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Home My WebLink AboutSDP 12-01; Vista La Costa Apartments; Site Development Plan (SDP) (4)Vista La Costa JN 121004 PRELIMINARY STORM WATER MANAGEMENT PLAN For Vista La Costa SDP xx-xx RECEIVED W4/? 0 8 2012 February 10, 2012 JN 12-1004 Prepared For: SJ Assets Management, Inc. In care of Diversified Development, Inc 7668 El Camino Real Carlsbad, CA 92009 Ste. 104-280 Prepared By: O'DAY CONSULTANTS 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92010 Nichole Fine Exp. 9/30/12 C 70035 G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 TABLE OF CONTENTS TABLE OF CONTENTS 2 1. PROJECT SETTING 4 2. APPLICABLE STORMWATER STANDARDS 5 2a. Storm Water Standards Questionnaire 5 2b. HMP Applicability Determination 5 3. IDENTIFY POLLUTANTS OF CONCERN 5 3a. Identify pollutants associated with type of project/use 5 3b. Identify watershed, hydrologic unit basin and receiving waters ...5 3d. Beneficial uses of receiving water 6 3e. Summarize primary pollutants of concem 7 4. SOURCE CONTROL MEASURES 7 4a. Description of site activities and potential sources of pollutants ..7 4b. Stormwater Pollutant Sources and Source Controls 7 5. LOW IMPACT DEVELOPMENT (LID) DESIGN STRATEGIES...7 5a. Optimization of site layout 7 5b. Layout and use of pervious surfaces 8 5c. Dispersal of runoff from impervious areas to pervious areas 8 6. INTEGRATED MANAGEMENT PRACTICES (IMP's) 8 6a. Selection process for IMP's 8 6b. Sizing factors for IMP'S -. 8 6c. Geotechnical recommendation on soil infiltration rates 9 6d. Infiltration calculations 9 7. TREATMENT CONTROL BMP's 9 8. HYDROMODIFICATION 9 9. DOCUMENTATION OF STORMWATER DESIGN 9 9a. Hydrology maps 9 9b. BMP Sizing Calculator 9 9c. Tabulation 10 10. BMP FACILITY MAINTENANCE REQUIREMENTS 10 10a. Ownership and responsibility of maintenance of BMP' s 10 10b. Summary of maintenance requiremenmts 10 11. SWMP CERTIFICATION STATEMENTS 11 G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 Attachments: 1. Vicinity map 2. Storm Water Standards Questionnaire 3. Figure 2-1 HMP Applicability Determination 4. Table 2-1: Anticipated and Potential Pollutants 5. San Diego Region Hydrologic Boundary Map 6. 303(d) list for impaired water bodies 7. Table 2-3 Beneficial Uses of Coastal Waters 8. Stormwater Pollutant Sources and Source Control Checklist 9. Figure 2-2 Decision Matrix 10. BMP exhibit 11. BMP Calculator Output and Bioretention Calculations G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 1. PROJECT SETTING This Storm Water Management Plan was prepared to support the application for construction plans of Vista La Costa, a 19-unit apartment project located in Lot 1 of CT 04-05. See Attachment 1 for Vicinity Map. Storm water run-off from the site is tributary to the Batiquitos Lagoon. Vista La Costa is a 0.88 acre site located 1.5 miles east of El Camino Real, north of Gibraltar Street in between Jerez Court and Romeria Street in the City of Carlsbad. A Drainage Study for Vista La Costa, dated February 15, 2012 was prepared by O'Day Consultants and will be referred to hereon as Reference 1. The existing site is mass graded per Grading Plans La Costa South, Unit No. 5, County of San Diego Dwg. L-5548 (Reference 2). Existing Conditions Currently, the site is mass-graded per Reference 2. The upper pad is at about elevation 61.0 and the lower pad is at elevation 55.5. On the northerly edge of the site a slope, steeper than 2:1, daylights into the La Costa Golf Course and Spa to the north. The site drains at 0.5% towards Gibraltar Street, to a curb inlet located on the southeast side of the site. The storm water then drains to a 48" RCP pipe, that runs along the easterly boundary of the site. The storm water outlets to the north, to a PCC lined drainage swale in the La Costa Golf Course and ultimately outlets to the Batiquitos Lagoon. Proposed Conditions 19 Multi-Family residential units are proposed for Vista La Costa: two main buildings, and a parking lot. A private driveway will be constructed between the two buildings and lead into underground parking garages. The drive aisle and the parking lot will be constructed of pervious pavement or pavers. The roof will drain to various bioretention areas located at the southwest and north sides of the site. Each bioretention area will have an underground detention facility to limit the outflow for hydromodification. The trench drain at the bottom of Private Drive 'A' will pick-up water from the driveway and will connect to the private storm drain system. See Reference 1 for the 100 year drainage calculations and drainage map. See Attachment 10 for the BMP exhibit depicting drainage areas to each BMP. The site is constrained by Type 'D' Soil. A 4" perforated drain surrounded by gravel will be used in the bioretention areas. G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 2. APPLICABLE STORMWATER STANDARDS 2a. Storm Water Standards Questionnaire Per the Storm Water Standards Questionnaire (SWSQ), this project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with additional stormwater criteria per the SUSMP. (See Attachment 2 for completed SWSQ) 2b. HMP Applicability Determination Per Figure 2-1 of the SUSMP, Hydromodification controls are required. (See Attachment 3 for Figure 2-1 HMP Applicability Determination.) It was determined that field investigations would not be conducted pursuant to the SCCWRP channel screening tools. Therefore the site must mitigate peak flows and durations based on a pre-project condition lower flow threshold of 0.1Q2. 3. IDENTIFY POLLUTANTS OF CONCERN 3a. Identify pollutants associated with type of project/use Per Table 2-1 of the SUSMP (see Attachment 4), the pollutants anticipated for : attached residential development and parking lots are listed as follows: 1. Sediments 2. Nutrients 3. Heavy metals 4. Trash and debris 5. Potential for oxygen demanding substances 6. Oil and grease from paved areas 7. Potential for bacteria and viruses 8. Pesticides from landscaping 3b. Identify watershed, hydrologic unit basin and receiving waters The project is located in the Batiquitos Hydrologic Subarea (904.51) of the San Marcos Watershed in the Carlsbad Hydrologic Unit in the San Diego Region (Attachment 5). The San Diego Water Board adopted the 2008 Clean Water Act Sections 305 (b) and 303 (d) Integrated Report on Evaluation of Surface Water Quality and Listing of Impaired Water Body G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 Segments for the San Diego Region (2008 Integrated Report) on December 16, 2009. The final 2008 Integrated Report was incorporated into the statewide 2010 Integrated Report that was approved by the State Water Board on August 4, 2010. On November 12, 2010, USEPA approved the 2008-2010 CWA Section 303 (d) List that includes listings for the San Diego Region. According to the 2008-2010 CWA Section 303 (d) List, Batiquitos Lagoon is not an impaired water body associated with the direct stormwater discharge from this project. It should be noted that the Pacific Ocean Shoreline at Moonlight State Beach (Cottonwood Creek Outlet) is listed for impairment of total coliform. (See Attachment 6) 3d. Beneflcial uses of receiving water The beneficial uses for the hydrologic unit are included in Attachment 7, and the definitions are listed below. This information comes from the Water Quality Control Plan for the San Diego Basin. REC 1 -Contract Recreation: Includes uses of water for recreational activities involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, swimming, wading, water-skiing, skin and SCUBA diving, surfing, white water activities, fishing, or use of natural hot springs. REC 2 -Non-Contact Recreation: Includes the uses of water for recreational activities involving proximity to water, but not normally involving body contact with water, where ingestion of water is reasonably possible. These include, but are not limited to, picnicking, sunbathing, hiking, beachcombing, camping, boating, tide pool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities. BIOL - Preservation of Areas of Special Biological SigniHcance EST - Estuarine Habitat: Includes the uses of water that support estuarine ecosystems including, but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish, or wildlife (e.g., estuarine mammals, waterfowl, shorebirds). WILD -Wildlife Habitat: Includes uses of water that support terrestrial ecosystems including but not limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or wildlife water food and sources. RARE - Rare, Threatened, or Endangered Species: Includes uses of water that support habitats necessary, at least in part, for the survival and successful maintenance of plant or animal species established under state or federal law as rare, threatened or endangered. MAR -Marine Habitat: Includes uses of water that support marine ecosystems including, but not limited to, preservation or enhancement or marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g., marine mammals, shorebirds). MIGR -Migration of Aquatic Organisms: Includes uses of water that support habitats necessary for migration, acclimatization between fresh and salt water, or other temporary activities by aquatic organisms, such as anadromous fish. SPWN- Spawning, Reproduction, and/or Early Development- Includes uses of water that support high quality aquatic habitats suitable for reproduction and early development of fish. This use is applicable only for the protection of anadromous fish. G:\031060\Drainage\SWMP.doc 6 Vista La Costa JN 121004 3e. Summarize primary pollutants of concern The primary pollutants of concem for this project are Sediment, Nutrients, Trash & Debris, Oxygen Demanding Substances, Oil & Grease, Bacteria a& Vimses, and Pesticides. The extensive use of bioretention facilities throughout the site should be a highly effective method of treating Coarse Sediment and Trash, and Pollutants that tend to associate with fine particles during treatment. Bioretention facilities also show medium effectiveness for treatment of Pollutants that tend to be dissolved following treatment. 4. SOURCE CONTROL MEASURES 4a. Description of site activities and potential sources of pollutants Potential sources of pollutants on the project site include: Building Roofs On-site storm drain inlets Landscape/Outdoor Pesticide Use Sidewalks 4b. Stormwater Pollutant Sources and Source Controls See attachment 8 for Stormwater Pollutant Sources and Source Control Checklist 5. LOW IMPACT DEVELOPMENT (LID) DESIGN STRATEGIES 5a. Optimization of site layout 1) Minimize Building Layout- By designing 3~story buildings with underground parking, the amount of impervious surface is reduced by VA. 2) Existing Soil- Due to the nature of the existing soil, it will need to be overexcavated for the building and driveway per geotechnical reccomendations. 3) Driveway- Width of driveway is limited to the minimum as required by the City of Carlsbad Fire Department, 24.0 feet wide. 4) Conserve Natural Areas- Not applicable, because the existing site has been mass- graded. G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 5b. Layout and use of pervious surfaces Permeable pavers or pavement will be used along the drive aisle and sidewalks, as well as the parking lot. 5c. Dispersal of runoff from impervious areas to pervious areas The roof water for Building 1 on the west side of the site will be conveyed to vegetated swales prior to entering the bioretention facilities (IMPs). The roof water for Building 2 will be conveyed to a combination of vegetated swales and private storm drain system prior to entering the bioretention facility (IMP). 6. INTEGRATED MANAGEMENT PRACTICES (IMP's) 6a. Selection process for IMP's According to Table 2-2 of the SUSMP, The majority of pollutants of concem for this project can be grouped in the category of Pollutants that tend to associate with fine particles during treatment. Nutrients also fall under the category of Pollutants that tend to be dissolved following treatment and Trash & Debris falls under the category of Coarse Sediment and Trash. According to Table 2-3, Infiltration Facilities provide the highest effectiveness for removal of pollutants in all three categories but our site is constrained by impermeable soils. Bioretention Facilities were chosen extensively throughout the site for their high removal rates for Coarse Sediment and Trash and Pollutants that tend to associate with fine particles during treatment and their medium removal rates for Pollutants that tend to be dissolved following treatment. Bioretention facilities detain stormwater and filter it slowly through soil or sand and are versatile in that they can be any shape and can be landscaped. The bioretention areas onsite were sized to treat stormwater as well as limit flow control for hydromodification. 6b. Sizing factors for IMP's 1) Lower flow threshold determination Field investigations were not conducted pursuant to SCCWRP screening tools. Therefore, the site must mitigate peak flows and durations based on a pre-project condition lower flow threshold of 0.1 Q2. 2) HMP Decision Matrix G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 IMP facilities were sized using the Decision Matrices in Figures 2-2. See Attachment 9. 6c. Geotechnical recommendation on soil inflltration rates Infiltration rates for Type 'D' soil are low, an underdrain will be utilized in bioretention areas. It is assumed the geotechnical engineer will recommend a liner around gravel surrounding perforated pipe and bioretention area. See Attachment 10 for BMP exhibit and bioretention section. 6d. Inflltration calculations Infiltration rates within the bioretention areas for the 18" soil/compost layer shall be 5 in/hr and shall be verified by the geotechnical engineer at the time of constmction. Infiltration into native soil will not be used at this site. 7. TREATMENT CONTROL BMP's Bioretention areas were sized for both treatment and hydromodification. 8. HYDROMODIFICATION Bioretention areas were sized for both treatment and hydromodification. 9. DOCUMENTATION OF STORMWATER DESIGN 9a. Hydrology maps Attachment 10 depicts the 1) Proposed Impervious Surface 2) Pervious Pavement and Landscaping proposed on Site and 3) the Self-Treating Areas and 4) The drainage area for each bioretention facility. 9b. BMP Sizing Calculator Output from the BMP Sizing Calculator is included in Attachment 11. G:\031060\Drainage\SWMP.doc Vista La Costa JN 121004 9c. Tabulation See Table in Attachment 11 10. BMP FACILITY MAINTENANCE REQUIREMENTS 10a. Ownership and responsibility of maintenance of BMP's The Owner and Developer will be responsible for the maintenance of treatment facilities. Ongoing maintenance will be assured by executing a Permanent Stormwater Quality BMP Maintenance Agreement that "mns with the land." 10b. Summary of maintenance requiremenmts Bioretention facilities remove pollutants primarily by filtering mnoff slowly through aerobic, biologically active soil. Routine maintenance is needed to ensure that flow is unobstmcted, that erosion is prevented, and that soils are held together by plant roots and are biologically active. Typical maintenance consists of the following: • Inspect inlets for channels, exposure of soils, or other evidence of erosion. Clear any obstmctions and remove any accumulation of sediment. Examine rock or other material used as a splash pad and replenish if necessary. • Inspect outlets for erosion or plugging. • Inspect side slopes for evidence of instability or erosion and correct as necessary. • Observe the surface of bioretention facility soil for uniform percolation throughout. If portions of the bioretention facility do not drain within 24 hours after the end of a storm, the soil should be tilled and replanted. Remove any debris or accumulations of sediment. • Confirm that check dams and flow spreaders are in place and level and that rivulets and channelization are effectively prevented. • Examine the vegetation to ensure that it is healthy and dense enough to provide filtering and to protect soils from erosion. Replenish mulch as necessary, remove fallen leaves and debris, pmne large shmbs or trees, and mow turf areas. When mowing, remove no more than 1/3 height of grasses. Confirm that irrigation is adequate and not excessive and that sprays do not directly enter overflow grates. Replace dead plants and remove noxious and invasive vegetation. • Abate any potential vectors by filling holes in the ground in and around the bioretention facility and by insuring that there are no areas where water stands longer than 48 hours following a storm. If mosquito larvae are present and persistent, contact the San Diego County Vector Control Program for information G:\031060\Drainage\SWMP.doc 10 Vista La Costa JN 121004 and advice. Mosquito larvicides should be applied only when absolutely necessary and then only by a licensed individual or contractor. 11. SWMP CERTIFICATION STATEMENTS 11a. Preparer's statement The selection, sizing, and preliminary design of stormwater treatment and other control measures in this plan meet the requirements of Regional Quality Control Board Order R9-2007-0001 and subsequent amendments. Nichole A. Fine, C70035, Exp. 9/30/12 Date lib. Owner's statement The selection, sizing, and preliminary design of stormwater treatment and other control measures in this plan meet the requirements of Regional Quality Control Board Order R9-2007-0001 and subsequent amendments. Diversified Development Date G:\031060\Drainage\SWMP.doc 11 cm OF OCEANSIDE HIWWAY CITY OF VISTA I CITY OF SAN MARCOS PACIFIC OCEAN PROJECT SITE an OF ENCINITAS VICINITY MAP NO SCALE ATTACHMENT 1 CITY OF CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov INSTRUCTIONS: To address post-development pollutants that may be generated from development projects, the City requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMP's) into the project design per the City's Standard Urban Stormwater Management Plan (SUSMP). To view the SUSMP, refer to the Engineering Standards (Volume 4, Chapter 2) at www.carlsbadca.qov/standards. Initially this questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to 'Standard Stormwater Requirements' or be subject to additional criteria called 'Priority Development Project Requirements'. Many aspects of project site design are dependent upon the storm water standards applied to a project. Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. If staff determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than initially assessed by you, this will result in the return ofthe development application as incomplete. In this case, please make the changes to the questionnaire and resubmit to the City. If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, please seek assistance from Land Development Engineering staff. A separate completed and signed questionnaire must be submitted for each new development application submission. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. In addition to this questionnaire, you must also complete, sign and submit a Project Threat Assessment Form with construction permits for the project. Please start by completing Section 1 and follow the instructions. When completed, sign the fonv at the end and submit this with your application to the city. SECTION 1 NEW DEVELOPMENT Does your project meet one or more of the following criteria: YES NO 1. Housina subdivisions of 10 or more dwellina units. ExarriDles: sinale familv homes, multi-familv homes, condominium and apartments X 2. Commercial - areater than 1-acre. Anv develooment other than heavv Industrv or residential. Examples: hospitals: laboratories and other medical facilities: educational institutions: recreational facilities: municipal facilities: commercial nurseries; multi-apartment buildings: car wash facilities: mini-malls and other business complexes; shopping malls; hotels; office buildings; public warehouses; automotive dealerships; airfields; and other light industrial facilities. 3. Heavv Industrial / Industrv- areater than 1 acre. Examples: manufacturinq olants. food processinq plants, metal working facilities, printing plants, and fleet storage areas (bus, truck, etc.). 4. Automotive repair shop. A facilitv categorized in any one of Standard Industrial Classification (SIC) codes 5013, 5014, 5541, 7532-7534, and 7536-7539 5. Restaurants. Anv facilitv that sells prepared foods and drinks for consumption, including stationarv lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (SIC code 5812), where the land area for development is greater than 5,000 square feet. Restaurants where land development is less than 5,000 square feet shall meet all SUSMP requirements except for structural treatment BMP and numeric sizing criteria requirements and hydromodification requirements. E-34 Page 1 of 3 REV 1/14/11 STORM WATER Devetopment Services Land Development Engineering •wm CITY OF STANDARDS Devetopment Services Land Development Engineering m CITY OF QUESTIONNAIRE 1635 Faraday Avenue •mi CARLSBAD E-34 760-602-2750 www.carlsbadca.gov 6. Hillside development. Anv development that creates more than 5.000 sauare feet of imoervious surface and is located in an area with known erosive soil conditions, where the development will grade on any natural slope that is twenty^five percent (25%) or greater. 7. Environmentallv Sensitive Area (ESA)'. All develooment located within or directiv adiacent^ to or discharoina directly* to an ESA (where discharges from the development or redevelopment will enter receiving waters within the ESA), which either creates 2,500 square feet or more of impervious surface on a proposed project site or increases the area of imperviousness of a proposed project site 10% or more of its naturally occurring condition. 8. Parkina lot. Area of 5.000 sauare feet or more, or with 15 or more oarkina soaces. and ootentiallv exposed to urban runoff 9. Streets, roads, hiahwavs, and freewavs. Anv paved surface that is 5.000 sauare feet or areater used for the transportation of automobiles, trucks, motorcycles, and other vehicles 10. Retail Gasoline Outlets. Servina more than 100 vehicles oer dav and areater than 5.000 sauare feet 11. Coastal Development Zone. Anv proiect located within 200 feet of the Pacific Ocean and (1) creates more than 2500 square feet of impervious surface or (2) increases impervious surface on property by more than 10%. 12. Afore than 1-acre of disturbance. Proiect results in the disturbance of 1-acre or more of land and is considered a Pollutant-generating Development Project''. X 1 Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. 2 "Directly adjacent" means situated within 200 feet ofthe Environmentally Sensitive Area. 3 "Discharging directly to" means outflow from a drainage conveyance system that is composed entirely of flows from fhe subject development or redevelopment site, and not commingled with flow from adjacent lands. 4 Pollutant-generating Development Projects are those projects that generate pollutants at levels greater than background levels. In general, these include all projects that contribute to an exceedance to an impaired water body or which create new impervious surfaces greater than 5000 square feet and/or intn^duce new landscaping areas that require routine use of fertilizers and pesticides, in most cases linear pathway projects that are for infrequent vehicle use, such as emergency or maintenance access, or for pedestrian or bicycle use, are not considered Pollutant-generating Development Projects if they are built with pervious surfaces or if they sheet flow to surrounding pervious surfaces. INSTRUCTIONS: Section 1 Results: If you answered YES to ANY of the questions above, your project is subject to Priority Development Project requirements. Skip Section 2 and please proceed to Section 3. Check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3. Additional storm water requirements will apply per the SUSMP. If you answered NO to ALL of the questions above, then please proceed to Section 2 and foilow the instructions. E-34 Page 2 of 3 REV 1/14/11 ^ CITY OF STORM WATER Development Services Land Development Engineering ->«• ^ CITY OF STANDARDS Development Services Land Development Engineering •m ^ CITY OF QUESTIONNAIRE 1635 Faraday Avenue CARLSBAD E-34 760-602-2750 www.carlsbadca.gov SECTION 2 SIGNIFICANT REDEVELOPMENT INSTRUCTIONS: Complete the questions below regarding your project YES NO 1. Project results in the disturbance of 1-acre or more of land and is considered a Pollutant-generating Development Project *? INSTRUCTIONS: If you answered NO, please proceed to question 2. If you answered YES, then you ARE a significant redevelopment and you ARE subject to PRIORITY DEVELOPMENT PROJECT requirements. Please check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3 below. 2. Is the project redeveloping an existing priority project type? (Priority projects are defined in Section 1) INSTRUCTIONS: If you answered YES, please proceed to question 3. If you answered NO, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER REQUIREMENTS. Please check the "does not meet PDP requirements" box in Section 3 below. 3. Is the work limited to trenching and resurfacing associated with utility work; resurfacing and reconfiguring surface parking lots and existing roadways; new sidewalk; bike lane on existing road and/or routine maintenance of damaged pavement such as pothole repair? Resurfacing/reconfiguring parking lots is where the work does not expose underlying soil during construction. INSTRUCTIONS: If you answered NO, then proceed to question 4. If you answered YES, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER REQUIREMENTS. Please check the "does not meet PDP requirements" box in Section 3 below. 4. Will your redevelopment project create, replace, or add at least 5,000 square feet of impervious surfaces on existing developed property or will your project be located within 200 feet of the Pacific Ocean and (1) create 2500 square feet or more of impervious surface or (2) increases impervious surface on the property by more than 10%? Replacement of existing impervious surfaces includes any activity that is not part of routine maintenance where impervious material(s) are removed, exposing underlying soil during construction. INSTRUCTIONS: If you answered YES, you ARE a significant redevelopment, and you ARE subject to PRIORITY DEVELOPMENT PROJECT requirements. Please check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3 below. Review SUSMP to find out if SUSMP requirements apply to your project envelope or the entire project site. If you answered NO, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER REQUIREMENTS. Please check the "does not meet PDP requirements" box in Section 3 below. *for definition see Footnote 4 on page 2 SECTION 3 QUESTIONNAIRE RESULTS My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with additional stormwater criteria per the SUSMP and I understand I must prepare a Storm Water Management Plan for submittal at time of application. I understand flow control (hydromodification) requirements may apply to my project. Refer to SUSMP for details. My project does not meet PDP requirements and must only comply with STANDARD STORMWATER REQUIREMENTS per the m Applicant Information and Signature Box Address: Assessor's Parcel Number(sV; _ . - , m Applicant Name: Applicant Title: •mm Applicant Signature: Date; m m E-34 Page 3 of 3 This Box for City Use Only City Concurrence: YES By: NO Project ID: REV 1/14/11 SECTION 2: DENTIFY POLLUTANTS, BMP SIZING AND SELECTION Re-destgn Ehergy Oissipaion Syg«m 14. HydromodiUcatlon Controls R«qulf«d Opto figun i.iol DtcltionMattx FIGURE 2-1. HMP Applicability Determination* *refer to expanded HMP exemption criteria below for justifications required on each node 30 City of Carlsbad SUSMP - January 14, 2011 SECTION 2: IDENTIFY POLLUTANTS, BMP SIZING AND SELECTION TABLE 2-1. ANTICIPATED AND POTENTIAL Pollutants Generated by Land Use Type. General Pollutant Categories Priority Project Categories Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances OU& Grease Bacteria & Viruses Pesticides Detached Residential Development X X X X X X X Attached Residential Development X X X P(l) P(2) P X Commercial Development >onc acre P(l) P(l) X P(2) X P(5) X P(3) P(5) I leavy Industry X X X X X X Automotive Repair Shops X X(4)(5) X X Restaurants X X X X P(l) Hillside Development > 5,000 ft2 X X X X X X Parking Lots P(l) P(l) X X P(l) X P(l) Retail Gasoline Outlets X X X X X Streets, Highways & Freeways X P(l) X X(4) X P(5) X X P(l) X = anticipated P = potential (1) A potential pollutant if landscaping exists on-site. (2) A potential pollutant if the project includes uncovered parking areas. (3) A potential pollutant if land use involves food or animal waste products. (4) Including petroleum hydrocarbons. (5) Including solvents. 23 City of Carisbad SUSMP - January 14, 2011 II II If i 1 If II li 11 II II II 11 li II If Appendix B All Decision 2008 1/27/2010 REGION WATER BODY NAME CALWATER NUMBER INTEGRATED REPORT CATEGORY DECISION ID DECISION REVISION STATUS POLLUTANT DECISION LISTING YEAR FINAL LISTING DECISION EXPECTED TMDL COMPLETION DATE g Pacific Ocean Shoreline, Aliso HSA, at Aliso Creek mouth 90113000 5 16946 Revised Total Coliform 2008 Do Not Delist from 303(d) list (TMDL required list) 01-Jan-2012 9 Pacific Ocean Shoreline, Aliso HSA, at Blue Lagoon 90113000 2 16945 Revised Enterococcus 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Aliso HSA, at Blue Lagoon 90113000 2 16944 Revised Fecal Coliform 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Aliso HSA, at Blue Lagoon 90113000 2 16943 Revised Total Coliform 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at Moonlight State Beach (Cottonwood Creek outlet) 5 17720 Original Enterococcus 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at Moonlight State Beach (Cottonwood Creek outlet) 5 17721 Original Fecal Coliform 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at Moonlight State Beach (Cottonwood Creek outlet) 5 17722 Original Total Coliform 2008 Do Not Delist from 303(d) list (TMDL required list) 01-Jan-2019 9 Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Batiquitos Lagoon Outlet) 90451000 2 16742 Revised Enterococcus 2008 Do Not List on 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Batiquitos Lagoon Outlet) 90451000 2 16745 Revised Fecal Coliform 2008 Do Not List on 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at South Carlsbad State Beach (Batiquitos Lagoon Outlet) 90451000 2 16746 Revised Total Coliform 2008 Do Not List on 303(d) list (TMDL required list) 43 1 1 IIII 1 1 1 1 1 1 1 i 1 II II 1 1 1 llllll 1 1 1 Appendix B All Decision 2008 REGION WATER BODY NAME CALWATER NUMBER INTEGRATED REPORT CATEGORY DECISION ID DECISION REVISION STATUS POLLUTANT DECISION LISTING YEAR FINAL LISTING DECISION EXPECTED TMDL COMPLETION DATE 9 Pacific Ocean Shoreline, Batiquitos HSA, at Swami's Beach 90451000 2 16527 Revised Enterococcus 2008 Do Not List on 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at Swami's Beach 90451000 2 16526 Revised Fecal Coliform 2008 Do Not List on 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Batiquitos HSA, at Swami's Beach 90451000 2 16525 Revised Total Coliform 2008 Do Not List on 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Buena Vista Lagoon Outiet 90421000 2 16959 Revised Enterococcus 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Buena Vista Lagoon Outiet 90421000 2 16958 Revised Fecal Coliform 2008 Delist fi-om 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Buena Vista Lagoon Outlet 90421000 2 16957 Revised Total Coliform 2008 Delist fi-om 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Carlsbad State Beach at Carlsbad Village 90421000 2 16962 Revised Enterococcus 2008 Delist ft-om 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Carlsbad State Beach at Carisbad Village 90421000 2 16961 Revised Fecal Coliform 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Carlsbad State Beach at Carisbad Village 90421000 2 16960 Revised Total Coliform 2008 Delist from 303(d) list (TMDL required list) 9 Pacific Ocean Shoreline, Buena Vista Creek HA, at Carisbad State Beach at Pine Ave 90421000 2 16965 Revised Enterococcus 2008 Delist fi-om 303(d) list (TMDL required list) 1/27/2010 44 II li II II II il 11 11 11 II 11 li II li II li II II li Table 2-3. BENEFICIAL USES OF COASTAL WATERS BENEFICIAL USE Hydrologic N A V R R C B r-W R M A R A M S W S Coastal Waters Unit Basin Number 1 N D N A V E C 1 E C 2 0 M M 1 0 L t: S T 1 L D A R E M A R Q U A 1 G R P w N A R M H E L L Pacific Ocean • • • • • • • • • • • • • Dana Point Harbor • • • • • • • • • • • Del Mar Boat Basin • • • • • • • • • • • Mission Bay • • • • • • • • • • • Oceanside Harbor • • • • • • • • • • • San Diego Bay ^ ^ • • • • • • • • • • • • • Coastal Lagoons Tijuana River Estuary 11.11 • • • • • • • • • • • Mouth of San Diego River 7.11 • • • • • • • • • • Famosa Slough and Channel 7.11 • • • • • • • • • • Los Penasquitos Lagoon ^ 6.10 • • • • • • • • • • San Dieguito Lagoon 5.11 • • • • • • • • • Batiquitos Lagoon 4.51 • • • • • • • • • San Elijo Lagoon 4.61 • • • • • • • • • Agua Hedionda Lagoon 4.31 • • • • • • • • • • • • • ' Includes the tidal prisms of the Otay and Sweetwater Rivers. ^ Fishing from shore or boat permitted, but other water contact recreational (REC-1) uses are prohibited. ^ The Shelter Island Yacht Basin portion of San Diego Bay is designated as an impaired water body for dissolved copper pursuant to Clean Water Act section 303(d). A Total Maximum Daily Load (TMDL) has been adopted to address this impairment. See Chapter 3, Water Quality Objectives for Pesticides, Toxicity and Toxic Pollutants and Chapter 4, Total Maximum Daily Loads. • Existing Beneficial Use Table 2-3 BENEFICIAL USES 2 - 52 tl li il ii ll il li i I 1 I I I li ll II II II II l i I i Stormwater Pollutant Sources and Source Control Checklist How to Use this Checklist: 1. Review Column 1 and identify which of these potential sources of stormwater pollutants apply to your project. Check each box that applies. 2. Review Column 2 and incorporate all of the corresponding applicable BMPs in your SUSMP Drawings. 3. Review Columns 3 and 4 and incorporate all of the corresponding applicable permanent controls and operational BMPs in a table in your SUSMP Drawings. For PDP's, in your SWMP, use the format shown in Table 3-1. In the SWMP, describe your specific BMPs in an accompanying narrative, and explain any special conditions or situations that required omitting BMPs or substituting alternatives. IF THESE SOURCES WILL BE ON THE PROJECT SITE ... THEN YOUR PROJECT SHOULD INCLUDE THESE SOURCE CONTROL BIMPs Potential Sources of Runoff Pollutants Permanent Controls—Show on SUSIVIP Drawings Permanent Controls—List in SWIMP Table and Narrative Operational BMPs—Include in SWIMP Table and Narrative ^ A. On-site stonn drain inlets 9^ Locations of inlets. ^ Mark all inlets with the words "No Dumping! Flows to Bay" or similar. 9^ Maintain and periodically repaint or replace inlet markings. Provide stormwater pollution prevention information to new site owners, lessees, or operators. ^ See appUcable operational BMPs in Fact Sheet SC-44, "Drainage System Maintenance," in the CASQA Stormwater Quahty Handbooks at www.cabmphandbooks.com ^ Include the following in lease agreements: "Tenant shall not allow anyone to discharge anything to storm drains or to store or deposit materials so as to create a potential discharge to storm drains." Page 1 of 9 II il ll II 11 li li li 11 li II li II II ii II II II li B. Interior floor drains and elevator shaft sump pumps State that interior floor drains and elevator shaft sump pumps will be plumbed to sanitary sewer. • Inspect and maintain drains to prevent blockages and overflow. ^ C. Interior parking garages State that parking garage floor drains will be pliunbed to the sanitary sewer. 13 Inspect and maintain drains to prevent blockages and overflow. • Dl. Need for futuie indoor & structural pest control • Note building design features that discourage entry of pests. Provide Integrated Pest Management information to owners, lessees, and operators. ^ DZ. Landscape/ Outdoor Pesticide Use • Show locations of native trees or areas of shrubs and ground cover to be undisturbed and retained. • Show self-retaming landscape areas, if any. • If a PDP, show stormwater treatment facilities. State that final landscape plans will accomplish all of the following. Q Preserve existing native trees, shrubs, and ground cover to the maximum extent possible. ^ Design landscaping to minimize irrigation and runoff, to promote surface infiltration where appropriate, and to miiumize the use of fertiUzers and pesticides that can contribute to stormwater pollution. 1^ Where landscaped areas are used to retain or detain stormwater, specify plants that are tolerant of saturated soil conditions. 13 Consider using pest-resistant plants, especially adjacent to hardscape. 2i To insure successful estabUshment, select plants appropriate to site soils, slopes, climate, sim, wind, rain, land use, air movement, ecological consistency, and plant interactions. BT Maintain landscaping using minimum or no pesticides. Si See appUcable operational BMPs in Fact Sheet SC-41, "Building and Groimds Maintenance," in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com of Provide IPM information to new owners, lessees and operators. ^ E. Pools, spas, ponds, decorative foimtains, and other water features. 'SL Show location of water feature and a sanitary sewer cleanout in an accessible area within 10 feet. Si If the local municipaUty requires pools to be plimibed to the sanitary sewer, place a note on the plans and state in the narrative that this connection will be made according to local requirements. • See appUcable operational BMPs in Fact Sheet SC-72, "Foimtain and Pool Maintenance," in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com Page 2 of 9 II ll II II li li li 11 II li II II li II il il II II II • F. Food service • For restaurants, grocery stores, and other food service operations, show location (indoors or in a covered area outdoors) of a floor sink or other area for cleaiung floor mats, containers, and equipment. • On the drawing, show a note that this drain will be connected to a grease interceptor before discharging to the sanitary sewer. • Describe the location and features of the designated cleaning area. • Describe the items to be cleaned in this faciUty and how it has been sized to insure that the largest items can be accommodated. 0 G. Refuse areas Show where site refuse and recycled materials will be handled and stored for pickup. See city standard drawing GS-16. If dumpsters or other receptacles • are outdoors, show how the designated area will be covered, graded, and paved to prevent run- on and show locations of berms to prevent runoff from the area. Any drams from diunpsters, Q compactors, and tallow bin areas shaU be coimected to a grease removal device before discharge to sanitary sewer. 0- State how site refuse will be handled and provide supporting detail to what is shown on plans, f^t.,, ^(2 {|| ft^ft? M State that signs will be posted on or near dumpsters with the words "Do not dump hazardous materials here" or similar. 3, State how the following wiU be implemented: Provide adequate niunber of receptacles. Inspect receptacles regularly; repair or replace leaky receptacles. Keep receptacles covered. Prohibit/prevent dumping of Uquid or hazardous wastes. Post "no hazardous materials" signs. Inspect and pick up Utter daily and clean up spills immediately. Keep spiU control materials available on- site. See Fact Sheet SC-34, "Waste Handling and Disposal" in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com Q H. Industrial processes. G Show process area. Q If industrial processes are to be located on site, state: "All process activities to be performed indoors. No processes to drain to exterior or to storm drain system." • See Fact Sheet SC-10, "Non- Stormwater Discharges" in the CASQA Stormwater QuaUty Handbooks at wvu'w.cabmphandbooks.com Page 3 of 9 I I i I I i I i i I IIII II II II II II II II II I. Outdoor storage of equipment or materials. (See rows J and K for source control measures for vehicle cleaning, repair, and maintenance.) Ql Show any outdoor storage areas, including how materials wiU be covered. Show how areas will be graded and bermed to prevent run- on or run-off from area. • Storage of non-hazardous Uquids shall be covered by a roof and/or drain to the sanitary sewer system, and be contained by berms, dikes, Uners, or vaults. • Storage of hazardous materials and wastes must be in compUance with the local hazardous materials ordinance and a Hazardous Materials Management Plan for the site. Include a detailed description of materials to be stored, storage areas, and structural features to prevent poUutants from entering storm drains. Where appropriate, reference documentation of compUance with the reqiurements of local Hazardous Materials Programs for: • Hazardous Waste Generation • Hazardous Materials Release Response and Inventory • CaUfornia Accidental Release (CalARP) • Aboveground Storage Tank • Uniform Fire Code Article 80 Section 103(b) & (c) 1991 • Underground Storage Tank • See the Fact Sheets SC-31, "Outdoor Liquid Container Storage" and SC- 33, "Outdoor Storage of Raw Materials " in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com Page 4- of 9 II II il II II II li I i i i I i II ii li il il ii II II • J. Vehicle and Equipment Cleaning • Show on drawings as appropriate: (1) Commercial/industrial faciUties having vehicle /equipment cleaning needs shall either provide a covered, bermed area for washing activities or discourage vehicle/equipment washing by removing hose bibs and installing signs prohibiting such uses. (2) Multi-dwelling complexes shall have a paved, bermed, and covered car wash area (unless car washing is prohibited on-site and hoses are provided with an automatic shut- off to discourage such use). (3) Washing areas for cars, vehicles, and eqiupment shall be paved, designed to prevent run-on to or nmoff from the area, and pliunbed to drain to the sanitary sewer. (4) Commercial car wash faciUties shaU be designed such that no runoff from the faciUty is discharged to the storm drain system. Wastewater from the faciUty shaU discharge to the sanitary sewer, or a wastewater reclamation system shaU be installed. If a car wash area is not provided, describe measures taken to discourage on-site car washing and explain how these wiU be enforced. Describe operational measures to implement the following (if appUcable): • Washwater from vehicle and equipment washing operations shall not be discharged to the storm drain system. • Car dealerships and similar may rinse cars with water only. • See Fact Sheet SC-21, "Vehicle and Equipment Cleaning," in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com Page 5 of 9 ii il II II il ii II li ii ii li il ll ll il ll ii Ii li K. Vehicle/Equipment Repair and Maintenance • Accommodate aU vehicle equipment repair and maintenance indoors. Or designate an outdoor work area and design the area to prevent run-on and runoff of stormwater. • Show secondary containment for exterior work areas where motor oil, brake fluid, gasoline, diesel fuel, radiator fluid, acid-containing batteries or other hazardous materials or hazardous wastes are used or stored. Drains shaU not be instaUed within the secondary containment areas. Q Add a note on the plans that states either (1) there are no floor drains, or (2) floor drains are connected to wastewater pretreatment systems prior to discharge to the sanitary sewer and an industrial waste discharge permit will be obtained. State that no vehicle repair or maintenance wiU be done outdoors, or else describe the required features of the outdoor work area. State that there are no floor drains or if there are floor drains, note the agency from which an industrial waste discharge permit wiU be obtained and that the design meets that agency's requirements. State that there are no tanks, containers or sinks to be used for parts cleaning or rinsing or, if there are, note the agency from which an industrial waste discharge permit wiU be obtained and that the design meets that agency's requirements. In the SUSMP report, note that all of the foUowing restrictions apply to use the site: No person shaU dispose of, nor permit the disposal, directly or indirectly of vehicle fluids, hazardous materials, or rinsewater from parts cleaning into storm drains. No vehicle fluid removal shaU be performed outside a building, nor on asphalt or ground surfaces, whether inside or outside a building, except in such a manner as to ensure that any spiUed fluid wiU be in an area of secondary contaitunent. Leaking vehicle fluids shaU be contained or drained from the vehicle immediately. No person shaU leave unattended drip pans or other open containers containing vehicle fluid, unless such containers are in use or in an area of secondary contaiimient. Page 6 of 9 il li 11 li li li II II 11 II li il il ll ii IIII • L. Fuel Dispensing Areas FueUng areas' shall have impermeable floors (i.e., ponland cement concrete or equivalent smooth impervious surface) that are: a) graded at the minimum slope necessary to prevent ponding; and b) separated from the rest of the site by a grade break that prevents run-on of stormwater to the maximum extent practicable. FueUng areas shaU be covered by a canopy that extends a minimum of ten feet in each direction from each pump. [Alternative: The fueling area must be covered and the cover's minimum dimensions must be equal to or greater than the area within the grade break or fuel dispensing area'.] The canopy [or cover] shaU not drain onto the fueling area. • The property owner shaU dry sweep the fueling area routinely. • See the Business Guide Sheet, "Automotive Service—Service Stations" in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com 1 The fueling area sliall be deiined as the aiea extending a minimum of 6.5 feet from the comer of each fuel dispenser or the length at which the hose and nozzle assembly may be operated plus a minimum of one foot, whichever is greater. Page 7 of 9 II I i II II II il 11 II il ii II li II ii li il li li • IM. Loading Docks • a Show a preliminary design for the loading dock area, including roofing and drainage. Loading docks shall be covered and/or graded to minimize run-on to and runoff from the loading area. Roof downspouts shaU be positioned to direct stormwater away from the loading area. Water from loading dock areas should be drained to the sanitary sewer where feasible. Direct connections to storm drains from depressed loading docks are prohibited. Loading dock areas draining directiy to the sanitary sewer shall be equipped with a spiU control valve or equivalent device, which shaU be kept closed during periods of operation. Provide a roof overhang over the loading area or install door skirts (cowling) at each bay that enclose the end of the trailer. • Move loaded and unloaded items indoors as soon as possible. • See Fact Sheet SC-30, "Outdoor Loading and Unloading," in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com • N. Fire Sprinkler Test Water Provide a means to drain fire sprinkler test water to the sanitary sewer. See the note in Fact Sheet SC-41, "Building and Grounds Maintenance," in the CASQA Stormwater QuaUty Handbooks at www.cabmphandbooks.com Page 8 of 9 ii li II ii II 11 ii 11 ii ll il ii li il il ii li ll O. Miscellaneous Drain or Wash Water Q Boiler drain lines Q Condensate drain Unes • Rooftop equipment • Drainage sumps • Roofing, gutters, and trim. • Boiler drain lines shaU be direcdy or indirectly connected to the sanitary sewer system and may not discharge to the storm drain system. • Condensate drain Unes may discharge to landscaped areas if the flow is small enough that runoff will not occur. Condensate drain Unes may not discharge to the storm drain system. Rooftop mounted equipment with potential to produce poUutants shaU p be roofed and/or have secondaiy containment. Any drainage sumps on-site shaU feature a sediment sump to reduce the ^ quantity of sediment in pumped water. Avoid roofing, gutters, and trim made of copper or othet unprotected metals that may leach into nmoff. ^ P. Plazas, sidewalks, and paiking lots. Plazas, sidewalks, and parking lots shaU be swept regularly to prevent the accumulation of Utter and debris. Debris from pressure washing shaU be coUected to prevent entry into the storm drain system. Washwater containing any cleaning agent or degreasei shaU be coUected and dischaiged to the sarutary sewer and not discharged to a storm drain. Page 9 of 9 SECTION 2: IDENTIFY POLLUTANTS, BMP SIZING AND SELECTION Consult with Geotechnical Engif^eer no 4. Size LIO and BMP Facilities for Flow Range of 0.1 Q, to Q •mi 165 m &<1 of Decision Matrix FIGURE 2-2. Mitigation Criteria and Implementation I 38 City of Carisbad SUSRAP - January 14, 2011 Attachment 11 Calculations for the Bioretention Areas In order to meet Hydromodification requirements outlined in the Final Hydromodification Plan prepared for the County of San Diego on January 13, 2011 by Brown and Caldwell, an IMP sizing factor was determined from Table 7-1. It is assumed that under the worst condition the bioretention facilities will be fully lined and shall be modeled as a flow-through planter. Per Table 7-1. Sizing Factors for Flow-Through Planter Lower Flow Threshold: 0.1Q2 Rain Gauge= Oceanside Soil Type: D Existing Slope: Flat Results: IMP sizing factor of 0.160 VI =0.1333 A V2 = 0.0960 A In order to get the volumes required by the hydromodification criteria, the vault volume (V2) required below the perforated pipe is calculated as follows: Vl= 10" X 0.04 A = 0.033A, 0.1333A-0.033A= O.lOA (add to V2) V2 = 0.096A-I-0.10A = 0.196A See Tables Below for a Summary of Bioretention Areas (Treatment Requirements Only) Post-DMA Soil DMA Project Surface DMA Area x Type IMP Name DMA Area Project Surface Runoff Runoff D BMPl Name (sf) type factor factor D BMPl l-I 4128 Roof 1.0 4128 IMP 1-LS 2173 Landscape 0.1 22 Sizing factor Minimum Area Proposed Area 4150 0.04 166 Total 166 290 IMP Area Post-DMA Soil DMA Project Surface DMA Area x Type IMP Name DMA Area Project Surface Runoff Runoff D BMP2 Name (sf) type factor factor D BMP2 2-1 3950 Roof 1.0 3950 IMP 2-LS 1780 Landscape 0.1 18 Sizing factor Minimum Area Proposed Area 3968 0.04 159 Total 159 320 IMP Area Post-DMA Soil DMA Project Surface type DMA Area x Type IMP Name DMA Name Area (sf) Project Surface type Runoff factor Runoff factor D BMP3 3-1 9160 Roof 1.0 9160 IMP 3-12 1870 Sidewalk 1.0 1870 Sizing factor Mmimum Area Proposed Area 3-LS 6270 Landscape 0.10 63 11093 0.04 444 Total 444 750 IMP Area See Tables Below for a Summary of Bioretention Areas (V2 Storage Requirements for Hydromodification) Post-DMA Soil DMA Project Surface type DMA Area x Type IMP Name m DMA Name Area (sf) Project Surface type Runoff factor Runoff factor D BMPl l-I 4128 Roof 1.0 4128 IMP Proposed Volume •mi 1-LS 2173 Landscape 0.1 22 Sizing factor Minimum Volume Proposed Volume m 4150 0.196 813 Total 813 875 IMP Area um Post-DMA Soil m, DMA Project Surface type DMA Area x Type IMP Name m DMA Name Area (sf) Project Surface type Runoff factor Runoff factor D BMP2 2-1 3950 Roof 1.0 3950 IMP Proposed Volume 2-LS 1780 Landscape 0.1 18 Sizing factor Minimum Volume Proposed Volume 3968 0.196 778 — Total 778 819 IMP Area m Post-DMA Soil DMA Project Surface type DMA Area x Typ e IMP Name mt m DMA Name Area (sf) Project Surface type Runoff factor Runoff factor D BMP3 me 3-1 9160 Roof 1.0 9160 IMP Proposed Volume m 3-12 1870 Sidewalk 1.0 1870 Sizing factor Mmimum Volume Proposed Volume m 3-LS 6270 Landscape 0.10 63 11093 0.196 2174 m Total 2174 2331 IMP Area A 48", 54" or 60" HDPE storm drain pipe will be located under the bioretention area. The volume of proposed storage was calculated using the area of the storage pipe cross-section minus a 6" emergency outfall at the top of the pipe multiplied by the length of the pipe. See Attachment 10 for bioretention area details. Summary Table for Underground Storage Volume Vault Vault Length of Area of Storm Drain mK Required Provided Chamber Chamber Size m BMPl 813 CF 875 CF 75' 11.66 SF 48" SD BMP 2 778 CF 819 CF 44' 18.61 SF 60" SD ml BMP3* 2174 CF 2331 CF 156' 14.94 SF 54" SD m *2~ 78 foot long 54" HDPE storm drains will be utilized to hand) e V2 for BMP3 In addition to the tabulated values above, the BMP LID Calculator was utilized to determine the size of the orifice to limit flow to 0.1Q2. The Flow-Thru Planter was modeled to determine the lower flow threshold. The orfice equation was utilized to determine the area of the opening, since the depth of head is different for the project site versus the flow through planter. Orifice Equation: Q= CA (2gd)i/2 Q = Lower Flow Threshold (0.1 Q2) C = Orifice Coefficient (0.67 for U.S. Traditional Units) g = gravitational acceleration (32.2 ft/s) d = flow depth above outlet A = Orifice cross-sectional area Summary Table for Orifice Outlet Calculations m BMP# 0.1Q2 (cfs)* A(sf) Diameter of Orifice (ft) Diameter of Orifice (in) mm BMP 1 0.002 42" 0.000199 0.0159 0.19 m BMP 2 0.002 54" 0.000175 0.0149 0.18 BMP3 0.006 48" 0.000558 0.0266 0.32 * For Lower flow threshold flowrates see attached BMP Calculator Output. ** Depth of head above the invert of the detention pipe is equal to the pipe diameter minus 6" for overflow outlet. I i .lepoA.Jsulti I I I I I 1 I I I i I i i I 1 I I I 1 • i i < i < i * Age'l of*z ' Project Summary Project Name Vista La Costa Project Applicant Diversified Development Jurisdiction City of Carlsbad Parcel (APN) 21629021 Hydrologic Unit Carlsbad Compliance Basin Summary Basin Name: Vista La Costa Receiving Water: Existing Channel NE Cor Rainfall Basin Oceanside Mean Annual Precipitation (Inches) 13.3 Project Basin Area (acres): 0.88 Watershed Area (acres): 0.00 SCCWRP Lateral Channel Susceptiblity (H, M, L): SCCWRP Vertifical Channel Susceptiblity (H, M, L): Overall Channel Susceptibility (H, M, L): HIGH Lower Flow Threshold (% of 2-Year Flow): 0.1 Drainage Management Area Summary ID Type BMP ID Description Area (ac) Pre-Project Cover Post Surface Type Drainage Soil Slope 13929 Drains to LID BMP 2 Buildingi- South 0.09 Pen/ious (Pre) Roofs Type D (high runoff - clay soi... Flat - slope (less ... 13930 Drains to LID BMP 2 Landscape2 0.04 Pervious (Pre) Landscaping Type D (high runoff - clay soi... Flat - slope (less ... 14435 Drains to LID BMP 3 Building 2 0.25 Pen/ious (Pre) Roofs Type D (high runoff - clay soi... Flat - slope (less ... 14436 Drains to LID BMP 3 Landscapes 0.14 Pen/ious (Pre) Landscaping Type D (high runoff - clay soi... Flat - slope (less ... 14444 Drains to LID BMP 1 Building 1 North 0.09 Pervious (Pre) Roofs Type D (high runoff - clay soi... Flat - slope (less ... 14445 Drains to LID BMP 1 Landscape1 0.05 Pen/ious (Pre) Landscaping Type D (high runoff - clay soi... Flat - slope (less ... http://uknow.brwncald.com/wastewater/Toolkits/Watershed/SiteToolkit/ReDortResult.a.sr)x?nid=138617<tbid=SDr-n001 ,<i^sir=n 7/17/7017 I i I ..%poil..Jbukl i I I I I I I 1 i I I I i I I I I I i • 1 • i i * i « A^AoA * 14446 Self-Treating BMP 1 Pavers at Parking Lot & ramp 0.09 Type D (high runoff - clay soi... 14447 Self-Treating BMP 1 Pavers in Driveway 0.09 Type D (high runoff - clay soi... 14448 Self-Treating BMP 1 Self-Treat South Building 2 0.03 Type D (high runoff - clay soi... LID Facility Summary BMP ID Type Description Plan Area (sqft) Volume 1(cft) Volume 2(cft) Orifice Flow (cfs) Orifice Size (inch) BMP 1 Flow-Through Planter Bioretention #1 662 551 397 0.002 0.2 BMP 2 Flow-Through Planter Bioretention #2 655 545 393 0.002 0.2 BMP 3 Flow-Through Planter Bioretention #3 1840 1532 1104 0.006 0.4 • t http://uknow.brwncald.com/wastewater/ToolkitsAVatershed/SiteToolkit/ReDortResult.asDX?Did=138617&bid=SDC-0001 &sic=n... 2/17/2012