City Engineering Department. Encroachment permits are required for all construction affecting public rights-of-way. This permitting process is the control point for the maximum possible reduction of cumulative traffic impacts and is designed to reduce direct and cumulative impacts to below a level of significance. Although the projects identified in Table 5-1 generate traffic conditions that may be cumulatively significant, the activities proposed within Agua Hedionda and Calavera creeks would not result in permanent contributions to this cumulative baseline. For these reasons, these project level components would not contribute considerably to a significant transportation or circulation impact. 5.0 Cumulative Impacts Page 5-18 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 5.2.2.5 Air Quality Planned development projects in the surrounding area (e.g., Robertson Ranch) would contribute to short-term cumulative air quality impacts due to construction activities and long-term cumulative impacts due to increased traffic. Development forecasted for the San Diego region will generate increased emission levels from transportation and stationary sources not only locally, but also regionally. Planned development projects in Carlsbad (see Table 5-1) would contribute to cumulative short-term air quality impacts due to construction and/or long-term cumulative impacts resulting from increases in traffic. The air quality effects of the Agua Hedionda and Calavera creeks projects would only be short-term. Temporary emissions generated from construction equipment and fugitive dust during construction activities would be minimized by incorporation of the dust control and construction emission control features. For these reasons, the project level DMP Update components would not result in a significant contribution to cumulative air quality impacts. 5.2.2.6 Noise Temporary noise from construction and maintenance activities for proposed project level DMP Update components has the potential to temporarily contribute to the generation of noise within the localized area of the projects. However, these activities would not result in any long-term noise impacts. The City’s Municipal Code, General Plan, Airport LUCP, and Noise Guidelines Manual are intended to control exposure of residents to excessive or prolonged increases in noise levels. Regulation and noise attenuation for other noise sources consistent with the City’s regulatory documents above would ensure that the cumulative noise impacts in the City are not substantial over the long term. In addition, the projects would incorporate measures consistent with the City’s Municipal Code and Noise Guidelines Manual to address anticipated noise effects. While implementation of the project level DMP Update components could temporarily generate noise in localized areas, this contribution to the overall noise environment would not be noticeable or result in long-term changes in the noise environment. For these reasons, these potential effects would not be cumulatively considerable. 5.2.2.7 Recreation No impacts to recreational facilities would occur from proposed project level DMP Update components. Additionally, the projects identified in Table 5-1 would not result in significant cumulative impacts to recreational services. Therefore, the project level components would not contribute to cumulative impacts to recreational services in the city. 5.0 Cumulative Impacts City of Carlsbad Drainage Master Plan Update EIR Page 5-19 04080135 Carlsbad DMP EIR.doc 12/11/2007 5.2.2.8 Geology/Soils Neither the project level DMP Update components nor the cumulative projects identified in Table 5-1 would result in substantial effects related to geology or soils. Geologic conditions in the region would essentially remain the same regardless of implementation of the project level DMP Update components. Therefore, the cumulative contribution to impacts related to geology and soils is considered less than significant. 5.2.2.9 Hydrology and Water Quality Water quality control measures identified in Table 3-6 and project-specific BMPs required in project-specific SWPPPs would minimize sediment loads and downstream erosion resulting from implementation of project level DMP Update components. In addition, implementation of project level DMP Update components would improve overall long-term water quality and drainage and indirectly improve long-term water quality within Agua Hedionda and Calavera creeks, and downstream to Agua Hedionda Lagoon, as described in Section 4.9. The project level DMP Update components would not substantially increase the amount of impervious surfaces and would serve to improve overall flood control and storm water conveyance in the project vicinity. In consideration of these effects, the proposed DMP Update and the Basin B projects would result in cumulatively beneficial effects to water quality, storm water conveyance, and flood control. For these reasons, the project level components would not significantly contribute to a cumulative hydrology or water quality impact. 