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HomeMy WebLinkAboutCT 04-11; Poinsettia Commons; Storm Water Management Plan; 2007-01-01RECORD COPY Initial STORM WATER MANAGEMENT PLAN POINSETTIA COMMONS CITY OF CARLSBAD, CA JANUARY 2007 Bate CARLSBAD TRACT No: 99>it) Prepared For: TRAMMELL CROW REsroENTiAL 949 South Coast Drive #400 Costa Mesa, CA 92626 €%*) Prepared By: PROJECT DESIGN CONSULTANTS Planning I Landscape Architecture I Environmental I Engineering I Survey Job No. 3153 Prepared by: Brinton Swift Reviewed by: Darlene Szczublewski Under the supervision of 701 B Street, Suite 800 San Diego, CA 92101 619.235.6471 Tel 619.234.0349 Fax Richard P. Hall, PE RCE 62034 Registration Expires 09/30/07 8ts :aw Ctfl TABLE OF CONTENTS 1. INTRODUCTION 1 2. PROJECT DESCRIPTION 2 3. POLLUTANTS AND CONDITIONS OF CONCERN 3 Anticipated and Potential Pollutants from the Project Area 3 Pollutants of Concern in Receiving Waters 4 Beneficial Uses 4 Impaired Water Bodies 5 Watershed Pollutants of Concern 6 Conditions of Concern 7 4. STORM WATER BEST MANAGEMENT PRACTICES 9 Site Design BMPs 9 Source Control BMPs 10 Project-Specific BMPs 12 Structural Treatment BMPs 12 Selected Treatment BMP(s) 13 BMP Plan Assumptions 14 5. PROJECT BMP PLAN IMPLEMENTATION 16 Construction BMPs 16 Recommended Post-Construction BMP Plan 16 Operation and Maintenance Plans 18 6. PROJECT BMP COSTS AND FUNDING SOURCES 19 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 15 Table 6. Post-Construction BMP Summary 17 Table?. BMP Costs 19 Table 8. Pollutant Removal Rates for Bioretention Systems 36 Table 9. Pollutant Removal Rates for Porous/Permeable Pavements 37 Table 10. Pollutant Removal Rates for Perimeter Sand Filter Systems 37 Table 11. Pollutant Removal Rates for Grate Inlet Skimmer Box 38 APPENDICES 1. Storm Water Requirements Applicability Checklist 2. Project Maps 3. Approved Waters End Soils Map 4. Drainage Calculations 5. Supplemental BMP Information 6. Discussion of Feasible BMP Treatment Options 7. References 8. Excerpts from Vernal Pool Study in 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; • Recommended BMP options for the project; • BMP device information for the recommended BMP options; and • Operation, maintenance, and funding for the recommended BMPs. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc 2. PROJECT DESCRIPTION This SWMP is provided for Poinsettia Commons. The Project site is located on the south side of the intersection of Embarcodaro Lane and Avenida Encinas and will develop a portion of Planning Area 5 (PA 5) and all of Lot 5. The Project site is bounded to the north by Avenida Encinas, to the south by Poinsettia Planning Area 2, 3, and 4 (a residential development), to the east by PA 5 (a residential development), and to the west by the San Diego Northern Railway. The vicinity and site maps are available in Appendix 2. The total project site consists of 5.35 acres. The Project proposes to construct multi-story mixed use buildings, a sub-terranean parking garage, and all the accompanying utilities, landscaping, and hardscaping. Development of the site will also include the re-alignment of Embarcodaro Lane. Currently the site consists of open space vegetated with native grasses and shrubs. Additionally, a portion of Lot 5 has been used as a parking area. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.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, trash and debris, oil and grease, bacteria and viruses, pesticides, and heavy metals. TABLE 1. ANTICIPATED AND POTENTIAL POLLUTANTS GENERATED BY LAND USE TYPE Project Categories Attached Residential Development Commercial Development Restaurants Parking Lots Roadways General Pollutant Categories Sediment X P(l) P(l) X Nutrients X P(l) P(l) P(l) Heavy Metals X X Organic Compounds P(2) X(4) Trash & Debris X X X X X Oxygen Demanding Substances P(l) P(5) X P(l) P(5) Oil& Grease P(2) X X X X Bacteria & Viruses P(l) P(3) X Pesticides X P(5) P(l) 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 0) A potential pollutant if land use involves food or animal waste products. (4) Including petroleum hydrocarbons (5) 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 P:\3153\ENGR\REPORTSWQTR\3153SWMP070118.doc -3- Pollutants of Concern in Receiving Waters The Poinsettia Commons Project is located in the Carlsbad Watershed (Hydrologic Unit 904) and is tributary to Batiquitos Lagoon.1 The sections below provide the beneficial uses and identification of impaired water bodies within the project's hydrologic area. Beneficial Uses The beneficial uses of the inland surface waters and the groundwater basins must not be threatened by the project. 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 Coastal Waters Batiquitos Lagoon 1 N 1 N U E 0 E O N hH E W E 1 E 1 E 1 E =i N C E AH5C E | N 5/5 N TABLE 3. BENEFICIAL USES FOR GROUNDWATER Hydrologic Area 904.5 "'•janr* Existing AGR Existing IND Existing Source: Water Quality Control Plan for the San Diego Basin, San Diego Regional Water Quality Control Board Notes for Tables 2 and 3: E: Existing 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. IND - 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. REC1 - 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. 1 Water Quality Control Plan for the San Diego Basin, San Diego Regional Water Quality Control Board P:\3153\ENGR\REPORTS\WQTR\3153SWMP070118.doc -4- 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 Significance (ASBS), where the preservation or enhancement of natural resources requires special protection. 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. AGR - Agricultural Supply: Includes use of water for farming, horticulture, or ranching including, but not limited to, irrigation, stock watering, or support of vegetation for range grazing. 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. P:\3153\ENGR\REPORTS\WQTR\3153SWMP070118.doc -5- The proposed project is not directly tributary to a 303(d) listed water body. The closest impaired water body is the Pacific Ocean at Buena Vista Creek, which is 303(d) listed for bacteria. 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 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 Agua Hidionda Lagoon, which is listed for dissolved 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 hydologic 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. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -6- 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: • Drainage Patterns: Rainfall from PAS generally sheetflows to the southwest and is collected in a public storm drain inlet where it is conveyed offsite in a backbone system. Rainfall from Lot 5 sheetflows to the southwest where it is collected in a storm drain inlet and is discharged at the north west corner of PA 2,3, and 4. Storm water then travels along the San Diego Northern Railway right of way where it enters a vernal pool. Storm water discharging to the vernal pool typically either infiltrates or evaporates. A soils map from the approved Waters End Project is included in Appendix 3 to define soil types in the vicinity of the Poinsettia Commons Project. Site development will generally maintain existing drainage patterns. Design of the existing backbone system was intended to account for development of the project site. In accordance with backbone design, proposed site drainage will sustain some flow to the northwest comer of PA 2, 3, and 4. Flows generated by PA 5 will be collected by area drains in the improved storm drain system, then conveyed to the existing backbone system. Runoff from the realigned Embarcadero Lane will be conveyed to the existing backbone system by ribbon gutters, area drains, and improved private stormdrain pipes. Flow generated by Lot 5 will sheet flow to the west, where it will be collected by area drains and conveyed to the southwest comer of PA 2, 3, and 4 via a private stormdrain and swale system. • Soil Conditions and Imperviousness: The project area consists of soil group A and D. Under existing conditions, the project area is 11% impervious and the runoff coefficient is 0.45. Under the proposed conditions, the project area will be 82% impervious and the overall runoff coefficient is expected to be 0.72. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -7- • Rainfall Runoff Characteristics: Under the proposed conditions, the site will generate a stormwater runoff peak flow rate of approximately 8.0 cfs (2-year storm) and 11.8 cfs (10-year storm). • Downstream Conditions: There are no expected adverse impacts on downstream conditions resulting from site development. The existing backbone system was designed to convey flows generated by the developed Project site. Site-generated runoff to the corner of PA 2, 3, and 4 increases from 4.8 cfs to 7.0 cfs. However, an initial investigation of the vernal pool, completed prior to development of PA 2, 3, and 4, indicated that approximatley 33 cfs entered the vernal pool in a 100-year storm in predeveloped conditions. Appendix 6 includes portions of the intial vernal pool study. Being that flows to the vernal pool are well below the predeveloped 33 cfs no adverse impact to downstream conditions are expected. P:\3153\ENGR\REPORTSWQTR\3153 SWMP 070118.doc -8- 4. STORM WATER BEST MANAGEMENT PRACTICES The City Storm Water Standards Manual (Section III.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 (III.2.A) as follows: • Maintain Pre-Development Rainfall Runoff Characteristics o Minimize impervious footprint - Streets, sidewalks, and parking lot aisles will be constructed to the minimum widths necessary, without compromising public safety. o Conserve natural areas - Natural drainage systems shall be used to the maximum extent practicable, o Minimize directly connected impervious areas - To the maximum extent practicable, drainage from rooftops and impervious areas will be discharged into landscaping prior to reaching the storm drain system. o Maximize canopy interception and water conservation consistent with the Carlsbad Landscape Manual - To the maximum extent practicable, existing native trees and shrubs shall be preserved and additional native and drought-tolerant trees and large shrubs shall be planted instead of non-drought tolerant exotics. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -9- • Protect Slopes and Channels o All slopes will be stabilized with native or drought tolerant vegetation where practicable, consistent with the Carlsbad Landscape Manual. o All outfalls will be equipped with an energy dissipation device and/or a riprap pad, in accordance with applicable standards and specifications to minimize erosion. Energy dissipaters shall be installed in such a way as to minimize impacts to receiving waters. Source Control BMPs The project addresses the source control BMPs required by the City Storm Water Standards (III.2.B) as follows: • Design Outdoor Materials Storage Areas to Reduce Pollution Introduction o There are no outdoor material storage areas proposed for this project. • Design Trash Storage Areas to Reduce Pollution Introduction o Trash storage areas shall be paved with an impervious surface, designed not to allow run-on from adjoining areas, screened or walled to prevent off-site transport of trash, and located in a covered area to prevent direct precipitation. • Provide Storm Water Conveyance System Stenciling and Signage o 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. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -10- o Signs and prohibitive language and/or graphical icons, which prohibit illegal dumping, will be posted at public access points along channels, creeks, trailheads, and parks within the project area. • Use Efficient Irrigation Systems and Landscape Design o Rain shutoff devices shall be employed to prevent irrigation during precipitation, consistent with the Carlsbad Landscape Manual. o Irrigation systems shall be designed to each landscape area's specific water requirements, consistent with the Carlsbad Landscape Manual. o 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 o 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 residents/tenants. o Residents and groundskeepers will be educated on pest management principles. o 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 o Covered Parking - Underground parking garage will provide covered parking to reduce pollution introduction. P:\3153\ENGR\REPORTSWQTR\3153SWMP070118.doc -11- o Storm Water Education - Educational materials on storm water issues and simple ways to prevent storm water pollution will be made available to residents. — Residents will be educated on general issues of storm water pollution prevention through the Public Participation and Outreach Programs operated by the City of Carlsbad and County of San Diego. 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. The Poinsettia Commons Project does include components that require project-specific BMPs. The City Storm Water Standards Manual lists several options for private roads. The Poinsettia Commons Project does not include any of these options. However, the intent of the Storm Water Standards is to reduce the discharge of pollutants from storm water conveyance systems to the Maximum Extent Practicable (MEP statutory standard) throughout the use of a developed site. The Poinsettia Commons Project meets this objective by including treatment BMPs before discharging to the storm drain system. Structural Treatment BMPs Target pollutants, removal efficiencies, expected flows, and space availability determine the selection of structural treatment BMP options. 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, heavy metals, and bacteria and viruses. Since few treatment control BMPs provides adequate removal efficiency for for bacteria, source control BMPs will provide additional pollutant removal for the bacteria and pesticides in conjunction with the treatment control BMPs selected. Therefore, based on the typical removal P:\3153VENGR\REPORTS\WQTR\3153SWMP070118.doc -12- efficiencies of the remaining target pollutants, the treatment BMP options considered include biofilters, detention basins, infiltration basins, wet ponds, filtration, and hydrodynamic separators. Appendix 5 discusses in detail all of the treatment BMP options considered for the Project. TABLE 4. STRUCTURAL TREATMENT CONTROL BMP SELECTION MATRIX Pollutant of Concern Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Bacteria Oil& Grease Pesticides Treatment Control BMP Categories Biofilters M L M U L L U M U Detention Basins H M M U H M U M U Infiltration Basins (1) H M M U U M H U U Wet Ponds or Wetlands H M H U U M U U U Drainage Inserts L L L L M L L L L Filtration H M H M H M M H U Hydrodynamic Separator Cy\Systems v ' M L L L M L L L L Notes for Table 4: L: Low removal efficiency (1) Including trenches and porous pavement M: Medium removal efficiency (2) 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 Selected Treatment BMP(s) Biofilters and hydrodynamic separator systems are the feasible options for this project. The Owner, Developer, and Project Team have selected to use a vegetated swale to treat runoff from Lot 5 and to utilize the existing regional CDS unit to treat runoff from PA 5. P:\3153\ENGR\REPORTS\WQTR\3I53 SWMP 070118.doc -13- 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 0.78 was used in the runoff calculations for the project area discharging into the existing backbone system, and a runoff coefficient of 0.83 was used for areas discharging to the grass swale. Runoff coefficients were obtained by calculating a weighted average over the contributing areas. • BMP Design Constraints o Locate outside public right-of-way o Facilitate access for maintenance o Avoid utility conflicts Table 9 summarizes the criteria that should be implemented in the design of the recommended project BMP. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -14- TABLE 9. BMP DESIGN CRITERIA BMP Hydrology BMP Option BMP Treated Flow Capacity Project Treatment Criteria C = runoff coefficient I = water quality treatment intensity A = acreage (Lot 5) Flow-based: Q=CIA Grass Swale 0.47 cfs C - 0.83 I = 0.2 in/hour A = 2.84 acres Q = 0.47 cfs C = runoff coefficient I = water quality treatment intensity A = acreage (including offsite PAS) Flow-based: Q=CIA CDS Unit 9.0 C = 0.78 I = 0.2 in/hour A = 5.35 acres Q = 0.83 cfs P:\3153\ENGR\REPORTS\WQTR\3153SWMP070118.doc -15- 5. PROJECT BMP PLAN IMPLEMENTATION This section identifies the recommended BMP 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 will be employed consistent with the NPDES General Permit for Storm Water Discharges Associated with Construction Activity. Water quality during construction will be protected by the Storm Water Pollution Prevention Plan (SWPPP) prepared for Poinsettia Commons, WDID# 9 37C342707. 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 BMP Plan PDC has identified the following water quality BMP plan for the Poinsettia Commons Project as a means to protect water quality and comply with City storm water requirement standards. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -16- The recommended post-construction BMP plan includes site design, source control, and treatment BMPs. The site design BMP options include reduction of impervious surfaces, conserve natural areas, minimization of directly connected areas, and protection of slopes and channels. The source control BMPs include inlet stenciling and signage, material storage, covered trash storage, efficient irrigation, storm water education, and integrated pest management principles. The treatment BMPs selected for this project are an existing CDS unit treating backbone discharges and a grass swale. TABLE 10. POST-CONSTRUCTION BMP SUMMARY Pollutant Pollutant Sources Mitigation Measures Sediment and Nutrients Trash and Debris Landscaped areas, rooftops, general use, trash storage areas, parking/driveways Reduction of impervious surfaces, minimization of directly connected impervious areas, protection of slopes and channels Inlet stenciling and signage, covered trash storage, efficient irrigation, storm water education, private roadway drainage diversion/treatment A grass swale and a CDS unit Pesticides Oxygen demanding substances Landscaped areas, general use Reduction of impervious surfaces, minimization of directly connected impervious areas, protection of slopes and channels Efficient irrigation, storm water education, integrated pest management principles A grass swale and a CDS unit Bacteria and Viruses General use, trash storage areas Covered trash storage, education of residents Heavy metals Oil and grease Organic compounds Parking/driveways Reduction of impervious surfaces, minimization of directly connected impervious areas Inlet stenciling and signage, stormwater education, private roadway drainage diversion/treatment A grass swale and a CDS unit P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -17- 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 recommended post-construction BMP for this project are located in Appendix 4. The Project BMP costs and the maintenance funding sources are provided in the following section. P:\3153\ENGR\REPORTS\WQTR\3153SWMP070118.doc -18- 6. PROJECT BMP COSTS AND FUNDING SOURCES Table 11 below provides the anticipated capital and annual maintenance costs for the selected BMPs. TABLE 11. BMP COSTS BMP OPTION Grass swale Single CDS Unit Model PSW50_42 Estimated Capital Costs $0.50 per square foot of grass swale Existing Approximate Annual Maintenance Costs $350 per acre of grass swale $1500 *A proprietary BMP may vary in cost at the manufacturer's discretion. The Developer will incur the capital cost for the BMP installation. The responsible party for long-term maintenance and funding is the Home Owners' Association (HOA) for Poinsettia Commons. P:\3153\ENGR\REPORTS\WQTR\3153 SWMP 070118.doc -19- APPENDIX 1 Storm Water Requirements Applicability Checklist 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? * 1 . Detached residential development of 1 0 or more units 2. Attached residential development of 10 or more units 3. Commercial development greater than 1 00,000 square feet 4. Automotive repair shop 5. Restaurant 6. Steep hillside development greater than 5,000 square feet 7. Project discharging to receiving waters within Environmentally Sensitive Areas 8. Parking lot greater than or equal to 5,000 ft/ or with at least 15 parking spaces, and potentially exposed to urban runoff 9. Streets, roads, highways, and freeways that would create a new paved surface that is 5,000 square feet or greater Yes S V •/ No ^ •/ •/ V S V * 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: 1 . New impervious areas, such as rooftops, roads, parking lots, driveways, paths and sidewalks? 2. New pervious landscape areas and irrigation systems? 3. Permanent structures within 100 feet of any natural water body? 4. Trash storage areas? 5. Liquid or solid material loading and unloading areas? 6. Vehicle or equipment fueling, washing, or maintenance areas? 7. Require a General NPDES Permit for Storm Water Discharges Associated with Industrial Activities (Except construction)? * 8. Commercial or industrial waste handling or storage, excluding typical office or household waste? 9. Any grading or ground disturbance during construction? 10. Any new storm drains, or alteration to existing storm drains? Yes •/ S S S S s No •/ V S S *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 D, below. Part C: Determine Construction Phase Storm Water Requirements. Would the project meet any of these criteria during construction? 1 . Is the project subject to California's statewide General NPDES Permit for Storm Water Discharges Associated With Construction Activities? 2. Does the project propose grading or soil disturbance? 3. Would storm water or urban runoff have the potential to contact any portion of the construction area, including washing and staging areas? 4. 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)? Yes ^ S S S No 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.] S A) High Priority 1) Projects where the site is 50 acres or more and grading will occur during the rainy season. 2) Projects 5 acres or more. 3) 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. 4) Projects, active or inactive, adjacent or tributary to sensitive water bodies. D B) Medium Priority 1) 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.) 2) 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. 3) Permit projects on private property where grading permits are required, however, Notice Of Intents (NOIs) and SWPPPs are not required. p C) Low Priority 1) Capital projects where minimal to no grading occurs, such as signal light and loop installations, street light installations, etc. 2) Permit projects in the public right-of-way where minimal to no grading occurs, such as pedestrian ramps, driveway additions, small retaining walls, etc. 3) 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 VOV/TYAMP NOT TO SCALE EXHIBIT A APPENDIX 3 Approved Waters End Soils Map \ v«v-.-a\«-f= Ti ;a- V -•>- €ND APPENDIX 4 Drainage Calculations Ml LJJJ-LL-LLMTT i i i rT i i i 2 Year Rainfall Event - 6 Hours i T jT| T 1 "r~ " » 1-]-! -m-i-M- County of San Diego Hydrology Manual \Lv Rainfall Isopluvials Isopluvial (inches) We Have San Diego Oivcrcd! THIS MAP IS PROVIDED WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Copyright SanGIS. AH Rights Reserved. This products may contain information from the SANDAG RegionalInformation System which cannot be reproduced without the written permission of SANDAG. This product may contain information which has been reproduced with permission granted by Thomas Brothers Maps. 3 Miles County of San Diego Hydrology Manual _r IT" Mi11 i-''1 Rainfall Isopluvials 2 Year Rainfall Event - 24 Hours L_^L_V^-L U'l i / i -.1*. i \ I * *i 1% I 44-U- |-U-i ULLJr i i i i .- \j-:^rJ'Ti-}nnro^rfa DPW We Have San Diego Covered! THIS MAP IS PROVIDED WITHOUT WARRANTY OF ANY KIND. EITHER EXPRESSOR IMPLIED, INCLUDING, BUT NOT LIMITED TO. THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Copyright SanGIS. Al Rights Reserved. This products may contain information from the SANDAG Regional Information System which cannot be reproduced without the written permission of SANDAG. This product may contain information which has been reproduced with permission granted by Thomas Brothers Maps. County of San Diego Hydrology Manual Riverside-G^u'nty• .^v4-—/—^r-f--- : ,, -H4-rt-f ' : Rainfall Isopluvials 10 Year Rainfall Event - 6 Hours Isopluvial (inches) H-M+H4- 4- 4_ L 1 _SQLANABEAC^_ |_J Q I 1 DEL '. '.' '3 D COJNTY •T^I—:,"t" i~-". — " ~ _h i -,-r rrri hrr r~n—-n DPW We Have San Diego Onrcrcd! >•" '.J-J-!I .l_,»ir j__i _ THIS MAP IS PROVIDED WITHOUT WAPJWNTY OF ANY KIND, EITHER EXPRESS OR IMPUED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.Copyright SanGIS. All Rights Reserved. This products may contain information from the SANDAG Regional information System which cannot be reproduced without the written permission of SANDAG. Thts product may contain information which has been reproduced with permission granted by Thomas Brothers Maps. ii. i'.to County of San Diego Hydrology Manual Rainfall Isopluvials 10 Year Rainfall Event - 24 Hours Isopluvial (inches) DPW ap*on«rfVfte*;tt**iGvo&vphk. Mynofctt Sanicm We Have San Diego Covered! THIS MAP IS PROVIDED WITHOUT WARRANTY OF ANY KINO. EITHER EXPRESS Oft IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FTTNESS FOR A PARTICULAR PURPOSE. Copyright SanGlS. All Rights Reserved. This products may contain information from the SANDAG RegionalC Information System which cannot be reproduced without theJ-( written permission of SANDAG. This product may contain information which has been reproduced with permission granted by Thomas Brothers Maps. 3 Miles San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 08/17/06 3153 POINSETTIA COMMONS SYSTEM 100 - PROPOSED CONDITIONS 2 YEAR STORM AUGUST 14, 2006 ********* Hydrology Study Control Information ********** Program License Serial Number 4049 Rational hydrology study storm event year is 2.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.200 24 hour precipitation(inches) = 1.800 P6/P24 = 66.7% Adjusted 6 hour precipitation (inches) = 1.170 Adjusted P6/P24 = 65.0% San Diego hydrology manual 'C' values used Process from Point/Station 100.000 to Point/Station 105.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [MEDIUM DENSITY RESIDENTIAL ] (7.3 DU/A or Less ) Impervious value, Ai = 0.400 Sub-Area C Value = 0.570 Initial subarea total flow distance = 70.000(Ft.) Highest elevation = 57.900(Ft.) Lowest elevation = 57.690 (Ft.) Elevation difference = 0.210(Ft.) Slope = 0.300 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.30 %, in a development type of 7.3 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 10.08 minutes TC = [1.8*(l.l-C)*distance(Ft.)*.5)/(% TC = [1.8*(1.1-0.5700)* ( 50.000*.5)/( 0.300* (1/3)]= 10.08 The initial area total distance of 70.00 (Ft.) entered leaves a remaining distance of 20.00 (Ft.) Using Figure 3-4, the travel time for this distance is 0.73 minutes for a distance of 20.00 (Ft.) and a slope of 0.30 % with an elevation difference of 0.06(Ft.) from the end of the top area Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr) 0.734 Minutes Tt=[(11.9*0.0038*3)/( 0.06)]*.385= 0.73 Total initial area Ti = 10.08 minutes from Figure 3-3 formula plus 0.73 minutes from the Figure 3-4 formula = 10.81 minutes Rainfall intensity (I) = 1.875(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.570 Subarea runoff = 0.043(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 105.000 to Point/Station 110.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 55.620(Ft.) Downstream point/station elevation = 54.700(Ft.) Pipe length = 75.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = 3 Calculated individual pipe flow = 0.043(CFS) Normal flow depth in pipe = 1.39(In.) Flow top width inside pipe = 2.99(In.) Critical Depth = 1.48(In.) Pipe flow velocity = 1.93(Ft/s) Travel time through pipe = 0.65 min. Time of concentration (TC) = 11.46 min. 0.043(CFS) 00 (In.) Process from Point/Station 115.000 to Point/Station **** SUBAREA FLOW ADDITION **** 110 .000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [LOW DENSITY RESIDENTIAL ] (1.0 DU/A or Less ) Impervious value, Ai = 0.100 Sub-Area C Value = 0.410 Time of concentration = 11.46 min. Rainfall intensity = 1.805(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.446 CA = 0.080 Subarea runoff = 0.102(CFS) for 0.140(Ac.) Total runoff = 0.145(CFS) Total area = 0.180(Ac.; Process from Point/Station 110.000 to Point/Station 120.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.700(Ft.) Downstream point/station elevation = 53.870 (Ft.) Pipe length = 165.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.145(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.145(CFS) Normal flow depth in pipe = 2.51(In.) Flow top width inside pipe = 5.92(In.) Critical Depth = 2.27(In.) Pipe flow velocity = 1.87(Ft/s) Travel time through pipe = 1.47 min. Time of concentration (TC) = 12.93 min. Process from Point/Station 121.000 to Point/Station **** SUBAREA FLOW ADDITION **** 120.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [LOW DENSITY RESIDENTIAL ] (2.9 DU/A or Less ) Impervious value, Ai = 0.250 Sub-Area C Value = 0.490 Time of concentration = 12.93 min. Rainfall intensity = 1.670(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.465 CA = 0.149 Subarea runoff = 0.104(CFS) for 0.140(Ac.) Total runoff = 0.249(CFS) Total area = 0.320(Ac.) Process from Point/Station 122.000 to Point/Station **** SUBAREA FLOW ADDITION **** 120.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Time of concentration = 12.93 min. Rainfall intensity = 1.670(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.570 CA = 0.251 Subarea runoff = 0.170(CFS) for 0.120(Ac.) Total runoff = 0.419(CFS) Total area = 0.440(Ac.) Process from Point/Station 121.000 to Point/Station 120.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.440(Ac.) Runoff from this stream = 0.419(CFS) Time of concentration = 12.93 min. Rainfall intensity = 1.670(In/Hr) Process from Point/Station 123.000 to Point/Station 125.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 30.000(Ft.) Highest elevation = 58.100 (Ft.) Lowest elevation = 57.580 (Ft.) Elevation difference = 0.520(Ft.) Slope = 1.733 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 70.00 (Ft) for the top area slope value of 1.73 %, in a development type of Office Professional In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.13 minutes TC = [1.8*(l.l-C)*distance(Ft.)".5)/(% slope*(1/3)] TC = [1.8* (1.1-0.8500)*( 70.000*.5)/( 1.733^(1/3)]= 3.13 Calculated TC of 3.134 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.083(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.079(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 125.000 to Point/Station 127.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 57.580(Ft.) End of street segment elevation = 55.600(Ft.) Length of street segment = 108.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 14.000(Ft.) Distance from crown to crossfall grade break = 12.500(Ft.) Slope from gutter to grade break (v/hz) = 0.083 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 10.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0170 Manning's N from gutter to grade break = 0.0170 Manning's N from grade break to crown = 0.0170 Estimated mean flow rate at midpoint of street = 0.218(CFS) Depth of flow = 0.155(Ft.), Average velocity = 2.002(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 1.500(Ft.) Flow velocity = 2.00(Ft/s) Travel time = 0.90 min. TC = 4.03 min. Adding area flow to street Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 3.083(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 0.145 Subarea runoff = 0.367(CFS) for 0.140(Ac.) Total runoff = 0.445(CFS) Total area = 0.170(Ac.) Street flow at end of street = 0.445(CFS) Half street flow at end of street = 0.445(CFS) Depth of flow = 0.211(Ft.), Average velocity = 1.838(Ft/s) Flow width (from curb towards crown)= 3.740(Ft.) Process from Point/Station 127.000 to Point/Station 120.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.085(Ft.) Downstream point/station elevation = 53.870(Ft.) Pipe length = 43.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.445(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.445(CFS) Normal flow depth in pipe = 3.86(In.) Flow top width inside pipe = 8.91(In.) Critical Depth = 3.61(In.) Pipe flow velocity = 2.47(Ft/s) Travel time through pipe = 0.29 min. Time of concentration (TC) = 4.32 min. Process from Point/Station 127.000 to Point/Station 120.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.170(Ac.) Runoff from this stream = 0.445(CFS) Time of concentration = 4.32 min. Rainfall intensity = Summary of stream data: Stream No. Flow rate (CFS) 3.083(In/Hr) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 0.419 0.445 1.000 * 0.542 * 1.000 * 1.000 * 12.93 4.32 1.000 * 1.000 * 0.334 * 1.000 * 1.670 3.083 0.419) + 0.445) + 0.419) + 0.445) + 0.660 0.586 Total of 2 streams to confluence: Flow rates before confluence point: 0.419 0.445 Maximum flow rates at confluence using above data: 0.660 0.586 Area of streams before confluence: 0.440 0.170 Results of confluence: Total flow rate = 0.660(CFS) Time of concentration = 12.930 min. Effective stream area after confluence = 0.610(Ac.) Process from Point/Station 120.000 to Point/Station 130.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.800(Ft.) Downstream point/station elevation = 52.660(Ft.) Pipe length = 225.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.660(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.660(CFS) Normal flow depth in pipe = 4.82(In.) Flow top width inside pipe = 8.98(In.) Critical Depth = 4.43(In.) Pipe flow velocity = 2.74(Ft/s) Travel time through pipe = 1.37 min. Time of concentration (TC) = 14.30 min. Process from Point/Station 135.000 to Point/Station **** SUBAREA FLOW ADDITION **** 130.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [LOW DENSITY RESIDENTIAL (1.0 DU/A or Less ) Impervious value, Ai = 0.100 Sub-Area C Value = 0.410 Time of concentration = 14.30 min. Rainfall intensity = 1.565(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.585 CA = 0.485 Subarea runoff = O.IOO(CFS) for 0.220(Ac.) Total runoff = 0.760(CFS) Total area = 0.830(Ac.) Process from Point/Station 140.000 to Point/Station **** SUBAREA FLOW ADDITION **** 130.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 14.30 min. Rainfall intensity = 1.565(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.659 CA = 0.738 Subarea runoff = 0.395(CFS) for 0.290(Ac.) Total runoff = 1.155(CFS) Total area = 1.120(Ac.) Process from Point/Station 130.000 to Point/Station 145.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.660 (Ft.) Downstream point/station elevation = 52.200 (Ft.) Pipe length = 127.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 6.27 (In.) Flow top width inside pipe = 11.99(In.) Critical Depth = 5.43(In.) Pipe flow velocity = 2.78(Ft/s) Travel time through pipe = 0.76 min. Time of concentration (TC) = 15.06 min. 1.155(CFS) 12.00(In.) 1.155(CFS) Process from Point/Station 155.000 to Point/Station **** SUBAREA FLOW ADDITION **** 145.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type (General Commercial ) Impervious value, Ai = 0.850 Sub-Area C Value = 0.820 Time of concentration = 15.06 min. Rainfall intensity = 1.514(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.729 CA = 1.451 Subarea runoff = 1.042(CFS) for 0.870(Ac.) Total runoff = 2.197(CFS) Total area = 1.990(Ac.) Process from Point/Station 145.000 to Point/Station 150.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.200 (Ft.) Downstream point/station elevation = 51.900(Ft.) Pipe length = 55.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 8.38(In.) Flow top width inside pipe = 11.02(In.) Critical Depth = 7.60(In.) Pipe flow velocity = 3.75(Ft/s) Travel time through pipe = 0.24 min. Time of concentration (TC) = 15.30 min. 2.197(CFS) 12.00(In.) 2.197(CFS) Process from Point/Station 145.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 150.000 Along Main Stream number: 1 in normal stream number 1 Stream flow area = 1.990(Ac.) Runoff from this stream = 2.197(CFS) Time of concentration = 15.30 min. Rainfall intensity = 1.498(In/Hr) Process from Point/Station 160.000 to Point/Station **** INITIAL AREA EVALUATION **** 165.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type (General Commercial ) Impervious value, Ai = 0.850 Sub-Area C Value = 0.820 Initial subarea total flow distance = Highest elevation = 58.700(Ft.) Lowest elevation = 57.300(Ft.) Elevation difference = 1.400(Ft.) Slope = 81.000(Ft.) 1.728 % Top of Initial Area Slope adjusted by User to 0.017 % Bottom of Initial Area Slope adjusted by User to 0.017 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.02 %, in a development type of General Commercial In Accordance With Figure 3-3 Initial Area Time of Concentration = 13.86 minutes TC = [1.8*(1.1-C)*distance(Ft.)*.5)/(% slope^(l/3)] TC = [1.8* (1.1-0.8200)*( 50.000^.5)/( 0.017^(1/3)]= 13.86 The initial area total distance of 81.00 (Ft.) entered leaves a remaining distance of 31.00 (Ft.) Using Figure 3-4, the travel time for this distance is 3.11 minutes for a distance of 31.00 (Ft.) and a slope of 0.02 % with an elevation difference of 0.01(Ft.) from the end of the top area Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]*.385 *60(min/hr) 3.106 Minutes Tt=[(11.9*0.0059*3)/( 0.01)]*.385= 3.11 Total initial area Ti = 13.86 minutes from Figure 3-3 formula plus 3.11 minutes from the Figure 3-4 formula = 16.97 minutes Rainfall intensity (I) = 1.402(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.820 Subarea runoff = 0.138(CFS) Total initial stream area = 0.120(Ac.) Process from Point/Station 165.000 to Point/Station 170.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 57.300(Ft.) Downstream point elevation = 55.700(Ft.) Channel length thru subarea = 240.000 (Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 66.660 Slope or 'Z' of right channel bank = 66.660 Estimated mean flow rate at midpoint of channel = O.SOO(CFS) Manning's 'N' = 0.017 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = O.SOO(CFS) Depth of flow = 0.091(Ft.), Average velocity = 0.909(Ft/s) Channel flow top width = 12.114(Ft.) Flow Velocity = 0.91(Ft/s) Travel time = 4.40 min. Time of concentration = 21.37 min. Critical depth = 0.081(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 1.208(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.845 CA = 0.634 Subarea runoff = Total runoff = Depth of flow = Critical depth = 0.628(CFS) for 0.630(Ac.) 0.766(CFS) Total area = 0.750(Ac.) 0.107(Ft.), Average velocity = 1.011(Ft/s) 0.096 (Ft.) Process from Point/Station 175.000 to Point/Station **** SUBAREA FLOW ADDITION **** 170.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.790 Time of concentration = 21.37 min. Rainfall intensity = 1.208(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.818 CA = 1.226 Subarea runoff = 0.716(CFS) for 0.750(Ac.) Total runoff = 1.48KCFS) Total area = 1.500 (Ac.) Process from Point/Station 180.000 to Point/Station **** SUBAREA FLOW ADDITION **** 170.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.790 Time of concentration = 21.37 min. Rainfall intensity = 1.208(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.808 CA = 1.898 Subarea runoff = 0.81KCFS) for 0.850 (Ac.) Total runoff = 2.293(CFS) Total area = 2.350(Ac.) Process from Point/Station 170.000 to Point/Station 150.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.350(Ft.) Downstream point/station elevation = 51.900(Ft.) Pipe length = 113.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 2.293(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 2.293(CFS) Normal flow depth in pipe = 8.05(In.) Flow top width inside pipe = 14.96(In.) Critical Depth = 7.25(In.) Pipe flow velocity = 3.42(Ft/s) Travel time through pipe = 0.55 min. Time of concentration (TC) = 21.92 min. Process from Point/Station 170.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 150.000 Along Main Stream number: 1 in normal stream number 2 Stream flow area = 2.350(Ac.) Runoff from this stream = 2.293(CFS) Time of concentration = 21.92 min. Rainfall intensity = 1.188(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( 1 ) 2.197 2.293 = 1.000 * 1.000 * 15.30 21.92 1.000 * 0.698 * 1 1 2.197) + 2.293) + Qmax(2) = 0.793 * 1.000 * 1.000 * 1.000 * 1.498 1.188 2.197) + 2.293) + 3 .798 4.035 Total of 2 streams to confluence: Flow rates before confluence point: 2.197 2.293 Maximum flow rates at confluence using above data: 3.798 4.035 Area of streams before confluence: 1.990 2.350 Results of confluence: Total flow rate = 4.035(CFS) Time of concentration = 21.919 min. Effective stream area after confluence = 4.340(Ac.) Process from Point/Station 150.000 to Point/Station 185.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.900(Ft.) Downstream point/station elevation = 51.700 (Ft.) Pipe length = 75.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 4.035(CFS) Nearest computed pipe diameter = 18.00(In.) Calculated individual pipe flow = 4.035(CFS) Normal flow depth in pipe = 11.57(In.) Flow top width inside pipe = 17.25(In.) Critical Depth = 9.22(In.) Pipe flow velocity = 3.36(Ft/s) Travel time through pipe = 0.37 min. Time of concentration (TC) = 22.29 min. Process from Point/Station 190.000 to Point/Station **** SUBAREA FLOW ADDITION **** 185.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Time of concentration = 22.29 min. Rainfall intensity = 1.175(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.780 CA = 3.791 Subarea runoff = 0.421(CFS) for 0.520(Ac.) Total runoff = 4.456(CFS) Total area = 4.860(Ac.) Process from Point/Station 185.000 to Point/Station 195.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.700(Ft.) Downstream point/station elevation = 51.070(Ft.) Pipe length = 210.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 4.456(CFS) Nearest computed pipe diameter = 18.00(In.) Calculated individual pipe flow = 4.456(CFS) Normal flow depth in pipe = 11.89(In.) Flow top width inside pipe = 17.04(In.) Critical Depth = 9.72(In.) Pipe flow velocity = 3.60(Ft/s) Travel time through pipe = 0.97 min. Time of concentration (TC) = 23.26 min. Process from Point/Station 197.000 to Point/Station **** SUBAREA FLOW ADDITION **** 195.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type (General Commercial ) Impervious value, Ai = 0.850 Sub-Area C Value = 0.820 Time of concentration = 23.26 min. Rainfall intensity = 1.144(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.784 CA = 4.193 Subarea runoff = 0.338(CFS) for 0.490(Ac.) Total runoff = 4.795(CFS) Total area = 5.350(Ac.) Process from Point/Station 195.000 to Point/Station 198.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.070(Ft.) Downstream point/station elevation = 48.500 (Ft.) Pipe length = 108.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 4.795(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 4.795(CFS) Normal flow depth in pipe = 8.67(In.) Flow top width inside pipe = 10.74(In.) Critical Depth = 10.87(In.) Pipe flow velocity = 7.89(Ft/s) Travel time through pipe = 0.23 min. Time of concentration (TC) = 23.49 min. End of computations, total study area = 5.350 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 08/17/06 3153 POINSETTIA COMMONS SYSTEM 200 - PROPOSED CONDITIONS 2 YEAR STORM AUGUST 16, 2006 ********* Hydrology Study Control Information ********** Program License Serial Number 4049 Rational hydrology study storm event year is 2.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.200 24 hour precipitation(inches) = 1.800 P6/P24 = 66.7% Adjusted 6 hour precipitation (inches) = 1.170 Adjusted P6/P24 = 65.0% San Diego hydrology manual 'C' values used Process from Point/Station 205.000 to Point/Station 210.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.340 Initial subarea total flow distance = 95.000(Ft.) Highest elevation = 57.130 (Ft.) Lowest elevation = 56.500(Ft.) Elevation difference = 0.630(Ft.) Slope = 0.663 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.66 %, in a development type of 2.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 11.09 minutes TC = [1.8* (l.l-C)*distance(Ft.p.5)/(% slopeA(l/3)J TC = [1.8*(1.1-0.3400)*( 50.000".5)/( 0.663^(1/3)]= 11.09 The initial area total distance of 95.00 (Ft.) entered leaves a remaining distance of 45.00 (Ft.) Using Figure 3-4, the travel time for this distance is 1.01 minutes for a distance of 45.00 (Ft.) and a slope of 0.66 % with an elevation difference of 0.30 (Ft.) from the end of the top area Tt = [11.9*length(Mi)^3)/(elevation change(Ft.))P.385 *60(min/hr) 1.010 Minutes Tt=[(11.9*0.0085A3)/ ( 0.30)1^.385= 1.01 Total initial area Ti = 11.09 minutes from Figure 3-3 formula plus 1.01 minutes from the Figure 3-4 formula = 12.10 minutes Rainfall intensity (I) = 1.743(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.340 Subarea runoff = 0.030(CFS) Total initial stream area = 0.050(Ac.) Process from Point/Station 210.000 to Point/Station 215.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 56.500(Ft.) Downstream point elevation = 55.820(Ft.) Channel length thru subarea = 72.000 (Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 25.000 Slope or 'Z' of right channel bank = 25.000 Estimated mean flow rate at midpoint of channel = 0.056(CFS) Manning's 'N' = 0.020 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.056(CFS) Depth of flow = 0.058(Ft.), Average velocity = 0.678(Ft/s) Channel flow top width = 2.881(Ft.) Flow Velocity = 0.68(Ft/s) Travel time = 1.77 min. Time of concentration = 13.87 min. Critical depth = 0.050(Ft.) Adding area flow to channel Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.340 Rainfall intensity = 1.596(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.340 CA = 0.048 Subarea runoff = 0.046(CFS) for 0.090(Ac.) Total runoff = 0.076(CFS) Total area = 0.140(Ac.) Depth of flow = 0.064(Ft.), Average velocity = 0.731(Ft/s) Critical depth = 0.057(Ft.) Process from Point/Station 215.000 to Point/Station 225.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.320(Ft.) Downstream point/station elevation = 53.870(Ft.) Pipe length = 80.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.076(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.076(CFS) Normal flow depth in pipe = 1.72(In.) Flow top width inside pipe = 5.42(In.) Critical Depth = 1.63(In.) Pipe flow velocity = 1.62(Ft/s) Travel time through pipe = 0.82 min. Time of concentration (TC) = 14.70 min. Process from Point/Station 230.000 to Point/Station **** SUBAREA FLOW ADDITION **** 225.000 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 14.70 min. Rainfall intensity = 1.538(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.784 CA = 0.674 Subarea runoff = 0.961(CFS) for 0.720(Ac.) Total runoff = 1.037(CFS) Total area = 0.860(Ac.) Process from Point/Station 225.000 to Point/Station 235.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.870 (Ft.) Downstream point/station elevation = 52.600(Ft.) Pipe length = 254.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter Calculated individual pipe flow = Normal flow depth in pipe = 6.59(In.) Flow top width inside pipe = 7.97(In.) Critical Depth = 5.60(In.) Pipe flow velocity = 2.99(Ft/s) Travel time through pipe = 1.42 min. Time of concentration (TC) = 16.11 min. 1.037(CFS) 9.00(In.) 1.037(CFS) Process from Point/Station 240.000 to Point/Station **** SUBAREA FLOW ADDITION **** 235.000 Decimal fraction soil group A Decimal fraction soil group B fraction soil group C fraction soil group D 000 000 000 000 Decimal Decimal [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 16.11 min. Rainfall intensity = 1.449(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.816 CA = 1.118 Subarea runoff = 0.583(CFS) for 0.510(Ac.) Total runoff = 1.620(CFS) Total area = 1.370(Ac.) Process from Point/Station 235.000 to Point/Station 245.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.600(Ft.) Downstream point/station elevation = 51.890(Ft.) Pipe length = 142.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter Calculated individual pipe flow = 1 Normal flow depth in pipe = 7.00(In.) Flow top width inside pipe = 11.83(In.) Critical Depth = 6.48(In.) Pipe flow velocity = 3.41(Ft/s) Travel time through pipe = 0.69 min. Time of concentration (TC) = 16.81 min. 1.620(CFS) 12.00(In.) 620(CFS) Process from Point/Station 350.000 to Point/Station **** SUBAREA FLOW ADDITION **** 245.000 Decimal fraction soil group A Decimal fraction soil group B group C group D 000 000 000 000 Decimal fraction soil Decimal fraction soil [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 16.81 min. Rainfall intensity = 1.410(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.829 CA = 1.500 Subarea runoff = 0.496(CFS) for 0.440(Ac.) Total runoff = 2.116(CFS) Total area = 1.810(Ac.; Process from Point/Station 245.000 to Point/Station 255.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.890(Ft.) Downstream point/station elevation = 51.330(Ft.) Pipe length = 112.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 2.116(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 2.116(CFS) Normal flow depth in pipe = 8.43(In.) Flow top width inside pipe = 10.98(In.) Critical Depth = 7.45(In.) Pipe flow velocity = 3.59(Ft/s) Travel time through pipe = 0.52 min. Time of concentration (TC) = 17.33 min. Process from Point/Station 260.000 to Point/Station 255.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 17.33 min. Rainfall intensity = 1.383(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.837 CA = 1.883 Subarea runoff = 0.488(CFS) for 0.440(Ac.) Total runoff = 2.604(CFS) Total area = 2.250(Ac.) Process from Point/Station 255.000 to Point/Station 265.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.330(Ft.) Downstream point/station elevation = 50.400 (Ft.) Pipe length = 186.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 2.604(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 2.604(CFS) Normal flow depth in pipe = 8.12(In.) Flow top width inside pipe = 14.95(In.) Critical Depth = 7.77(In.) Pipe flow velocity = 3.84(Ft/s) Travel time through pipe = 0.81 min. Time of concentration (TC) = 18.13 min. Process from Point/Station 270.000 to Point/Station 265.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 18.13 min. Rainfall intensity = 1.343(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.843 CA = 2.327 Subarea runoff = 0.521(CFS) for 0.510(Ac.) Total runoff = 3.125(CFS) Total area = 2.760(Ac.) Process from Point/Station 275.000 to Point/Station **** SUBAREA FLOW ADDITION **** 265.000 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.340 Time of concentration = 18.13 min. Rainfall intensity = 1.343(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.829 CA = 2.354 Subarea runoff = 0.037(CFS) for 0.080(Ac.) Total runoff = 3.162(CFS) Total area = 2.840(Ac.) Process from Point/Station 265.000 to Point/Station 280.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 50.400 (Ft.) Downstream point/station elevation = 50.020(Ft.) Pipe length = 21.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 3.162(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 3.162(CFS) Normal flow depth in pipe = 7.11(In.) Flow top width inside pipe = 11.79(In.) Critical Depth = 9.14(In.) Pipe flow velocity = 6.52(Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 18.19 min. End of computations, total study area = 2.840 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 08/17/06 3153 POINSETTIA COMMONS SYSTEM 100 - PROPOSED CONDITIONS 10 YEAR STORM AUGUST 14, 2006 ********* Hydrology Study Control Information ********** Program License Serial Number 4049 Rational hydrology study storm event year is 10.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.700 24 hour precipitation(inches) = 3.000 P6/P24 = 56.7% San Diego hydrology manual 'C' values used Process from Point/Station 100.000 to Point/Station 105.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [MEDIUM DENSITY RESIDENTIAL ] (7.3 DU/A or Less ) Impervious value, Ai = 0.400 Sub-Area C Value = 0.570 Initial subarea total flow distance = 70.000(Ft.) Highest elevation = 57.900(Ft.) Lowest elevation = 57.690(Ft.) Elevation difference = 0.210(Ft.) Slope = 0.300 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.30 %, in a development type of 7.3 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 10.08 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slope^(l/3)] TC = [1.8*(1.1-0.5700)*( 50.000^.5)/( 0.300A(1/3)]= 10.08 The initial area total distance of 70.00 (Ft.) entered leaves a remaining distance of 20.00 (Ft.) Using Figure 3-4, the travel time for this distance is 0.73 minutes for a distance of 20.00 (Ft.) and a slope of 0.30 % with an elevation difference of 0.06(Ft.) from the end of the top area Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr) 0.734 Minutes Tt=[ (11.9*0.0038A3)/( 0.06)]*.385= 0.73 Total initial area Ti = 10.08 minutes from Figure 3-3 formula plus 0.73 minutes from the Figure 3-4 formula = 10.81 minutes Rainfall intensity (I) = 2.724(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.570 Subarea runoff = 0.062(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 105.000 to Point/Station 110.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 55.620(Ft.) Downstream point/station elevation = 54.700 (Ft.) Pipe length = 75.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = 3 Calculated individual pipe flow = 0.062(CFS) Normal flow depth in pipe = 1.74(In.) Flow top width inside pipe = 2.96(In.) Critical Depth = 1.80(In.) Pipe flow velocity = 2.11(Ft/s) Travel time through pipe = 0.59 min. Time of concentration (TC) = 11.40 min. 0.062(CFS) 00(In.) Process from Point/Station 115.000 to Point/Station **** SUBAREA FLOW ADDITION **** 110.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [LOW DENSITY RESIDENTIAL ] (1.0 DU/A or Less ) Impervious value, Ai = 0.100 Sub-Area C Value = 0.410 Time of concentration = 11.40 min. Rainfall intensity = 2.632(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.446 CA = 0.080 Subarea runoff = 0.149(CFS) for 0.140(Ac.) Total runoff = 0.211(CFS) Total area = 0.180(Ac.; Process from Point/Station 110.000 to Point/Station **** PIPEFLOW TRAVEL TIME (Program estimated size) **** 120.000 Upstream point/station elevation = 54.700(Ft.) Downstream point/station elevation = 53.870 (Ft.) Pipe length = 165.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.211(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.211(CFS) Normal flow depth in pipe = 3.11(In.) Flow top width inside pipe = 6.00(In.) Critical Depth = 2.76(In.) Pipe flow velocity = 2.06(Ft/s) Travel time through pipe = 1.34 min. Time of concentration (TC) = 12.74 min. Process from Point/Station 121.000 to Point/Station **** SUBAREA FLOW ADDITION **** 120.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [LOW DENSITY RESIDENTIAL ] (2.9 DU/A or Less ) Impervious value, Ai = 0.250 Sub-Area C Value = 0.490 Time of concentration = 12.74 min. Rainfall intensity = 2.450(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.465 CA = 0.149 Subarea runoff = 0.154(CFS) for 0.140(Ac.) Total runoff = 0.365(CFS) Total area = 0.320(Ac.) Process from Point/Station 122.000 to Point/Station **** SUBAREA FLOW ADDITION **** 120.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Time of concentration = 12.74 min. Rainfall intensity = 2.450(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.570 CA = 0.251 Subarea runoff = 0.250(CFS) for 0.120(Ac.) Total runoff = 0.614(CFS) Total area = 0.440(Ac.) Process from Point/Station 121.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 120.000 Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.440(Ac.) Runoff from this stream = 0.614(CFS) Time of concentration = 12.74 min. Rainfall intensity = 2.450(In/Hr) Process from Point/Station 123.000 to Point/Station 125.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Initial subarea total flow distance = 30.000 (Ft.) Highest elevation = 58.100(Ft.) Lowest elevation = 57.580(Ft.) Elevation difference = 0.520(Ft.) Slope = 1.733 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 70.00 (Ft) for the top area slope value of 1.73 %, in a development type of Office Professional In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.13 minutes TC = [1.8*(1.1-C)*distance(Ft.)*.5)/(% slopeA(l/3)] TC = [1.8*(1.1-0.8500)* ( 70.000*.5)/( 1.733^(1/3)]= 3.13 Calculated TC of 3.134 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 4.479(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.850 Subarea runoff = 0.114(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 125.000 to Point/Station 127.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 57.580(Ft.) End of street segment elevation = 55.600(Ft.) Length of street segment = 108.000 (Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 14.000(Ft.) Distance from crown to crossfall grade break = 12.500(Ft.) Slope from gutter to grade break (v/hz) = 0.083 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 10.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0170 Manning's N from gutter to grade break = 0.0170 Manning's N from grade break to crown = 0.0170 Estimated mean flow rate at midpoint of street = 0.348(CFS) Depth of flow = 0.196(Ft.), Average velocity = 1.815(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 2.991(Ft.) Flow velocity = 1.81(Ft/s) Travel time = 0.99 min. TC = 4.13 min. Adding area flow to street Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 4.479(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.850 CA = 0.145 Subarea runoff = 0.533(CFS) for 0.140(Ac.) Total runoff = 0.647(CFS) Total area = 0.170(Ac.) Street flow at end of street = 0.647(CFS) Half street flow at end of street = 0.647(CFS) Depth of flow = 0.233(Ft.), Average velocity = 1.935(Ft/s) Flow width (from curb towards crown)= 4.816(Ft.) Process from Point/Station 127.000 to Point/Station 120.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.085(Ft.) Downstream point/station elevation = 53.870(Ft.) Pipe length = 43.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.647(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.647(CFS) Normal flow depth in pipe = 4.78(In.) Flow top width inside pipe = 8.98(In.) Critical Depth = 4.38(In.) Pipe flow velocity = 2.71(Ft/s) Travel time through pipe = 0.26 min. Time of concentration (TC) = 4.39 min. Process from Point/Station 127.000 to Point/Station 120.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.170(Ac.) Runoff from this stream = 0.647(CFS) Time of concentration = 4.39 min. Rainfall intensity = 4.479(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 0.614 0.647 = 1.000 * 0.547 * 1.000 * 1.000 * 12.74 4.39 1.000 * 1.000 * 0.345 * 1.000 * 2 .450 4.479 0.614) + 0.647) + 0.614) 0.647) 0.969 0.859 Total of 2 streams to confluence: Flow rates before confluence point: 0.614 0.647 Maximum flow rates at confluence using above data: 0.969 0.859 Area of streams before confluence: 0.440 0.170 Results of confluence: Total flow rate = 0.969(CFS) Time of concentration = 12.740 min. Effective stream area after confluence = 0.610(Ac. Process from Point/Station 120.000 to Point/Station 130.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.800 (Ft.) Downstream point/station elevation = 52.660 (Ft.) Pipe length = 225.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.969(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.969(CFS) Normal flow depth in pipe = 6.21(In.) Flow top width inside pipe = 8.32(In.) Critical Depth = 5.41(In.) Pipe flow velocity = 2.98(Ft/s) Travel time through pipe = 1.26 min. Time of concentration (TC) = 14.00 min. Process from Point/Station 135.000 to Point/Station **** SUBAREA FLOW ADDITION **** 130.000 Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C Decimal fraction soil group D [LOW DENSITY RESIDENTIAL (1.0 DU/A or Less ) Impervious value, Ai = 0.100 Sub-Area C Value = 0.410 0.000 0.000 0.000 1.000 Time of concentration = 14.00 min. Rainfall intensity = 2.305(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.585 CA = 0.485 Subarea runoff = 0.151(CFS) for 0.220(Ac.) Total runoff = 1.119(CFS) Total area = 0.830(Ac.) Process from Point/Station 140.000 to Point/Station **** SUBAREA FLOW ADDITION **** 130.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 14.00 min. Rainfall intensity = 2.305(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.659 CA = 0.738 Subarea runoff = 0.582(CFS) for 0.290(Ac.) Total runoff = 1.701(CFS) Total area = 1.120(Ac.) Process from Point/Station 130.000 to Point/Station 145.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.660(Ft.) Downstream point/station elevation = 52.200(Ft.) Pipe length = 127.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = 1 Normal flow depth in pipe = 8.07(In.) Flow top width inside pipe = 11.26(In.) Critical Depth = 6.65(In.) Pipe flow velocity = 3.03(Ft/s) Travel time through pipe = 0.70 min. Time of concentration (TC) = 14.70 min. 1.70KCFS) 12.00 (In.) 701 (CFS) Process from Point/Station 155.000 to Point/Station **** SUBAREA FLOW ADDITION **** 145.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type (General Commercial ) Impervious value, Ai = 0.850 Sub-Area C Value = 0.820 Time of concentration = 14.70 min. Rainfall intensity = 2.234(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.729 CA = 1.451 Subarea runoff = 1.541(CFS) for 0.870(Ac.) Total runoff = 3.242(CFS) Total area = 1.990(Ac.) Process from Point/Station 145.000 to Point/Station 150.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.200(Ft.) Downstream point/station elevation = 51.900(Ft.) Pipe length = 55.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 3.242(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 3.242(CFS) Normal flow depth in pipe = 9.07(In.) Flow top width inside pipe = 14.67 (In.) Critical Depth 8.71(In.) Pipe flow velocity = 4.18(Ft/s) Travel time through pipe = 0.22 min. Time of concentration (TC) = 14.92 min. Process from Point/Station 145.000 to Point/Station 150.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 1.990(Ac.) Runoff from this stream = 3.242(CFS) Time of concentration = 14.92 min. Rainfall intensity = 2.213(In/Hr) Process from Point/Station 160.000 to Point/Station 165.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (General Commercial ) Impervious value, Ai = 0.850 Sub-Area C Value = 0.820 Initial subarea total flow distance = 81.000(Ft.) Highest elevation = 58.700(Ft.) Lowest elevation = 57.300 (Ft.) Elevation difference = 1.400(Ft.) Slope = 1.728 % Top of Initial Area Slope adjusted by User to 0.017 % Bottom of Initial Area Slope adjusted by User to 0.017 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.02 %, in a development type of General Commercial In Accordance With Figure 3-3 . Initial Area Time of Concentration = 13.86 minutes TC = [1.8*(l.l-C)*distance(Ft.)*.5)/(% slope*(l/3)] TC = [1.8*(1.1-0.8200)* ( 50.000*.5)/( 0.017A(1/3)]= 13.86 The initial area total distance of 81.00 (Ft.) entered leaves a remaining distance of 31.00 (Ft.) Using Figure 3-4, the travel time for this distance is 3.11 minutes for a distance of 31.00 (Ft.) and a slope of 0.02 % with an elevation difference of 0.01(Ft.) from the end of the top area Tt = [11.9*length(Mi)*3)/(elevation change(Ft.))P.385 *60(min/hr) 3.106 Minutes Tt=[(11.9*0.0059*3)/( 0.01)]*.385= 3.11 Total initial area Ti = 13.86 minutes from Figure 3-3 formula plus 3.11 minutes from the Figure 3-4 formula = 16.97 minutes Rainfall intensity (I) = 2.037(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.820 Subarea runoff = 0.200(CFS) Total initial stream area = 0.120(Ac.) Process from Point/Station 165.000 to Point/Station 170.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 57.300(Ft.) Downstream point elevation = 55.700(Ft.) Channel length thru subarea = 240.000(Ft.) Channel base width = 0.000 (Ft.) Slope or 'Z' of left channel bank = 66.660 Slope or 'Z' of right channel bank = 66.660 Estimated mean flow rate at midpoint of channel = 0.695(CFS) Manning's 'N' = 0.017 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.695(CFS) Depth of flow = 0.103(Ft.), Average velocity = 0.987(Ft/s) Channel flow top width = 13.704(Ft.) Flow Velocity = 0.99(Ft/s) Travel time = 4.05 min. