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HomeMy WebLinkAboutPIP 06-10; BRESSI RANCH INDUSTRIAL LOTS; STORM WATER MANAGEMENT PLAN; 2007-02-01STORM WATER MANAGEMENT PLAN BREssI INDUSTRIAL LOTS 19-22 CITY OF CARLSBAD, CA FEBRUARY 2007 PIP 06-10 Prepared For: CARLSBAD - B. C. MANAGEMENT CORPORATION 4350 Executive Drive, Suite 301 San Diego, CA 92121 wij Prepared By: 701 B Street, Suite 800 PROJECT DESIGN CONSULTANTS San Diego, CA92101 Planning I Landscape Architecture I Environmental I Engineering I Survey 619.235.6471 Tel 619.234.0349 Fax Job No. 3370.10. 11l1U Prepared by: C. D. Szczublewski . OFESSI D Under the supervision of CO LU C 62034 . I Y,- Lj P \ *\, EXP. 09/30/0 ca Richard P. Hall, PE RCE 62034 Registration Expires 09/30/07 'k2c!' (fori 10 1 4d_1 TABLE OF CONTENTS INTRODUCTION .1 PROJECT DESCRIPTION .2 POLLUTANTS AND CONDITIONS OF CONCERN......................................................3 Anticipated and Potential Pollutants from the Project Area................................................3 Pollutants of Concern in Receiving Waters.........................................................................3 BeneficialUses........................................................................................................4 ImpairedWater Bodies ............................................................................................. 5 Watershed Pollutants of Concern............................................................................6 Conditionsof Concern.........................................................................................................6 STORM WATER BEST MANAGEMENT PRACTICES.................................................9 SiteDesign BMPs ................................................................................................................ 9 SourceControl BMPs........................................................................................................10 Project-Specific BMPs ......................................................................................................11 Structural Treatment BMPs...............................................................................................12 Selected Treatment BMP(s)...................................................................................13 BMPPlan Assumptions.....................................................................................................15 PROJECT BMP PLAN IMPLEMENTATION.................................................................17 ConstructionBMPs............................................................................................................17 Recommended Post-Construction BUT Plan.....................................................................17 Operation and Maintenance Plans ...................................................................................... 18 PROJECT BMP COSTS AND FUNDING SOURCES....................................................19 LE TABLES Table 1. Anticipated and Potential Pollutants Generated by Land Use Type .................................3 Table 2. Beneficial Uses for Inland Surface Waters .................................. 4 Table 3. Beneficial Uses for Groundwater......................................................... 4 Table 4. Structural Treatment Control BMP Selection Matrix ......................... 13 Table 5. BMP Design Criteria........................................................................ 16 Table 6. Post-Construction BMP Summary................................................. 18 Table7. BMP Costs......................................................................................................................19 APPENDICES Storm Water Requirements Applicability Checklist Project Maps Drainage Calculations Discussion of Feasible Treatment BMP Options Supplemental BMP Information References 111 1. INTRODUCTION As part of the Final Engineering Phase of development, this Storm Water Management Plan (SWMP) was prepared to define recommended project Best Management Practice (BMP) options that satisfy the requirements identified in the following documents: City of Carlsbad Standard Urban Storm Water Mitigation Plan, Storm Water Standards, County of San Diego Watershed Protection, Storm Water Management and Discharge Control Ordinance (County Ordinance 9589), Standard Specifications for Public Works Construction, San Diego Regional NPDES Storm Water Permit (Order Number 2001-01, NPDES Number CAS0108758), and NPDES General Permit for Storm Water Discharges Associated with Construction Activity Water Quality Order 99-08-DWQ. Specifically, this report includes the following: Project description and location with respect to the Water Quality Control Plan for the San Diego Basin (Basin Plan); BMP design criteria and water quality treatment calculations; Selected BMP.options for the project; BMP device information for the selected BMP options; and Operation, maintenance, and funding for the selected BMPs. P:3370ENGRREPORTS\WQTR3370. I Los I9-223310.I SWMP 061 207.doc - 1 - 2. PROJECT DESCRIPTION This SWMP is provided for Bressi Industrial Lots 19-22. The overall Bressi Ranch Development is located in the City of Carlsbad (92009) and is bounded by: 1) Palomar Airport Road to the north, 2) Melrose Drive to the east, 3) El Camino Real to the west, and 4) Poinsettia Drive to the south. Within the Bressi Ranch Development, this project is one of 40 industrial lots, located south of Palomar Airport Road. Lots 19 through 22 are on the northwest corner of Innovation Way and Gateway Road. The vicinity and site maps are available in Appendix 2. The total project site consists of 8.3 acres. The preliminary site plan shows twelve buildings on the site with associated surface parking. The project area currently consists of fàur mass graded lots per the Bressi Ranch Mass Grading project (Dwg# 421-3A). The perimeters of the site have been stabilized for sediment control and temporary desilting basins have been constructed in the southwest corners of each lot. The storm drain backbone system, roadways, and common utility improvements have been completed per Dwg# 400-88,421-3, and 400-80. Lots 19 through 22 will comply with the City of Carlsbad Storm Water Standards by implementing appropriate site design, source control, and treatment BMPs. In developing Lots 19 through 22, the primary treatment BMPs will be biofiltration (grass swales) and hydrodynamic separation (Bio Clean Nutrient Separating Baffle Box or equivalent device). Since the proposed development of Lots 19 through 22 does not involve industrial activities, the project will not be required to comply with the Waste Discharge Requirements for Discharge of Storm Water Associated with Industrial Activities (Water Quality Order Number 97-03-DWQ, NPDES Number CAS000001). Lots 19 through 22 will be covered under the San Diego Regional NPDES Storm Water Permit (Order Number 2001-01, NPDES Number CA50108758) and NPDES General Permit for Storm Water Discharges Associated with Construction Activity (Water Quality Order Number 99-08-DWQ). P:3370ENGRREPORTS\WQTR3370. I Lots I9-22\3370.I SWMP 061207.doc -2- 3. POLLUTANTS AND CONDITIONS OF CONCERN Anticipated and Potential Pollutants from the Project Area Based on land use, potential pollutants from the site under existing conditions include sediment, nutrients, and trash and debris. Anticipated pollutants from the site under proposed conditions include sediment, nutrients, organic compounds, trash and debris, oxygen demanding substances, oil and grease, pesticides, and heavy metals. TABLE 1. ANTICIPATED AND POTENTIAL POLLUTANTS GENERATED BY LAND USE TYPE General Pollutant Categories Heavy Organic Trash Oxygen Oil & Bacteria Project Categories Sediment Nutrients Metals Compounds & Demanding Greas e & Pesticides Debris Substances Viruses Commercial Development P(1) P(l) P(2) X P(5) X P(3) P(5) Parking Lots P(l) P(1) X X P(1) X P(1) Notes for Table 1: (1) A potential pollutant if landscaping exists onsite. X = Anticipated Pollutant (2) A potential pollutant if the project includes uncovered parking areas. P = Potential Pollutant A potential pollutant if land use involves food or animal waste products. Including petroleum hydrocarbons Including solvents Source: "Table 2. Anticipated and Potential Pollutants Generated by Land Use Type," City of Carlsbad, Public Works Department, Standard Urban Storm Water Mitigation Plan, Storm Water Standards, A Manual for Construction & Permanent Storm Water Best Management Practices Requirements, April 2003, pg. 12 Pollutants of Concern in Receiving Waters The Bressi Industrial Lots 19-22 Project is located in the Carlsbad Watershed (Hydrologic Unit 904) and is tributary to San Marcos Creek.' The sections below provide the beneficial uses and identification of impaired water bodies within the project's hydrologic area. 'Water Quality Control Plan for the San Diego Basin, San Diego Regional Water Quality Control Board pu370'ENaRgEp0RTsWQTR3370.1 Lois I9-22G370.I SWMP 061207.doc -3- Beneficial Uses The beneficial uses of the inland surface waters and the groundwater basins must not be threatened .by theproject. Tables 2 and 3 list the beneficial uses for the surface waters and groundwater within - the project's hydrologic area. . . TABLE 2. BENEFICIAL USES FOR INLAND SURFACE WATERS OR MIDI 54 I~zq I d4 San Marcos Creek + E E E N N N E .N N N N N. E N TABLE 3. BENEFICIAL USES FOR GROUNDWATER --- . . GR ND gi! Batiquitos, 904.51 . + E E Source: Water Quality Control Plan for the San Diego Basin, San Diego Regional Water Quality Control Board Notes for Tables 2 and 3: . +: Exempt from use . E: Existing beneficial use . • .. P: Potential beneficial use.' N: Not a beneficial use MUN - Municipal and Domestic Supply: Includes use of water for community, military, or individual water supply systems including, but not limited to, drinking water supply. AGR - Agricultural Sipply: Includes use of water for farming, horticulture, or ranching including, but not limited to, irrigation, stock watering, or support of vegetation for iange grazing. . RECI - Contact Recreation: Includes use 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. - REC2 - Non-Contact Recreation: Includes use of water for recreation involving proximity to water, but not normally involving body contact with water where ingestion of water is reasonably possible. These uses include, but are not limited to, picnicking, sunbathing, hiking, camping, boating, tide pool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities. COMM - Commercial and Sport Fishing: Includes the uses of water for commercial or recreational collection of fish, shellfish, or other organisms including, but not limited to, uses involving organisms intended for human consumption or bait purposes. - BIOL - Preservation of Biological Habitats of Special Significance: Includes uses of water that support designated. areas or habitats, such as established refuges, parks, sanctuaries, ecological reserves, or Areas of Special Biological Significaiice (ASBS), where the preservation or enhancement of natural resources requires special protection. P:3370ENGR\REPORTS'iWQFR3370.I Lou I9-22%3370.I SWMP06I2O1.dac -' .. • . EST - Estuarine Habitat: Includes uses of water that support estuarine ecosystems including, but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish, shellfish, 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 and food 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 of marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g., marine mammals, shorebirds). AQUA - Aquaculture: Includes the uses of water for aquaculture or mariculture operations including, but not limited to, propagation, cultivation, maintenance, or harvesting of aquatic plants and animals for human consumption or bait purposes. 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. WARM - Warm Freshwater Habitat: Includes uses of water that support warm water ecosystems including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish or wildlife, including invertebrates. SHELL - Shellfish Harvesting: Includes uses of water that support habitats suitable for the collection of filter-feeding shellfish (e.g., clams, oysters and mussels) for human consumption, commercial, or sport purposes. END - Industrial Services Supply: Includes use of water for industrial activities that do not depend primarily on water quality including, but not limited to, mining, cooling water supply, hydraulic conveyance, gravel washing, fire protection, or oil well re-pressurization. Impaired Water Bodies Section 303(d) of the Federal Clean Water Act (CWA, 33 Usc 1250, et seq., at 1313(d)), requires States to identify and list waters that do not meet water quality standards after applying certain required technology-based effluent limits (impaired water bodies). The list is known as the Section 303(d) list of impaired waters. The proposed project is not directly tributary to a 303(d) listed water body. The closest impaired water body is the Pacific Ocean Shoreline, San Marcos HA, which is 303(d) listed for bacteria indicators, eutrophic, and sedimentation/siltation. In addition to the Section 303(d) list of impaired waters, the State of California also identifies waters of concern that may be included on the 303(d) list in the very near future. These waters have some indications that they are impaired, but there is currently insufficient data to meet the P3370ENCRREPORTSWQTR\3370.I Lots 19-223370. I SWMP 061207.doc -5- requirements for inclusion on the 303(d) list of impaired waters. This list is known as the Monitoring List (2002). The proposed project is not directly tributary to a Monitoring List (2002) water body. The closest Monitoring List (2002) water body is the Aqua Hedionda Lagoon, which is listed for copper and selenium. Watershed Pollutants of Concern The proposed project is located within the Batiquitos Hydrologic Sub-Area (904.51) of the Carlsbad Watershed, part of the San Marcos Hydrologic Area. The cities of Carlsbad, San Marcos, and Encinitas are entirely within this Hydrologic Unit (HU). The Carlsbad HU is approximately 210 square miles in area with numerous important surface hydrologic features such as the Batiquitos Lagoon. Approximately 48% of the Carlsbad Watershed is urbanized. The dominant land uses are residential (29%), commercial/industrial (6%), freeways and roads (12%), agriculture (12%), and vacant/undeveloped (32%). The population of the Carlsbad HU is approximately 500,000 residents, making it the third most densely populated in San Diego County. A high percentage of undeveloped land is privately owned and the population of the area is projected to increase to over 700,000 by 2015. Therefore, effective planning measures will be needed to prevent development from further degrading water quality in the region. According to the Carlsbad Watershed Urban Runoff Management Program, the pollutants of concern for the watershed are bacterial indicators, sedimentation/siltation (total suspended solids and turbidity), diazinon, total dissolved solids, nutrients, and trash. Taking into account the watershed pollutants of concern, the proximity of the impaired water bodies, and the potential pollutants from the proposed development, the target pollutants are sediment, nutrients, pesticides, and heavy metals. Conditions of Concern A drainage study was conducted by a California Registered Civil Engineer (RCE) to identify the conditions of concern for this project. The drainage calculations are available in Appendix 3. Following is the summary of findings from the study: P:3370ENCRORTSWQTR3370.I Lois I9-223370. I SWMP 061207.doc Drainage Patterns: Under existing conditions, most of the runoff from Lots 19 through 22 sheet flows to the southwest and into their respective desilting basins. Dirt swales along the southern and western perimeters channel the remainder of the runoff into the desilting basins. The desilting basins are equipped with nprap and an emergency spillway. The outlet structures discharge to an onsite storm drain system, which connects to the backbone storm drain system of the Bressi Ranch Development. The backbone storm drain system empties into a detention basin, located on the west side of Alicante Road, —750 feet south of Town Garden Road, in Open Space 1 (OS 1). The detention basin discharges to an unnamed creek and natural canyon in OS!, which eventually merges into San Marcos Creek. Under proposed conditions, storm water from the perimeter buildings will be discharged through downspouts to grass swales. Storm water from the buildings within the parking area will be discharged through downspouts to the parking areas. Runoff from the parking areas will enter swales or sheet flow to onsite inlets and into the onsite storm drain system. Storm water from the swales will enter the onsite storm drain system through onsite inlets. The onsite storm drain system will connect into the Bressi backbone storm drain system, which discharges to the detention basin before entering the unnamed creek and natural canyon in OS!, which eventually merges with San Marcos Creek. Soil Conditions and Imperviousness: The hydrological characteristics of the majority of the site soil type can be classified as being within soil group D, as defined in the Soil Conservation District of the U.S. Department of Agriculture. Type D soils have a very slow infiltration rate when thoroughly wetted; they are chiefly clays that have a high shrink- swell potential, or soils that have a high permanent water table, or soils that have a claypan or clay layer at or near the surface, or soils that are shallow over nearly impervious material. Under existing conditions, the project area mass graded and heavily compacted, reducing its imperviousness to approximately 45% impervious with a runoff coefficient of 0.60.2 Under the proposed conditions, the project area land use type will be Industrial, which is generally about 90% impervious and the overall runoff coefficient is expected to be 0.85.2 2 Based on Land Use Criteria Table 3-1 from the County of San Diego Hydrology Manual, June 2003 Lcs 19-223370.I SWMP 061207.doc -7- Rainfall Runoff Characteristics: Under existing conditions, the project area generates a stormwater runoff peak flow rate of approximately 12.35 cfs (2-year storm) and 17.13 cfs (10-year storm). Under the proposed conditions, the site will generate a stormwater runoff peak flow rate of approximately 26.86 cfs (2-year storm) and 35.62 cfs (10-year storm). Downstream Conditions: There is no expected adverse impact on downstream conditions, as existing drainage patterns will be maintained. The detention basin will reduce the impact of the increase in storm water flow due to the development, and the design of the outfall pipes will protect against high velocity erosion. Water quality will be maintained throughout the development due to the implementation of site design, source control, and treatment BMPs. P:3370ENGR\REPORTSWQTh3310.I Lo*s 19-223370.1 SWMP 061207.doc -8- 4. STORM WATER BEST MANAGEMENT PRACTICES The City Storm Water Standards Manual (Section ffl.2) requires the implementation of applicable site design, source control, priority project requirements, and treatment control BMPs. Site Design BMPs The project addresses the site design BMPs required by the City Storm Water Standards (ffl.2.A) as follows: Maintain Pre-Development Rainfall Runoff Characteristics Minimize impervious footprint - The sidewalks and parking lot aisles will be constructed to the minimum widths necessary, without compromising public safety, to allow for as much landscaping as possible. Conserve natural areas - There are no natural areas to conserve on this project site. - Natural open space was conserved/protected at other locations within the Bressi Ranch Master Development. Minimize directly connected impervious areas - Runoff from the perimeter buildings and impervious areas as well as the entire southeast quarter of the site will be discharged into perimeter landscaping and grass swales prior to reaching the storm drain system. Maximize canopy interception and water conservation consistent with the Carlsbad Landscape Manual - Native and drought-tolerant trees and large shrubs shall be planted instead of non-drought tolerant exotics. Protect Slopes and Channels P43370%ENGRREPORTSWQTR3370.I Lou I9-223370.I SWMP06I2O7.doc -9- -' All slopes will be stabilized with native or drought tolerant vegetation or an equivalent erosion control BMP, consistent with the Carlsbad Landscape Manual. Runoff will be conveyed safely away from the tops of slopes by grass swales. Runoff from Lots 19-22 is discharged to the Alicante Road detention basin that drains into Open Space I. The outfall from the detention basin is equipped with an energy dissipation device/riprap pad, in accordance with applicable standards and specifications to minimize erosion and protect the unnamed creek and the natural canyon into which it drains. Source Control BMPs The project addresses the source control BMPs required by the City Storm Water Standards (ffl.2.B) as follows: Design Trash Storage Areas to Reduce Pollution Introduction The trash storage area will be paved with an impervious surface, designed not to allow run-on from adjoining areas, and screened or walled to prevent off-site transport of trash. Trash receptacles will be affixed with lids to prevent direct precipitation. Provide Storm Water Conveyance System Stenciling and Signage All storm water conveyance system inlets and catch basins within the project area shall be labeled, stamped, or stenciled with prohibitive language (such as: "NO DUMPING - I LIVE DOWNSTREAM") and graphical icons to discourage illegal dumping, as approved by the City of Carlsbad and to the satisfaction of the City Engineer. Legibility of stenciling and signage will be maintained. P\3370\ENGRREPORTSWQfl3370.I Lots 19-2M370.1 SWMP 0612074cc -10- Use Efficient Irrigation Systems and Landscape Design Rain shutoff devices shall be employed to prevent irrigation during precipitation, consistent with the Carlsbad Landscape Manual. Irrigation systems shall be designed to each landscape area's specific water requirements, consistent with the Carlsbad Landscape Manual. Flow reducers and shutoff valves triggered by pressure drop will be used to control water loss from broken sprinkler heads or lines. Employ Integrated Pest Management Principles The need for pesticide use shall be reduced to the maximum extent practicable by including pest-resistant or well-adapted native plant varieties and by distributing Integrated Pest Management (IPM) education materials to future site tenants. Only professional pest controllers will be used for the application of pesticides. Materials on how to control pests using non-toxic methods will be made available to maintenance personnel. Additional Source Control BMPs Storm Water Education - Information on Public Participation and Outreach Programs operated by the City of Carlsbad and County of San Diego will be made available to tenants, as well as educational materials on storm water issues and simple ways to prevent storm water pollution. Project-Specific BMPs The City Storm Water Standards Manual requires specific BMPs if the project includes private roads, residential driveways and guest parking, dock areas, maintenance bays, vehicle and equipment wash areas, outdoor processing areas, surface parking areas, non-retail fueling areas, or steep hillside landscaping. Bressi Ranch Industrial Lots 19-22 includes surface parking areas. The City Storm Water Standards Manual lists one option for surface parking areas: "Where landscaping P3370ENGRREP0RTS\WQTR3370.I Lois 19-2Z3370.1 SWMP 0612074OC is proposed in surface parking areas (both covered and uncovered), incorporate landscape areas into the drainage design." Lots 19-22 include this option by incorporating grass swales with curb breaks around the perimeter of the parking area. In addition, by regularly sweeping the parking area, the amount of pollutants (sediment, trash, oil and grease) entering storm drains and receiving waters will be greatly reduced.3 Structural Treatment BMPs The selection of structural treatment BMP options is determined by the target pollutants, removal efficiencies, expected flows, and space availability. Table 4 is a selection matrix for structural treatment BMPs based on target pollutants and removal efficiencies. Taking into account the Watershed pollutants of concern, the proximity of the impaired water bodies, and the potential pollutants from the proposed development, the target pollutants for this project in order of general priority are sediment, nutrients, pesticides, and heavy metals. Since no treatment control BMPs provide adequate removal efficiency for pesticides, source control BMPs will provide additional pollutant removal for the pesticides in conjunction with the treatment control BMPs selected. Therefore, based on the typical removal efficiencies of the remaining target pollutants, the treatment BMP options to consider include biofilters, detention basins, infiltration basins, wet ponds, filtration, and hydrodynamic separators. Appendix 4 discusses in detail all of the treatment BMP options considered for the Project. Street Sweeping and Vacuuming, CASQA, California Stormwater BMP Handbook, Construction, January 2003 P:3370ENGR\REPORTS\WQTRu370.I Lots I9-22u370. I SWMP 061207.doc -12-. TABLE 4. STRUCTURAL TREATMENT CONTROL BMP SELECTION MATRIX Treatment Control BMP Categories Detention Infiltration Wet Drainage Hydrodynamic Pollutant of Concern Biofilters Basins Basins (1) Ponds or Inserts Filtration Separator Wetlands Systems (2) Sediment M H H H L H M Nutrients L M M M L M L Heavy Metals M M M H L H L Organic Compounds U U U U L M L Trash & Debris L H U U M H M Oxygen Demanding L M M M L M L Substances Bacteria u u H u L M L Oil& Grease M M U U L H L Pesticides I u u u u L u L Notes for Table 4: L: Low removal efficiency Including trenches and porous pavement M: Medium removal efficiency Also known as hydrodynamic devices and baffle boxes H: High removal efficiency U: Unknown removal efficiency Source: "Table 4. Structural Treatment Control BMP Selection Matrix," City of Carlsbad, Public Works Department, Standard Urban Storm Water Mitigation Plan, Storm Water Standards, A Manual for Construction & Permanent Storm Water Best Management Practices Requirements, April 2003, pg. 21 Recommended Treatment BMP(s) Biofiltration and HDS units are the selected treatment BMP options for this project. The Owner, Developer, and Project Team have decided to use grass swales and a Bio Clean Nutrient Separating Baffle Box with an oil boom or an equivalent device as the primary treatment BMPs for Lots 19-22. The following addresses the selected treatment BMPs for this project by area and pollutant source. P:\3370\ENGR\REPORTSWQTR'.3370. I Lots 19-22\3370.1 SWMP 070213.doc - 13 - Buildings Runoff from the rooftops is a source of potential pollutants from the buildings that is not adequately addressed by site design and source control BMPs. To the maximum extent practicable, runoff from the buildings will be collected by downspouts and discharged into perimeter swales at points allowing for the greatest time of concentration. Any residual runoff from the buildings will enter the onsite storm drain system and will be treated by the Bio Clean Nutrient Separating Baffle Box or an equivalent device. Surface Parking Areas Potential pollutants from airborne deposition, lack of infiltration, and the presence of vehicles are not adequately addressed by site design and source control BMPs. To mitigate these sources, grass swales will be used to collect and treat runoff; curb breaks will allow sheet flow to enter the swales, which will be located along the parking lot perimeter. Nine studies were conducted on grassy earthen channels designed for water quality between 1981 and 2002. The average removal efficiencies are listed below: BMP Type Total Suspended Solids Total Nitrogen Total Phosphorus Bacteria Nitrates (NO3) Metals Grass swales 89% 72.5% 43% -46% 42% 93-98% Using biofiltration to treat the parking lot runoff also fulfills the individual priority project category requirement for surface parking areas. The parking area will be cleaned when needed, using a dry clean method. By regularly sweeping the parking area, the amount of pollutants (sediment, trash, oil and grease) entering storm drains and receiving waters will be greatly reduced. In addition, the Baffle Box is equipped with an oil boom and a skimmer to collect hydrocarbons. Site Runoff Due to the site plan, a single hydrodynamic separator has been selected to treat 41% of the site runoff. A Bio Clean Nutrient Separating Baffle Box or an equivalent device will be used in conjunction with the grass swales as the primary treatment BMPs for the site. Grass swales will pre- treat some of the runoff entering the Baffle Box. The Bio Clean Baffle Box will treat the entire 100- year flow directed to it, including runoff from the upstream lot (Lot 23), prior to off-site discharge P:'.3370\ENGRREPORTS\WQTR3370.I Lots I9-22\3370.I WIMP 0702 I3.doc -14- not a water quality feature; it is only designed to attenuate peak flows from the development. Some of the increase in peak flow from Lots 19-22 will be mitigated through the use of the grass swales. Average removal efficiencies from three independent studies are listed below for the Bio Clean Nutrient Separating Baffle Box: BMP Type Total Suspended Solids Total Nitrogen Total Phosphorus Bio Clean Nutrient Separating Baffle Box 81.9% 29.2% 60.4% Grass swales will be the only treatment BUT for runoff from the southern half of the site. Capacity calculations and exhibits for the grass swales can be found in Appendix 3. Table summaries are included on the exhibits. BMP Plan Assumptions The following assumptions were made in calculating the required BMP sizes: Only flows generated onsite will be treated. All offsite flow treatment will be the responsibility of the upstream owners. . A runoff coefficient, 'C' value, of 0.85 was used as the average in the runoff calculations for the project area. BMP Design Constraints Locate outside public right-of-way Facilitate access for maintenance Avoid utility conflicts Table 5 summarizes the criteria that should be implemented in the design of the selected project BMPs. P:3370.ENGR\REPORTS\WQTR\3370.1 Lots 19.223370.I SWMP 070213.doc -15 - TABLE 5 BMP DESIGN CRITERIA - - .. d'BMP Hydrology .,.. BMP Optin r . BMP Capacity Project Trament Criteria Minimum Residence • Time oflOmin. C = runoff coefficient' : .. Maximum Slope of • C= 0.85 I = water quality ' Grass Swales 2.1% (averaged over 1=02 in/hour 2 treatment intensity - entire length of swale) A = acreage Treating —59% of site Side Slopes no steeper A = 4.9 acres Flow-based: Q=CLA . than 3:1 Minimum Length of = 0.83 cfs - 100 ft. C = rtmoff coefficient Peak Design Flow = C= 0.85 I = water quality Bio Clean Nutrient 30 cfs I =0 2 in/hour(2) 'treatment intensity Separating Baffle Box Treatment Design A = acreage 'Treating -P1% of site Flow = 15 cfs A= 3.4 acres Flow-based: Q=CLA Qioo = 17.2 cfs Q = 0.68 cfs --1585 linear feet of swale proposed with a minimum width of 5'= 7925 ft2 Based on San Diego Municipal Storm Water Permit (Order No. 2001-01) Section F. 1.b.(2)(c) P:3370\ENGR\REPORTS\WQTR3370.I Lots I9-22\3370.I SWMP 070213.doc -16- 5. PROJECT BMP PLAN IMPLEMENTATION This section identifies the recommended BUT options that meet the applicable storm water and water quality ordinance requirements. This includes incorporating BMPs to minimize and mitigate for runoff contamination and volume from the site. The plan was developed per the proposed roadway and lot layout/density associated with the site. Construction BMPs During construction, BMPs such as desilting basins, silt fences, sand bags, gravel bags, fiber rolls, and other erosion control measures may be employed consistent with the NPDES Storm Water Pollution Prevention Plan (SWPPP). The objectives of the SWPPP are to: Identify all pollutant sources, including sources of sediment that may affect the water quality of storm water discharges associated with construction activity from the construction site; Identify non-storm water discharges; Identify, construct, implement in accordance with a time schedule, and maintain BMPs to reduce or eliminate pollutants in storm water discharges and authorized non-storm water discharges from the construction site during construction; and Develop a maintenance schedule for BMPs installed during construction designed to reduce or eliminate pollutants after construction is completed (post-construction BMPs). Recommended Post-Construction BMIP Plan PDC has identified a water quality BMP plan for the Bressi Industrial Lots 19-22 Project. The following BMP plan is subject to change pending City review and implementation of future policy requirements. P:\3370\ENGR\REPORTSWQTR\3370. I Lots 19-22\3370.1 SWMP 0702 I3.dac -17- The post-construction BMP plan includes site design, source control, and treatment BMPs. The site design BMP options include reduction of impervious surfaces, minimization of directly connected areas, and protection of slopes and channels. The source control BMPs include inlet stenciling and signage, protected trash storage design, efficient irrigation and landscape design, storm water education, and integrated pest management principles. The treatment BMPs selected for this project are biofiltration (grass swales) and an HDS unit (Bio Clean Nutrient Separating Baffle Box with oil boom or equivalent device). TABLE 6. POST-CONSTRUCTION BMP SUMMARY Pollutant Pollutant Sources Mitigation Measures Reduction of impervious surfaces, minimization of Sediment and Landscaped areas, directly connected impervious areas, protection of slopes Nutrients rooftops, general use, Inlet stenciling and signage, protected trash storage, trash storage areas, efficient irrigation and landscape design, storm water Trash and parking/driveways education Debris Biofiltration, HDS unit Pesticides Reduction of impervious surfaces, minimization of directly connected impervious areas, protection of slopes Oxygen demanding Landscaped areas, general use Efficient irrigation and landscape design, storm water substances education, integrated pest management principles Biofiltration, HDS unit Bacteria and Viruses General use, trash Protected trash storage, storm water education storage areas Heavy metals Reduction of impervious surfaces, minimization of Oil and grease Parking/driveways directly connected impervious areas Organic Inlet stenciling and signage, storm water education compounds Biofiltration, HDS unit Operation and Maintenance Plans The City Municipal Code requires a description of the long-term maintenance requirements of proposed BMPs and a description of the mechanism that will ensure ongoing long-term maintenance. Operation and maintenance plans for the selected post-construction BMP for this project are located in Appendix 5. The Project BMP costs and the maintenance funding sources are provided in the following section. P:3370ENGRREPORTSWQTR\3370.I Lots I9-22.3370.I SWMP070213.doc -18- 6. PROJECT BMP COSTS AND FUNDING SOURCES Table 7 below provides the anticipated capital and annual maintenance costs for the selected BMPs. TABLE 7. BMP COSTS BMROPTION Or $0.75 per & of grass swale Grass swale $5,943.75 for 7,925 ft2 $350 per acre of grass swale (2) Bio Clean Nutrient Separating Baffle Box $18,750 (1) $750 NSBB 5-10-84 A proprietary BMP may vary in cost at the manufacturer's discretion; installation not included. Annual maintenance costs are incorporated into the annual landscaping maintenance costs. The Developer will incur the capital cost for the BMP installation. At this time, the responsible• party for long-term maintenance and funding for Bressi Industrial Lots 19-22 is Urban + West + Strategies, 936 E. Santa Ana Boulevard, Santa Ana, CA, 92701. The contact person is Kimberly Hutchings, Vice President Development, (714) 567-9260, ext.202. A Business Owners' Association (BOA) will take responsibility for long-term maintenance and funding as soon as one is established. P:\3370\ENGR\REPORTS\WQTR\3370.1 Lots 19-22\3370.1 SWMP 0702 I3.doc -19- APPENDIX 1 Storm Water Requirements Applicability Checklist APPENDIX A STORM WATER REQUIREMENTS APPLICABILITY CHECKLIST Complete Sections 1 and 2 of the following checklist to determine your project's permanent and construction storm water best management practices requirements. This form must be completed and submitted with your permit application. Section 1. Permanent Storm Water BMP Requirements: If any answers to Part A are answered "Yes," your project is subject to the "Priority Project Permanent Storm Water BMP Requirements" and "Standard Permanent Storm Water BMP Requirements" in Section III, "Permanent Storm Water Selection Procedure" in the Storm Water Standards manual. If all answers to Part A are "No," and any answers to Part B are "Yes," your project is only subject to the "Standard Permanent Storm Water BMP Requirements." If every question in Part A and B is answered "No," your project is exempt from permanent storm water requirements. Part A: Determine Priority Project Permanent Storm Water BMP Requirements. Does the project meet the definition of one or more of the priority project categories? * Yes No Detached residential development of 10 or more units Attached residential development of 10 or more units - I Commercial development greater than 100,000 square feet Automotive repair shop Restaurant I Steep hillside development greater than 5,000 square feet / Project discharging to receiving waters within Environmentally Sensitive Areas I Parking lot greater than or equal to 5,000 fe or with at least 15 parking spaces, and potentially exposed to urban runoff - Streets, roads, highways, and freeways that would create a new paved surface that is 5,000 square feet or greater 1 - * Refer to the definitions section in the Storm Water Standards for expanded definitions of the priority project categories. Limited Exclusion: Trenching and resurfacing work associated with utility projects are not considered priority projects. Parking lots, buildings and other structures associated with utility projects are priority projects if one or more of the criteria in Part A is met. If all answers to Part A are "No", continue to Part B. Part B: Determine Standard Permanent Storm Water Requirements. Does the project propose: Yes No New impervious areas, such as rooftops, roads, parking lots, driveways, paths and sidewalks? New pervious landscape areas and irrigation systems? Permanent structures within 100 feet of any natural water body? Trash storage areas? I - Liquid or solid material loading and unloading areas? I Vehicle or equipment fueling, washing, or maintenance areas? I Require a General NPDES Permit for Storm Water Discharges Associated with Industrial Activities (Except construction)? * - Commercial or industrial waste handling or storage, excluding typical office or household waste? / Any grading or ground disturbance during construction? I Any new storm drains, or alteration to existing storm drains? I - *To find out if your project is required to obtain an individual General NPDES Permit for Storm Water Discharges Associated with Industrial Activities, visit the State Water Resources Control Board web site at, http://www.swrcb.ca.gov/stormwtr/industrial.html Section 2. Construction Storm Water BMP Requirements: If the answer to question 1 of Part C is answered "Yes," your project is subject to Section IV, "Construction Storm Water BMP Performance Standards," and must prepare a Storm Water Pollution Prevention Plan (SWPPP). If the answer to question 1 is "No," but the answer to any of the remaining questions is "Yes," your project is subject to Section IV, "Construction Storm Water BMP Performance Standards," and must prepare a Water Pollution Control Plan (WPCP). If every question in Part C is answered "No," your project is exempt from any construction storm water BMP requirements. If any of the answers to the questions in Part C are "Yes" complete the construction site prioritization in Part 0, below. Part C: Determine Construction Phase Storm Water Requirements. Would the project meet any of these criteria during construction? Yes No Is the project subject to California's statewide General NPDES Permit for Storm Water Discharges Associated With Construction Activities? Does the project propose grading or soil disturbance? Would storm water or urban runoff have the potential to contact any portion of the construction area, including washing and staging areas? Would the project use any construction materials that could negatively affect water quality if discharged from the site (such as, paints, solvents, concrete, and stucco)? / Part D: Determine Construction Site Priority In accordance with the Municipal Permit, each construction site with construction storm water BMP requirements must be designated with a priority: high, medium, or low. This prioritization must be completed with this form, noted on the plans, and included in the SWPPP or WPCP. Indicate the project's priority in one of the check boxes using the criteria below, existing and surrounding conditions of the project, the type of activities necessary to complete the construction, and any other extenuating circumstances that may pose a threat to water quality. The City reserves the right to adjust the priority of the projects both before and during construction. [Note: The construction priority does NOT change construction BMP requirements that apply to projects; all construction BMP requirements must be identified on a case-by-case basis. The construction priority does affect the frequency of inspections that will be conducted by the City staff. See Section IV.1 for more details on construction BMP requirements.] v' A) High Priority Projects where the site is 50 acres or more and grading will occur during the rainy season. Projects 5 acres or more. Projects 5 acres or more within or directly adjacent to or discharging directly to a coastal lagoon or other receiving water within an environmentally sensitive area. Projects, active or inactive, adjacent or tributary to sensitive water bodies. B) Medium Priority Capital Improvement Projects where grading occurs, however a Storm Water Pollution Prevention Plan (SWPPP) is not required under the State General Construction Permit (i.e., water and sewer replacement projects, intersection and street re-alignments, widening, comfort stations, etc.) Permit projects in the public right-of-way where grading occurs, such as installation of sidewalk, substantial retaining walls, curb and gutter for an entire street frontage, etc., however SWPPPs are not required. Permit projects on private property where grading permits are required, however, Notice Of Intents (NOls) and SWPPPs are not required. C) Low Priority Capital projects where minimal to no grading occurs, such as signal light and loop installations, street light installations, etc. Permit projects in the public right-of-way where minimal to no grading occurs, such as pedestrian ramps, driveway additions, small retaining walls, etc. Permit projects on private property where grading permits are not required, such as small retaining walls, single- family homes, small tenant improvements, etc. APPENDIX 2 Project Maps PACIFIC OCEAN CARLSBAD BL V Ir D. LQ \z Unnamed tributar CT) ~ fl 0 (I) z —EMBcNCY8PLLWAy SCALE 1"=40' PREPARED BY CDS CITY OF CARLSBAD DRAINAGE SWALES 8RESSI INDUSTRIAL LOTS 19-00 El- ONSITE STORM DRAIN SYSTEM JOB # 337010 PROJECT DESIGN CONSULTANTS SITE MAP roe Planning I Landscape Architecture I Enviro nental I Engineering I Survey CONSTRUCTION DRIVEWAY 701 B Street Suite 800 San Diego CA 92101 EXISTING CONDITIONS P \337O\ENGR\REPoRS\wTI?\337o 1 Lots 19-22\Existing dwg 6/2/2005 1032 FENTRANCE/EXrr CREATED 6/2/06 619 235 6471 Tel 619 234 0349 Fax EXHIBIT A ri LII. APPENDIX 3 Drainage Calculations Bressi Industrial Lots 19-22 WQTR Drainage Sheet flow and the rational method were used to determine the conservative, preliminary site runoff flow rates. The precipitation (P) was taken from the County Rainfall Isopluvials, included in Appendix 3. The duration (D)/time of concentration (Ta) calculation was taken from the Rational Formula - Overland Time of Flow Nomograph in the County Hydrology Manual (Fig.3-3). The intensity (I) calculation was taken from the Intensity - Duration - Design Chart, Fig.3-1 in the County Hydrology Manual. 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UIU UN 111111111111111111ang, aganNbUUUUUR UIIIIII ....UU.UUNUUiUlllUlllulll.UUUuIuIUNhlllIlullllluluIll ••UUUUUI'hIUIUllIlI --- U UU UU ••uUhNihl liii IIIIIUU UUU I liii IUI Ill 11111111111 •MUU •• UUU UI'II Ullill •••MU•UUuuu•uUUIuuIifluuulIiiIuiUuiiUIuIIHuIIuIIIIuuuIuI MUU•UUUUIUIIIIUIIIII . .u..• u.uiI oil i Ili Ili 11111 on UUI *1111 gill Ili uu,1u111111 -- u.• uu uuui 111111 I.'uII ......u.i.uu.u.i,uuuiii,i,u..Ii.IuIuIuuIuuIuuIumI m will u..uu•uIUuuuuIIIUIII' ..u...auu.uuuuUuIIIIIIIHhIuIUUIIIUIIUuuIIIIIIIUhuIuuI.UM•uuuUUuIUlihuuPuIPI .............u.,iu,iiuuiuinuuuiiiiiiiu,iiuiuhuiuuimiiui.... noun uuluuulullulliuuul •••••u••iuuuIu•uIuuuulluuuIuuulugIu.uuIuIuIuIuuIuhIIuI•u••IuuuIuuIIuuIIuuuuuuI R..•mu.u...uu.,i,lumuIumu.uunnuIuuIuuuIuIIuI..I•IUIUuuuIuuIHhuuuIII momommono mom milli 1111111111111111111111111111111111 W 111111111111111 low ME NOON 111111111111111 Will UUUUR•UlIuuIuuuuIIIuuuIIIIIIIIHHIuIuIulIlIIIIUlIIIIIIIIIIlIUUNIuIuuuuuuuuuuuItuIIIIII •••u•uIIIIuI milli uIIIIuuuIIIIIIUhIIIuuIIuuIIlIIIIIIIIIIIIIIIIII INNUIIuuuIuuIIIIIu1IuIlIlII RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (C) Copyright 1982-2005 Advanced Engineering Software (ace) Ver. 2.0 Release Date: 06/01/2005 License ID 1509 Analysis prepared by: Project Design Consultants 701 B Street Suite 800 San Diego, Ca. 92101 ********************** DESCRIPTION OF STUDY ********************** * 3370 - BRESSI INDUSTRIAL LOTS 19-22 * * ULTIMATE CONDITIONS - LINE 100, TO BAFFLE BOX * * 2 YEAR STORM EVENT * ************************************************************************** FILE NAME: 5100Y2.DAT TIME/DATE OF STUDY: 13:55 12/12/2006 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 1985 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) 2.00 6-HOUR DURATION PRECIPITATION (INCHES) = 1.340 SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.85 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: ONLY PEAK CONFLUENCE VALUES CONSIDERED *USER..DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (PT) (FT) SIDE / SIDE/ WAY (FT) (Fr) (PT) (Fr) (n) 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS: Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* **************************************************************************** FLOW PROCESS FROM NODE 100.00 TO NODE 105.00 IS CODE 21. ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<< COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA PLOW-LENGTH(FEET) = 265.00 UPSTREAM ELEVATION(FEET) = 369.60 DOWNSTREAM ELEVATION(FEET) = 366.80 ELEVATION DIFFERENCE(FEET) = 2.80 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 7.192 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.793 SUBAREA RUNOFF(CFS) = 0.52 TOTAL AREA(ACRES) = 0.22 TOTAL RUNOFF(CFS) = 0.52 FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<ccc 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.793 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA(ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.55 TOTAL AREA(ACRES) = 0.45 TOTAL RUNOFF(CFS) = 1.07 TC(MIN.) = 7.19 FLOW PROCESS FROM NODE 105.00 TO NODE 110.00 Is CODE = 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOWc<.c<< >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) .c<<c< ELEVATION DATA: UPSTREAM(FEET) = 366.80 DOWNSTREAM(FEET) = 366.10 CHANNEL LENGTH THRU SUBAREA(FEET) = 135.00 CHANNEL SLOPE = 0.0052 CHANNEL BASE(FEET) = 5.00 'Z FACTOR = 99.000 MANNINGS FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 2 YEAR RAINFALL INTENSITY(INCH/HOUR) 2.356 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.40 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.04 AVERAGE FLOW DEPTH(FEET) = 0.09 TRAVEL TIME(MIN.) = 2.17 Tc(MIN.) 9.36 SUBAREA AREA (ACRES) = 0.30 SUBAREA RUNOFF (CFS) = 0.67 TOTAL AREA(ACRES) = 0.75 PEAR FLOW RATE(CFS) = 1.74 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) 1.13 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 400.00 FEET. PLOW PROCESS FROM NODE 110.00 TO NODE 120.00 IS CODE = 41 >>>>>COMPUTE PIPE-PLOW TRAVEL TIME THRU SUBAREAc<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<ccc ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 358.20 FLOW LENGTH(FEET) = 90.00 MANNINGS N = 0.013. DEPTH OF FLOW IN 18.0 INCH PIPE IS 4.3 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.31 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 1.74 PIPE TRAVEL TIME(MIN.) = 0.28 Tc(MIN.) = 9.64 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 490.00 FEET. PLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = >>>>>DESIGNATE INDEPENDENT STREAM FOR CONPLUENCEccccc TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 9.64 RAINFALL INTENSITY(INCH/HR) = 2.31 TOTAL STREAM AREA(ACRES) 0.75 PEAR FLOW RATE(CFS) AT CONFLUENCE = 1.74 * ****** * ***** ***** * ****** ******** ***************** ********* ********* * **** FLOW PROCESS FROM NODE 200.00 TO NODE 205.00 IS CODE 21 >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIScccc< INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT • .9500 SOIL CLASSIFICATION IS D' S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 110.00 UPSTREAM ELEVATION(FEET) = 366.35 DOWNSTREAM ELEVATION(FEET) = 363.50 ELEVATION DIFFERENCE(FEET) = 2.85 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 2.062 *CAUTION: SUBAREA SLOPE EXCEEDS COUNTY NOMOGRAPH DEFINITION. EXTRAPOLATION OF NOMOGRAPH USED. TIME OF CONCENTRATION ASSUMED AS 6-MIN. 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.139 SUBAREA RUNOFF(CFS) = 0.54 TOTAL AREA (ACRES) = 0.18 TOTAL RUNOFF (CFS) = 0.54 FLOW PROCESS FROM NODE 205.00 TO NODE 120.00 IS CODE = 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOWccccc >>>,TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 363.50 DOWNSTREAM(FEET) = 362.20 CHANNEL LENGTH THRU SUBAREA(FEET) = 180.00 CHANNEL SLOPE = 0.0072 CHANNEL BASE(FEET) = 5.00 MZ" FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 2 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.520 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.51 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.23 AVERAGE FLOW DEPTH(FEET) = 0.09 TRAVEL TIME(MIN.) = 2.43 Tc(MIN.) = 8.43 SUBAREA AREA(ACRES) = 0.81 SUBAREA RUNOFF(CFS) = 1.94 TOTAL AREA(ACRES) = 0.99 PEAK FLOW RATE(CFS) = 2.48 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.11 FLOW VELOCITY(FEET/SEC.) = 1.38 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 120.00 = 290.00 FEET. FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< >>>>>AND COMPUTE VARIOUS CONFLUENCE!) STREAM VALUES<cc<c TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 8.43 (J RAINFALL INTENSITY(INCH/HR) =. 2.52 TOTAL STREAM AREA (ACRES) = 0.99 PEAK PLOW RATE (CFS) AT CONFLUENCE = 2.48 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CPS) (MIN.) (INCH/HOUR) (ACRE) 1 1.74 9.64 2.311 0.75 2 2.48 8.43 2.520 0.99 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CPS) (MIN.) (INCH/HOUR) 1 4.07 8.43 2.520 2 4.01 9.64 2.311 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CPS) = 4.07 Tc(MIN.) = 8.43 TOTAL AREA(ACRES) 1.74 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 490.00 FEET. FLOW PROCESS FROM NODE 120.00 TO NODE 130.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<c< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 358.00 DOWNSTREAM(FEET) = 354.50 FLOW LENGTH(FEET) 94.00 MANNING'S N 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 8.46 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 4.07 PIPE TRAVEL TIME(MIN.) = 0.19 Tc(MIN.) = 8.62 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 130.00 = 584.00 FEET. FLOW PROCESS FROM NODE 130.00 TO NODE 130.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOWccccc 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.485 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA(ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.54 TOTAL AREA(ACRES) = 1.97 TOTAL RUNOFF(CFS) 4.61 TC(MIN.) = 8.62 FLOW PROCESS FROM NODE 130.00 TO NODE 140.00 Is CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<c<cc >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)c<.c<< ELEVATION DATA: UPSTREAM(FEET) 354.30 DOWNSTREAM(FEET) 352.57 PLOW LENGTH(FEET) = 65.03 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.76 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.61 PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 8.76 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 140.00 = 649.03 FEET. FLOW PROCESS FROM NODE 140.00 TO NODE 145.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<c<< ELEVATION DATA: UPSTREAM(FEET) = 352.18 DOWNSTREAM(FEET) = 351.24 FLOW LENGTH(FEET) = 54.64 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 7.5 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 6.61 GIVEN PIPE DIAMETER(INCH) 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 4.61 PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 8.89 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 145.00 = 703.67 FEET. FLOW PROCESS FROM NODE 145.00 TO NODE 150.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<cc<c >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) 351.24 DOWNSTREAM(FEET) = 349.80 FLOW LENGTH(FEET) = 83.70 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 7.5 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 6.61 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES 1 PIPE-FLOW(CFS) = 4.61 PIPE TRAVEL TIME(MIN.) = 0.21 Tc(MIN.) = 9.10 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 787.37 FEET. FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE.c<<<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 9.10 RAINFALL INTENSITY(INCH/HR) = 2.40 TOTAL STREAM AREA(ACRES) = 1.97 PEAK FLOW RATE (CFS) AT CONFLUENCE = 4.61 FLOW PROCESS FROM NODE 300.00 TO NODE 305.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<cc<< INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 165.00 UPSTREAM ELEVATION(FEET) = 362.55 DOWNSTREAM ELEVATION(FEET) = 361.70 ELEVATION DIFFERENCE(FEET) = 0.85 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.326 TIME OF CONCENTRATION ASSUMED AS 6-MIN. 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.139 SUBAREA RUNOFF(CFS) = 0.66 TOTAL AREA(ACRES) = 0.22 TOTAL RUNOFF(CFS) = 0.66 * ******** *** * ***** ******* *** ********* ********* * *** * ************* * FLOW PROCESS FROM NODE 305.00 TO NODE 310.00 IS CODE = 51 >,>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW.c<<<c >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <<ccc ELEVATION DATA: UPSTREAM(FEET) = 361.70 DOWNSTREAM(FEET) = 359.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 160.00 CHANNEL SLOPE = 0.0169 CHANNEL BASE(FEET) = 5.00 "ZN FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.724 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.21 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.81 AVERAGE FLOW DEPTH(FEET) 0.09 TRAVEL TIME(MIN.) = 1.48 Tc(MIN.) = 7.48 SUBAREA AREA(ACRES) = 1.20 SUBAREA RUNOFF(CFS) = 3.11 TOTAL AREA(ACRES) = 1.42 PEAK FLOW RATE(CFS) = 3.76 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.11 FLOW VELOCITY(FEET/SEC.) = 2.10 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 310.00 = 325.00 FEET. * ********************* *** ***** ******* **** *** *** ************* *** * * ****** *** ** FLOW PROCESS FROM NODE 310.00 TO NODE 150.00 IS CODE = 41 >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAc<cc< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<cc<< ELEVATION DATA: UPSTREAM(FEET) = 353.50 DOWNSTREAM(FEET) = 349.80 FLOW LENGTH(FEET) = 148.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.1 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.17 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 3.76 PIPE TRAVEL TXME(MIN.) = 0.34 Tc(MIN.) = 7.82 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 150.00 = 473.00 FEET. ** *** ********* ************* ***** *** ** ** **** ******** ************ * **** * FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<cc<c >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUEScccc< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.82 RAINFALL INTENSITY (INCH/HR) = 2.65 TOTAL STREAM AREA(ACRES) = 1.42 PEAK FLOW RATE(CFS) AT CONFLUENCE = 3.76 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 4.61 9.10 2.399 1.97 2 3.76 7.82 2.646 1.42 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 7.94 7.82 2.646 2 8.02 9.10 2.399 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 8.02 Tc(MIN.) = 9.10 TOTAL AREA(ACRES) = 3.39 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 787.37 FEET. FLOW PROCESS FROM NODE 150.00 TO NODE 160.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<ccc< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<.c ELEVATION DATA: UPSTREAM(FEET) = 349.60 DOWNSTREAM(FEET)*= 347.67 FLOW LENGTH(FEET) = 107.36 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0-INCH PIPE IS 10.2 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.74 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-F'LOW(CFS) = 8.02 PIPE TRAVEL TIME(MIN.) = 0.23 Tc(MIN.) = 9.34 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 160.00 = 894.73 FEET. FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<c<<c TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 9.34 RAINFALL INTENSITY (INCH/HR) = 2.36 TOTAL STREAM AREA(ACRES) = 3.39 PEAK FLOW RATE(CPS) AT CONFLUENCE = 8.02 FLOW PROCESS FROM NODE 400.00 TO NODE 405.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODEccc<< USER-SPECIFIED VALUES ARE AS FOLLOWS: TC(MIN) = 9.50 RAIN INTENSITY(INCH/HOUR) = 2.33 TOTAL AREA (ACRES) 4.33 TOTAL RUNOFF(CFS) = 10.00 FLOW PROCESS FROM NODE 405.00 TO NODE 410.00 IS CODE = 41 >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<c<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 349.25 DOWNSTREAM(FEET) 349.01 FLOW LENGTH(FEET) = 40.10 MANNING'S N = 0.013 DEPTH OF FLOW IN 24.0 INCH PIPE IS 13.7 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.41 GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CPS) 10.00 PIPE TRAVEL TIME(MIN.) = 0.12 Tc(MIN.) = 9.62 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 410.00 = 513.10 FEET. FLOW PROCESS FROM NODE 410.00 TO NODE 410.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.314 GRASS GOOD COVER RUNOFF COEFFICIENT = .4500 SOIL CLASSIFICATION IS AD" S.C.S. CURVE NUMBER (AMC II) = 80 SUBAREA AREA(ACRES) 0.20 SUBAREA RUNOFF(CFS) = 0.21 TOTAL AREA(ACRES) = 4.53 TOTAL RUNOFF(CFS) = 10.21 TC(MIN.) = 9.62 FLOW PROCESS FROM NODE 410.00 TO NODE 160.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME T}IRU SUBAREA<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) = 348.51 DOWNSTREAM(FEET) = 347.00 FLOW LENGTH(FEET) = 251.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 24.0 INCH PIPE IS 13.8 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.45 GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 10.21 PIPE TRAVEL TIME(MIN.) = 0.77 Tc(MIN.) = 10.39 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 160.00 764.10 FEET. FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<.c<c< 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.203 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA (ACRES) = 0.28 SUBAREA RUNOFF(CFS) = 0.52 TOTAL AREA(ACRES) 4.81 TOTAL RUNOFF(CFS) = 10.73 TC(MIN.) = 10.39 FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 Is CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<c<< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<c< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 10.39 RAINFALL INTENSITY(INCH/HR) = 2.20 TOTAL STREAM AREA(ACRES) = 4.81 PEAK FLOW RATE (CFS) AT CONFLUENCE = 10.73 ** CONFLUENCE DATA.. STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 8.02 9.34 2.360 3.39 2 10.73 10.39 2.203 4.81 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. * * PEAK FLOW RATE TABLE * * STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 18.04 9.34 2.360 2 18.22 10.39 2.203 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 18.22 Tc(MIN.) = 10.39 TOTAL AREA(ACRES) = 8.20 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 160.00= 894.73 FEET. FLOW PROCESS FROM NODE 160.00 TO NODE 162.00 Is CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 346.67 DOWNSTREAM(FEET) = 345.49 FLOW LENGTH(FEET) = 177.05 MANNINGS N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 5.80 PIPE FLOW VELOCITY = (TOTAL FLOW) / (PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 18.22 PIPE TRAVEL TIME(MIN.) = 0.51 Tc(MIN.) = 10.90 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 162.00 = 1071.78 FEET. FLOW PROCESS FROM NODE 162.00 TO NODE 165.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAc<.ccc >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<c<< ELEVATION DATA: UPSTREAM(FEET) = 345.49 DOWNSTREAM(FEET) = 345.11 FLOW LENGTH(FEET) 56.32 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 5.80 PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 18.22 PIPE TRAVEL TIME(MIN.) = 0.16 Tc(MIN..) = 11.06 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 165.00 = 1128.10 FEET. **************************************************************************** FLOW PROCESS FROM NODE 165.00 TO NODE 165.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< 2 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.115 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS D' S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA(ACRES) = 0.35 SUBAREA RUNOFF(CFS) 0.63 TOTAL AREA(ACRES) = 8.55 TOTAL RUNOFF(CFS) = 18.85 TC(MIN.) = 11.06 * ******** * * ******* ***************** *********** * *** *** * ************ ****** *** * FLOW PROCESS FROM NODE 165.00 TO NODE 165.00 Is CODE 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEcc<.cc TOTAL NUMBER OF STREAMS 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 11.06 RAINFALL INTENSITY(INCH/HR) = 2.12 TOTAL STREAM AREA(ACRES) =i 8.55 PEAK FLOW RATE(CFS) AT CONFLUENCE 18.85 **************************************************************************** FLOW PROCESS FROM NODE 700.00 TO NODE 705.00 IS CODE = 21 ---------------------------------------------------------------------------- >,>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<cccc INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT -..9500 SOIL CLASSIFICATION IS DH S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 200.00 UPSTREAM ELEVATION(FEET) = 362.30 DOWNSTREAM ELEVATION(FEET) = 360.00 ELEVATION DIFFERENCE(FEET) = 2.30 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.645 TIME OF CONCENTRATION ASSUMED AS 6-MIN. 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.139 SUBAREA RUNOFF(CPS) = 1.16 TOTAL AREA(ACRES) = 0.39 TOTAL RUNOFF(CFS) = 1.16 FLOW PROCESS FROM NODE 705.00 TO NODE 710.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOWcc<c< >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)-c<<<< ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 357.62 CHANNEL LENGTH THRU SUBAREA(FEET) = 140.00 CHANNEL SLOPE = 0.0170 CHANNEL BASE(FEET) = 5.00 FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.794 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.41 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.97 AVERAGE FLOW DEPTH(FEET) = 0.09 TRAVEL TIME(MIN.) = 1.19 Tc(MIN.) = 7.19 SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 2.50 TOTAL AREA(ACRES) = 1.33 PEAK FLOW RATE(CFS) = 3.66 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.11 FLOW VELOCITY(PEET/SEC.) 2.10 LONGEST FLOWPATH FROM NODE 700.00 TO NODE 710.00 = 340.00 FEET. * * * * * * * * * * * * * * * * * * * * * ** * * * * * * * ** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * FLOW PROCESS FROM NODE 710.00 TO NODE . 165.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAc<<c< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) = 347.62 DOWNSTREAM(FEET) 345.31 FLOW LENGTH(FEET) = 104.00 MANNING'S N = 0.013 DEPTH OF PLOW IN 18.0 INCH PIPE IS 6.2 INCHES PIPE-FLOW VELOCXTY(FEET/SEC.) = 6.82 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 3.66 PIPE TRAVEL TIME(MIN.) = 0.25 Tc(MIN.) = 7.44 LONGEST FLOWPATH FROM NODE 700.00 TO NODE 165.00 = 444.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 165.00 TO NODE 165.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<C<.C.0 >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<c< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.44 RAINFALL INTENSITY (INcH/HR) = 2.73 TOTAL STREAM AREA(ACRES) = 1.33 PEAK FLOW RATE(CFS) AT CONFLUENCE = 3.66 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 18.85 11.06 2.115 8.55 2 3.66 7.44 2.732 1.33 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. * * PEAK PLOW RATE TABLE * * STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 18.25 7.44 2.732 2 21.68 11.06 2.115 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 21.68 Tc(MIN.) = 11.06 TOTAL AREA(ACRES) = 9.88 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 165.00 = 1128.10 FEET. **************************************************************************** FLOW PROCESS FROM NODE 165.00 TO NODE 170.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAc<<cc >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<c ELEVATION DATA: UPSTREAM(FEET) = 344.91 DOWNSTREAM(FEET) = 344.88 FLOW LENGTH(FEET) = 5.00 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(PEET/SEC.) = 6.90 PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES PIPE-FLOW(CFS) = 21.68 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 11.07 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 170.00 = 1133.10 FEET. END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 9.88 TC(MIN.) = 11.07 PEAK FLOW RATE(CFS) = 21.68 END OF RATIONAL METHOD ANALYSIS RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SPIN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (c) Copyright 1982-2005 Advanced Engineering Software (aes) Ver. 2.0 Release Date: 06/01/2005 License ID 1509 Analysis prepared by: Project Design Consultants 701 B Street Suite 800 San Diego, Ca. 92101 ********t***************** DESCRIPTION OF STUDY ********************** * 3370 - BRESSI INDUSTRIAL LOTS 19-22 * ULTIMATE CONDITIONS - LINE 500, AFTER BAFFLE BOX * * 2 YEAR STORM EVENT * * ********** * ** *************************** *************** **** ** ******* * FILE NAME: S500Y2.DAT TIME/DATE OF STUDY: 13:57 12/12/2006 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 1985 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 2.00 6-HOUR DURATION PRECIPITATION (INCHES) = 1.340 SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.85 SAM DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: ONLY PEAK CONFLUENCE VALUES CONSIDERED *USERDEFID STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (FT) (Fr) SIDE / SIDE/ WAY (FT) (FT) (IT) (Fr) (n) 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS: Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) (Depth)*(Velocity) Constraint = 6.0 (PTFT/S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* FLOW PROCESS FROM NODE 100.00 TO NODE 175.00 IS CODE 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODEc<<<< USER-SPECIFIED VALUES ARE AS FOLLOWS: TC(MIN) = 11.07 RAIN INTENSITY(INCH/HOUR) = 2.11 TOTAL AREA(ACRES) = 9.88 TOTAL RUNOFF(CFS) = 21.68 FLOW PROCESS FROM NODE 175.00 TO NODE 180.00 IS CODE 41 ----------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAc<.c<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) 344.48 DOWNSTREAM(FEET) 344.43 FLOW LENGTH(FEET) = 7.00 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) 6.90 PIPE FLOW VELOCITY = (TOTAL FLOW) / (PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 21.68 PIPE TRAVEL TXME(MIN.) 0.02 Tc(MIN.) = 11.09 LONGEST FLOWPATH FROM NODE 0.00 TO NODE 180.00 = 7.00 FEET. FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = 10 ---------------------------------------------------------------------------- >>>>MAIN-STREAM MEMORY COPIED ONTO MEMORY BANK U 1 <<<<< FLOW PROCESS FROM NODE 500.00 TO NODE 505.00 Is CODE = 21 ---------------------------------------------------------------------------- >>>>>RATXONAL METHOD INITIAL SUBAREA ANALYSIS<cccc COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = 8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 155.00 UPSTREAM ELEVATION(FEET) = 366.80 DOWNSTREAM ELEVATION(FEET) = 365.90 ELEVATION DIFFERENCE(FEET) = 0.90 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.715 2 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.919 SUBAREA RUNOFF(CFS) = 0.72 TOTAL AREA(ACRES) = 0.29 TOTAL RUNOFF(CFS) = 0.72 FLOW PROCESS FROM NODE 505.00 TO NODE 510.00 Is CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW.c<<<c >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<.cc<< ELEVATION DATA: UPSTREAM(FEET) = 365.90 DOWNSTREAM(FEET) = 359.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 450.00 CHANNEL SLOPE = 0.0147 CHANNEL BASE(FEET) = 12.00 "Z" FACTOR = 2.000 MANNING'S FACTOR = 0.022 MAXIMUM DEPTH(FEET) = 2.00 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.003 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS D' S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL. TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.12 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.41 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 5.33 Tc(MIN.) = 12.04 SUBAREA AREA(ACRES) = 0.47 SUBAREA RUNOFF(CFS) - 0.80 TOTAL AREA (ACRES) 0.76 PEAK FLOW RATE (CFS) = 1.52 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.08 FLOW VELOCITY(FEET/SEC.) = 1.54 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 510.00 = 605.00 FEET. FLOW PROCESS FROM NODE 510.00 TO NODE 510.00 IS CODE ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEcccc< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 12.04 RAINFALL INTENSITY (INCH/ER) = 2.00 TOTAL STREAM AREA(ACRES) = 0.76 PEAK FLOW RATE (CFS) AT CONFLUENCE = 1.52 FLOW PROCESS FROM NODE 600.00 TO NODE 605.00 IS CODE = 21 -------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<c<c INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS 'D' S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 145.00 UPSTREAM ELEVATION(FEET) = 366.80 DOWNSTREAM ELEVATION(FEET) = 362.80 ELEVATION DIFFERENCE(FEET) = 4.00 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 2.318 *CAUTION: SUBAREA SLOPE EXCEEDS COUNTY NOMOGRAPH DEFINITION. EXTRAPOLATION OF NOMOGRAPH USED. TIME OF CONCENTRATION ASSUMED AS 6-MIN. 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.139 SUBAREA RUNOFF(CFS) = 0.98 TOTAL AREA(ACRES) = 0.33 TOTAL RUNOFF(CFS) = 0.98 FLOW PROCESS FROM NODE 605.00 TO NODE 510.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>COMPUTE TRAPEZOIDAL CHANNEL FLOWc<<cc >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<c<c ELEVATION DATA: UPSTREAM(FEET) = 362.80 DOWNSTREAM(FEET) = 359.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 195.00 CHANNEL SLOPE = 0.0179 CHANNEL BASE(FEET) = 5.00 "Z FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 2 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.690 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW (CFS) = 2.72 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.00 AVERAGE FLOW DEPTH(FEET) = 0.09 TRAVEL TIME(MIN.) = 1.62 Tc(MIN.) = 7.62 SUBAREA AREA(ACRES) = 1.36 SUBAREA RUNOFF(CFS) = 3.48 TOTAL AREA(ACRES) = 1.69 PEAK FLOW RATE(CFS) = 4.46 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.12 FLOW VELOCITY(FEET/SEC.) = 2.23 LONGEST FLOWPATH FROM NODE 600.00 TO NODE 510.00 = 340.00 FEET. FLOW PROCESS FROM NODE 510.00 TO NODE 510.00 IS CODE = ---------------------------------------------------------------------------- ,>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEc<c.c< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUEScc<<c TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.62 RAINFALL INTENSITY(INCH/HR) = 2.69 TOTAL STREAM AREA(ACRES) 1.69 PEAK FLOW RATE(CFS) AT CONFLUENCE = 4.46 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CPS) (MIN.) (INCH/HOUR) (ACRE) 1 1.52 12.04 2.003 0.76 2 4.46 7.62 2.690 1.69 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CPS) (MIN.) (INCH/HOUR) 1 5.59 7.62 2.690 2 4.84 12.04 2.003 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 5.59 Tc(MIN.) = 7.62 TOTAL AREA(ACRES) = 2.45 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 510.00 = 605.00 FEET. * ******* ****** ********* ** * ** *********** ** * ********* ****** ********* ***** *** ** FLOW PROCESS FROM NODE 510.00 TO NODE 180.00 IS CODE 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<.c<cc >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) c<<<< ELEVATION DATA: UPSTREAM(FEET) = 359.30 DOI4NSTREAZI(FEET) = 354.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 300.00 CHANNEL SLOPE = 0.0177 CHANNEL BASE(FEET) = 12.00 "Z" FACTOR = 2.000 MANNING'S FACTOR = 0.022 MAXIMUM DEPTH(FEET) 2.00 2 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.337 GRASS GOOD COVER RUNOFF COEFFICIENT = .4500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 80 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CPS) = 5.66 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.69 AVERAGE FLOW DEPTH(FEET) = 0.17 TRAVEL TIME(MIN.) = 1.86 Tc(MIN.) = 9.48 SUBAREA AREA (ACRES) = 0.13 SUBAREA RUNOFF (CFS) = 0.14 TOTAL AREA(ACRES) = 2.58 PEAK FLOW RATE(CPS) = 5.73 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.17 FLOW VELOCITY(FEET/SEC.) = 2.72 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 180.00 = 905.00 FEET. c. FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = if ---------------------------------------------------------------------------- >>>>>CONFLUENCE MEMORY SANK * 1 WITH THE MAIN-STREAM MEMORY<<<cc ** MAIN STREAM CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CPS) (MIN.) (INCH/HOUR) (ACRE) 1 5.73 9.48 2.337 •2.58 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 180.00 = 905.00 FEET. ** MEMORY BANK * 1 CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 21.68 11.09 2.112 9.88 LONGEST FLOWPATH FROM NODE 0.00 TO NODE 180.00 7.00 FEET. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CPS) (MIN.) (INCH/HOUR) 1 25.33 9.48 2.337 2 26.86 11.09 2.112 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 26.86 Tc(MIN.) = 11.09 TOTAL AREA(ACRES) = 12.46 END OF STUDY SUMMARY: - - - TOTAL AREA(ACRES) = 12.46 TC(MIN.) = 11.09 PEAK FLOW RATE(CFS) = 26.86 END OF RATIONAL METHOD ANALYSIS RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (c) Copyright 1982-2005 Advanced Engineering Software (ace) Ver. 2.0 Release Date: 06/01/2005 License ID 1509 Analysis prepared by: Project Design Consultants 701 B Street Suite 800 San Diego, Ca. 92101 DESCRIPTION OF STUDY ************************** * 3370 - BRESSI INDUSTRIAL LOTS 19-22 * * ULTIMATE CONDITIONS - LINE 100, TO BAFFLE BOX * * 10 YEAR STORM EVENT S * ************************************************************************** FILE NAME: S100Y10.DAT TIME/DATE OF STUDY: 13:52 12/12/2006 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: ---------------------------------------------------------------------------- 1985 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 10.00 6-HOUR DURATION PRECIPITATION (INCHES) = 1.860 SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.85 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: ONLY PEAK CONFLUENCE VALUES CONSIDERED *USERDEPINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW S MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (PT) (Fr) SIDE / SIDE/ WAY (Fr) (PT) (FT) (PT) (n) 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS: Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) (Depth)*(Velocity) Constraint = 6.0 (FTFT/S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* *** **** ************ ** **** ****** * •**** **** ************** * ************* * * FLOW PROCESS FROM NODE 100.00 TO NODE 105.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<cc<c COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 265.00 UPSTREAM ELEVATION(FEET) = 369.60 DOWNSTREAM ELEVATION(FEET) = 366.80 ELEVATION DIFFERENCE(FEET) = 2.80 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 7.192 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.876 SUBAREA RUNOFF(CFS) = 0.72 TOTAL AREA(ACRES) = 0.22 TOTAL RUNOFF(CPS) = 0.72 FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 81 ,>>>>P.DDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<cc 10 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.876 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA(ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.76 TOTAL AREA(ACRES) = 0.45 TOTAL RUNOFP(CFS) = 1.48 TC(MIN.) = 7.19 **************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 110.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <c<c< ELEVATION DATA: UPSTREAM(FEET) = 366.80 DOWNSTREAM(FEET) = 366.10 CHANNEL LENGTH THRU SUBAREA(FEET) = 135.00 CHANNEL SLOPE = 0.0052 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.308 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS Di S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.95 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.12 AVERAGE FLOW DEPTH(FEET) = 0.11 TRAVEL. TIME(MIN.) = 2.00 Tc(MIN.) = 9.19 SUBAREA AREA(ACRES) = 0.30 SUBAREA RUNOFF(CFS) 0.94 TOTAL AREA(ACRES) = 0.75 PEAK FLOW RATE(CFS) = 2.43 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.12 FLOW VELOCITY(FEET/SEC.) = 1.21 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 400.00 FEET. FLOW PROCESS FROM NODE 110.00 TO NODE 120.00 IS CODE = 41 >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<.C<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <c<<< ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 358.20 PLOW LENGTH(FEET) = 90.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.1 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.85 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 2.43 PIPE TRAVEL TIME(MIN.) = 0.26 Tc(MIN.) = 9.45 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 490.00 FEET. FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 9.45 RAINFALL INTENSITY(INCH/HR) = 3.25 TOTAL STREAM AREA(ACRES) 0.75 PEAK FLOW RATE(CFS) AT CONFLUENCE = 2.43 FLOW PROCESS FROM NODE 200.00 TO NODE 205.00 IS CODE = 21 >>>>>RATIONAL METHOD INITIAL SUBAREA PNALYSIS<.cc.c< INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "Dm- S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 110.00 UPSTREAM ELEVATION(FEET) = 366.35 DOWNSTREAM ELEVATION(FEET) = 363.50 ELEVATION DIFFERENCE(FEET) = 2.85 URBAN SUBAREA OVERLAND TIME OF PLOW(MIN.) = 2.062 *CAUTION: SUBAREA SLOPE EXCEEDS COUNTY NOMOGRAPH DEFINITION. EXTRAPOLATION OF NOMOGRAPH USED. TIME OF CONCENTRATION ASSUMED AS 6-MIN. 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.357 SUBAREA RUNOFF(CFS) = 0.75 TOTAL AREA (ACRES) 0.18 TOTAL RUNOFF(CFS) = 0.75 FLOW PROCESS FROM NODE 205.00 TO NODE 120.00 IS CODE = 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOWc<c.cc >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <<ccc ELEVATION DATA: UPSTREAM(FEET) 363.50 DOWNSTREAM(FEET) = 362.20 CHANNEL LENGTH THRU SUBAREA(FEET) 180.00 CHANNEL SLOPE = 0.0072 CHANNEL BASE(FEET) = 5.00 'Z' FACTOR = 99.000 MANNINGS FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.546 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.11 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.33 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 2.26 Tc(MIN.) = 8.26 SUBAREA AREA(ACRES) = 0.81 SUBAREA RUNOFF(CFS) = 2.73 TOTAL AREA(ACRES) = 0.99 PEAK FLOW RATB(CFS) = 3.47 END OF SUBAREA CHANNEL PLOW HYDRAULICS: DEPTH(FEET) = 0.13 PLOW VELOCITY(FEET/SEC.) = 1.56 LONGEST FLOWPATH FROM NODE 200.00 TO NODE 120.00 = 290.00 FEET. FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE.c<<c< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES.C<<<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 8.26 RAINFALL INTENSITY (INCH/FR) 3.55 TOTAL STREAM AREA(ACRES) = 0.99 PEAK FLOW RATE (CFS) AT CONFLUENCE = 3.47 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CPS) (MIN.) (INCH/HOUR) (ACRE) 1 2.43 9.45 3.250 0.75 2 3.47 8.26 3.546 0.99 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. * * PEAK FLOW RATE TABLE * * STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 5.70 8.26 3.546 2 5.61 9.45 3.250 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 5.70 Tc(MIN.) = 8.26 TOTAL AREA (ACRES) = 1.74 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 490.00 FEET. FLOW PROCESS FROM NODE 120.00 TO NODE 130.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<c<.cc ,>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<c ELEVATION DATA: UPSTREAM(FEET) = 358.00 DOWNSTREAM(FEET) = 354.50 FLOW LENGTH(FEET) = 94.00 MANNINGS N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.8 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 9.29 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 5.70 PIPE TRAVEL TIME(MIN.) = 0.17 Tc(MIN.) = 8.42 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 130.00 = 584.00 FEET. FLOW PROCESS FROM NODE 130.00 TO NODE 130.00 IS CODE = 81 ---------------------------------------------------------------------------- >,.>>>ADDITION OF SUBAREA TO MAINLINE PEAK FWW<<<cc 10 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.500 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA (ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.76 TOTAL AREA(ACRES) 1.97 TOTAL RUNOFF(CFS) = 6.46 TC(MIN.) = 8.42 FLOW PROCESS FROM NODE 130.00 TO NODE 140.00 Is CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<c<< ELEVATION DATA: UPSTREAM(FEET) = 354.30 DOWNSTREAM(FEET) = 352.57 FLOW LENGTH(FEET) = 65.03 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 8.0 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 8.49 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 6.46 PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 8.55 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 140.00 = 649.03 FEET. FLOW PROCESS FROM NODE 140.00 TO NODE 145.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <ccc ELEVATION DATA: UPSTREAM(FEET) 352.18 DOWNSTREAM(FEET) = 351.24 FLOW LENGTH(FEET) = 54.64 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 9.1 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.22 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 6.46 PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 8.68 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 145.00 703.67 FEET. FLOW PROCESS FROM NODE 145.00 TO NODE 150.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPTJTE PIPE-FLOW TRAVEL TIME THRU SUBAREAcc<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ELEVATION DATA: UPSTREAM(FEET) = 351.24 DOWNSTREAM(FEET) 349.80 FLOW LENGTH(FEET) = 83.70 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 9.1 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.22 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 6.46 PIPE TRAVEL TIME(MIN.) = 0.19 Tc(MIN.) = 8.87 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 787.37 FEET. FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 8.87 RAINFALL INTENSITY (INCH/ER) = 3.39 TOTAL STREAM AREA (ACRES) 1.97 PEAK FLOW RATE (CFS) AT CONFLUENCE = 6.46 FLOW PROCESS FROM NODE 300.00 TO NODE 305.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<c INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 165.00 UPSTREAM ELEVATION(FEET) = 362.55 DOWNSTREAM ELEVATION(FEET) = 361.70 ELEVATION DIFFERENCE(FEET) = 0.85 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.326 TIME OF CONCENTRATION ASSUMED AS 6-MIN. 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.357 SUBAREA RUNOFF(CFS) = 0.91 TOTAL AREA(ACRES) = 0.22 TOTAL RUNOFF(CFS) = 0.91 FLOW PROCESS FROM NODE 305.00 TO NODE 310.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOWc<.c<c >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <<<cc ELEVATION DATA: UPSTREAM(FEET) = 361.70 DOWNSTREAM(FEET) = 359.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 160.00 CHANNEL SLOPE = 0.0169 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.832 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.11 TRAVEL TIME THRU SUBAREA.BASED ON VELOCITY(FEET/SEC.) = 2.02 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 1.32 Tc(MIN.) 7.32 SUBAREA AREA (ACRES) = 1.20 SUBAREA RUNOFF (CFS) = 4.37 TOTAL AREA (ACRES) = 1.42 PEAK FLOW RATE (CFS) = 5.28 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) 0.13 FLOW VELOCITY(FEET/SEC.) = 2.37 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 310.00 325.00 FEET. FLOW PROCESS FROM NODE 310.00 TO NODE 150.00 IS CODE 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBARBA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<ccc ELEVATION DATA: UPSTREAM(FEET) = 353.50 DOWNSTREAM(FEET) 349.80 FLOW LENGTH(FEET) = 148.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 7.3 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.86 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 5.28 PIPE TRAVEL TIME(MIN.) = 0.31 Tc(MIN.) = 7.64 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 150.00 = 473.00 FEET. FLOW PROCESS FROM NODE .150.00 TO NODE 150.00 Is CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEccccc >>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUESccccc TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.64 RAINFALL INTENSITY (INCH/HR) = 3.73 TOTAL STREAM AREA (ACRES) = 1.42 PEAK FLOW RATE (CFS) AT CONFLUENCE = 5.28 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 6.46 8.87 3.385 1.97 2 5.28 7.64 3.730 1.42 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR. 2 STREAMS. ** PEAK FLOW RATE TABLE . ** STREAM RUNOFF Tc INTENSITY NUMBER (CPS) (MIN.) (INCH/HOUR) 1 11.14 7.64 3.730 2 11.25 8.87 3.385 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 11.25 Tc(MIN.) = 8.87 TOTAL AREA (ACRES) = .3.39 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 150.00 = 787.37 FEET. FLOW PROCESS FROM NODE 150.00 TO NODE 160.00 Is CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAccccc >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 349.60 DOWNSTREAM(FEET) = 347.67 FLOW LENGTH(FEET) = 107.36 MANNING'S N = 0.013 DEPTH OF FLOW IN 18.0 INCH PIPE IS 12.9 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 8.27 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.25 PIPE TRAVEL TIME(MIN.) = 0.22 Tc(MIN.) = 9.09 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 160.00 = 894.73 FEET. FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 9.09 RAINFALL INTENSITY(INCH/HR) 3.33 TOTAL STREAM AREA(ACRES) = 3.39' PEAK FLOW RATE(CFS) AT CONFLUENCE = 11.25 FLOW PROCESS FROM NODE 400.00 TO NODE 405.00 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<c<c USER-SPECIFIED VALUES ARE AS FOLLOWS: TC(MIN) = 9.35 RAIN INTENSITY(INCH/HOUR) = 3.27 TOTAL AREA(ACRES) = 4.33 TOTAL RUNOFF(CFS) = 12.00 FLOW PROCESS FROM NODE 405.00 TO NODE 410.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<c<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<c<<< ELEVATION DATA: UPSTREAM(FEET) = 349.25 DOWNSTREAM(FEET) = 349.01 FLOW LENGTH(FEET) = 40.10 MANNING'S N = 0.013 DEPTH OF PLOW IN 24.0 INCH PIPE IS 15.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.63 GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 12.00 PIPE TRAVEL TIME(MIN.) = 0.12 Tc(MIN.) 9.47 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 410.00 = 513.10 FEET. FLOW PROCESS FROM NODE 410.00 TO NODE 410.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.246 GRASS GOOD COVER RUNOFF COEFFICIENT = .4500 SOIL CLASSIFICATION IS "U" S.C.S. CURVE NUMBER (AMC II) = 80 SUBAREA AREA(ACRES) = 0.20 SUBAREA RUNOFF(CFS) = 0.29 TOTAL AREA(ACRES) = 4.53 TOTAL RUNOFF(CFS) = 12.29 TC(MXN.) = 9.47 * ** * * * ***** * *** *********** *** ********* *********** * ***************** ***** FLOW PROCESS FROM NODE 410.00 TO NODE 160.00 IS CODE = 41 ----------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<ccc ELEVATION DATA: UPSTREAM(FEET) 348.51 DOWNSTREAM(FEET) = 347.00 FLOW LENGTH(FEET) = 251.00 MANNING'S N = 0.013 DEPTH OF FLOW IN 24.0 INCH PIPE IS 15.6 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 5.67 GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES 1 PIPE-FLOW(CFS) = 12.29 PIPE TRAVEL TIME(MIN.) = 0.74 Tc(MIN.) - 10.21 LONGEST FLOWPATH FROM NODE 300.00 TO NODE 160.00 = 764.10 FEET. FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >,.>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOWcccc< 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.093 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92: SUBAREA AREA(ACRES) = 0.28 SUBAREA RUNOFF(CFS) = 0.74 TOTAL AREA(ACRES) = 4.81 TOTAL RUNOFF(CFS) = 13.03 TC(MIN.) = 10.21 * *** *** ************ ******* ***** ******** * * ********* **** ******* FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<cc<< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES.c<c<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 10.21 RAINFALL INTENSITY (INCH/HR) = 3.09 TOTAL STREAM AREA (ACRES) = 4.81 PEAK FLOW RATE (CFS) AT CONFLUENCE = 13.03 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 11.25 9.09 3.333 3.39 2 13.03 10.21 3.093 4.81 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CPS) (MIN.) (INCH/HOUR) 1 23.34 9.09 3.333 2 23.47 10.21 3.093 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 23.47 Tc(MIN.) = 10.21 TOTAL AREA(ACRES) = 8.20 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 160.00 = 894.73 FEET. FLOW PROCESS FROM NODE 160.00 TO NODE 162.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREAc<<c >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<c ELEVATION DATA: UPSTREAM(FEET) 346.67 DOWNSTREAM(FEET) = 345.49 FLOW LENGTH(FEET) = 177.05 MP.NNINGS N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 7.47 PIPE FLOW VELOCITY = (TOTAL FLOW) / (PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 23.47 PIPE TRAVEL TIME(MIN.) = 0.39 Tc(MIN.) = 10.60 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 162.00 1071.78 FEET. **************************************************************************** FLOW PROCESS FROM NODE 162.00 TO NODE 165.00 IS CODE = 41 >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<c<<< ELEVATION DATA: UPSTREAM(FEET) = 345.49 DOWNSTREAM(FEET) = 345.11 FLOW LENGTH(FEET) = 56.32 MANNINGS N 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 7.47 PIPE FLOW VELOCITY = (TOTAL FLOW) / (PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 23.47 PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 10.73 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 165.00 = 1128.10 FEET. FLOW PROCESS FROM NODE 165.00 TO NODE 165.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<.cc.c< 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.995 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "0" S.C.S. CURVE NUMBER (AMC II) = 92 SUBAREA AREA (ACRES) = 0.35 SUBAREA RUNOFF(CFS) = 0.89 TOTAL AREA(ACRES) = 8.55 TOTAL RUNOFF(CFS) = 24.36 TC(MIN.) = 10.73 FLOW PROCESS FROM NODE 165.00 TO NODE 165.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<c<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 10.73 RAINFALL INTENSITY (INCH/HR) = 3.00 TOTAL STREAM AREA (ACRES) = 8.55 PEAR FLOW RATE(CFS) AT CONFLUENCE 24.36 FLOW PROCESS FROM NODE 700.00 TO NODE 705.00 IS CODE 21 >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSISc<<<< INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 200.00 UPSTREAM ELEVATION(FEET) = 362.30 DOWNSTREAM ELEVATION(FEET) = 360.00 ELEVATION DIFFERENCE(FEET) - 2.30 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.645 TIME OF CONCENTRATION ASSUMED AS 6-MIN. 10 YEAR RAINFALL INTENSITY (INCH/HOUR) 4.357 SUBAREA RUNOFF(CFS) = 1.61 TOTAL AREA(ACRES) = 0.39 TOTAL RUNOFF(CFS) = 1.61 * ****** ** *** **** ********************* *** * ****** **** * ** PLOW PROCESS FROM NODE 705.00 TO NODE 710.00 IS CODE = 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<c >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT).c<<<< ELEVATION DATA: UPSTREAM(FEET) = 360.00 DOWNSTREAM(FEET) = 357.62 CHANNEL LENGTH THRU SUBAREA(FEET) = 140.00 CHANNEL SLOPE = 0.0170 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.906 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS D' S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) 3.35 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.11 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 1.11 Tc(MIN.) = 7.11 SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 3.49 TOTAL AREA(ACRES) = 1.33 PEAR FLOW RATE(CFS) = 5.10 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.13 FLOW VELOCITY(FEET/SEC.) = 2.29 LONGEST FLOWPATH FROM NODE 700.00 TO NODE 710.00 = 340.00 FEET. FLOW PROCESS FROM NODE 710.00 TO NODE 165.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 347.62 DOWNSTREAM(FEET) = 345.31 FLOW LENGTH(FEET) = 104.00 MANNING'S N = 0.013 DEPTH OF PLOW IN 18.0 INCH PIPE IS 7.4 INCHES PIPE-FLOW VELOCITY(FEET/SEC.) = 7.47 GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 5.10 PIPE TRAVEL TIME(MIN.) = 0.23 Tc(MIN.) 7.34 LONGEST FLOWPATH FROM NODE 700.00 TO NODE 165.00 = 444.00 FEET. FLOW PROCESS FROM NODE 165.00 TO NODE 165.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEc<c<c >>>>>P.ND COMPUTE VARIOUS CONFLUENCED STREAM VALUESC<C<< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION(MIN.) = 7.34 RAINFALL INTENSITY(INCH/HR) = 3.83 TOTAL STREAM AREA(ACRES) = 1.33 PEAK FLOW RATE(CFS) AT CONFLUENCE = 5.10 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER (CPS) (MIN.) (INCH/HOUR) (ACRE) 1 24.36 10.73 2.995 8.55 2 5.10 7.34 3.826 1.33 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. * * PEAK FLOW RATE TABLE * * STREAM RUNOFF Tc INTENSITY NUMBER (CPS) (MIN.) (INCH/HOUR) 1 24.17 7.34 3.826 2 28.36 10.73 2.995 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) 28.36 Tc(MIN.) = 10.73 TOTAL AREA(ACRES) = 9.88 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 165.00 = 1128.10 FEET. FLOW PROCESS FROM NODE 165.00 TO NODE 170.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<C< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) = 344.91 DOWNSTREAM(FEET) = 344.88 FLOW LENGTH(FEET) = 5.00 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 9.03 PIPE FLOW VELOCITY = (TOTAL FLOW) / (PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = PIPE-FLOW(CFS) = 28.36 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 10.74 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 170.00 = 1133.10 FEET. END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 9.88 TC(MIN.) = 10.74 PEAK FLOW RATE(CFS) = 28.36 END OF RATIONAL METHOD ANALYSIS RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 2003,1985,1981 HYDROLOGY MANUAL (C) Copyright 1982-2005 Advanced Engineering Software (ace) Ver. 2.0 Release Date: 06/01/2005 License ID 1509 Analysis prepared by: Project Design Consultants 701 B Street Suite 800 San Diego, Ca. 92101 DESCRIPTION OF STUDY * 3370 - BRESSI INDUSTRIAL LOTS 19-22 * * ULTIMATE CONDITIONS - LINE 500, AFTER BAFFLE BOX * * 10 YEAR STORM EVENT * FILE NAME: 5500Y10.DAT TIME/DATE OF STUDY: 13:56 12/12/2006 ---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: 1985 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 10.00 6-HOUR DURATION PRECIPITATION (INCHES) 1.860 SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.85 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: ONLY PEAK CONFLUENCE VALUES CONSIDERED *USERDEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (PT) (FT) SIDE / SIDE/ WAY (PT) (FT) (FT) (PT) (n) 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS: Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *•* * * * * * * * * * * * * * * * * * * * * * * * * * * * * PLOW PROCESS FROM NODE 100.00 TO NODE 175.00 IS.CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<c< USER-SPECIFIED VALUES ARE AS FOLLOWS: TC(MIN) = 10.74 RAIN INTENSITY(INCH/HOUR) = 2.99 TOTAL AREA(ACRES) = 9.88 TOTAL RUNOFF(CFS) = 28.36, FLOW PROCESS FROM NODE '175.00 TO NODE 180.00 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<ccc< >>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<.c<< ELEVATION DATA: UPSTREAM(FEET) 344.48 DOWNSTREAM(FEET) = 344.43 FLOW LENGTH(FEET) 7.00 MANNING'S N = 0.013 ASSUME FULL-FLOWING PIPELINE PIPE-FLOW VELOCITY(FEET/SEC.) = 9.03 PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 28.36 PIPE TRAVEL TIME(MIN.) = 0.01 Tc(MIN.) = 10.75 LONGEST PLOWPATH FROM NODE 0.00 TO NODE 180.00 = 7.00 FEET. FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = 10 ---------------------------------------------------------------------------- >>>>,MAIN-STREAM MEMORY COPIED ONTO MEMORY BANK t 1 cccc< FLOW PROCESS FROM NODE 500.00 TO NODE 505.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS.cc.cc< COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS 'D" S.C.S. CURVE NUMBER (AMC II) = 92 INITIAL SUBAREA FLOW-LENGTH(FEET) 155.00 UPSTREAM ELEVATION(FEET) = 366.80 DOWNSTREAM ELEVATION(FEET) = 365.90 ELEVATION DIFFERENCE (FEET) 0.90 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.715 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.052 SUBAREA RUNOFF(CFS) = 1.00 TOTAL AREA(ACRES) = 0.29 TOTAL RUNOFF(CFS) = 1.00 FLOW PROCESS FROM NODE 505.00 TO NODE 510.00 IS CODE = 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<cc >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <<<<< ELEVATION DATA: UPSTREAM(FEET) 365.90 DOWNSTREAM(FEET) = 359.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 450.00 CHANNEL SLOPE = 0.0147 CHANNEL BASE(FEET) = 12.00 "Z" FACTOR = 2.000 MANNING'S FACTOR = 0.022 MAXIMUM DEPTH(FEET) =. 2.00 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.881 COMMERCIAL DEVELOPMENT RUNOFF COEFFICIENT = .8500 SOIL CLASSIFICATION IS "D' S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.58 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.60 AVERAGE FLOW DEPTH(FEET) = 0.08 TRAVEL TIME(MIN.) = 4.68 Tc(MIN.) = 11.39 SUBAREA AREA(ACRES) = 0.47 SUBAREA RUNOFF(CFS) = 1.15 TOTAL AREA(ACRES) 0.76 PEAK FLOW RATE(CFS) = 2.15 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 1.73 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 510.00 605.00 FEET. FLOW PROCESS FROM NODE 510.00 TO NODE 510.00 IS CODE = 1 >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE.c<<.c< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: TIME OF CONCENTRATION(MIN.) = 11.39 RAINFALL INTENSITY (INCH/HR) 2.88 TOTAL STREAM AREA(ACRES) = 0.76 PEAK FLOW RATE (CFS) AT CONFLUENCE 2.15 FLOW PROCESS FROM NODE 600.00 TO NODE 605.00 IS CODE = 21 ---------------------------------------------------------------------------- >,>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIScc.ccc INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) 92 INITIAL SUBAREA FLOW-LENGTH(FEET) = 145.00 UPSTREAM ELEVATION(FEET) = 366.80 DOWNSTREAM ELEVATION(FEET) = 362.80 ELEVATION DIFFERENCE (FEET) 4.00 URBAN SUBAREA OVERLAND TIME OF FLOW(MIN.) = 2.318 *CAUTION: SUBAREA SLOPE EXCEEDS COUNTY NOMOGRAPH DEFINITION. EXTRAPOLATION OF NOMOGRAPH USED. TIME OF CONCENTRATION ASSUMED AS 6-MIN. 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.357 SUBAREA RUNOFF(CFS) = 1.37 TOTAL AREA(ACRES) 0.33 TOTAL RUNOFF(CFS) = 1.37 FLOW PROCESS FROM NODE 605.00 TO NODE 510.00 IS CODE = 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<c.c.cc >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) c<<<< ELEVATION DATA: UPSTREAM(FEET) = 362.80 DOWNSTREAM(FEET) = 359.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 195.00 CHANNEL SLOPE = 0.0179 CHANNEL BASE(FEET) = 5.00 -Zn FACTOR = 99.000 MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00 10 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.777 INDUSTRIAL DEVELOPMENT RUNOFF COEFFICIENT = .9500 SOIL CLASSIFICATION IS nH S.C.S. CURVE NUMBER (AMC II) = 92 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.80 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.19 AVERAGE FLOW DEPTH(FEET) = 0.11 TRAVEL TIME(MIN.) = 1.49 Tc(MIN.) = 7.49 SUBAREA AREA(ACRES) = 1.36 SUBAREA RUNOFF(CFS) = 4.88 TOTAL AREA(ACRES) = 1.69 PEAK FLOW RATE(CFS) = .6.25 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.13 FLOW VELOCITY(FEET/SEC.) = 2.54 LONGEST FLOWPATH FROM NODE 600.00 TO NODE 510.00 = 340.00 FEET. FLOW PROCESS FROM NODE 510.00 TO NODE 510.00 IS CODE = ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEccc<< >>>>>P.ND COMPUTE VARIOUS CONFLUENCED STREAM VALUES.<.c< TOTAL NUMBER OF STREAMS = 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION (MIN.) 749 RAINFALL INTENSITY(INCH/HR) = 3.78 TOTAL STREAM AREA(ACRES) = 1.69 PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.25 ** CONFLUENCE DATA ** STREAM RUNOFF Tc INTENSITY AREA NUMBER . (CPS) (MIN) (INCH/HOUR) (ACRE) 1 2.15 11.39 2.881 0.76 2 6.25 7.49 3.777 1.69 RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR) 1 7.89 7.49 3.777 2 6.91 11.39 2.881 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 7.89 Tc(MIN.) = 7.49 TOTAL AREA (ACRES) = 2.45 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 510.00 = 605.00 FEET. FLOW PROCESS FROM NODE 510.00 TO NODE 180.00 IS CODE 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< >>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <<<<c ELEVATION DATA: UPSTREAM(FEET) = 359.30 DOWNSTREAM(FEET) 354.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 300.00 CHANNEL SLOPE = 0.0177 CHANNEL BASE(FEET) = 12.00 nzn FACTOR = 2.000 MANNING'S FACTOR = 0.022 MAXIMUM DEPTH(FEET) = 2.00 10 YEAR RAINFALL INTENSITY (INCH/HOUR) = 3.328 GRASS GOOD COVER RUNOFF COEFFICIENT = .4500 SOIL CLASSIFICATION IS MD" S.C.S. CURVE NUMBER (AMC II) = 80 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 7.98 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY (FEET/SEC.) = 3.08 AVERAGE FLOW DEPTH(FEET) = 0.21 TRAVEL TIME(MIN.) = 1.62 Tc(MIN.) = 9.11 SUBAREA AREA(ACRES) = 0.13 SUBAREA RUNOFF(CFS) = 0.19 TOTAL AREA (ACRES) = 2.58 PEAK FLOW RATE(CFS) = 8.08 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 0.21 FLOW VELOCITY(FEET/SEC.) 3.09 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 180.00 = 905.00 FEET. * ****** ******* * ********* **** ************ ****** ** ** * ***** FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = 11 ---------------------------------------------------------------------------- >>>>>CONFLTJENCE MEMORY BANK * 1 WITH THE MAIN-STREAM MEMORY<c<cc * * MAIN STREAM CONFLUENCE DATA * * STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 8.08 9.11 3.328 2.58 LONGEST FLOWPATH FROM NODE 500.00 TO NODE 180.00 = 905.00 FEET. * * MEMORY BANK * 1 CONFLUENCE DATA * * STREAM RUNOFF Tc INTENSITY AREA NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE) 1 28.36 10.75 2.991 9.88 LONGEST FLOWPATH FROM NODE 0.00 TO NODE 180.00 = 7.00 FEET. ** PEAK FLOW RATE TABLE ** STREAM RUNOFF Tc INTENSITY NUMBER (CFS) (MIN.) (INCH/HOUR)- 1 33.57 9.11 3.328 2 35.62 10.75 2.991 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: PEAK FLOW RATE(CFS) = 35.62 Tc(MIN.) = 10.75 TOTAL AREA(ACRES) = 12.46 END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 12.46 TC(MIN.) = 10.75 PEAK FLOW RATE (CFS) 35.62 END OF RATIONAL METHOD ANALYSIS H H O 16 20 4O 60 0 SWALE NUMBER SCALE 1"40' PREPARED BY CDS CITY OF CARLSBAD DIRECTION OF FLOW IN SWALE . . NORTHERN SWALE DATA NO. DRAINAGE AREA C—VALUE WQ Q LENGTH VELOCITY RLSVENCE TIME 1 0.331 ac. 0.542 0.0359 cfs 280' 0.12 ft/s 39 min. 2 0.281 ac. 0.663 0.0373 cfs 125' 0.15 ft/s 14 min. 1 0.132 ac. 0.450 0.0119 cfs 100' 0.08 ft /s 21 min. .•• .:. ,.... .:..•..±:.... ..:. ....:. .:..:. ... ••.•.• .i...: •. ••.••••• :....:. .....:... ...:L•. ••.. ...........................................................1.!....•.::•.........:.. •.• ... •.•.••• •. .•.•• •. ••. ......::. I 11 CAM 1T::: \ H 51 rFG 364.96 BLDG 12 &354.96 IS I 2A 50' •1' JQ8: iifU.1U II PROJECT DESIGN .CONSULTANTS Planning I Landscape Architecture I Environmental I Engineering I Survey STLJT7-1 SWALE MAP 701 B Street Suite 800 San Diego CA 92101 CREATED 02/13/07 6192356471 Tel 619234 0349 Fax SHEET 2 OF 2 P \3370\ENGR\REPoI?Ts\WQTI?\3370 1 Lots 19-22\Swales south dwg 2/16/2007 9.22 AM Northern Swale #1 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Channi / Flow Element Trapezoidal Chann Method Manning's Formula Solve For Channel Depth Input Data Mannings Coeffic 0.250 Channel Slope 011300 ft/ft Left Side Slope 3.00 H : V Right Side Slope 3.00. H: V Bottom Width 3.00 ft Discharge 0.04 cfs Results Depth 0.09 ft Flow Area 0.3 ft2 Wetted Perimi 3.58 ft Top Width 3.55 ft Critical Depth 0.02 ft Critical Slope 3.710315 ft/ft Velocity 0.12 ft/s Velocity Head 0.00 ft Specific Enerç 0.09 ft Froude Numb 0.07 Flow Type Subcritical Project Engineer: Employee of PDC p:\...swaIes on bressi industrial lots 19-22.1m2 PROJECIDESIGN CONSULTANTS FlowMaster v7.0 [7.0005] 02/15/07 05:41:46 PM © Haestad Methods, Inc. 37 Brookslde Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Northern Swale #2 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Chann Flow Element Trapezoidal Chanrn Method Manning's Formula Solve For Channel Depth Input Data Mannings Coeffic 0.250 Channel Slope 021440 ft/ft Left Side Slope 3.00 H : V Right Side Slope 3.00 H : V Bottom Width 3.00 ft Discharge 0.04 cfs Results Depth 0.08 ft Flow Area 0.2 ft2 Wetted Perimi 3:49 ft Top Width 3.46 ft Critical Depth 0.02 ft Critical Slope 3.672258 ft/ft Velocity 0.15 ft/s Velocity Head 0.00 ft Specific Enerç 0.08 ft Froude Numb. 0.10 Flow TypeSubcritical Project Engineer: Employee of PDC INSULTANTS FlowMaster v7.0 [7.0005) terbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Northern Swale #3 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Channi Flow Element Trapezoidal Chann Method Manning's Formula Solve For Channel Depth Input Data Mannings Coeffic 0.250 Channel Slope 009500 ft/ft Left Side Slope 3.00 H : V Right Side Slope 3.00 H : V Bottom Width 3.00 ft Discharge 0.01 cfs Results Depth 0.05 ft Flow Area 0.2 ft2 Wetted Perimi 3.31 ft Top Width 3.30 ft Critical Depth 0.01 ft Critical Slope 4.974573 ft/ft Velocity 0.08 ft/s Velocity Head 0.00 ft Specific Enerç 0.05 ft Froude Numb 0.06 Flow Type 3ubcritical Project Engineer: Employee of PDC p:\...swales on bressi industrial lots 19-22.fm2 PROJ ECTDESIGN CONSULTANTS FlowMaster v70 [7.00051 02/15/07 05:42:14 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page .1 of 1 .2. Southern Swale #4 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Channi Flow Element Trapezoidal Channt Method Manning's Formula Solve For Channel Depth Input Data Mannings Coeffic 0.250 Channel Slope 020000 ft/ft Left Side Slope 3.00 H : V Right Side Slope 3.00 H : V Bottom Width 3.00 ft Discharge 0.05 cfs Results Depth 0.10 ft Flow Area 0.3 ft2 Wetted Perimi 3.60 ft Top Width 3.57 If Critical Depth 0.02 ft Critical Slope 3.364873 ft/ft Velocity 0.16 ft/s Velocity Head 0.00 ft Specific Enerç 0.10 It Froude Numb. 0.10 Flow Type Subcritical Project Engineer: Employee of PDC p:\...\swales on bressi Industrial lots 19-22.fm2 PROJECTDESIGN CONSULTANTS FlowMaster v7.0 [7.0005] 02/15/07 05:42:41 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Southern Swale #5 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Chann Flow Element Trapezoidal Chann Method Manning's Formula Solve For Channel Depth Input Data Mannings Coeffic 0.250 Channel Slope 020300 ft/ft Left Side Slope 3.00 H : V Right Side Slope 3.00 H : V Bottom Width 5.00 ft Discharge 0.34 cis Results Depth 0.21 It Flow Area 1.2 ft2 Wetted Perimi 6.36 It Top Width 6.29 It Critical Depth 0.05 It Critical Slope 2.506235 ft/ft Velocity 0.28 ft/s Velocity Head 0.00 It Specific Enerç 0.22 It Froude Numb 0.11 Flow Type Subcritical Project Engineer: Employee of PDC p:\...\swales on bressi industrial lots 19-22.fm2 PROJECTDESIGN CONSULTANTS FlowMaster v7.0 17.00051 02/15/07 05:43:04 PM © Haestad Methods, Inc. 37 Brookslde Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Southern Swale #6 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Channt Flow Element Trapezoidal Chann Method Manning's Formula Solve For Channel Depth Input Data Mannings Goeffic 0.250 Channel Slope 015600 ft/It Left Side Slope 3.00 H : V Right Side Slope 3.00 H : V Bottom Width 5.00 ft Discharge 0.23 cfs Results Depth 0.18 It Flow Area 1.0 ft2 Wetted Perimu 6.17 ft Top Width 6.11 It Critical Depth 0.04 It Critical Slope 2.704110 ft/ft Velocity 0.22 fills Velocity Head 0.00 ft Specific Enerç 0.19 ft Froude Numb 0.10 Flow Type Subcritical Project Engineer: Employee of PDC p:\...\swales on breast industrial lots 19-22.tm2 PROJECTDESIGN CONSULTANTS FlowMaster v7.0 (7.0005) 02/15/07 05:43:31 PM © Haestad Methods, Inc. 37 Brookslcle Road Waterbury, CT 06708 USA +1-203-755-1666 Pagel of 1 Southern Swale #7 Worksheet for Trapezoidal Channel Project Description Worksheet Trapezoidal Channi Flow Element Trapezoidal Channi Method Mannings Formula Solve For Channel Depth Input Data Mannings Coeff Ic 0.250 Channel Slope 021300 ft/ft Left Side Slope 3.00 H : V Right Side Slope 3.00 H : V Bottom Width 3.00 ft Discharge 0.11 cis Results Depth 0.14 ft Flow Area 0.5 ft2 Wetted Perimi 3.91 ft Top Width 3.86 ft Critical Depth 0.03 ft Critical Slope 2.924086 ft/ft Velocity 0.22 ft/s Velocity Head 0.00 ft Specific Enerç 0.14 ft Froude Numb. 0.11 Flow Type 3ubcritical Project Engineer: Employee of PDC p:\...\swales on bressi industrial lots 19-22.fm2 PROJECTDESIGN CONSULTANTS FlowMaster v7.0 [7.0005] 02115/07 05:43:56 PM © Haestad Methods, Inc. 37 Brookslde Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 APPENDIX 4 Discussion of Feasible Treatment BMP Options The following is a discussion of feasible treatment BMP options. The owner and the design team will consider the recommended BMP options from each category before selecting the primary treatment BMP system for the project, which will be located on page 12 of the main report. Detention Basins Detention basins (a.k.a. dry extended detention ponds, dry ponds, extended detention basins, detention ponds, extended detention ponds) are basins with controlled outlets designed to detain storm water runoff, allowing particles and associated pollutants to settle. Detention basins may be designed to include vegetation, allowing for further pollutant removal through infiltration and natural pollutant uptake by vegetation. Detention basins are among the most widely applicable storm water management practices. They should be used for drainage areas of at least 10 acres, and they can be used with almost all types of soils and geology. Detention basins are useful as flood control devices, but they can be designed for improving water quality also. Detention and retention can be accomplished using geotextiles or waterproof liners to wrap a structure. These subsurface storage devices (pipe galleries, Rainstore grid system, vaults, etc.) provide multiple uses in the same footprint. Subsurface storage can create an efficient storage space below parking or landscaped areas, designed to support heavy loads. Recommended Detention Basin Option Based on the size of the individual lots, detention basins are not a feasible option for placement within the project boundaries. Detention basins are already installed and in use by the Bressi Ranch Master Development. Infiltration Infiltration devices, such as infiltration trenches/basins and porous/permeable pavement rely on the filtering ability of soils or other materials to treat urban runoff discharges and reduce discharge amounts. Infiltration Basins and Trenches Infiltration basins and trenches are storm water control structures that provide both retention and treatment of storm water runoff. The natural physical, biological, and chemical processes taking place in the infiltration basins and trenches remove pollutants including particulates, organic matter, metals, dissolved metals, and nutrients. Water is percolated through soils, where filtration and biological action remove pollutants. These systems require a minimum soil infiltration rate of 0.5 inches/hour and at least 4 feet between the bottom of the structure and seasonal ground water levels to work efficiently. Porous/Permeable Pavement Porous/permeable pavement also mitigates storm water runoff through infiltration. These infiltration systems use a combination of load-bearing, durable surfaces with underlying layered structures to allow infiltration and treatment of storm water. Porous/permeable pavement can be used over soils with low infiltration rates and in areas with low traffic volumes, making them highly appealing for urban redevelopment projects. There are several types of proprietary permeable pavements: . UNI Eco-Stone: UNI Eco-Stone is a true interlocking concrete paver that is capable of supporting heavier vehicle loads than other permeable pavements and can be installed in several different patterns. UNI Eco-Stone consists of conventional concrete unit payers with the added feature of permeability. The notched design creates voids between the payers and the void area is filled with a graded aggregate suitable for the filtration of the project. In some cases, the use of filter layers or geotextiles may be required.4 GravelPave: GravelPave is an interlocking structure that is designed to tolerate high frequency and low speed traffic. GravelPave is a ring and grid structure on a non-woven polyester fabric that is installed on the top-wearing course of roads, driveways, parking lots, and trails. The GravelPave mats are then filled with 3/16" minus sharp gravel of various colors, creating a filtration layer for stormwater runoff.5 ' http://www.uni-groupusa.org/uni-eco-.htm, brochures hup://www.invisiblestructures.comIGV2/gravelpave.htm, brochures GrassPave: GrassPave is a porous paving system that provides load-bearing strength while protecting vegetation root systems from deadly compaction. High void spaces within the entire cross-section promote excellent root development while providing storage capacity and treatment for storm water runoff. GrassPave is a plastic sub-surface reinforcement structure that is produced and distributed in rolls, which makes it easier to cut and install than other grass paving products.6 Geoblock: The Geoblock porous paving system is a series of interlocking, high-strength blocks made from recycled materials. The system provides load-bearing strength and the most demanding turf protection, allowing for vigorous growth of turf grass.7 Recommended Infiltration Option The soil type (D) in the area of the Bressi Industrial Lots 19-22 Project does not provide the required infiltration rate required for infiltration basins; therefore, they are not feasible for this project. The porous/permeable pavements have good pollutant removal rates for heavy metals and sedimentation. Research has also shown that the storm water pollutants are trapped in the first 4-8 inches in the UNI Eco-Stone system, which allows for easier removal of the pollutants by means of sweeping and other maintenance procedures. Studies show that the .UNI Eco-Stone system reduces the concentrations of oils and greases, heavy metals, and bacteria in runoff. Several studies show that UNI Eco-Stone outperforms other permeable pavement options. At this time, porous/permeable pavement is not recognized as a treatment BMP, but it is recommended as a site design BMP with the following pollutant removal efficiencies: Pollutant Removal Rates for Porous/Permeable Pavements Lead Zinc Copper Cadmium Total Suspended Solids 50-98% 62-99% 42% 33% 95% SOURCE: Stormwater Magazine May/June 2003 Issue. 6 http://www.invisib1estructures.com/GP2/grasspave.htm, brochures 7 hup:llwww.sspco.org/geoblock.html Wet Ponds Wet ponds need sufficient drainage area to maintain the permanent pool. In humid regions, this is typically about 25 acres, but a greater area may be needed in regions with less rainfall.8 A wet pond is not an option for this project due to spatial constraints, drainage area requirements, and reports of vector problems associated with wet ponds. Filtration Systems Filtration systems include biofilters, sand and organic filters, and proprietary devices. Biofilters Biofiltration includes grass swales, buffer strips, flow-through or infiltration planter boxes, and bioretention areas, providing effective treatment through filtration, biological uptake, and attenuation of storm water runoff.9 . Grass swales: These linear filtration practices can be used on sites with slopes of less than 4 percent. They are well suited to treat roadway runoff and they aide in reducing runoff velocities. . Buffer strips: These vegetated surfaces are designed to treat sheet flow from adjacent areas. Like grass swales, buffer strips function by reducing runoff velocities to filter sediment and other pollutants and provide some infiltration into underlying soils. Flow-through planter boxes'° or Filterra catch basins": These natural filtration areas are designed to allow runoff to filter through layers of topsoil (thus capturing pollutants) and then be collected in a perforated underdrain and discharged to the MS4. The planter is sized to accept runoff and temporarily store the water in a reservoir on top of the soil; water should drain through the planter within 3-4 hours after a storm event. National Menu of Best Management Practices for Storm Water Phase II, US EPA 9 CASQA, California Stormwater BMP Handbook, New Development and Redevelopment 10 Stormwater Management Manual, September 2002 Prince George's County, Maryland, Department of Environmental Resources, Programs and Planning Division . Bioretention areas: These landscape features are designed to provide treatment of storm water runoff. These areas are typically shallow, landscaped depressions, located within small pockets of residential land uses. During storms, the runoff ponds above the mulch and soil of the bioretention system. The runoff filters through the mulch and soil mix, typically being collected in a perforated underdrain and returned to the MS4. An example of a low impact development bioretention BMP is a rain garden. 12 Sand and Organic Filters For sand and organic filtration systems, there are five basic storm water filter designs: Surface sand filter: This is the original sand filter design with the filter bed and sediment chamber placed aboveground. The surface sand filter is designed as an offline system that receives only the smaller water quality events. Underground filter: This is the original sand filter design with the filter bed and sediment chamber placed underground. It is an offline system that receives only the smaller water quality events. Perimeter filter: This is the only filtering option that is an online system with an overflow chamber to accommodate large storm events.13 Organic media filter: This is a slight modification to the surface sand filter, with the sand medium replaced with or supplemented by an organic medium to enhance pollutant removal of many compounds. . Multi-Chamber Treatment Train: This is an underground system with three filtration chambers designed to achieve very high pollutant removal rates. Proprietary Devices Proprietary filtration devices include offline filtration systems, online filter units, and filtration based inlet inserts. Proprietary catch basin insert devices contain a filtering medium placed inside the stormwater system's catch basins. The insert can contain one or more treatment mechanisms, 12 Prince George's County, Maryland, Department of Environmental Resources, Programs and Planning Division which include filtration, sedimentation, or gravitational absorption of oils. The water flows into the inlet, through the filter, where pollutants and contaminants are removed, and then into the drainage system. There are two primary designs for inlet inserts. One design uses fabric filter bags that are suspended in place by the grate or by retainer rods placed across the catch basin. The fabric filter design includes a skirt that directs the storm water flow to a pouch that may be equipped with oil-absorbing pillows. These inlet inserts are typically equipped with "Bypass Ports" to prevent flooding during large storm events. Maintenance on the fabric filter inserts includes periodic inspection and replacement of the entire insert when it becomes clogged with captured pollutants. The other design for inlet inserts uses stainless steel, High-Density Polyethylene (HDPE), or other durable materials to form a basket or cage-like insert placed inside the catch basin. This basket contains the filter medium and absorbent materials that treat the storm water as it passes through. These inlet inserts are also equipped with bypass pathways to allow normal operation of the storm drain system during large storm events. Maintenance on the basket-type inlet inserts includes periodic inspection and removal and replacement of the filter medium and absorbent materials (not the entire inlet insert). There are several types of proprietary inlet inserts for both design types 14: Fabric Filter Bag Design Stream Guard: Stream Guard works by initially capturing sediment and trash and debris, and then combats dissolved oil, nutrients and metals through a filter media. Ultra-Drainguard: Ultra-Drainguard works by initially capturing sediment and trash and debris, and then combats dissolved oil, nutrients and metals through a filter media. The Ultra-Drainguard has an oil absorbent pillow that can be replaced separate from the filter during times of large free-oil runoff. • Basket-type Inlet Inserts ' EPA 832-F-99-007 14 http:llwww.epa.govlregionl/assistance/ceius/stormwater/techs AbTech Ultra-Urban Filter: The Ultra-Urban Filter is a cost-effective BMP designed for use in storm drains that experience oil and grease pollution accompanied by sediment and trash and debris. The oil is permanently bonded to a SmartSponge, while sediment and trash and debris are captured in an internal basket. AquaGuard: AquaGuard works by initially capturing sediment and trash and debris, and then combats dissolved oil, nutrients and metals through a filter media. AquaGuard compares to others by being easy to handle, i.e. no special lifting equipment for filter removal Bio Clean: Bio Clean has designed an Inlet Skimmer Box to trap sediment, grass, leaves, organic debris, floating trash, and hydrocarbons, utilizing hydrocarbon absorbing cellulose and a series of stainless steel filter screens. The boom traps large debris as well as absorbing oil and grease. A diffuser plate is used to minimize resuspension of trapped sediment. Skimmer boxes come is a variety of shapes and sizes to fit all manner of curb inlets and catch basins. Bio Clean also produces an inline Downspout Filter unit, which can adapt to 4", 6", or 8" pipes. 15 FloGard: FloGard uses catch basin filtration, placing catch basin insert devices with a filter medium just under the grates of the stormwater system's catch basins. FloGard handles non-soluble solids such as sediment, gravel, and hydrocarbons, which are all potential pollutants originating from the roof and parking lot. FloGard is available for standard catch. basins and for roof downspouts. 16 Recommended Filtration Option Depending on the proposed site drainage patterns, biofiltration (grass swales) may be applicable to this project. Swales are natural BMP systems that can add to the value of the site. Studies have shown the effectiveness and efficiency of natural systems or "low-impact development" (LID) over "high-tech" systems. According to studies done in Maryland, LID treats over 90% of the total 15 http://www.bioc1eanenvironmentaI.net volume using less than 1% of the urban landscape. The following pollutant removal efficiencies can be expected from grassed swales. Grassed swale pollutant removal efficiency data Removal Efficiencies (% Removal) Study TSS TP TN NO3 Metals Bacteria Type Caltrans 2002 77 8 67 66 83-90 -33 Dry swales Goldberg 1993 67.8 4.5 - 31.4 42-62 -100 Grassed channel Seattle Metro and Washington Department of Ecology 1992 60 45 - -25 2-16 -25 Grassed channel Seattle Metro and Washington Department of Ecology 1992 83 29 - -25 46-73 -25 Grassed channel Wang et al., 1981 80 - - - 70-80 - Dry swale Dorman et al., 1989 98 18 - 45 37-81 - Dry swale Harper, 1988 87 83 84 80 88-90 - Dry swale Kercher et al., 1983 99 99 99 99 99 - Dry swale Harper, 1988 81 17 40 52 37-69 - Wet swale f Koon, 1995 67 39 - 9 -35 to 6 - Wet swale SOURCE: CASQA Stormwater BMP Handbook for New Development and Redevelopment Surface sand and media filters as well as the multi-chamber treatment train have space requirements that make them unappealing for this project site. In comparison, permeable pavement gives similar pollutant removal rates as the multi-chamber treatment train, while performing multiple uses on the project site (e.g., driveways, parking, sidewalks, etc.). The perimeter filter and many proprietary filtration designs are well suited for areas with limited land availability for structural controls. The perimeter sand filter includes a sediment chamber and a filter bed with flow typically entering the system through grates at ground level. Pollutant Removal Rates for Perimeter Sand Filter Systems Metals (iron, lead, zinc) Total Phosphorus Total Nitrogen Total Kjeldahl Nitrogen 45% 33% 21% 46% Total Organic Carbon Biochemical Oxygen Demand Fecal Coliform Total Suspended Solids 48% 70% 76% 70% SOURCE: Gaul, 1990, EPA 832-F-99-007, Sept. 1999 Unfortunately, sand filters have a high potential for clogging if proper maintenance is not conducted or if the system receives water with high amounts of sediment or trash and debris. Typical maintenance requirements for perimeter sand filter systems include monthly inspections and periodic removal of accumulated trash, paper, and debris and removal and replacement of the top layers of sand, gravel, and/or filter fabric. Perimeter sand filter systems may also require periodic removal of vegetative growth. Therefore, sand filters have extremely high maintenance costs compared to proprietary filtration designs. Of the two types of proprietary filtration based inlet insert designs, experience within Southern California has shown the basket-type inlet inserts to be more reliable and less cumbersome for maintenance and proper operation.'7 Suntree Technologies, of Cape Canaveral, Florida commissioned Creech Engineering, Inc. and Universal Engineering to perform testing on a Grate Inlet Skimmer Box (GISB) to determine its pollutant removal effectiveness for sediment and grass clippings. The Public Works/Engineering Department of El Monte, California provided ABN Environmental Laboratories with four runoff samples (one control and three test samples collected from Longo Toyota) to be tested for metals, oil and grease, and MBAS (soap). Based on the analysis results, the filtration was effective in retaining the tested metals as well as the oil and grease and sediment. However, the device was unable to retain the MBAS (soap) as indicated by the following test results. 17 Correspondence with the City of Dana Point, the City of Encinitas, and the City of Santa Monica Pollutant Removal Rates for Grate Inlet Skimmer Box Oil and Grease Total Phosphorus Total Nitrogen Total Suspended Solids 90-99% 37% 24% 73% Chromium Aluminum Lead Copper 89% 98-99% 73-93% 93-97% Iron Nickel Zinc Soap 98-99% 57-86% 92-97% (-4)-(-62)% Therefore, the best type of filtration system for Bressi Industrial Lots 19-22 is biofiltration (grass swales). If biofiltration is not able to treat the required runoff volume, proprietary filtration based inlet insert may be used in conjunction with the swales, such as downspout filters or catch basin inlet inserts. Hydrodynamic Separator Systems Hydrodynamic separator systems (HDS) or Continuous Flow Deflection Systems (CFDS) are flow- through structures with a settling or separation unit to remove sediments and other pollutants that are widely used in storm water treatment. No outside power source is required, because the energy of the flowing water allows the sediments to efficiently separate. Depending on the type of unit, this separation may be by means of swirl action or indirect filtration. Hydrodynamic separator systems are most effective where the materials to be removed from runoff are heavy particulates that can be settled or floatables that can be captured, rather than solids with poor settleability or dissolved pollutants. For hydrodynamic separator systems, there are six major proprietary types 18: BaySaver®: The BaySaver Stormwater Treatment System meets regulations for non-point source pollution control. The system operates using gravity flow and density differences to 18 hup://www.epa.gov/regionl/assistance/ceitts/stormwater/techs remove oils, fine suspended solids, and floatables (trash and other debris) from stormwater runoff. Bio Clean Nutrient Separating Baffle Box' 9: The Bio Clean Baffle Box captures foliage, litter, sediment, phosphate; the whole flow is treated. Turbulence deflectors prevent captured sediment from re-suspending. Hydrocarbons collect in front of the skimmer and are absorbed by an oil boom. Nutrient rich vegetation and litter are captured in a filtration screen system held above the static water, allowing it to dry out between storms. This separation prevents nutrients from leaching into the static water and flushing out with the next storm, as well as preventing bacterial buildup. Continuous Deflective Separation (CDS): CDS technology separates settleable particulate matter from stormwater runoff, capturing almost 100 percent of the floatable material. A sorbent material can be added to remove unattached oil and grease. Downstream Defender: Downstream Defender traps sediment while intercepting oil and grease with a small head loss. Stormceptor®: Stormceptor traps sediment while intercepting oil and grease. Vortechs'': Vortechs combines baffle walls, circular grit chambers, flow control chambers, and an oil chamber, removing hydrocarbons, settleable solids, and floatables from the storm water runoff. Recommended Hydrodynamic Separator Option All of the abovementioned devices are designed specifically for sediment removal with the idea being that a majority of the pollutants of concern will attach themselves to the sediment. They all capture oil and trash (floatables). All of the manufacturers provide design assistance and guarantees on their units. BaySaver, Bio Clean, Downstream Defender, and Vortechnics have the best removal efficiencies, based on third party testing. The BaySaver and the Bio Clean Baffle Box are the most economical. The CDS unit and Vortechs unit have the smallest footprints. The Bressi Ranch Master Development utilizes CDS units as the primary treatment BMPs, treating runoff prior to entering 19 http:llwww.biocleanenvironmental.netl detention basins. To supplement this treatment method, the Bio Clean Nutrient Separating Baffle Box is recommended as a CFDS unit for Lots 19-22. The Bio Clean unit can separate out trash and debris, which would cause problems downstream, and by allowing for additional sedimentation, the master development detention basins will have an increased lifespan. Feasible Treatment BMP(s) Biofikration (grass swales) in conjunction with proprietary filtration based inlet inserts, and HDS/CFDS units are the feasible options for this project. APPENDIX 5 Supplemental BMP Information Operational & Maintenance Guidelines for Baffle Boxes The Bio Clean Nutrient Separating Baffle Box treating the storm water for Bressi Industrial Lots 19-22 will be located outside the public right-of-way and will be constructed, maintained, and funded by the development's Business Owners' Association (BOA). The Operational and Maintenance Plan of the Baffle Box includes: Inspection of its structural integrity and its biomass separating basket for damage. Animal and vector control. . Periodic sediment removal to optimize performance. Scheduled trash and debris removal to prevent obstruction. Preventive maintenance of BMP equipment and structures. Erosion and structural maintenance to maintain the performance of the Baffle Box. Inspection Frequency The device will be inspected and inspection visits will be completely documented: Once a month at a minimum. After every large storm (after every storm monitored or those storms with more than 0.50 inch of precipitation.) On a weekly basis during extended periods of wet weather. Aesthetic and Functional Maintenance Aesthetic maintenance is important for public acceptance of storm water facilities. Functional maintenance is important for performance and safety reasons. Both forms of maintenance are combined into an overall Storm Water Management System Maintenance Program. The following activities are included in the aesthetic maintenance program: Graffiti Removal: Graffiti will be removed in a timely manner to upkeep the appearance of the Baffle Box and discourage additional graffiti or other acts of vandalism. Functional maintenance has two components: -preventive maintenance and corrective maintenance. Preventive maintenance activities to be instituted at the Baffle Box are: Trash and debris removal. Trash and debris accumulation, as part of the operation and maintenance program at the Baffle Box, will be monitor once a month and alter every large storm event. Trash and debris will be removed from the Baffle Box annually (at end of wet season), or when material is at 85% of the biomass basket capacity (-25 inches deep), whichever occurs first. Sediment removal. Sediment accumulation, as part of the operation and maintenance program at the Baffle Box, will be monitored once a month and after every large storm (0.50 inch). Sediment will be removed from the Baffle Box annually (at end of wet season), or when material is at 85% of the Baffle Box's sump capacity (-30 inches deep), whichever occurs first. Characterization and disposal of sediment will comply with applicable local, county, state or federal requirements. Mechanical components. Regularly scheduled maintenance will be performed on fences, gates, and locks. Mechanical components will be operated during each maintenance inspection to assure continued performance. Elimination of mosquito breeding habitats. The most effective mosquito control program is one that eliminates potential breeding habitats; therefore, keep hatches closed when not inspecting or servicing. Corrective maintenance is required on an emergency or non-routine basis to correct problems and to restore the intended operation and safe function of the Baffle Box. Corrective maintenance activities include: Removal of debris and sediment. Sediment, debris, and trash, which impede the hydraulic functioning of' the Baffle Box will be removed and properly disposed. Temporary arrangements will be made for handling the sediments until a permanent arrangement is made. Structural repairs. Once deemed necessary, repairs to structural components of the Baffle Box and its inlet and outlet structures will be done within 30 working days. Qualified individuals (i.e., the manufacturer's representatives) will conduct repairs where structural damage has occurred. Erosion repair. Where factors have created erosive conditions (i.e., pedestrian traffic, concentrated flow, etc.), corrective steps will be taken to prevent loss of soil and any subsequent danger to the performance of the Baffle Box. There are a number of corrective actions than can be taken. These include erosion control blankets, riprap, or reduced flow through the area. Designers or contractors will be consulted to address erosion problems if the solution is not evident. Elimination of animal burrows. Animal burrows will be filled and steps taken to remove the animals if burrowing problems continue to occur (filling and compacting). If the problem persists, vector control specialists will be consulted regarding removal steps. This consulting is necessary as the threat of rabies in some areas may necessitate the animals being destroyed rather than relocated. If the BMP performance is affected, abatement will begin. Otherwise, abatement will be performed annually in September. General facility maintenance. In addition to the above elements of corrective maintenance, general corrective maintenance will address the overall facility and its associated components. If corrective maintenance is being done to one component, other components will be inspected to see if maintenance is needed. Debris and Sediment Disposal Waste generated at the Baffle Box is ultimately the responsibility of the BOA for Bressi Industrial Lots 19-22. Disposal of sediment, debris, and trash will comply with applicable local, county, state, and federal waste control programs. Hazardous Waste Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous wastes generated onsite will be handled and disposed of according to applicable local, state, and federal regulations. A solid or liquid waste is considered a hazardous waste if it exceeds the criteria list in the CCR, Title 22, Article 11. Operational & Maintenance Guidelines for Vegetated Swale The operational and maintenance needs of a Swale are: Vegetation management to maintain adequate hydraulic functioning and to limit habitat for disease-carrying animals. Animal and vector control. Periodic sediment removal to optimize performance. Trash, debris, grass trimmings, tree pruning, and leaf collection and removal to prevent obstruction of a Swale. Removal of standing water, which may contribute to the development of aquatic plant communities or mosquito breeding areas. Erosion and structural maintenance to prevent the loss of soil and maintain the performance of the Swale. Inspection Frequency The facility will be inspected and inspection visits will be completely documented: • Once a month at a minimum. After every large storm (after every storm monitored or those storms with more than 0.50 inch of precipitation.) • On a weekly basis during extended periods of wet weather. Aesthetic and Functional Maintenance Aesthetic maintenance is important for public acceptance of stormwater facilities. Functional maintenance is important for performance and safety reasons. Both forms of maintenance will be combined into an overall Stormwater Management System Maintenance. Aesthetic Maintenance The following activities will be included in the aesthetic maintenance program: Grass Trimming. Trimming of grass will be done on the swales, around fences, at the inlet and outlet structures, and sampling structures. Weed Control. Weeds will be removed through mechanical means. Herbicide will not be used because these chemicals may impact water quality. Functional Maintenance Functional maintenance has two components: preventive maintenance and corrective maintenance. Preventive Maintenance Preventive maintenance activities to be instituted at a Swale are: Trash and Debris. During each inspection and maintenance visit to the site, debris and trash removal will be conducted to reduce the potential for inlet and outlet structures and other components from becoming clogged and inoperable during storm events. Sediment Removal. Sediment accumulation, as part of the operation and maintenance program at a Swale, will be monitored once a month during the dry season, after every large storm (0.50 inch), and monthly during the wet season. Specifically, if sediment reaches a level at or near plant height, or could interfere with flow or operation, the sediment will be removed. If accumulation of debris or sediment is determined to be the cause of decline in design performance, prompt action (i.e., within ten working days) will be taken to restore the Swale to design performance standards. Actions will include using additional fill and vegetation and/or removing accumulated sediment to correct channeling or ponding. Characterization and Appropriate disposal of sediment will comply with applicable local, county, state, or federal requirements. The swale will be regraded, if the flow gradient has changed, and then replanted with sod. Removal of Standing Water. Standing water must be removed if it contributes to the development of aquatic plant communities or mosquito breeding areas. Fertilization and Irrigation. Where appropriate, fertilizers and irrigation will be used to maintain the vegetation. Elimination of Mosquito Breeding Habitats. The most effective mosquito control program is one that eliminates potential breeding habitats. Corrective Maintenance Corrective maintenance is required on an emergency or non-routine basis to correct problems and to restore the intended operation and safe function of a Bio-filter. Corrective maintenance activities include: Removal of Debris and Sediment. Sediment, debris, and trash, which impede the hydraulic functioning of a bio-filter and prevent vegetative growth, will be removed and properly disposed. Temporary arrangements will be made for handling the sediments until a permanent arrangement is made. Vegetation will be re-established after sediment removal. Structural Repairs. Once deemed necessary, repairs to structural components of a bio-filter and its inlet and outlet structures will be done within 10 working days. Qualified individuals (i.e., the designers or contractors) will conduct repairs where structural damage has occurred. Embankment and Slope Repairs. Once deemed necessary, damage to the embankments and slopes of bio-filters will be repaired within 10 working days). Erosion Repair. Where a reseeding program has been ineffective, or where other factors have created erosive conditions (i.e., pedestrian traffic, concentrated flow, etc.), corrective steps will be taken to prevent loss of soil and any subsequent danger to the performance of a bio-filter. There are a number of corrective actions than can be taken. These include erosion control blankets, riprap, sodding, or reduced flow through the area. Designers or contractors will be consulted to address erosion problems if the solution is not evident. Fence Repair. Repair of fences will be done within 30 days to maintain the security of the site. Elimination of Animal Burrows. Animal burrows will be filled and steps taken to remove the animals if burrowing problems continue to occur (filling and compacting). If the problem persists, vector control specialists will be consulted regarding removal steps. This consulting is necessary as the threat of rabies in some areas may necessitate the animals being destroyed rather than relocated. If the BMP performance is affected, abatement will begin. Otherwise, abatement will be performed annually in September. General Facility Maintenance. In addition to the above elements of corrective maintenance, general corrective maintenance will address the overall facility and its associated components. If corrective maintenance is being done to one component, other components will be inspected to see if maintenance is needed. Debris and Sediment Disposal Waste generated in the bio-filters is ultimately the responsibility of the BOA for Bressi Industrial Lots 19-22. Disposal of sediment, debris, and trash will comply with applicable local, county, state, and federal waste control programs. Hazardous Waste Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous wastes generated onsite will be handled and disposed of according to applicable local, state, and federal regulations. A solid or liquid waste is considered a hazardous waste if it exceeds the criteria listed in the CCR, Title 22, Article 11. Section 6 Long-term Maintenance of BMPs 6.1 Introduction The long-term performance of BMPs hinges on ongoing and proper maintenance. In order for this to occur, detailed maintenance plans are needed that include specific maintenance activities and frequencies for each type of BMP. In addition, these should include indicators for assessing when "as needed" maintenance activities are required. The fact sheets included in this volume contain the basic information needed to develop these maintenance plans, but municipalities and other regulatory agencies also need to identify the responsible party and potentially to address funding requirements. The following discussion is based primarily on data developed by Homer et al. (1994) and information available at http://www.stormwatercenter.net/ 6.2 Critical Regulatory Components Critical regulatory components identified by Homer et al. (1994) include: Regulations should officially designate a responsible party, frequently the development site owner, to have ultimate responsibility for the continued maintenance of stormwater facilities. This official designation provides the opportunity for appropriate preparation and budgeting prior to actually assuming responsibilities. It also facilitates enforcement or other legal remedies necessary to address compliance or performance problems once the facility has been constructed. Regulations should dearly state the inspection and maintenance requirements. Inspection and maintenance requirements should also comply with all applicable statutes and be based on the needs and priorities of the individual measure or facility. A clear presentation will help owners and builders comply, and inspectors enforce requirements. Regulations should contain comprehensive requirements for documenting and detailing maintenance. A facility operation and maintenance manual should be prepared containing accurate and comprehensive drawings or plans of the completed facility and detailed descriptions and schedules of inspection and maintenance. The regulations should delineate the procedure for maintenance noncompliance. This process should provide informal, discretionary measures to deal with periodic, inadvertent noncompliance and formal and severe measures to address chronic noncompliance or performance problems. In either case, the primary goal of enforcement is to maintain an effective BMP - the enforcement action should not become an end in itself. Regulations should also address the possibility of total default by the owner or builder by providing a way to complete construction and continue maintenance. For example, the public might assume maintenance responsibility, if so, the designated public agency must be alerted and possess the necessary staffing, equipment, expertise, and funding to assume this responsibility. Default can be addressed through bonds and other performance January 2003 California Stormwater BMP Handbook 6-1 Errata 9-04 New Development and Redevelopment www.cabmphandbooks.com Section 6 Long-term Maintenance of BMPs guarantees obtained before the project is approved and construction begins. These bonds can then be used to fund the necessary maintenance activities. The regulations must recognize that adequate and secure funding is needed for facility inspection and maintenance, and provide for such funding. 6.3 Enforcement Options A public agency will sometimes need to compel those responsible for facility construction or maintenance to fulfill their obligations. Therefore, the maintenance program must have enforcement options for quick corrective action. Rather than a single enforcement measure, the program should have a variety of techniques, each with its own degree of formality and legal weight. The inspection program should provide for nonconforming performance and even default, and contain suitable means to address all stages. Prior to receiving construction approval, the developer or builder can be forced to provide performance guarantees. The public agency overseeing the construction can use these guarantees, usually a performance bond or other surety in an amount equal to some fraction of the facility's construction cost, to fund maintenance activities. Enforcement of maintenance requirements can be accomplished through a stormwater maintenance agreement, which is a formal contract between a local government and a property owner designed to guarantee that specific maintenance functions are performed in exchange for permission to develop that property (http: //www.stormwatercenter.netl). Local governments benefit from these agreements in that responsibility for regular maintenance of the BMPs can be placed upon the property owner or other legally recognized party, allowing agency staff more time for plan review and inspection. 6.4 Maintenance Agreements Maintenance agreements can be an effective tool for ensuring long-term maintenance of on-site BMPs. The most important aspect of creating these maintenance agreements is to dearly define the responsibilities of each party entering into the agreement. Basic language that should be incorporated into an agreement includes the following: Performance of Routine Maintenance Local governments often find it easier to have a property owner perform all maintenance according to the requirements of a Design Manual. Other communities require that property owners do aesthetic maintenance (i.e., mowing, vegetation removal) and implement pollution prevention plans, but elect to perform structural maintenance and sediment removal themselves. Maintenance Schedules Maintenance requirements may vary, but usually governments require that all BMP owners perform at least an annual inspection and document the maintenance and repairs performed. An annual report must then be submitted to the government, who may then choose to perform an inspection of the facility. 6-2 California Stormwater BMP Handbook January 2003 New Development and Redevelopment Errata 9-04 www.cabmphandbooks.com Section 6 Long-term Maintenance of BMPs 3. Inspection Requirements Local governments may obligate themselves to perform an annual inspection of a BMP, or may choose to inspect when deemed necessary instead. Local governments may also wish to include language allowing maintenance requirements to be increased if deemed necessary to ensure proper functioning of the BMP. Access to BMPs The agreement should grant permission to a local government or its authorized agent to enter onto property to inspect BMPs. If deficiencies are noted, the government should then provide a copy of the inspection report to the property owner and provide a timeline for repair of these deficiencies. Failure to Maintain In the maintenance agreement, the government should repeat the steps available for addressing a failure to maintain situation. Language allowing access to BMPs cited as not properly maintained is essential, along with the right to charge any costs for repairs back to the property owner. The government may wish to include deadlines for repayment of maintenance costs, and provide for liens against property up to the cost of the maintenance plus interest. Recording Of The Maintenance Agreement An important aspect to the recording of the maintenance agreement is that the agreement be recorded into local deed records. This helps ensure that the maintenance agreement is bound to the property in perpetuity. Finally, some communities elect to include easement requirements into their maintenance agreements. While easement agreements are often secured through a separate legal agreement, recording public access easements for maintenance in a maintenance agreement reinforces a local governments right to enter and inspect a BMP. Examples of maintenance agreements include several available on the web at httb: //www.stormwatercenter.net/ 6.5 Public Funding Sources If local agencies are willing to assume responsibility for stormwater BMPs, it is essential to identify the long-term funding sources. Several of these are described below: General Tax Revenues Tax revenues are an obvious source of funding, particularly for the long-term inspection and maintenance of existing runoff and drainage facilities. The benefits and protection to the public from continued safe and effective operation of the facility justifies using revenues from general funds. To use tax revenues, particularly from a general fund, the inspection and maintenance program must annually compete with all other programs included in the governments annual operating budget. This inconsistent and unreliable funding makes securing a long-term financial January 2003 California Stormwater BMP Handbook 6-3 Errata 9-04 New Development and Redevelopment www.cabmphandbooks.com Section 6 Long-term Maintenance of BMPs commitment to inspection and maintenance difficult and subject to political pressures. Nevertheless, tax revenues remain a popular funding source because the collection and disbursement system is already in place and familiar. Utility Charges Using utility charges to fund inspection and maintenance is a somewhat recent application of an already established financing technique. In addition, several municipalities and counties throughout the country have runoff management, drainage, and flood control authorities or districts to provide residents with runoff related services. Using utility charge financing has several advantages. By addressing only runoff needs and benefits, utility funding avoids competing with other programs and needs. Utility funding also demonstrates a direct link between the funding and the services it provides. This approach can require an entirely new operating system and organization that needs legal authorization to exist, operate, and assess charges. The effort required to create such an entity can deter many, although the continued success of established authorities and growth of new ones have done much to allay concerns over the effort required. In a runoff utility, the user charges are often based on the need for services rather than the benefits derived from them. While charges are based on actual costs to inspect and maintain runoff facilities and measures within the service area, the assessed rate structure should relate to site characteristics. These include properly area size, extent of impervious coverage, and other factors with a direct and demonstrable effect on runoff. To be fair, the rate structure should also remain simple and understandable to the ratepayer. To finance the stormwater utility in Prince William County, Virginia, residential and nonresidential owners of developed property pay based on the amount of impervious area (rooftops, paved areas, etc.) on their property. Residents pay $10.38 billed twice a year ($20.76 total annual fee) for detached singe-family homes. Town home and condominium owners will Pay $7.785 billed twice a year ($i.57 total annual fee). Nonresidential property owners pay $0.84 per ;000 ft2 of impervious area per month. Fee adjustments or credits may be available if a stormwater management system is already in place. The fee will be on the real estate bills. Fees for the stormwater utility in Austin, Texas are higher with. residential users billed $5.79/mo, while commercial users pay $94.62/mo/acre of impervious cover. These fees cover not only maintenance of existing BMPs, but also capital improvement projects related to the drainage infrastructure. Permit Fees Collecting permit fees to finance runoff inspection and maintenance is a long standing funding procedure. Most governmental entities, local, county, and state, can establish and collect fees and other charges to obtain operating funds for programs and services. Many inspection services, most notably the construction inspection of both ESC measures and permanent drainage and runoff management facilities, are financed at least in part through fees collected by permitting agencies. Unlike taxes or some utility charges, inspection costs are borne by those who need them. 6-4 California Stormwater BMP Handbook January 2003 New Development and Redevelopment Errata 9-04 www.cabmphandbooks.com Section 6 Long-term Maintenance of BMPs The permit fee collection program should have a demonstrable link to the runoff management or drainage systems. The public agency should demonstrate a direct link between the permit fees collected and the permitted project. One method is using dedicated accounts for individual projects and facilities. Finally, the rate structure should reflect site characteristics such as area size or imperviousness that directly relate to the measure or facility by affecting runoff or erosion. Dedicated Contributions Public agencies at times have used developer contributions to fund long-term facility maintenance. This approach is particularly appropriate in single-family residential subdivisions, where numerous individual property owners served by a single runoff facility can result in confusion over who has maintenance responsibility. The exact funding technique depends on many factors, including community attitude and knowledge, economic and political viability, and program needs and costs. Some techniques, including permit fees and dedicated contributions, may be more appropriate for short-term activities, such as construction inspection. Other utility charges and specialized tax revenues may apply to all phases of an inspection and maintenance program but require considerable effort and special legal authorization to operate. January 2003 California Stormwater BMP Handbook 6-5 Errata 9-04 New Development and Redevelopment www.cabmphandbooks.com Treatment BMP SettingThe Structure jjjLSLt CL (jjl Ithsili Units Sits Only 3To4 Feet Below Flow Line Of Pipe. Ile . AISJ Ux ~11 t.11TUfv-1q) 0 'Yt III j r LL' Unit Require Minimal Amount Of Head To Operate Al thituii [w UJI 32911 Js fl +•12 .••* . -t• - i1t T", y In Line Design Treats High Flow Rates L1i \!'tLi ENViRONMENTAL SERVICES, 1NC. L_... Nutrient rich vsg.tatlon and litter are captur.d In filtration screen system. Sedlnmr,t.. ottte to the $10"8104" During Storm Event - I O.fl.eo. tk,mmn. $n.luiut$ •.. BOdmmsnt Test Results from Vortecnlchs Website proves that these systems are a source of nutrient pollution. A stonnwater BMP being a source of pollution doesn't make sense. I j I totet. I'n'esi lttuwt*l Ct -SI_.bat. Titer, Is. POrtal Kcemal.( TN. Look at the cleanliness or the water In our system. It has been reported that small fish have been found living In this system. All Pollutants Captured In these Systems are allowed to float In the Standing Water. This allows organics to leach their nutrients into the water and allows litter to decompose In the water. This leads to Increased levels of nutrients, septic conditions and overall decreased water quality. - - 4- Separated from the Competition" N.4$ant rich v..,.teb.n and liii., are .bc. atetto water end dries out tew.sn stern.W~ft. With the organic ps5uten1 Is asparated frten water, the systen. do.s not go septic. Sklnwrer S.dlm.nl s.imsnt S. rdl.n.ttt After Storm Event Pollutants captured in Upper Screen are allowed to dry out between storm events. Water Is kept clean and clear The Nutrient Separating Baffle Box Separates Organics (Debris) and Litter from the Standing Water. LF ., Iwo / When this debris Is kept In a wet state, the nutrients will leach out and resuspend In the water column In a few days, becoming a source of nutrients pollution. (ASC Monitorü Gtliis for Measuring Stonnwr Groat Solids Stonuwater Magazine, Nov/Dec 2005, page 10) v... - _____ •ujt•it ____•Biftl. teparaIIng Box _____ ____ '! - Standard Depth - Shallow Profile 7 ON Organics and Trash are Captured In Upper Screen, Separated from the Standing Water. Separating these pollutants cuts down on maintenance costs and gives maintenance crews a two stage cleaning option Organics and Trash Floating In the Water Held within this System. This leads to septic conditions. Dewatering o these pollutants also Increase maintenance costs. This Systems Small Footprint and Shallow Proffle reduces excavation costs and cuts down on installation time. High Excavation and Installation Costs - .- 19- LEFT END flEW PLAN ViEW 3-3o4-0 r 72 60 024 6 TYP RIGHT END ViEW - 732 - FRONT flEW LI fNl Y E I—I !'J c z_. c' c i E Q E L "C). IN! 8 B - i C:' - 4- FLOW. TREATMENT. & BYPASS SPECIFICATIONS FOR THE 810MA55 SEPARATING BASKET 1./n flow Pipe Area 3.1 so.rr. 2. Open Orifice Area in 30 .6 50 FT Biomass Seporoting Basket 3.Treotoble Flow Area With No Blockage - 30.6 SO.FT. Treatable Flow Area With 50X Blockage - 15.3 50. FT. Treatable Flow Area With 75X Blockage - 7.6 50. FT. 6.Minimum Bypass Available 5.2 SOFT. (With Basket 100X Full) SCREENED BOTTOMS - - -- HINGED BASKET STORAGE = 41.9 CU. FT. (1.6 CU YD.) TURBULENCE DEFLECTORS GROUT Tfl' SEDIMENT STORAGE -- 96 X 36 SCREENJ24 RCP P - ' AM.- SYSTEM t -4J7-fl3 l .IIJ7-?53 Lower Front Chamber - 50 CU. FT. Lower Middle Chamber - 48.8 CU. FT. Lower Rear Chamber— 41.2 CU. FT. TOTAL 140 CU. FT. (5.2 CU YD.) REAR I.YEW NOTES: RECQ(.A'.AEISIOEO IE SIZE5 I Z t .30" 30 HOLES 4 BAFFLE TYP Ii STORM BOOM ,- SKIMMER i.iuuiiuurai g j1111111111111 m I•ILIIHiLi RISER HEIGHT VARIES mc sTcrcmc n IUS ORAIW.0 IS MumLr wIENOEO ro Of INSTALLED IN Orr ROO LOC*INS IN7H LESS rw 3• Or coWR. S7RLCflS Alt WAVILY AVAI.A( MR ALL OINER CI1N& cONS4J SLIN7ltE TECh- pLoQEs R(pRtS(NTATIV TON XTA1LS CONCRETE 28 DAY COMPRESSIVE STRENGTH tc5.000 PSI. REINFORCINCASTM A-615, GRADE 60. J. SUPPORTS AN H20 LOADING AS INDICATED BY AASHTO, JOINT SEALANT. BUTYL RUBBER SS-S-00210 ALL WALLS. TOP + BOTTOM ARE 6 THICK. PEAK DESIGN FLOW 31.2 C.F.S. (BASED ON 6 FT. PER SEC. FLOW MULTIPLIED BY THE MIN. BYPASS AVAILABLE.) 11srRIBu TED 8': I 810 CLEATSJ ENVIROr-.1f4ENTEL SE%.nCE I .O. BOX 669. OCEANSIDE. CA. 92049 I TEL. 760-4.3.3-7640 F.AX:760-4.3.3—.3176 Eme.I: i,febiocIeariari,i.-avmer1taI.rIat P0 Box 869 Oceanside, CA 92049 Ph: 760-433-7640 Fax: 760-433-3176 www.biocleanenvironmentaLnet Specifications Concrete Nutrient Separating Baffle Box Product Description Recommended Cubic Yards Pipe Size & Volume CFS Model#: NSBB 4-6-72, Concrete Nutrient Separating Baffle Box Inside Dimensions: 4' wide x 6' long x 72" tall. 8" to 18" 2.5 Cu yd. - Box Cu yd. - Basket .43 Complete with screen system, turbulence deflectors and skimmer 12 CFS 2.93 Cu YD - Total system withStorm Boom. Model#: NSBB 4-8-84, Concrete Nutrient Separating Baffle Box Inside Dimensions: 4' wide x 8' long x 84" tall 3.4 Cu yd. - Box Complete with screen system, turbulence deflectors, and skimmer 12" to 18" .76 CU yd. - Basket system with Storm Boom. 3OCFS 4.16 Cu yd. - Total Model#: NSBB 5-10-84, Concrete Nutrient Separating Baffle Box Inside Dimensions: 5' wide x 10' long x 84" tall. 12" to 30" 5.2 Cu yd. - Box Complete with screen system, turbulence deflectors, and skimmer 30 CFS 1.6 Cu yd. - Basket system with Storm Boom. 6.8 Cu yd. - Total Model#: NSBB 6-12-84, Concrete Nutrient Separating Baffle Box Inside Dimensions: 6' wide x 12' long x 84" tall. 18" to 36" 7.5 Cu yd. - Box Complete with screen system, turbulence deflectors, and skimmer 45 CFS 2.1 Cu yd. - Basket system with Storm Boom. 9.6 Cu yd. - Total Model#: NSBB 8-12-96, Concrete Nutrient Separating Baffle Box Inside Dimensions: 8' wide x 12' long x 96" tall. 36" to 48" 10 Cu yd. - Box Complete with screen system, turbulence deflectors, and skimmer 60 CFS 2.5 CU yd. - Basket system with Storm Boom. 12.5 Cu yd. - Total Model#: NSBB 8-14-96, Concrete Nutrient Separating Baffle Box Inside Dimensions: 8' wide x 14' long x 96" tall. 40" to 54" 11.8 Cu yd. - Box Complete with screen system, turbulence deflectors, and skimmer 65 CFS 4.1 Cu yd. - Basket system with Storm Boom. 15.9 Cu yd. - Total Model#: NSBB 10-14-96, Concrete Nutrient Separating Baffle Box Inside Dimensions: 10' wide x 14' long x 96" tall. 48" to 72" 14.8 Cu yd. - Box Complete with screen system, turbulence deflectors, and skimmer 95 CFS ..AiCu yd. - Basket system with Storm Boom. 19.3 Cu yd. - Total Nutrient Separating Baffle Boxes are pre-assembled prior to delivery to the job site and a Bio Clean Environmental Services, Inc. representative is available to oversee the installation. Mir Our Bio-Sorb oil absorbing polymers are uniquely formulated to clean up... Spills Chemical Spills Fuel Oil Splits Diesel Oil Spills Control and absorb oil and hydrocarbons on any surface - including water Control oil spills and slicks In harbor and dock areas Control oil contamination in municipal run-off a Remove oil contamination from plant process water Clean-up fuel spills on highways Absorb hydrocarbon vapors and fumes 300 188.00 How Are Bio-Sorb Oil Absorbing Polymers Unique?' Bio-Sorb oil absorbing polymers function by first attracting hydrocarbons to the surface of the polymer to adsorb the liq- uid, followed immediately by Internally absorbing the media into its structure. Blo-Sorb oil absorbing polymers will not absorb water, which lends the material a unique usefulness for separating and collecting hydrocarbons from water mix- tures. Most notably, the polymer can commonly absorb from 20% to 200% or more of Its own weight of chemical or petro- leum derived liquids. Furthermore, because of the unique absorption characteristic of the material, Bio-Sorb becomes dry to the touch shortly after sorption. For What Applications May Biosorb Oil Absorbing Polymers beUseful? Potential applications for Bio3orb hydrocarbon absorbing materials are numerous as a result of their unique nature. One can imagine applications for commercial, industrial, defense and ecological markets. Stormwater Filters ° Concentrate Gamer Material for Liquid Additives O Removing Oil or Chemicals from Contaminated Water Streams or Water/Soil Slurries industrial Work Area Collection Mats 0 Spill Containment and Collection C Odor Barrier/Collector for Flavor Oils and Fragrances O Collection of Volatile Organic Compounds (VOC's) ° Many Others P.O. BOX 869 PHONE: 760.433.7640 OCEANSIDE, CA nbcleaewormiertta).net FAX: 760.433.3176 MME (seconds) Uptake C 0 0.00 0.0000 1 30.0 60.0: 104.00 107.00 2 3 120 128.00 4 180 155.00 240 164.00 ENVIRONMENTAL SERVICES, INC.L" P 0 Box 869, Oceanside, CA 92049 (760) 433-7640 Fax (760) 433-3176 Manual for Cleaning & Maintenance of Litter Nutrient Separation Baffle Box Your development or building has installed a Bio Clean Environmental Litter Nutrient Separation Baffle Boxes. The attached map shows the location of each of the systems. These systems were installed to comply with the State Water Resources Control Board for Nonpoint Source Pollution Control and Watershed Programs, implemented in 2000. It is the responsibility of the Homeowners Association or building owner to maintain and clean these systems and keep documentation on file. Documentation should include, but is not limited to, date of cleaning, type of debris and trash, organics, sediments and hydrocarbon by- products that were removed. These records must be readily available to be viewed by a city inspector, Water Control Board person or any future controlling board that may handle these inspections. The NSBB comes with a 10 year warranty which can become void if not properly maintained. The following procedures are necessary to maintain, clean and inspect your units. You may wish to contact Bio Clean Environmental Services directly to service your units to protect your warranty. Procedures for Cleaning and Maintaining Stormwater Filters The NSBB should be inspected within the first 6 months of installation to determine the frequency of cleaning. The inspection will determine how often the unit should be cleaned. It is recommended the NSBB be cleaned once to twice a year. Remove manhole covers to gain access to filter basket Remove all trash, debris, organics and all sediments collected by the basket. This can be performed by a vacuum truck or removed by hand. Please Note: Any entry into a unit will require Close Confinement equipment and certified training. S. Once basket has been completely cleaned, lift access hatches to expose sediments that have been captured below. A vacuum truck will be necessary to remove sediments. The advantage with the NSBB is the top basket can be cleaned separately and the sediment chambers below do not have to be cleaned until they are full. This also prevents the removal of any water from the system till the chambers below need to be cleaned. Page 2 of 2 Evaluation of the hydrocarbon booms shall be performed at each cleaning. If the booms are filled with hydrocarbons and oils they should be changed out. Booms should be changed out a minimum of at least once a year. Transport all debris, trash, organics and sediments to approved facility for disposal in accordance with local and state requirements. The hydrocarbon boom is classified as hazardous material and will have to picked up and disposed of as hazardous waste. Hazardous material can only be handled by a certified hazardous waste framed person. A report shall be filled out on the collected type of debris and condition of the filter. This report must be available for inspection upon request. See sample of report. CONTACT INFORMATION FOR SALES, INSTALLATION, OR MAINTENANCE SERVICE: BIO CLEAN ENVIRONMENTAL SERVICES, INC. P.O. BOX 869 OCEANSIDE, CA 92049 TEL: (760) 433-7640 FAX: (760) 433-3176 WWW.BIOCLEANENVIRONMENTAL.NET INSTALLATION NOTES: BIO CLEAN ENVIRONMENTAL SERVICES, INC. INLET FILTER INSERTS SHALL BE INSTALLED PURSUANT TO THE MANUFACTURER'S RECOMMENDATIONS AND THE DETAILS ON THIS SHEET. INLET FILTER INSERT SHALL PROVIDE FOR COVERAGE OF ENTIRE INLET OPENING, INCLUDING INLET WING(S) WHERE APPLICABLE, TO DIRECT ALL FLOW TO BASKET(S). ATTACHMENTS TO INLET WALLS SHALL BE MADE OF NON- CORROSIVE HARDWARE. FILTRATION BASKET STRUCTURE SHALL BE MANUFACTURED OF MARINE GRADE FIBERGLASS, GEL COATED FOR ULTRAVIOLET PROTECTION. FILTRATION BASKET FINE SCREEN AND COARSE CONTAINMENT SCREEN SHALL BE MANUFACTURED OF STAINLESS STEEL. FOR INLET FILTER INSERTS THAT INCLUDE THE SHELF SYSTEM, SHELF SYSTEM SHALL BE MANUFACTURED OF MARINE GRADE FIBERGLASS, GEL COATED FOR ULTRAVIOLET PROTECTION. MAINTENANCE NOTES: BIO CLEAN ENVIRONMENTAL SERVICES, INC. RECOMMENDS CLEANING AND DEBRIS REMOVAL MAINTENANCE A MINIMUM OF FOUR TIMES PER YEAR, AND REPLACEMENT OF HYDROCARBON BOOMS A MINIMUM OF TWICE PER YEAR. FOLLOWING MAINTENANCE AND/OR INSPECTION, THE MAINTENANCE OPERATOR SHALL PREPARE A MAINTENANCE/INSPECTION RECORD. THE RECORD SHALL INCLUDE ANY MAINTENANCE ACTIVITIES PERFORMED, AMOUNT AND DESCRIPTION OF DEBRIS COLLECTED, AND CONDITION OF FILTER. THE OWNER SHALL RETAIN THE MAINTENANCE/INSPECTION RECORD FOR A MINIMUM OF FIVE YEARS FROM THE DATE OF MAINTENANCE. THESE RECORDS SHALL BE MADE AVAILABLE TO THE GOVERNING MUNICIPALITY FOR INSPECTION UPON REQUEST AT ANY TIME. ANY PERSON PERFORMING MAINTENANCE ACTIVITIES MUST HAVE COMPLETED A MINIMUM OF OSHA 24-HOUR HAZARDOUS WASTE WORKER (HAZWOPER) TRAINING. FOR GRATE INLET UNITS: REMOVE GRATE TO GAIN ACCESS TO INLET FILTER INSERT. WHERE POSSIBLE THE MAINTENANCE SHOULD BE PERFORMED FROM THE GROUND SURFACE. NOTE: ENTRY INTO AN UNDERGROUND STORMWATER VAULT SUCH AS AN INLET VAULT REQUIRES CERTIFICATION IN CONFINED SPACE TRAINING. FOR CURB INLET UNITS: REMOVE MANHOLE LID TO GAIN ACCESS TO INLET FILTER INSERT. WHERE POSSIBLE THE MAINTENANCE SHOULD BE PERFORMED FROM THE GROUND SURFACE. NOTE: ENTRY INTO AN UNDERGROUND STORMWATER VAULT SUCH AS AN INLET VAULT REQUIRES CERTIFICATION IN CONFINED SPACE TRAINING. REMOVE ALL TRASH, DEBRIS, ORGANICS, AND SEDIMENTS COLLECTED BY THE INLET FILTER INSERT. EVALUATION OF THE HYDROCARBON BOOM SHALL BE PERFORMED AT EACH CLEANING. IF THE BOOM IS FILLED WITH HYDROCARBONS AND OILS IT SHOULD BE REPLACED. ATTACH NEW BOOM TO BASKET WITH PLASTIC TIES THROUGH PRE-DRILLED HOLES IN BASKET. TRANSPORT ALL DEBRIS, TRASH, ORGANICS AND SEDIMENTS TO APPROVED FACILITY FOR DISPOSAL IN ACCORDANCE WITH LOCAL AND STATE REQUIREMENTS. THE HYDROCARBON BOOM IS CLASSIFIED AS HAZARDOUS MATERIAL AND WILL HAVE TO BE PICKED UP AND DISPOSED OF AS HAZARDOUS WASTE. HAZARDOUS MATERIAL CAN ONLY BE HANDLED BY A CERTIFIED HAZARDOUS WASTE TRAINED PERSON (MINIMUM 24- HOUR HAZWOPER). Targeted Constituents ( Sediment A / Nutrients . / Trash . 1 Metals A / Bacteria . / Oil and Grease A / Organics A Legend (Removal Effectiveness) Low • High A Medium Vegetated Swale TC-30 Design Considerations Tributary Area Area Required Slope Water AvailabiL Description Vegetated swales are open, shallow channels with vegetation covering the side slopes and bottom that collect and slowly convey runoff flow to downstream discharge points. They are designed to treat runoff through filtering by the vegetation in the channel, filtering through a subsoil matrix, and/or infiltration into the underlying soils. Swales can be natural or manmade. They trap particulate pollutants (suspended solids and trace metals), promote infiltration, and reduce the flow velocity of stormwater runoff. Vegetated swales can serve as part of a stormwater drainage system and can replace curbs, gutters and storm sewer systems. California Experience Caltrans constructed and monitored six vegetated swales in southern California. These swales were generally effective in reducing the volume and mass of pollutants in runoff. Even in the areas where the annual rainfall was only about 10 inches/yr, the vegetation did not require additional irrigation. One factor that strongly affected performance was the presence of large numbers of gophers at most of the sites. The gophers created earthen mounds, destroyed vegetation, and generally relnecd the effectiveness of the controls for TSS reduction. Advantages If properly designed, vegetated, and operated, swales can serve as an aesthetic, potentially inexpensive urban development or roadway drainage conveyance measure with significant collateral water quality benefits. California Stormwater Quality Association January 2003 California Stormwater BMP Handbook 1 of 13 New Development and Redevelopment www.cabmphandbooks.com TC-30 Vegetated Swale Roadside ditches should be regarded as significant potential swale/buffer strip sites and should be utilized for this purpose whenever possible. Limitations Can be difficult to avoid channelization. May not be appropriate for industrial sites or locations where spills may occur Grassed swales cannot treat a very large drainage area. Large areas may be divided and treated using multiple swales. A thick vegetative cover is needed for these practices to function properly. They are impractical in areas with steep topography. They are not effective and may even erode when flow velocities are high, if the grass cover is not properly maintained. In some places, their use is restricted by law: many local municipalities require curb and gutter systems in residential areas. Swales are mores susceptible to failure if not properly maintained than other treatment BMPs. Design and Sizing Guidelines Flow rate based design determined by local requirements or sized so that 85% of the annual runoff volume is discharged at less than the design rainfall intensity. Swale should be designed so that the water level does not exceed 2/3rds the height of the grass or 4 inches, which ever is less, at the design treatment rate. Longitudinal slopes should not exceed 2.5% Trapezoidal channels are normally recommended but other configurations, such as parabolic, can also provide substantial water quality improvement and may be easier to mow than designs with sharp breaks in slope. Swales constructed in cut are preferred, or in fill areas that are far enough from an adjacent slope to minimize the potential for gopher damage. Do not use side slopes constructed of fill, which are prone to structural damage by gophers and other burrowing animals. A diverse selection of low growing, plants that thrive under the specific site, climatic, and watering conditions should be specified. Vegetation whose growing season corresponds to the wet season are preferred. Drought tolerant vegetation should be considered especially for swales that are not part of a regularly irrigated landscaped area. The width of the swale should be determined using Manning's Equation using a value of 0.25 for Manning's n. 2 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Vegetated Swale TC-30 Construction/Inspection Considerations Include directions in the specifications for use of appropriate fertilizer and soil amendments based on soil properties determined through testing and compared to the needs of the vegetation requirements. Install swales at the time of the year when there is a reasonable chance of successful establishment without irrigation; however, it is recognized that rainfall in a given year may not be sufficient and temporary irrigation may be used. If sod tiles must be used, they should be placed so that there are no gaps between the tiles; stagger the ends of the tiles to prevent the formation of channels along the swale or strip. Use a roller on the sod to ensure that no air pockets form between the sod and the soil. Where seeds are used, erosion controls will be necessary to protect seeds for at least 75 days after the first rainfall of the season. Performance The literature suggests that vegetated swales represent a practical and potentially effective technique for controlling urban runoff quality. While limited quantitative performance data exists for vegetated swales, it is known that check dams, slight slopes, permeable soils, dense grass cover, increased contact time, and small storm events all contribute to successful pollutant removal by the swale system. Factors decreasing the effectiveness of swales include compacted soils, short runoff contact time, large storm events, frozen ground, short grass heights, steep slopes, and high runoff velocities and discharge rates. Conventional vegetated swale designs have achieved mixed results in removing particulate pollutants. A study performed by the Nationwide Urban Runoff Program (NURP) monitored three grass swales in the Washington, D.C., area and found no significant improvement in urban runoff quality for the pollutants analyzed. However, the weak performance of these swales was attributed to the high flow velocities in the swales, soil compaction, steep slopes, and short grass height. Another project in Durham, NC, monitored the performance of a carefully designed artificial swale that received runoff from a commercial parking lot. The project tracked 11 storms and concluded that particulate concentrations of heavy metals (Cu, Pb, Zn, and Cd) were reduced by approximately 50 percent. However, the swale proved largely ineffective for removing soluble nutrients. The effectiveness of vegetated swales can be enhanced by adding check dams at approximately 17 meter (50 foot) increments along their length (See Figure i). These dams maximize the retention time within the swale, decrease flow velocities, and promote particulate settling. Finally, the incorporation of vegetated filter strips parallel to the top of the channel banks can help to treat sheet flows entering the swale. Only 9 studies have been conducted on all grassed channels designed for water quality (Table i). The data suggest relatively high removal rates for some pollutants, but negative removals for some bacteria, and fair performance for phosphorus. January 2003 California Stormwater BMP Handbook 3 of 13 New Development and Redevelopment www.cabmphandbooks.com TC-30 Vegetated Swale Table 1 Grassed swale pollutant removal efficiency data Removal Efficiencies (% Removal) - Study TSS TP TN NO3 Metals Bacteria Type Caltrans 2002 77 8 67 66 83-90 -33 dry swales Goldberg 1993 67.8 4.5 - 31.4 42-62 -100 grassed channel Seattle Metro and Washington 60 45 Department of Ecology 1992 - -25 2-16 -25 grassed channel Seattle Metro and Washington 83 29 Department of Ecology, 1992 - -25 46-73 -25 grassed channel Yang et al, 1981 8o - - - 70-80 - dry swale Dorman et al., 1989 98 18 - 45 37-81 - thy swale Harper, 1988 87 83 84 8o 88-90 - dry swale Kercher et al, 1983 99 99 99 99 99 - dry swale Harper, 1988. 81 17 40 52 37-69 - et swale Koon, 1995 67 39 - 9 -35 to 6 - ket swale While it is difficult to distinguish between different designs based on the small amount of available data, grassed channels generally have poorer removal rates than wet and dry swales, although some swales appear to export soluble phosphorus (Harper, 1988; Koon, 1995). It is not clear why swales export bacteria. One explanation is that bacteria thrive in the warm swale soils. Siting Criteria The suitability of a swale at a site will depend on land use, size of the area serviced, soil type, slope, imperviousness of the contributing watershed, and dimensions and slope of the swale system (Schueler et al., 1992). In general, swales can be used to serve areas of less than 10 acres, with slopes no greater than 5 %. Use of natural topographic lows is encouraged and natural drainage courses should be regarded as significant local resources to be kept in use (Young et al., 1996). Selection Criteria (NCTCOG, 1993) Comparable performance to wet basins Limited to treating a few acres Availability of water during dry periods to maintain vegetation Sufficient available land area Research in the Austin area indicates that vegetated controls are effective at removing pollutants even when dormant. Therefore, irrigation is not required to maintain growth during dry periods, but may be necessary only to prevent the vegetation from dying. 4 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Vegetated Swale TC-30 The topography of the site should permit the design of a channel with appropriate slope and cross-sectional area. Site topography may also dictate a need for additional structural controls. Recommendations for longitudinal slopes range between 2 and 6 percent. Flatter slopes can be used, if sufficient to provide adequate conveyance. Steep slopes increase flow velocity, decrease detention time, and may require energy dissipating and grade check. Steep slopes also can be managed using a series of check dams to terrace the swale and reduce the slope to within acceptable limits. The use of check dams with swales also promotes infiltration. Additional Design Guidelines Most of the design guidelines adopted for swale design specify a minimum hydraulic residence time of g minutes. This criterion is based on the results of a single study conducted in Seattle, Washington (Seattle Metro and Washington Department of Ecology, 1992), and is not well supported. Analysis of the data collected in that study indicates that pollutant removal at a residence time of 5 minutes was not significantly different, although there is more variability in that data. Therefore, additional research in the design criteria for swales is needed. Substantial pollutant removal has also been observed for vegetated controls designed solely for conveyance (Barrett et al, 1998); consequently, some flexibility in the design is warranted. Many design guidelines recommend that grass be frequently mowed to maintain dense coverage near the ground surface. Recent research (Colwell et al., 2000) has shown mowing frequency or grass height has little or no effect on pollutant removal. Summary of Design Recommendations i) The swale should have a length that provides a minimum hydraulic residence time of at least 10 minutes. The maximum bottom width should not exceed 10 feet unless a dividing berm is provided. The depth of flow should not exceed 2/3rds the height of the grass at the peak of the water quality design storm intensity. The channel slope should not exceed 2.5%. A design grass height of 6 inches is recommended. Regardless of the recommended detention time, the swale should be not less than 100 feet in length. The width of the swale should be determined using Manning's Equation, at the peak of the design storm, using a Manning's n of 0.25. The swale can be sized as both a treatment facility for the design storm and as a conveyance system to pass the peak hydraulic flows of the 100-year storm if it is located "on-line." The side slopes should be no steeper than 3:1 (H:V). Roadside ditches should be regarded as significant potential swale/buffer. strip sites and should be utilized for this purpose whenever possible. If flow is to be introduced through curb cuts, place pavement slightly above the elevation of the vegetated areas. Curb cuts should be at least 12 inches wide to prevent clogging. Swales must be vegetated in order to provide adequate treatment of runoff. It is important to maximize water contact with vegetation and the soil surface. For general purposes, select fine, close-growing, water-resistant grasses. If possible, divert runoff (other than necessary irrigation) during the period of vegetation January 2003 California Stormwater BMP Handbook 5 of 13 New Development and Redevelopment www.cabmphandbooks.com TC-30 Vegetated Swale establishment. Where runoff diversion is not possible, cover graded and seeded areas with suitable erosion control materials. Maintenance The useful life of a vegetated swale system is directly proportional to its maintenance frequency. If properly designed and regularly maintained, vegetated swales can last indefinitely. The maintenance objectives for vegetated swale systems include keeping up the hydraulic and removal efficiency of the channel and maintaining a dense, healthy grass cover. Maintenance activities should include periodic mowing (with grass never cut shorter than the design flow depth), weed control, watering during drought conditions, reseeding of bare areas, and clearing of debris and blockages. Cuttings should be removed from the channel and disposed in a local composting facility. Accumulated sediment should also be removed manually to avoid concentrated flows in the swale. The application of fertilizers and pesticides should be minimal. Another aspect of a good maintenance plan is repairing damaged areas within a channel. For example, if the channel develops ruts or holes, it should be repaired utilizing a suitable soil that is properly tamped and seeded. The grass cover should be thick; if it is not, reseed as necessary. Any standing water removed during the maintenance operation must be disposed to a sanitary sewer at an approved discharge location. Residuals (e.g., silt, grass cuttings) must be disposed in accordance with local or State requirements. Maintenance of grassed swales mostly involves maintenance of the grass or wetland plant cover. Typical maintenance activities are summarized below: Inspect swales at least twice annually for erosion, damage to vegetation, and sediment and debris accumulation preferably at the end of the wet season to schedule summer maintenance and before major fall runoff to be sure the swale is ready for winter. However, additional inspection after periods of heavy runoff is desirable. The swale should be checked for debris and litter, and areas of sediment accumulation. Grass height and mowing frequency may not have a large impact on pollutant removal. Consequently, mowing may only be necessary once or twice a year for safety or aesthetics or to suppress weeds and woody vegetation. Trash tends to accumulate in swale areas, particularly along highways. The need for litter removal is determined through periodic inspection, but litter should always be removed prior to mowing. Sediment accumulating near culverts and in channels should be removed when it builds up to 75 mm (3 in.) at any spot, or covers vegetation. Regularly inspect swales for pools of standing water. Swales can become a nuisance due to mosquito breeding in standing water if obstructions develop (e.g. debris accumulation, invasive vegetation) and/or if proper drainage slopes are not implemented and maintained. 6 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com 7 of 13 Vegetated Swale TC-30 Cost Construction Cost Little data is available to estimate the difference in cost between various swale designs. One study (SWRPC, 1991) estimated the construction cost of grassed channels at approximately $0.25 per ft2• This price does not include design costs or contingencies. Brown and Schueler (1997) estimate these costs at approximately 32 percent of construction costs for most stormwater management practices. For swales, however, these costs would probably be significantly higher since the construction costs are so low compared with other practices. A more realistic estimate would be a total cost of approximately $0.50 per ft2, which compares favorably with other stormwater management practices. TC-30 Vegetated Swale Table 2 Swale Cost Estimate (SEWRPC, 1991) Unit Cost Total Cost Low Moderate High Low Moderate High Component Unit Extent Mobil ation/ Swab 1 $107 $274 $441 $107 $274 $441 Damobiflzation-Light Site Preparation Clearing Acre 0.5 $2,200 $3,600 $6400 $1,100 $1,900 $2,700 Grubbing Acre 0.25 $3,800 $5,200 $6,600 $950 $1,300 $1,650 General E:ior Yd 372 $2.10 $3.70 $6.30 $761 $1,378 $1,972 Laval and TIP 1,210 $0.20 $0.35 $0.50 $242 $424 $605 Sites Dave Salvaged Topsoil Seed, and Mulch' Yd2 I 1,210 WAO $1.00 $1.80 $454 $1,210 $1,936 SocP Yd 1,210 $1.20 $240 $3.60 $1452 $2,904 $4,356 Subtotal - - -- - -- $5,116 $9,368 $13,680 Contingencies, Swale 1 25% 25% 25% $1,279 $2,347 $3415 Total -- - -- - -- $8,395 $11,735 $17,075 Source: (SE RPC, 1991) Note: Mobiiltionldernobilation refers to the organization and planning Involved in establishing a vegetative swab. 'Swale has a bottom width of 1.0 foot, a top width of 10 feet with 1:3 side slopes, and a 1,000-foot length. b Area cleared = (top width + 10 feet) x swale length. C Area grubbed = (top width x swale length). 'Volume excavated = (0.67 x top wldthx swale depth) x swale length (parabolic cross-section). Area tilled = (top width + &swale depth2) x swale length (parabolic cross-section). 3(top width) Area seeded = area cleared x 0.5. Area sodded = area cleared x 0.5. 8 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Vegetated Swale TC-30 Table 3 Estimated Maintenance Costs (SEWRPC. 19911 Swale Size (Depth and Top Width) Component Unit Cost Comment 1.5 Foot Depth, One- 3-Foot Depth, 3-Foot Foot Bottom Width, Bottom Width, 21-Foot 10-Foot Top Width Top Width Lawn Mowing $0.85 11,000 fP/ moiMng $0.14 I lincerfoot $0.21 I linear foot Lawn maintenance arce=(top width + lO feet) x length. Maw eight times per year General Lawn Care $9.00 11,000 fi/ year $0.18 I lincerfoot $0.28 I linear foot Lawn maintenance area = (top width+ lo foot) xlength Swale Debris and Utter $0.10 / linear foot lyear $0.10 /llncerfoot $0.10 l linear foot - Removal Grass Reseeding with $0.301yd2 $0.011 linearfact $0.01 /linear foot Area revegelatod equals 1% Mulch and Fertilizer of lawn maintenance area per year Program Administration and $0.151 linear Ibat 1 year, $0.15 1lincerfoot $0.15 /linear foot Inspect Ibur times per year Swale Inspection plus $25/ inspection Total -- $0.58 ' Ilnearfoot $ 0.15/ Ilno& toot - January 2003 California Stormwater BMP Handbook 9 of 13 New Development and Redevelopment www.cabmphandbooks.com TC-30 Vegetated Swale Maintenance Cost Caltrans (2002) estimated the expected annual maintenance cost for a swale with a tributary area of approximately 2 ha at approximately $2,700. Since almost all maintenance consists of mowing, the cost is fundamentally a function of the mowing frequency. Unit costs developed by SEWRPC are shown in Table 3. In many cases vegetated channels would be used to convey runoff and would require periodic mowing as well, so there may be little additional cost for the water quality component. Since essentially all the activities are related to vegetation management, no special training is required for maintenance personnel. References and Sources of Additional Information Barrett, Michael E., Walsh, Patrick M., Malina, Joseph F., Jr., Charbeneau, Randall J, 1998, "Performance of vegetative controls for treating highway runoff," ASCE Journal of Environmental Engineering, Vol. 124, No. ii, pp. 1121-1128. Brown, W., and T. Schueler. 1997. The Economics of Stormwater BMPs in the Mid-Atlantic Region. Prepared for the Chesapeake Research Consortium, Edgewater, MD, by the Center for Watershed Protection, Ellicott City, MD. Center for Watershed Protection (CWP). 1996. Design of Stormwater Filtering Systems. Prepared for the Chesapeake Research Consortium, Solomons, MD, and USEPA Region V, Chicago, IL, by the Center for Watershed Protection, Ellicott City, MD. Colwell, Shanti R., Homer, Richard R., and Booth, Derek B., 2000. Characterization of Performance Predictors and Evaluation of Mowing Practices in Biofiltration Swales. Report to King County Land And Water Resources Division-and others by Center for Urban Water Resources Management, Department of Civil and Environmental Engineering, University of Washington, Seattle, WA Dorman, M.E., J. Hartigan, R.F. Steg, and T. Quasebarth. 1989. Retention, Detention and Overland Flow for Pollutant Removal From Highway Stormwater Runoff. Vol. 1. FHWA/RD 89/202. Federal Highway Administration, Washington, DC. Goldberg. 1993. Dayton Avenue Swale Biofiltration Study. Seattle Engineering Department, Seattle, WA. Harper, H. 1988. Effects of Stormwater Management Systems on Groundwater Quality. Prepared for Florida Department of Environmental Regulation, Tallahassee, FL, by Environmental Research and Design, Inc., Orlando, FL. Kercher, W.C., J.C. Landon, and R. Massarelli. 1983. Grassy swales prove cost-effective for water pollution control. Public Works, 16:53-55. Koon, J. 1995. Evaluation of Water Quality Ponds and Swales in the Issaquah/East Lake Sammamish Basins. King County Surface Water Management, Seattle, WA, and Washington Department of Ecology, Olympia, WA. Metzger, M. E., D. F. Messer, C. L. Beitia, C. M. Myers, and V. L. Kramer. 2002. The Dark Side Of Stormwater Runoff Management: Disease Vectors Associated With Structural BMPs. Stormwater 3(2): 24-39.Oaldand, P.H. 1983. An evaluation of stormwater pollutant removal 10 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Vegetated Swale TC-30 through grassed swale treatment. In Proceedings of the International Symposium of Urban Hydrology, Hydraulics and Sediment Control, Lexington, KY: pp. 173-182. Occoquan Watershed Monitoring Laboratory. 1983. Final Report: Metropolitan Washington Urban Runoff Project. Prepared for the Metropolitan Washington Council of Governments, Washington, DC, by the Occoquan Watershed Monitoring Laboratory, Manassas, VA. Pitt, R., and J. McLean. 1986. Toronto Area Watershed Management Strategy Study: Humber River Pilot Watershed Project. Ontario Ministry of Environment, Toronto, ON. Schueler, T. 1997. Comparative Pollutant Removal Capability of Urban BMPs: A reanalysis. Watershed Protection Techniques 2(2):379-383. Seattle Metro and Washington Department of Ecology. 1992. Biofiltration Swale Performance: Recommendations and Design Considerations. Publication No. 657. Water Pollution Control Department, Seattle, WA. Southeastern Wisconsin Regional Planning Commission (SWRPC). 1991. Costs of Urban Nonpoint Source Water Pollution Control Measures. Technical report no. 31. Southeastern Wisconsin Regional Planning Commission, Waukesha, WI. U.S. EPA, 1999, Stormwater Fact Sheet: Vegetated Swales, Report # 832-F-99-006 http://www.epa.gov/owm/mtb/vegswale.pdf, Office of Water, Washington DC. Wang, T., D. Spyridakis, B. Mar, and R. Homer. 1981. Transport, Deposition and Control of Heavy Metals in Highway Runoff. FHWA-WA-RD-39-10. University of Washington, Department of Civil Engineering, Seattle, WA. Washington State Department of Transportation, 1995, Highway Runoff Manual, Washington State Department of Transportation, Olympia, Washington. Welborn, C., and J. Veenhuis. 1987. Effects of Runoff Controls on the Quantity and Quality of Urban Runoff in Two Locations in Austin, 1X. USGS Water Resources Investigations Report No. 87-4004. U.S. Geological Survey, Reston, VA. Yousef, Y., M. Wanielista, H. Harper, D. Pearce, and R. Tolbert. 1985. Best Management Practices: Removal of Highway Contaminants By Roadside Swales. University of Central Florida and Florida Department of Transportation, Orlando, FL. Yu, S., S. Barnes, and V. Gerde. 1993. Testing of Best Management Practices for Controlling Highway Runoff. FHWA/VA-93-R16. Virginia Transportation Research Council, Charlottesville, VA. Information Resources Maryland Department of the Environment (MDE). 2000. Maryland Stormwater Design Manual. www.mde.state.md.us/environment/wma/stormwatermanual. Accessed May 22, 2001. Reeves, E. 1994. Performance and Condition of Biofilters in the Pacific Northwest. Watershed Protection Techniques 1(3):117-119. January 2003 California Stormwater BMP Handbook 11 of 13 New Development and Redevelopment www.cabmphandbooks.com TC-30 Vegetated Swale Seattle Metro and Washington Department of Ecology. 1992. Biofiltration Swale Performance. Recommendations and Design Considerations. Publication No. 657. Seattle Metro and Washington Department of Ecology, Olympia, WA. USEPA 1993. Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters. EPA-840-B-92-002. U.S. Environmental Protection Agency, Office of Water. Washington, DC. Watershed Management Institute (WMI). 1997. Operation, Maintenance, and Management of Stormwater Management Systems. Prepared for U.S. Environmental Protection Agency, Office of Water. Washington, DC, by the Watershed Management Institute, Ingleside, MD. 12 of 13 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Vegetated Swale TC-30 Provide fcpur (a) Crms section of swab with check dam. protection. Notation: L = Length otawal. Impoundment area per check dam (ft) (b) Dimensional view ofswele Impoundment area. 01 = Depth ofthnck dam (ft) S3 Bottom ee of ewsie (WIn W : Top width otcheck dam (ft) We a Bottom width of check dam (It) Zns= Ratio of horizontal to vmtical change In awalo side slope (tuft) January 2003 California Stormwater BMP Handbook 13 of 13 New Development and Redevelopment www.cabmphandbooks.com Dec. 1, 1992 Street Sweeping Description Street sweeping involves the use of specialized equipment to remove litter, loose gravel, soil, pet waste, vehicle debris and pollutants, dust, de-icing chemicals, and industrial debris from road surfaces. Street sweeping equipment can consist of a truck or truck-like vehicle equipped with multiple brushes, pick-up deflector, holding bin, water sprayer, vacuum nozzle and filter, or a combination of some or all of these features. Pollutants Controlled and Impacts When done regularly, street sweeping can remove 5 0-90% of street pollutants that potentially can enter surface water through storm sewers. Street sweepers will also make road surfaces less slippery in light rains, improve aesthetics by removing litter, and control pollutants which can be captured by the equipment. Application Land Use Transportation, urban Soil/Topography/Climate Street sweeping is not effective on snow covered roads. When to Apply Street sweeping is typically done in the early morning hours when traffic is light. It is sometimes necessary to control parking by placing signs which limit the hours or the side of the Street in which parking is allowed. Where to Apply Street sweeping is applicable on urban streets with curb and gutter, or paved drainageways. Relationship With Other BMPs Sweeping is recommended at least four times per year on all Porous Asphalt Pavement. Street sweeping in some areas may decrease the frequency in which Catch Basins need to be cleaned. Specifications General Considerations: Approximately 90% of the contaminants will accumulate within 12 inches of the curb, therefore, only one sweep is generally necessary to remove contaminants. When replacing gutters or constructing new ones in urban areas, consider installing broader concrete gutters to increase street cleaning efficiency. SW-1 Damaged pavement is not possible to clean effectively and should be resurfaced in areas where street cleaning is done. Use vacuum sweepers on dry pavement only. Frequency of Sweeping: The frequency in which street sweeping should be done is very controversial, and the schools of thought range from "not at all" to "every other day." Some studies have shown that street sweeping may have a negative effect by breaking down aggregated particles (clumps of particles) into fine particles which can be carried more easily by runoff. We feel that the goal of street sweeping should be to keep the larger-sized pollutants from entering storm sewers. We recommend Street sweeping: -after heavy rain storms in which sediment is present on the streets; and -adjacent to construction sites where sediment has left the site and entered the street; and -at least once during the fall to collect leaves and keep them out of the sewer system; and -at least once during the spring to collect garbage and coarse sediment left behind during snow melt. The effectiveness of street sweeping appears to be primarily dependent upon the frequency of sweeping and the interval between storms. Additional considerations are operator skill and the number of cars parked at the curb. Other factors in order of importance are: total mass of the area to be swept and its relation to loadings on other areas not accessible to sweepers; the efficiency of sweepers compared to the storm runoff of the pollutant of interest; and local storm characteristics. Types of Sweepers: Street sweeping effectiveness is a function of sweeping frequency, number of passes per sweeping, equipment speed and pavement conditions. Below are two types of street sweepers. Keep in mind that street sweeping equipment is manufactured by more than one company and each company competes for design efficiency. Mechanical broom street sweepers are effective in removing larger particles, but are not effective in removing fine, pollutant-laden dust and dirt (smaller than 400 microns). These small particles contain the majority of pollutants found on the streets (i.e. oxygen demanding substances, nutrients, metals, oils). The removal efficiency for these machines is 50%, assuming a smoothly paved surface, particles greater than 400 microns, and the absence of parked vehicles. These are less expensive to operate than vacuum sweepers. Vacuum-type street sweepers are more efficient in removing dust and dirt particles (about 90%) than mechanical broom sweepers. However, vacuum sweepers are ineffective when the pavement is wet. SW-2 Maintenance In order to increase the effectiveness of street sweeping, roads should be kept well-surfaced. SW-3 Site Design & Landscape Planning SD-10 Design Objectives Maximize Infiltration Provide Retention I?l Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Description Each project site possesses unique topographic, hydrologic, and vegetative features, some of which are more suitable for development than others. Integrating and incorporating appropriate landscape planning methodologies into the project design is the most effective action that can be done to minimize surface and groundwater contamination from stormwater. Approach Landscape planning should couple consideration of land suitability for urban uses with consideration of community goals and projected growth. Project plan designs should conserve natural areas to the extent possible, maximize natural water storage and infiltration opportunities, and protect slopes and channels. Suitable Applications Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. Design Considerations Design requirements for site design and landscapes planning should conform to applicable standards and specifications of agencies with jurisdiction and be consistent with applicable Ceneil Plan and Local Area Plan policies. :anury C1D1r California Stormwater BMP Handbook 1 of 4 New Development and Redevelopment www, cahmpbandbooks. corn SD-10 Site Design & Landscape Planning Designing New Installations Begin the development of a plan for the landscape unit with attention to the following general principles: Formulate the plan on the basis of dearly articulated community goals. Carefully identify conflicts and choices between retaining and protecting desired resources and community growth- Map and assess land suitability for urban uses. Include the following landscape features in the assessment wooded land, open unwooded land, steep slopes, erosion-prone soils, foundation suitability, soil suitability for waste disposal, aquifers, aquifer recharge areas, wetlands, floodplains, surface waters, agricultural lands, and various categories of urban land use. When appropriate, the assessment can highlight outstanding local or regional resources that the community determines should be protected (e.g., a scenic area, recreational area, threatened species habitat, farmland, fish run). Mapping and assessment should recognize not only these resources but also additional areas needed for their sustenance. Project plan designs should conserve natural areas to the extent possible, maximize natural water storage and infiltration opportunities, and protect slopes and channels. Conserve Natural Areas during Landscape Planning If applicable, the following items are required and must be implemented in the site layout during the subdivision design and approval process, consistent with applicable General Plan and Local Area Plan policies: Cluster development on least-sensitive portions of a site while leaving the remaining land in a natural undisturbed condition. Limit clearing and grading of native vegetation at a site to the minimum amount needed to build lots, allow access, and provide fire protection. Maximize trees and other vegetation at each site by planting additional vegetation, clustering tree areas, and promoting the use of native and/or drought tolerant plants. Promote natural vegetation by using parking lot islands and other landscaped areas. Preserve riparian areas and wetlands. Maximize Natural Water Storage and Infiltration Opportunities Within the Landscape Unit Promote the conservation of forest cover. Building on land that is already deforested affects basin hydrology to a lesser extent than converting forested land. Loss of forest cover reduces interception storage, detention in the organic forest floor layer, and water losses by evapotranspiration, resulting in large peak runoff increases and either their negative effects or the expense of countering them with structural solutions. Maintain natural storage reservoirs and drainage corridors, including depressions, areas of permeable soils, swales, and intermittent streams. Develop and implement policies and 2 of 4 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Site Design & Landscape Planning SD-10 regulations to discourage the clearing, filling, and channelization of these features. Utilize them in drainage networks in preference to pipes, culverts, and engineered ditches. Evaluating infiltration opportunities by referring to the stormwater management manual for the jurisdiction and pay particular attention to the selection criteria for avoiding groundwater contamination, poor soils, and hydrogeological conditions that cause these facilities to fail. If necessary, locate developments with large amounts of impervious surfaces or a potential to produce relatively contaminated runoff away from groundwater recharge areas. Protection of Slopes and Channels during Landscape Design Convey runoff safely from the tops of slopes. Avoid disturbing steep or unstable slopes. Avoid disturbing natural channels. Stabilize disturbed slopes as quickly as possible. Vegetate slopes with native or drought tolerant vegetation. Control and treat flows in landscaping and/or other controls prior to reaching existing natural drainage systems. Stabilize temporary and permanent channel crossings as quiddy as possible, and ensure that increases in run-off velocity and frequency caused by the project do not erode the channel. Install energy dissipaters, such as riprap, at the outlets of new storm drains, culverts, conduits, or channels that enter unlined channels in accordance with applicable specifications to minimize erosion. Energy dissipaters shall be installed in such a way as to minimize impacts to receiving waters. Line on-site conveyance channels where appropriate, to reduce erosion caused by increased flow velocity due to increases in tributary impervious area. The first choice for linings should be grass or some other vegetative surface, since these materials not only reduce runoff velocities, but also provide water quality benefits from filtration and infiltration If velocities in the channel are high enough to erode grass or other vegetative linings, nprap, concrete soil cement, or geo-grid stabilization are other alternatives. . Consider other design principles that are comparable and equally effective. Redeveloping Existing Installations Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment If the definition applies, the steps outlined under "designing new installations" above should be followed. January 2003 California Stormwater BMP Handbook 3 of 4 New Development and Redevelopment www.cabmphandbooks.com SD-10 Site Design & Landscape Planning Redevelopment may present significant opportunity to add features which had not previously been implemented. Examples include incorporation of depressions, areas of permeable soils, and swales in newly redeveloped areas. While some site constraints may exist due to the status of already existing infrastructure, opportunities should not be missed to maximize infiltration, slow runoff, reduce impervious areas, disconnect directly connected impervious areas. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Stormwater Management Manual for Western Washington, Washington State Department of Ecology, August 2001. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft Febniary 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. 4 of 4 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com All green space can be BIORETENTION AREA LIMIT PEA GRAVEL CURTAIN DRAIN UNDERDRAIN SYSTEM TO STORM DRAIN GRASS SWALE PEA GRAVEL DIAPHRAGMS designed to be hydrologically functional and treat runoff. PAVEMENT pt INLET DEFLECTORS WITh CURB OPENING Pollutant Removal Oil and Grease'Over 95% Removal Dr. Eric Seagren - University Maryland Removal Mechanism Capture by mulch / soil / bacteria Metabolized by bacteria Pollutant Removal Potential of Aerobic Plant / Microbe / Soil Bioretention Systems TSS - 95% Heavy Metals - 99% Oil and Grease - 95% Total Phosphorous - 80% Total Nitrogen - 40% Coliform - 80% Treat over 90% of total volume in less than 1% of the urban landscape. *PLANT MATERLALS : - 3 - - --- I I I S a.. -"-'r 115 c- •iio r!j' ru j-. - jLL ili ~ It I ii'l ~!Ill li . 11111 -i-- A : i1llllllM 11 SD-12 Design Objectives Maximize Infiltration Provide Retention [?1 Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of I mproper Materials Contain Pollutants Collect and Convey Efficient Irrigation NEW Description Irrigation water provided to landscaped areas may result in excess irrigation water being conveyed into stormwater drainage systems. Approach Project plan designs for development and redevelopment should include application methods of irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance system. Suitable Applications Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. (Detached residential single-family homes are typically excluded from this requirement.) Design Considerations Designing New Installations The following methods to reduce excessive irrigation runoff should be considered) and incorporated and implemented where determined applicable and feasible by the Permittee: Employ rain-triggered shutoff devices to prevent irrigation after precipitation. Design irrigation systems to each landscape area's specific water requirements. Include design featuring flow reducers or shutoff valves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines. Implement landscape plans consistent with County or City water conservation resolutions) which may include provision of water sensors, programmable irrigation times (for short cycles), etc. rivac 003 Clifornia Stormwater 5Mb Handbook 1 of 2 Nev,, Development and Redevelopment Vvww. cabmphanclbooks. corn SD-12 Efficient Irrigation Design timing and application methods of irrigation water to minimize the runoff of excess irrigation water into the storm water drainage system. Group plants with similar water requirements in order to reduce excess irrigation runoff and promote surface filtration. Choose plants with low irrigation requirements (for example, native or drought tolerant species). Consider design features such as: - Using mulches (such as wood chips or bar) in planter areas without ground cover to minimize sediment in runoff - Installing appropriate plant materials for the location, in accordance with amount of sunlight and climate, and use native plant materials where possible and/or as recommended by the landscape architect - Leaving a vegetative barrier along the property boundary and interior watercourses, to act as a pollutant filter, where appropriate and feasible - Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain growth Employ other comparable, equally effective methods to reduce irrigation water runoff. Redeveloping Existing Installations Various jurisdictional storinwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed. Other Resources A Manual for the Standard Urban Storinwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. 2 of 2 Caflfomla Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Inlet Stenciling and Signage U.S. Environmental Protection Agency National Pollutant Discharge Elimination System (NPDES) _____ Recent Additions I Contact Us Print Version Search NPDES: EPA Home> OW Home > OWM Home > NPDES Home> Storm Water> Menu of BMPs Construction Activities -2003 Construction General Permit -Oil and Gas Public Involvement/Participation Stormwater Home Storm Drain Marking Description Storm drain marking involves labeling storm .. drain inlets with plaques, tiles, painted, or . pre cast messages warning citizens not to r—i--- 1 - dump pollutants into the drains The generallymessages are a simple phrase or graphic remind those passing by that the storm drains connect to local waterbodies and that dumping will pollute those waters. '.•., . - Some storm drain markers specify which waterbody the inlet drains to or name the particular river, lake or bay. Common messages include. No Dumping. Drains to Water Source, Drains to River, and "You Storm drains can be labeled with stencils to Dump It, You Drink It. No Waste Here.' In discourage dumping addition, storm drain markers often have pictures to convey the message, including a shrimp, common game fish, or a graphic depiction of the path from drain to waterbody. Communities with a large Spanish-speaking population might wish to develop markers in both English and Spanish, or use a graphic alone. Top Applicability Municipalities can undertake storm drain marking projects throughout the entire community, especially in areas with sensitive waters or where trash, nutrients, or biological oxygen demann have been identified as high priority pollutants. However, regardless of the condition of the waterbody, the signs can raise awareness about the connection between storm drains and receiving waters and can help to deter littering, excess fertilizer use, dumping, and other practices that contribute to nonpoint source pollution. Municipalities should prioritize drains for marking, because marking all drains within a municipality would be prohibitively expensive. The drains should be carefully selected to send the message to the maximum number of citizens (for example, in areas of high pedestrian traffic) and to target drains leading to waterbodies where illegal dumping has been identified as a source of pollution. Implementation Municipal crews or volunteers can affix or stencil messages on storm drains. Some municipalities feel that having their own crews do the work produces better results and eliminates liability and safety concerns. Other times volunteer groups conduct marking projects in cooperation with a municipality. In such an arrangement, volunteer groups provide the labor and the municipality provides supplies, safety equipment, and a map and/or directions to the drains to be marked. The benefits of using volunteers are lower cost and increased public awareness of storm water pollutants and their path to waterbodies. A municipality can establish Industrial Activity -Multi-Sector General Permit Municipal MS4s -Large & Medium -Small Stormwater Outreach Materials Phase I & Phase Ii -Menu of BMPs -Urbanized Area Maps a program to comprehensively address storm drain marking and actively recruit volunteer groups to help, or the municipality can facilitate volunteer groups that take the initiative to undertake a marking project. Whether the municipality or a volunteer group initiates a stenciling project, the municipality should designate a person in charge of the storm drain marking program. Many municipalities will designate a person from the public works or water quality department to coordinate marking projects by volunteer groups, while others might work with their communications department. Because these programs depend heavily on volunteer labor, organizers and coordinators should possess skills in recruiting, training, managing, and recognizing volunteers. Organizers and coordinators should provide the following: Marking kits containing all materials and tools needed to carry out a marking project A map of the storm drains to be marked Training for volunteers on safety procedures and on the technique for using stencils or affixing signs Safety equipment (traffic cones, safety vests, masks and/or goggles for spray paint, and gloves if glue is used) Incentives and rewards for volunteers (badges, T-shirts, certificates). The coordinator might also wish to provide pollutant-tracking forms to collect data on serious instances of dumping. Participants in storm drain marking projects can note storm drains that are clogged with debris or show obvious signs of dumping. This enables city crews to target cleanup efforts. Organizers should instruct volunteers on what kinds of pollutants to look for and how to fill out data cards. Volunteers also should record the locations of all storm drains labeled during the project for the city to track. Additionally, the participants should convene after the event to talk about what they have found. Their reactions and impressions can help organizers improve future marking projects. If a municipality chooses to initiate a storm drain marking program and solicit the help of volunteer organizations, they can advertise through a variety of channels. Outreach strategies include the following: Distributing pamphlets and brochures to area service organizations Placing articles in local magazines Taking out newspaper ads Placing an environmental insert in the local newspaper Making presentations at community meetings Developing public service announcements for radio Creating a web site with background and contact information as well as photos and stories from past marking events (the references section contains a list of storm drain marking web sites from communities across the country) Newspapers can be notified to get advance coverage of a planned storm drain marking event. Newspapers might choose to cover the event itself as an environmental feature story to further public awareness. A news release issued for the day of the event can draw television and/or newspaper coverage. Public service announcements made before the event also will help to reinforce the message. Additionally, some municipalities can have volunteers distribute door hangers in the targeted neighborhoods to notify residents that storm drain marking is taking place. The hangers explain the purpose of the project and offer tips on how citizens can reduce urban runoff in general. For any volunteer project to be successful, volunteers must feel they have done something worthwhile. Communities active in storm drain marking have developed a variety of ways to recognize volunteers, including Providing each participant with a certificate of appreciation and/or letter of thanks signed by the mayor Distributing logo items such as T-shirts, hats, badges, plastic water bottles, or other items to participants before or after the event Holding a picnic or small party after the event with refreshments donated by a local business Providing coupons for free pizza, hamburgers, ice cream, or movies donated by local merchants Taking pictures of storm drain marking teams before, during, and after the event to create a pictorial record of volunteers' activity. Since marking projects take place on city streets, volunteer safety is of utmost importance. The city might wish to designate lower-traffic residential areas as targets for volunteer marking and provide safety equipment and training. Most programs require that marking be done in teams, with at least one person designated to watch for traffic. Adult supervision is needed when volunteers are school children or members of youth groups. Most cities also require participating volunteers (or their parents, in the case of minors) to sign a waiver of liability. An attorney for the municipality should be consulted to determine what liability exists and how to handle this issue. Materials Permanent signs made from aluminum, ceramic, plastic, or other durable materials can be affixed with adhesive or heat applied to the street or sidewalk surface. These markers last longer than stenciled messages and need only glue to affix them to storm drain inlets. Many stock designs are available, or a municipality can develop or commission a design that is specific to the locality, such as with the name of the waterbody to which the inlet drains. These permanent signs can also be neater and easier to read from a distance. Tiles or plaques can be dislodged by pedestrian traffic if they are disturbed before the glue dries, so care should be taken to exclude pedestrians from areas where signs have been affixed recently. The reference section provides web resources for purchasing storm drain markers. Alternatively, communities can use stencils and paint to label their storm drains. Some communities stencil directly onto the curb, street, or sidewalk, while others first paint a white background and then stencil over it. The most commonly used stencils are made of Mylar, a flexible plastic material that can be cleaned and reused many times. However, stencils can also be made from cardboard, aluminum, or other material. Because painted stencils are not as durable as other types of markers, the message might need to be retouched or reapplied every few years. The reference section lists web sites where stencils can be purchased. Paint or ink can be sprayed on or applied by brush and roller. Spray paint is quickest and probably the easiest to apply neatly. Regions that do not meet federal air-quality standards should avoid using spray paints, since many contain air-polluting propellants. It is recommended to use "environmentally friendly paint that contains no heavy metals and is low in volatile organic compounds. Care should be taken to prevent any materials from entering the storm drain. Storm drain messages can be placed flat against the sidewalk surface just above the storm drain inlet, while others are placed on the curb facing the Street or on the street itself, either just upstream of the storm drain or on the street in front of the drain. However, messages placed on the street might wear out or be dislodged sooner. Another option is to retrofit or equip new developments with catch basins, grates, or inlet covers that are pre-cast with a storm water education message. This option is the longest lasting and most costly of the storm drain marking alternatives. It does not, however, foster public participation because the messages require installation by professionals or city crews. Westchester County, New York, and the City of White Plains have begun installing the DEco Curb catch basins cast with location-specific messages on county and city roads (Westchester County Department of Planning, 2001). The reference section provides a link to a manufacturer of cast iron storm water messages. Benefits Storm drain marking projects offer an excellent opportunity to educate the public about the link between the storm drain system and water quality. In addition to the labeled storm drains, media coverage of the program or storm drain marking event can increase public awareness of storm water issues. Volunteer groups can provide additional benefits by picking up trash near the marked storm drains and by noting where maintenance is needed. Additionally, marking projects can provide a lead-in to volunteer monitoring projects and increase community participation in a variety of other storm water-related activities. Limitations A storm drain marking program is generally effective, inexpensive, and easy to implement. However, larger communities can have many storm drain inlets, so volunteer coordinators need to be skilled at recruiting and organizing the efforts of volunteers to provide adequate coverage over large areas. Safety considerations might also limit marking programs in areas where traffic congestion is high. Other environmental considerations, such as the use of propellants in spray paint in areas that do not meet air quality standards, should be taken into account. Finally, stenciled messages will require repainting after years of weather and traffic, and tiles and permanent signs might need replacement if they are improperly installed or subject to heavy traffic or vandalism. Effectiveness By raising public awareness of urban runoff, storm drain marking programs should discourage practices that generate nonpoint source pollutants. As with any public education project, however, it is difficult to precisely measure the effect that storm drain marking programs have on human behavior. Surveys of public recognition of the storm drain message or surveys that capture changes in behavior can indicate whether a storm drain marking program is effective. It is not easy to measure reductions in certain components of urban runoff, which by definition is diffuse in origin. Some municipalities attempt to assess the effectiveness of storm drain marking programs by periodically examining water samples from targeted storm drain outf aIls (places where storm drains empty into a waterbody). If the storm drains leading to a particular outfall have been labeled, and if the levels of pollutants from that outfall decline after the labels were put in place, one can assume the labeling has had some deterrent effect. This monitoring can be conducted by the same volunteer groups that marked the drains and can be incorporated into existing volunteer monitoring programs or can initiate the development of a new program. Cities also infer storm drain marking program success from increases in the volume of used motor oil delivered to used-oil recycling centers. Others measure success in terms of how many drains are marked and the number of requests received by volunteer groups to participate in the program. They can also take into consideration the number of cleanups conducted by the city as a result of reports made by volunteers. Costs Plastic stencils, which can last for 25 to 500 stencilings, depending on whether paint is sprayed or applied with a brush or roller, can be purchased for $10-$15.50 depending on the size, materials, quantity purchased, and manufacturer. Metal stencils, which last longer, can cost $100 or more. Storm drain markers vary in cost depending on materials, design requirements, and the amount purchased. It is important to contact the manufacturer when pricing storm drain markers because custom sizes, shapes, and designs, such as those that specify a local waterbody, can increase the unit cost. For stock messages, however, ceramic tile markers cost approximately $7, whereas plastic markers of 4-inch diameter range in cost from $1 and $2.95 depending on material composition and quantity purchased. Glue for affixing the markers costs approximately $0.25 per application. Door hangers and other educational materials that complement the markers can also be purchased from some manufacturers, and oftentimes a "starter kit" is offered that includes a suite of materials to conduct a public outreach campaign. References How To Develop a Storm Drain Marking Program and Conduct Projeàts: East Dakota Water Development District. No date.Storm Drain Stenciling. lhttp://www.brookings.com/bswf/teachers/tp2.htm lIT dkclamir).J J. Accessed February 20, 2004. Hunter, A. 1995. Storm Drain Stenciling: The Street-River Connection. Fhtto://www.eoa.gov/volunteer/fa1195/urbwatlo.htm]. Last updated December 8, 1998. Accessed February 13, 2001. The Ocean Conservancy. 2003. Storm Drain Sentries. [p:/Iwww.oceanconservancy.org/dyhamic/learrilDroprams/sentries/sentries.htm lEx1Tdisc1iwr>l1. Accessed February 20, 2004. The Rivers Project, Southern Illinois University at Edwardsville. No Date. Gateway Area Storm Sewer Stenciling Project. Flhttp://www.siue.edu/OSME/river/stenciling/Storm.html I1T dc3a1m1r)'1J. Accessed February 20, 2004. Texas Natural Resource Conservation Commission. No date. Storm Drain Stenciling: Preventing Water Pollution. ____ Fhttp://www.tnrcc.state.tx.us/exec/oppr/cc2000/storm drain.html Tnhu1m)l1. Accessed February 13, 2001. Purchase Markers: ACP International. No date. Storm Drain Markers.___________ FhttP://www.acDinternational.comfstormdrain.phD IE.tT diIc13imI!r>l]. Accessed February 20, 2004. Clayworks. No date. Storm Drain Marking Program. lhttix//www.clayworks.net/stormwater.html 11T4ic3aimrr)]. Accessed February 20, 2004. Das Manufacturing, Inc. 2001. Storm Drain Markers. Fhttp:I/www.curbmarker.com/storrn/ lIX1T disclaimer ).l]. Accessed February 20, 2004. Purchase Stencils: Clean Ocean Action. 2000. Storm Drain Stenciling. Fhttø:I/www.cleanoceanaction.ora/Stenciling/StormDrains.html lFSITdIichimrr)1]. Last updated June 23, 2000. Accessed February 13, 2001. Earthwater Stencils, Ltd. 1997. Earthwater Stencils, Ltd. FhttD:/Iwww.earthwater-stencils.com Last updated 1991. Accessed February 14, 2001. Almetek Industries, Inc. 2004. Innovative Signs and ID Marking Systems. [http://www.drainmarkers.com IL1Td1c1aimr>I]. Accessed August 10, 2004. Purchase Cast Iron Messages: East Jordan Iron Works. 2003. Construction and Municipal Casting: NPDES Phase II Storm Water Regulation. Fhttp://www.eiiw.com/products.phtml?catici=36 Accessed February 19, 2004. Communities With Storm Drain Marking Web Sites: Brevard County, Florida. No date. Storm Drain Markers. _ FhttD:I/www.brevstorm.org/edu stormdrain markers.cfm Accessed February 20, 2004. City of Austin, Texas. 1995. Storm Drain Marking. [httø:/Iwww.ci.austin.tx.us/watershed/stormdrain marking.htm ITdi1cr>1]. Accessed February 20, 2004. City of Fort Worth, Texas. 2003. Storm Drain Marking Program. lhttD:I/ci.fort-worth.tx.us/dem/fishsipn.htm IL'clTdlclaimcr>I]. Last updated February 4, 2003. Accessed February 20, 2004. Connecticut Department of Environmental Protection, Office of Long Island Sound Programs. 2003. Storm Drain Marker Program. _ Fhttp:I/deD.state.ct.us/olisp/stormdrain/stormdrainmarker.pdf IxITdichim1>1]. Last updated February 1, 2003. Accessed February 20, 2004. City of Charlotte and Mecklenburg County, North Carolina. 2002. Charlotte-Mecklenburg Storm Drain Marking Program. Fhtt:I/www.charmeck.org/Departments/LU ESNWater+and+Land+Resources/Programs/ Water+Quality/Storm+Drain+Marking.htrn Accessed February 20, 2004. Communities With Storm Drain Stenciling Web Sites: City of Berkley, California, Department of Public Works. No date. Storm Drain Sewer Stenciling. ______ lhttD:IIwww.ci.berkelev.ca.us/PW/Storm/stencil.html Accessed February 13,2001. City of Honolulu, Hawaii. No date. Volunteer Activities. Fhttixl/www.cleanwaterhonolulu.com/drain.html lE-ITdi1c111m1r>I]. Accessed February 14, 2001. City of Portland, Oregon, Environmental Services. No date. Storm Drain Stenciling. FhttD:/Iwww.enviro.ci.portland.or.us/sds.htm 11Tdj3Jjmrr)I 1. Accessed February 14, 2001. Clemson Extension Office. No date. Storm Drain Stenciling South Carolina Paint The Drain" Campaign. [http:I/virtual.clemson.edu/groups/watergualitv/STENCIL.HTM [1Tduda1r)'l]. Accessed February 14, 2001. Friends of the Mississippi River.2000. Storm Drain Stenciling Program. Fhttp://www.fmr.org/stencil.html liXITdicIi'mr>I]. Last updated 2000. Accessed February 14,2001. Communities With Pre-Cst Storm Drain Message Web Site: Westchester County Department of Planning. 2001. New Catch Basins Curb Polluters. Storm Drain. Stenciling Tips NOTE: You may check out the storm drain stencil and a stenciling kit with the necessary paint, brushes, and other materials from: I Love A Clean San Diego, Inc. 4891 Pacific Highway, Suite 115 San Diego, CA 92110 (619) 291-0103 Stencil Placement: The stencil needs to be painted above the storm drain. The stencil message should be readable from the roadside. If the curb is red, paint directly above the red area. 110- 8 1 32 *Please remember not sit/stand in the street while completing this project* Stenciling Steps: Wipe the street curb with cloth. The area to be painted should be as clean as possible so the paint will adhere properly. Place the stencil in the location you've selected. Use wide masking tape to tape only the perimeter of the first stencil without taping down the inside of the stencil itself. (This will form the 8" x 32" rectangular background for y0uto paint white.). Open white paint only. Stir paint with mixing stick. Paint the rectangular area white. USE PAINT SPARINGLY!!! Remember, neatness is very important. If your storm drains are relatively close together, paint all the white backgrounds first, then return to paint the Think Blue stencil so the white paint has time to dry. Very Important: Make sure the paint is dry. Then tape the Think Blue stencil (illustrated above) on top of the white background. Open the blue paint, stir, and dab the blue paint sparingly using the Think Blue stencil. TIPS: If painting a rough surface, firmly hold down the stencil and dab (don't brush) the letters and the figure. Be careful not to get paint underneath the stencil. The key to success is to USE AS LITTLE PAINT ON YOUR BRUSH AS POSSIBLE. When finished painting, wipe off any paint on the outside of the container and tightly replace the lid to the paint. Anytime you stop painting for more than a couple minutes, place the brush in its plastic bag to keep the brush from drying. that threaten aquatic invertebrates. Several other types of insecticides have the potential to cause harm, especially malathion, carbaryl, and the pyrethroids. All pesticides must be used with caution and should never be allowed to go into storm water, as their impact in some cases is not known. Environmental regulations Agencies involved in pesticide regulation and water quality: California Department of Pesticide Regulation California State Water Resources Control Board U.S. Environmental Protection Agency Water The Federal Clean Water Act of 1972 requires that a written plan (called a Total Maximum Daily Load or TMDL) be developed for every water body that is impaired and does not meet water quality standards. Many California rivers and creeks have been identified as impaired. Find out more about the TMDL process and which water bodies have been identified: U.S. EPA TMDL Program California State Water Resources Control Board TMDL Program Illustration by Celeste Rusconi. Home I Manage Pests I Resources I Research I Search I Statewide IPM Program, Agriculture and Natural Resources, University of California All contents copyright © 2004 The Regents of the University of California. All rights reserved. For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage casts, or in the U.S., contact your local Cooperative Extension office for assistance. IWATER/U/watqual.html revised: March 29. 2004. Contact webmaster. process before releasing water into the river, they do not actually detoxify pesticides, thus sending residue into our waterways. How to avoid problems Use alternatives to pesticides when possible. If you must use pesticides, follow all instructions on the product label for proper use and be sure to store and dispose of all pesticides properly. Home I Manage Pests I Resources I Research I Search I Statewide IPM Program, Agriculture and Natural Resources, University of California All contents copyright @2004 The Regents of the University of California. All rights reserved. For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manace pests, or in the U.S., contact your local Cooperative Extension office for assistance. IWATER/U/stormdrain.html revised: March 29, 2004. Contact webmaster. EST MOTES February 2006 - - - Pubi. Pubi. No. Pubi. Pubi. No. Title Date No. Pp. Title Date No. Pp. Anntfal Bluegrass...............................................rev. 4/03 7464 3 Fruittree Leafroller on Ornamental and Anthracnose ..................................................... rev. 10/03 7420 4 Fruit Trees..............................................................3/00 7473 3 Ants....................................................................rev. 04/05 7411 6 Fungus Gnats, Shore Flies, Moth Flies, Aphids.................................................................rev. 5/00 7404 4 and March Flies.............................................rev. 8/01 7448 4 Apple Scab..........................................................rev. 8/01 7413 3 Giant Whitefly............................................................1/02 7400 3 Bark Beetles.........................................................rev. 4/04 7421 4 Glassy-winged Sharpshooter.................................11/01 7492 4 Bed Bugs..............................................................rev. 9/02 7454 2 Grasshoppers..............................................................9/02 74103 2 Bee and Wasp Stings.........................................rev. 2/03 7449 3 Green Kyllinga...................................................rev. 4/03 7459 3 Bermudagrass.....................................................rev. 9/02 7453 4 Hackberry Woolly Aphid.................................rev. 6/05 74111 3 Bordeaux Mixture....................................................11/00 7481 3 Head Lice.............................................................rev. 8/01 7446 4 Boxelder Bug...............................................................5/04 74114 3 Hobo Spider................................................................4/01 7488 3 Brown Recluse and Other Recluse Spiders ...........1/00 7468 4 Hoplia Beetle..............................................................9/02 7499 2 California Ground Squirrel..............................rev. 1/02 7438 5 Horsehair Worms............................................rev. 12/03 7471 2 California Oakworm ......................................... rev. 6/00 7422 4 House Mouse............................................................11/00 7483 4 Carpenter Ants..................................................rev. 11/00 7416 2 Kikuyugrass.......................................................rev. 4/03 7458 3 Carpenter Bees....................................................rev. 204 7417 2 Lace Bugs ............................... . ........................... rev. 12/00 7428 2 Carpenterworm..........................................................1/03 74105 4 Lawn Diseases: Prevention and Management 1/02 7497 8 Carpet Beetles....................................................rev. 4/01 7436 4 Lawn Insects.......................................................rev. 3/03 7476 6 Clearwing Moths...............................................rev. 4/04 7477 6 Leaf Curl............................................................rev. 12/00 7426 2 Cliff Swallows....................................................rev. 7/05 7482 4 Lizards.......................................................................10/04 74120 2 Clothes Moths ................. ................................. rev. 12/00 7435 3 Lyme Disease in California....................................12/00 7485 3 Clovers.......................................................................11/01 7490 3 Millipedes and Centipedes......................................3/00 7472 3 Cockroaches..............................................................11/99 7467 6 Mistletoe .............................................................. rev.2/06 7437 3 Codling Moth ................................................... rev.12/05 7412 6 Moles............................................................................5/04 74115 3 Common Knotweed................................................12/00 7484 2 Mosquitoes..................................................................2/98 7451 3 Common Purslane ........................................... rev.10/03 7461 3 Mushrooms and Other Nuisance Fungi Conenose Bugs .................................................. rev.11/02 7455 3 in Lawns.................................................................9/02 74100 4 Cottony Cushion Scale .................................... rev.12/03 7410 3 Nematodes..................................................................8/01 7489 5 Crabgrass ............................................................ rev.9/02 7456 4 Nutsedge ............................................................. rev.4/03 7432 4 Creeping Woodsorrel and Bermuda Oak Pit Scales ..................................................... rev.1/04 7470 2 Buttercup ........................................................ rev.1/02 7444 4 Oleander Leaf Scorch................................................7/00 7480 3 Dallisgrass............................11/01 7491 3 Olive Fruit Fly..........................................................12/03 74112 4 Dandelions..................................................................1/00 7469 3 Opossum.....................................................................4/05 74123 4 Delusory Parasitosis..........................................rev. 8/03 7443 2 Pantry Pests .......................................................rev. 9/02 7452 4 Deer..............................................................................6/04 74117 3 Perennial Pepperweed............................................10/04 74121 4 Dodder.........................................................................1/02 7496 4 Pitch Canker...............................................................2/03 74107 5 Drywood Termites.............................................rev. 9/02 7440 6 Plantains......................................................................6/00 7478 3 Earwigs........................................................................9/02 74102 2 Pocket Gophers..................................................rev. 1/02 7433 4 Elm Leaf Beetle...................................................rev. 2/04 7403 6 Poison Oak..........................................................rev. 5/01 7431 4 Eucalyptus Longhorned Borers.......................rev. 1/00 7425 4 Powdery Mildew on Fruits and Berries...............11/01 7494 5 Eucalyptus Redgum Lerp Psyllid...................rev. 1/06 7460 4 Powdery Mildew on Ornamentals........................11/01 7493 4 Eucalyptus Tortoise Beetle.......................................1/03 74104 4 Powdery Mildew on Vegetables.....................rev. 11/01 7406 3 Field Bindweed...................................................rev. 4/03 7462 4 Psyllids................................................................rev. 5/01 7423 6 Fire Blight..........................................................rev. 10/03 7414 3 Rabbits.................................................................rev. 1/02 7447 5 Fleas....................................................................rev. 11/00 7419 4 Raccoons......................................................................6/04 74116 3 Flies ...................................................................... rev. 4/04 7457 4 Rats...............1/03 74106 8 (Continued on page 2) PDFs of these Pest Notes and HTML versions with color photos are available online at www.ipm.ucdavis.edu. + 1PM For other ANR publications, go to www.anrcatalog.ucdavis.edu. UNIVERSITY OF CALIFORNIA • AGRICULTURE AND NATURAL RESOURCES Page 1 of 2 TES February 2006 - - - Title Publ. Date Publ. No. No. Pgs. (continued from page 1) Rattlesnakes................................................................6/04 74119 4 Redhumped Caterpillar............................................3/00 7474 2 Red Imported Fire Ant..............................................4/01 7487 3 Roses in the Garden and Landscape: Cultural Practices and Weed Control........rev. 7/03 7465 4 Roses in the Garden and Landscape: Diseases and Abiotic Disorders................rev. 10/03 7463 3 Roses in the Garden and Landscape: Insect and Mite Pests and Benefidals ................ 9/99 7466 4 Russian Thistle ......................................................... 12/00 7486 3 Scales....................................................................rev. 4/01 7408 5 Scorpions.....................................................................8/03 74110 4 Sequoia Pitch Moth ............................................ rev.3/04 7479 4 Skunks.........................................................................7/04 74118 3 Silverfish and Firebrats ............................................. 3/00 7475 4 Snails and Slugs ................................................. rev.5/03 7427 4 SootyMold..................................................................3/03 74108 2 Spider Mites ...................................................... rev.12/00 7405 3 Spiders................................................................. rev.5/00 7442 4 Spotted Spurge ................................................... rev.1/02 7445 4 Sudden Oak Death in California .............................. 4/02 7498 5 Sycamore Scale ................................................. rev.12/00 7409 2 Termites ............................................................... rev.5/01 7415 6 Thrips................................................................... rev. 5/01 7429 6 Tree Squirrels.............................................................4/05 74122 4 Voles (Meadow Mice) ........................................ rev.1/02 7439 4 Walnut Husk Fly .............................................. rev.12/00 7430 2 Weed Management in Landscapes.................rev. 8/01 7441 6 Weed Management in Lawns..................................1/04 74113 8 Whiteflies ............................................................ rev.9/02 7401 4 Wild Blackberries ............................................... rev.4/02 7434 4 Windscorpion...........................................................11/01 7495 1 Wood-boring Beetles in Homes......................rev. 11/00 7418 3 Wood Decay Fungi in Landscape Trees.................3/03 74109 4 Woodpeckers ............................... ... .. ... 6105 74124 3 Wood Wasps and Horntails ........................... rev. 12/00 7407 2 Yellow jackets and Other Social Wasps............rev. 8/01 7450 4 Yellow Starthistle...............................................rev. 7/03 7402 4 PDFs of these Pest Notes and HTML versions with color photos are available online at wwwipm.ucdavis.edu. ,4; 1PM For other ANR publications, go to www.anrcatalog.ucdavis.edu. UNIVERSITY OF CALIFORNIA • AGRICULTURE AND NATURAL RESOURCES Page 20f2 Nutsedge Oak Pit Scales Oleander Leaf Scorch Olive Fruit Fly Millipedes and Centipedes Mistletoe Mosquitoes Mushrooms and Other Nuisance Fungi in Lawns Scales Nematodes Scorpions These guides and more information about Integrated Pest Management are available at http://www.ipm.ucdavis.edu fl UC+IPM For more gardening publications, go to the ANR online catalog http://www.anrcatalog.ucdavis.edu Can't download? Visit your local UC Cooperative Extension office 4/04 Annual Bluegrass Anthracnose Ants Aphids Apple Scab Bark Beetles Bed Bugs Bee and Wasp Stings Bermudagrass Bordeaux Mixture Brown Recluse and Other Recluse Spiders California Ground Squirrel California Oakworm Carpenter Ants Carpenter Bees Carpenterworm Carpet Beetles Clearwing Moths Cliff Swallows Clothes Moths Clovers Cockroaches Codling Moth Common Knotweed Common Purslane Conenose Bugs Cottony Cushion Scale Crabgrass Creeping Woodsorrel and Bermuda Buttercup Dallisgrass Dandelions Delusory Parasitosis Dodder Drywood Termites Earwigs Elm Leaf Beetle Eucalyptus Longhorned Borers Eucalyptus Redgum Lerp Psyllid Eucalyptus Tortoise Beetle Sequoia Pitch Moth Silverfish and Firebrats Snails and Slugs Sooty Mold Spider Mites Spiders Spotted Spurge Sudden Oak Death in California Sycamore Scale Termites Thrips Voles (Meadow Mice) Walnut Husk Fly Weed Management in Landscapes Weed Management in Lawns Whiteflies Wild Blackberries Windscorpion Wood-boring Beetles in Homes Wood Decay Fungi in Landscape Trees Wood Wasps and Horntails Yellowjackets and Other Social Wasps Yellow Starthistle Field Bindweed Fire Blight Fleas Flies Fruittree Leafroller on Ornamental and Fruit Trees Fungus Gnats, Shore Flies, Moth Flies, and March Flies Giant Whitefly Glassy-winged Sharpshooter Grasshoppers Green Kyllinga Hackberry Woolly Aphid Head Lice Hobo Spider Hoplia Beetle Horsehair Worms House Mouse Kikuyugrass Lace Bugs Lawn Diseases: Prevention and Management Lawn Insects Leaf Curl Lyme Disease in California Pantry Pests Pitch Canker Plantains Pocket Gophers Poison Oak Powdery Mildew on Fruits and Berries Powdery Mildew on Ornamentals Powdery Mildew on Vegetables Psyllids Rabbits Rats Redhumped Caterpillar Red Imported Fire Ant Roses in the Garden and Landscape: Cultural Practices and Weed Control Roses in the Garden and Landscape: Diseases and Abiotic Disorders Roses in the Garden and Landscape: Insect and Mite Pests and Beneficials Russian Thistle Storm Water Education APPENDIX 6 References References City of Carlsbad, City of Carlsbad Standard Urban Storm Water Mitigation Plan, Storm Water Standards San Diego Regional Water Quality Control Board, Water Quality Control Plan for the San Diego Basin (Basin Plan) and Amendments, March 1997 San Diego Regional NPDES Storm Water Permit (Order Number 2001-01, NPDES Number CASO 108758), February 2001 NPDES General Permit for Storm Water Discharges Associated with Construction Activity Water Quality Order 99-08-DWQ, March 2003 State Water Resources Control Board, Resolution NO. 2003-0009, Approval of the 2002 Federal Clean Water Act Section 303(d) List of Water Quality Limited Segments, February 2003 State-Water Resources Control Board, Resolution NO. 2003-0009, Approval of the 2002 Federal Clean Water Act Section 303(d) List of Water Quality Limited Segments - Monitoring List, February 2003 San Diego County Hydrology Manual, Prepared by the County of San Diego Department of Public Works Flood Control Section, June 2003 Final Carlsbad Watershed Urban Runoff Management Program FY 04/05 Annual Report, January 2006 Project Design Consultants' Drainage Report for Bressi Industrial Lots 19-22, December 2006 California Stormwater Quality Association, Stormwater Best Management Practice Handbook - New Development and Redevelopment, January 2003 National Menu of Best Management Practices for Storm Water Phase H, US EPA Correspondence with the City of Dana Point, the City of Encinitas, and the City of Santa Monica Protocol for Developing Pathogen TMDLS, US EPA 2002 Aquashield, Inc. 2003 Stormwater Management Inc. AbTech Industries Bio Clean Environmental Services, Inc. Bowhead Manufacturing Co. CDS Technologies, Inc. Comm Clean Hydro International Invisible Structures, Inc. Kristar Enterprises, Inc. Soil Stabilization Products Company, Inc. Stormceptor Technical Manual, Rinker Materials, January 2003 Stonnwater Magazine May/June 2003 Issue Ultra Tech International, Inc. UNI-GROUP U.S.A. Vortechnics DesignManual, 2004