5.2.2.10 Biological Resources Prior to the implementation of the mitigation measures recommended in this EIR, project- specific impacts associated with dredging and improvements to Agua Hedionda and Calavera creeks would result in potentially significant impacts to biological resources. These impacts would also be significant when considered together with other development projects in Carlsbad and region, due to loss of sensitive habitat. However, the mitigation measures recommended in Section 4.10 of this EIR have been developed consistent with the Carlsbad HMP, which takes a regional and cumulative approach to establishing mitigation requirements. Mitigation would be accomplished through the assessment and mitigation of project-specific impacts associated with dredging and improvements to Agua Hedionda and Calavera creeks consistent with the ratios established in the Carlsbad HMP. For this reason, although the impacts caused by the Agua Hedionda and Calavera creeks projects would contribute to significant biological impacts in the region and would be significant prior to mitigation, implementation of mitigation measures Bio-1 5.0 Cumulative Impacts Page 5-20 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 through Bio-8 would reduce these impacts to a less than significant level, both directly and in consideration of the cumulative context. 5.2.2.11 Cultural Resources No impacts to cultural resources are anticipated to occur from proposed project level DMP Update components. Therefore, the project level components would not contribute to cumulative impacts to cultural resources. 5.2.2.12 Paleontological Resources No impacts to paleontological resources are anticipated to occur from proposed project level DMP Update components. Therefore, the project level components would not contribute to cumulative impacts to paleontological resources. 6.0 Other Considerations Required by CEQA City of Carlsbad Drainage Master Plan Update EIR Page 6-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 CHAPTER 6.0 – OTHER CONSIDERATIONS REQUIRED BY CEQA 6.1 GROWTH-INDUCING IMPACTS CEQA Guidelines (Section 15126.2(d)) require a discussion of growth-inducing impacts. A project may be considered growth inducing when it: • fosters economic growth, population growth, or construction of additional housing, either directly or indirectly, in the surrounding environment in excess of established projections; • removes obstacles to population growth or additional housing; • burdens existing community services facilities beyond current/projected capacities; and/or • encourages or facilitates other growth-inducing activities that could significantly affect the environment (i.e., secondary effects). Growth is generally dependent on the availability of existing utilities and public services in an area. The provision of new public utilities and services in an undeveloped area can induce growth in that area. Such growth may or may not be anticipated in local land use planning documents. If a project stimulates development of unanticipated urban uses, it would have a growth-inducing effect. Growth inducement can also occur if a proposed project makes it more feasible to increase the density of development in the surrounding areas in excess of established projections. Growth may be considered beneficial, detrimental, or of little significance to the environment, depending on its actual impacts to the environmental resources present (i.e., secondary growth effects). The causes of growth typically involve a complex and varied relationship among several factors, including economic setting, employment opportunities, natural population increase, public policies, and local environment. All of these can influence the rate and extent of growth. 6.1.1 Program Level Impact Analysis The City has proposed updating the existing 1994 MDSQMP because substantial changes in land use and development patterns, coupled with the inability of some existing drainage facilities to provide 100-year flood protection, required a reevaluation of citywide drainage needs. The DMP 6.0 Other Considerations Required by CEQA Page 6-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Update proposes drainage infrastructure and improvements required to accommodate storm flows resulting from future planned development within Carlsbad. Implementation of the DMP Update would not result in significant environmental impacts as a result of potential growth inducement because the proposed DMP Update would not extend public services or access into any areas where they previously were not available or approved. Facility sizes and capacity were determined assuming maximum buildout of the city, as guided by the General Plan and Growth Management Plan. It is anticipated that development will occur consistent with the existing General Plan, Growth Management Plan, current zoning designations, and other applicable land planning regulations. The General Plan Land Use Element and Growth Management Plan include the performance standard that requires drainage facilities to be provided concurrent with development (City of Carlsbad 1994). Project components AFA and AFB are located in Local Facility Management Zone 25, a zone in which a facilities plan has yet to be proposed or approved. A facilities plan must be approved before any development proposals may be approved. Growth inducement is generally focused on (1) developing an undeveloped parcel and the potential extension and demand for services, and (2) increasing employment and indirect demand for housing as a result of employment. Existing growth management policies for Carlsbad address the provision of adequate services prior to allowing development to occur. The facilities proposed in the DMP Update are required to provide adequate drainage, flood protection, and storm water quality control prior to any new development in the city. Implementation of the DMP Update would not alter existing zoning or land use designations and would therefore not allow for the development of land currently not planned for development to occur. One of the goals of the DMP Update is to provide adequate drainage to accommodate 100-year storm flows in developed areas that are currently subject to flooding due to deficient facility capacities. Although the DMP Update would remove from the 100-year floodplain existing developed areas currently subject to flooding during 100-year storm events, the City does not anticipate existing land use designations in these areas to be changed as a result of implementation of the DMP Update. The proposed DMP Update components would not generate new jobs and therefore would not increase employment opportunities in the city. For these reasons, implementation of the DMP Update would not result in growth that is beyond that currently anticipated by the City or affected service providers. 6.0 Other Considerations Required by CEQA City of Carlsbad Drainage Master Plan Update EIR Page 6-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 6.1.2 Project Level Impact Analysis The proposed drainage improvements in Agua Hedionda and Calavera creeks (components B and BN) would involve dredging and channel improvements. The projects would reduce flooding risk in the Rancho Carlsbad residential community by removing as many of the 278 lots as feasible to outside of the existing 100-year flood zone boundary. The proposed dredging and improvements would not involve any development or the creation of additional housing. Although the implementation of project components would reduce the 100-year flood hazard areas along Agua Hedionda and Calavera creeks, this would not promote development in the vicinity, which is currently built out to the project boundary within the Rancho Carlsbad residential community. The improvements to Agua Hedionda and Calavera creeks will restore 100-year flood capacity in the creeks and the floodplain for Rancho Carlsbad to the original design from 1969. The proposed improvements to Agua Hedionda and Calavera creeks are consistent with the objective of the DMP Update to provide flood protection to existing development in the city. The land adjacent to the proposed DMP Update area is either currently developed, planned for future development within the General Plan Land Use Element (independent of the proposed project), or designated as open space by the City’s HMP. The City does not anticipate changing any land use designations as a result of implementation of the projects in Agua Hedionda and Calavera creeks. Implementation of the project level DMP Update components would not result in the development of currently undeveloped land or the generation of new employment opportunities. Therefore, the project level DMP Update components would not be considered growth inducing, either directly or indirectly. 6.2 SIGNIFICANT IRREVERSIBLE ENVIRONMENTAL CHANGES Section 21100(b)(2)(B) of the CEQA Statutes and Section 15126.2(c) of the CEQA Guidelines require that an EIR analyze the extent to which a proposed project’s primary and secondary effects would affect the environment and commit nonrenewable resources to uses that future generations would not be able to reverse. “Significant irreversible environmental changes” include the use of nonrenewable natural resources during the initial and continued phases of the project, should this use result in the unavailability of these resources in the future. Primary impacts and, particularly, secondary impacts generally commit future generations to similar uses. Irretrievable commitments of these resources are required to be evaluated in an EIR to ensure that such consumption is justified (CEQA Guidelines Section 15126.2(c)). Approval of the DMP Update would cause irreversible environmental changes consisting of the following: 6.0 Other Considerations Required by CEQA Page 6-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Alteration of the human environment as a consequence of the development process. In particular, the DMP Update would result in the alteration of natural drainages, sensitive biological habitats, and wetlands to provide drainage improvements, flood protection, and indirect improvements to storm water quality control. Impacts to these sensitive resources would be reduced to a less than significant level with the mitigation measures included in this EIR. Use of nonrenewable natural resources for construction, operation and maintenance of project components. The proposed DMP Update would not use nonrenewable fossil fuels, such as diesel, gasoline, or oil for construction equipment at a greater rate than other typical construction projects, increase the overall rate of use of any nonrenewable natural resource, or result in the substantial depletion of any nonrenewable resource. 6.3 SIGNIFICANT ENVIRONMENTAL EFFECTS Analysis of environmental impacts caused by the proposed DMP Update has been performed and is contained in Chapter 4.0 (Environmental Analysis). Significant environmental impacts have been identified for the following impacts areas: • Noise (Program Level) • Biological Resources (Program and Project Levels) • Cultural Resources (Program Level) • Paleontological Resources (Program Level) Significant impacts for each issue area would be reduced to a less than significant level with the incorporation of design features (Table 3-6) and implementation of the mitigation measures identified in this EIR. The DMP Update would not result in any significant unavoidable environmental impacts. 6.4 EFFECTS NOT FOUND TO BE SIGNIFICANT CEQA Guidelines (Section 15128) require that the environmental document include a brief discussion of the environmental issue areas found not to be significant. This EIR addresses all probable and foreseeable possible impacts of the proposed DMP Update. Based on the analysis in Chapter 4.0, the following environmental issue areas were found to be less than significant: 6.0 Other Considerations Required by CEQA City of Carlsbad Drainage Master Plan Update EIR Page 6-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 • Land Use (Program and Project Levels) • Agricultural Resources (Program and Project Levels) • Visual Resources (Program and Project Level) • Transportation/Circulation (Program and Project Levels) • Air Quality (Program and Project Levels) • Noise (Project Level) • Recreation (Program and Project Levels) • Geology/Soils, including Mineral Resources (Program and Project Level) • Hydrology/Water Quality (Program and Project Levels) • Cultural Resources (Project Level) • Paleontological Resources (Project Level) Based on the public scoping process for this project (refer to Section 1.3), several environmental issue areas were not considered to be areas of controversy and were not anticipated to result in any impacts from implementation of the DMP Update. These issues are briefly summarized below and are not addressed in the environmental analysis (Chapters 4.0 or 5.0) of this EIR. This discussion is applicable to both program and project level DMP Update components, as well as proposed operation and maintenance activities. Population and Housing The DMP Update would extend and improve existing drainage infrastructure within Carlsbad to meet the drainage needs of anticipated development within the city. The proposed DMP Update components would be phased so that drainage infrastructure would be constructed and improved prior to or concurrently with approved development. The construction, operations, and maintenance of DMP Update components would not provide additional housing within the city, result in growth inducement (see Section 6.1.1), or have an effect on the City’s projected population and housing needs. Energy Resources The construction, operations, and maintenance of project components proposed in the DMP Update would not significantly affect local or regional energy supplies, nor would the projects conflict with adopted energy conservation plans. Some of the proposed DMP Update project components, and operation and maintenance activities would require energy to construct and 6.0 Other Considerations Required by CEQA Page 6-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 maintain. However, construction of DMP Update components would be temporary and maintenance would not require excessive amounts of fuel or energy. Public Services and Utilities The DMP Update proposes the construction, operation, and/or maintenance of stormwater drainage facilities within the city. No potentially significant environmental impacts to public utilities beyond those described in Chapter 4.0 (Environmental Analysis) and Chapter 5.0 (Cumulative Impacts) would occur from implementation of the DMP Update. No significant impacts to public services would occur with implementation of the DMP Update. Implementation of the DMP Update would not affect emergency medical, police, or fire protection services, or create a need for additional protection services. In fact, the projects proposed in the DMP Update are intended to improve flood protection in the city. Implementation of required traffic control plans during construction of components would ensure that emergency access remains open at all times on major roadways. The roads impacted by proposed pipeline trenching from some components would be restored to their original condition or better, after construction, as discussed in Section 4.4 (Transportation/Circulation). The DMP Update would not affect power, natural gas, communication, or water and wastewater systems. The City would coordinate with utility companies and implement standard measures to avoid service interruptions during construction of specific components. Potential relocation of utilities for program level DMP Update components would be identified during project-specific design and engineering. The project level DMP Update components (B and BN) would not involve relocation of utilities and have been engineered to avoid impacts to existing utilities within the project area. To avoid impacts onto existing utilities, locations of known utility lines will be marked prior to construction. For some proposed project components or operation and maintenance activities, use of SDG&E’s rights-of-way may be required. In these instances, the City would coordinate with SDG&E to ensure access to utility facilities and service to customers are maintained. It is not anticipated that relocation of any SDG&E facilities would be required for implementation of the various project components. Nonetheless, access and potential relocation issues, as well as grading or encroachment into SDG&E rights-of-way, would be determined during project design for each project component. Access, relocation, grading, or encroachment within an SDG&E easement would be granted by SDG&E through a Joint Use Agreement. In some cases, if SDG&E holds a fee title to the lands under their transmission line, then the City must acquire an 6.0 Other Considerations Required by CEQA City of Carlsbad Drainage Master Plan Update EIR Page 6-7 04080135 Carlsbad DMP EIR.doc 12/11/2007 easement from SDG&E to construct a new drainage facility. No special permission is required to conduct maintenance of storm drainage facilities within an SDG&E easement. Hazards and Hazardous Materials A safe construction plan and a traffic control plan in addition to standard building design requirements would be implemented during the construction of specific DMP Update components to ensure public safety. A spill contingency plan would be in place during project- specific construction, operations, or maintenance to mitigate any accidental hazardous materials impacts. Implementation of the DMP Update would not produce any hazardous materials. Rather, the DMP Update components are intendedwould indirectly result in beneficial improvements to improve storm water quality, thus providing a health benefit to the community. Phase I reports would be prepared for DMP Update components, as required, during project level environmental review to identify potential risks from hazardous materials. There are no known current or historic uses at the Agua Hedionda and Calavera creeks project area that may have resulted in a release of hazardous materials and no known potentially contaminated sites exist within the project site (www.geotracker.waterboards.ca.gov and Department of Toxic Substances Control 2007). As disclosed in Section 4.3.4 of this EIR, tested soil at the project site was within acceptable ranges of NOAA sediment quality guidelines and indicative of uncontaminated sediments. 6.0 Other Considerations Required by CEQA Page 6-8 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 This page intentionally left blank. 7.0 Alternatives City of Carlsbad Drainage Master Plan Update EIR Page 7-1 04080135 Carlsbad DMP EIR.doc 12/11/2007 CHAPTER 7.0 – ALTERNATIVES CEQA Guidelines Section 15126(d)(2) specifies that the range of potential alternatives to be examined in an EIR shall include those that could feasibly accomplish most of the basic purposes of the project and could avoid or substantially lessen one or more of the significant effects. CEQA specifically requires the discussion of a “no project” alternative. In addition, CEQA requires that a reasonable range of alternatives to the project be discussed, including alternative locations. The reasonable range includes alternatives that focus on mitigation or avoidance of significant effects associated with the proposed DMP Update, that permit a reasoned choice for the decision maker, and that are feasible. Section 15126(d)(5) states that among the factors that may be taken into account when addressing the feasibility of alternatives are site availability, economic viability, availability of infrastructure, general plan consistency, other plans or regulatory limitations, jurisdictional boundaries, and whether the proponent can reasonably acquire, control, or otherwise have access to the alternative site. A discussion of alternatives that were considered, but ultimately rejected, is also provided in Section 7.1. In the following sections, each alternative is first described and then analyzed in consideration of the proposed DMP Update, according to whether it would have a beneficial or adverse effect. The alternatives analysis evaluates each identified alternative with respect to each issue area, in comparison to the DMP Update, as proposed. The alternative analysis also discusses the ability of each alternative to achieve the objectives of the DMP Update, as set forth in Section 3.2 of this EIR. Section 7.5 summarizes these findings and presents the conclusion about which alternative is the environmentally superior alternative. 7.1 ALTERNATIVES CONSIDERED Alternatives that were considered but ultimately rejected are described below to demonstrate the range of alternatives that were considered. A brief discussion explaining why these alternatives were not considered further for a comparative analysis is also provided. 7.1.1 Program Level Alternative Drainage System Location – An alternative that is often considered for an alternatives analysis involves altering the location of a proposed project. For the DMP Update, 7.0 Alternatives Page 7-2 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 this would involve an alternative location of the overall drainage system in the city. It is not reasonable to construct an entirely new drainage system, and an alternative location for the entire system is infeasible, as infrastructure is located or would be constructed in specific locations identified as critical parts of overall drainage systems. General locations of drainage facilities are determined by existing hydrology/drainage, topography, and development. For these reasons, alternative locations for proposed facilities are not considered further in this analysis. No Impacts within or adjacent to the Coastal Zone or HMP Preserve – To minimize potential impacts to the Coastal Zone and/or HMP preserve areas from implementation of DMP Update components, this alternative would eliminate implementation of proposed components or activities that would be located within or adjacent to the Coastal Zone or HMP preserve. This alternative would not be reasonable because it would not address necessary drainage improvements or additional facility requirements in the entire Coastal Zone or HMP preserve areas, which together encompass approximately 13,588 acres, or 50 percent of the city. Facilities located within or adjacent to the HMP preserve and Coastal Zone are integral components of the overall drainage systems for each basin. This alternative would result in potential flooding hazards and impacts to water quality over large areas in the city and would, therefore, not achieve the objectives of the DMP Update. For these reasons, this alternative is not considered further in this analysis. No Impacts within or adjacent to Sensitive Habitats or Wetlands – This alternative would eliminate proposed components or activities that would be located within or adjacent to the sensitive habitats or wetlands to minimize impacts to sensitive biological and water resources. However, similar to the alternative described above, this alternative would not address necessary drainage improvements or additional facility requirements in areas within or adjacent to sensitive habitats or wetlands, resulting in potential flooding hazards and impacts to water quality within these areas, as well as downstream. This alternative would not achieve the overall objectives of the DMP Update. For these reasons, this alternative is not considered further in this analysis. No Dredging or Vegetation Removal Alternative – This alternative would avoid any dredging activities or vegetation removal as part of any component or operation and maintenance activity proposed in the DMP Update. This alternative would reduce overall water quality and noise impacts, minimize vegetation disturbance, and eliminate construction-related traffic impacts associated with dredging activities. However, capacity-related deficiencies in existing drainage infrastructure are often caused by accumulated silt, sand, overgrown vegetation, and debris. Dredging and vegetation removal are necessary to restore and maintain the 100-year flood capacity of deficient facilities. This alternative would not adequately address capacity-related 7.0 Alternatives City of Carlsbad Drainage Master Plan Update EIR Page 7-3 04080135 Carlsbad DMP EIR.doc 12/11/2007 facility deficiencies, which would result in flood hazards and adverse impacts to water quality from sediment loading and debris. Therefore, this alternative would not meet the purpose or overall objective of the DMP Update. A more reasonable option than to completely eliminate any dredging or vegetation removal would be to allow only nonmechanized dredging or vegetation removal to reduce impacts associated with large-scale dredging projects and clear- cutting of vegetation. This reduced-scale alterative is considered more feasible than prohibiting all mechanized dredging/vegetation removal and is evaluated in comparison to the DMP Update in Section 7.2.1. 7.1.2 Project Level Following the 1996 amendment to the MDSQMP to include Agua Hedionda Creek as a PLDA project (see Section 3.1.1), the City contracted Rick Engineering Company to conduct a study to evaluate various design alternatives to achieve 100-year flood capacity in Agua Hedionda and Calavera creeks (Rick Engineering Company 2004). The design alternatives considered various combinations of the following actions: improvements to Calavera Dam and the existing BJB Basin, construction of new detention basins (referred to as Melrose, Faraday, and BJ in the Rick Engineering Company report), and channel improvements and dredging within Agua Hedionda Creek. Dredging and maintenance within Calavera Creek were not considered as part of these alternatives. These alternatives were ultimately rejected, however, because they did not provide 100-year flood protection for as many lots as feasible (compared to the proposed DMP Update components, which would alleviate all but nine lots from inundation during a 100-year flood event). Alternatives that were considered but determined infeasible are summarized briefly below. These alternatives are described in more detail in the Rick Engineering Company report (2004), included in Appendix B. Feasible alternatives to the proposed drainage improvements in Agua Hedionda and Calavera creeks are evaluated in Section 7.3. No Action Alternative - The no action alternative evaluated in the Rick Engineering Company report modeled a 100-year flood event under the existing channel topography (at the time of the study), with ultimate buildout hydrology. This alternative involved no channel modifications or maintenance to Agua Hedionda or Calavera creeks and assumed no improvements to Calavera Dam or modifications/construction of detention basins (Melrose, Faraday, BJB, and BJ). This alternative would subject up to 260 of the 278 Rancho Carlsbad lots to inundation during a 100-year flood event and, therefore, was considered infeasible. 7.0 Alternatives Page 7-4 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 Existing Conditions Detained Alternative - This alternative also modeled a 100-year flood event under the existing channel topography at the time of the Rick Engineering Company study, with ultimate buildout hydrology but assumed modifications/construction of the four detention basins mentioned above, as well as improvements to Calavera Dam. This alternative would subject up to 225 lots to inundation during a 100-year flood event and, therefore, was considered infeasible. Alternative A - This alternative assumed existing conditions in Calavera Creek and modeled maintenance of approximately 2,500 feet of Agua Hedionda Creek, between El Camino Real and just downstream of Rancho Carlsbad Drive. The ultimate development hydrology was the same as described above for the Existing Conditions Alternative. Agua Hedionda would be graded to the original trapezoidal channel geometry from the 1969 grading plans for Rancho Carlsbad, including 2:1 (H:V) side slopes and a bottom width of 44 to 58 feet. This alternative would subject up to 163 lots to inundation during a 100-year flood event and, therefore, was considered infeasible. Alternative B - This alternative assumed existing conditions in Calavera Creek and modeled maintenance of approximately 3,100 feet of Agua Hedionda Creek between Cannon Road Bridge and just downstream of Rancho Carlsbad Drive. The ultimate development hydrology was the same as described above for the Existing Conditions Alternative. Grading would occur in Agua Hendionda Creek to remove accumulated sediment and create a trapezoidal channel with 2:1 (H:V) side slopes and a 70-foot bottom width. This alternative would subject up to 33 lots to inundation during a 100-year flood event and, therefore, was considered infeasible. In addition to the design alternatives discussed above, the cCity evaluated the potential for incorporating various additionalother design elements into the proposed project design, such as various slope options, pilot channels, and upstream desilting basins. However, none of these features provided added flood protection and therefore were rejected. The City also evaluated the potential use of the Rancho Carlsbad golf course for a detention component. However, it was determined that the golf course was not a feasible option because it would not provide adequate detention capacity and would require extensive excavation. 7.2 Program Level Alternatives Analysis The following provides a comparative alternatives analysis for the proposed DMP Update. Alternatives are evaluated and compared by each resource area to identified impacts of the proposed DMP Update, as evaluated in Chapter 4.0 of this EIR. 7.0 Alternatives City of Carlsbad Drainage Master Plan Update EIR Page 7-5 04080135 Carlsbad DMP EIR.doc 12/11/2007 7.2.1 No Mechanized Dredging/Vegetation Removal Alternative Dredging and/or vegetation removal is proposed for some DMP Update components to improve and/or maintain facilities deficient in containing a 100-year flood. This alternative would prohibit use of mechanized equipment to conduct dredging or vegetation removal during construction, operation, or maintenance of proposed or future DMP components. Dredging and vegetation removal would instead be conducted in specified locations by ground crews using nonmechanized hand tools. This alternative would eliminate the possibility of large-scale dredging/vegetation removal projects. The primary purpose of this alternative would be to reduce impacts to biological resources and water quality associated with dredging and vegetation removal. 7.2.1.1 Land Use Like the DMP Update, the No Mechanized Dredging/Vegetation Removal Alternative would not divide an established community, no land uses designation or zoning changes would be required, and it is assumed that development would occur according to the General Plan and other land use policies. As described in Section 4.1, the DMP Update would not have a potentially significant land use impact. The DMP Update proposes conducting large-scale mechanized dredging and/or vegetation removal in channels that do not meet 100-year flood capacity due to excessive quantities of accumulated sediment, vegetation, and debris, which could not be removed using only hand tools. While small localized areas could be effectively cleared of vegetation or accumulated sediment, the No Mechanized Dredging/Vegetation Removal Alternative would prevent large-scale dredging and/or vegetation removal requiring the use of mechanized equipment. This could result in potential flood hazards within channels that would not meet 100-year flood capacity through only nonmechanized dredging and/or vegetation removal. Inadequate drainage infrastructure resulting in flooding hazards would be inconsistent with the General Plan and would result in an impact to land use (see Section 4.1). For these reasons, this alternative would result in greater land use impacts than the DMP Update. 7.2.1.2 Agricultural Resources Similar to the DMP Update, the No Mechanized Dredging/Vegetation Removal Alternative would not result in the conversion of Important Farmland or convert agriculture land use to nonagricultural uses. This alternative is considered environmentally similar to the DMP Update for the agricultural resources issue area. 7.0 Alternatives Page 7-6 City of Carlsbad Drainage Master Plan Update EIR 04080135 Carlsbad DMP EIR.doc 12/11/2007 7.2.1.3 Visual Resources The DMP Update would not have potentially significant impacts to visual resources. Although no large-scale clear-cutting of vegetation would be implemented with the No Mechanized Dredging/Vegetation Removal Alternative, this alternative would still allow removal of vegetation in undeveloped open space areas through the use of hand tools, which may result in degradation of views. The temporary visual impact associated with the loss of vegetation would likely be similar to the proposed DMP Update and would require landscaping to be incorporated into project-specific design, as identified in Table 3-6. This alternative would be considered environmentally similar to the DMP Update with respect to visual resources. 7.2.1.4 Transportation/Circulation The DMP Update would not result in significant impacts to transportation/circulation. The No Mechanized Dredging/Vegetation Removal Alternative would have fewer short-term construction- related traffic impacts because it would reduce truck traffic required to remove large quantities of material generated from mechanized dredging/vegetation removal activities. However, sediment/vegetation removed by hand would still be trucked out. Additionally, more workers may be required to complete sediment/vegetation removed by hand, generating more vehicle trips to and from the work site. The duration of sediment and vegetation removal by hand also may exceed the time necessary to accomplish the same tasks by mechanized means. Like the DMP Update, this alternative would still have short-term construction-related traffic impacts from other construction activities, which would be minimized through implementation of the traffic control measures identified in Table 3-6. This alternative would not have long-term impacts to traffic. The No Mechanized Dredging/Vegetation Removal Alternative is considered environmentally similar to the DMP Update with respect to transportation/circulation. 7.2.1.5 Air Quality The DMP Update would not result in significant air quality impacts. Incorporation of construction measures in Table 3-6 would minimize construction-related air quality contamination from fugitive dust and exhaust. The No Mechanized Dredging/Vegetation Removal Alternative would also not result in significant air quality impacts and would reduce localized air quality impacts such as fugitive dust and exhaust that may occur with the use of mechanized equipment for dredging/vegetation removal activities. This alternative would have less potential for fugitive dust and exhaust than the DMP Update, but because neither this alternative nor the DMP Update would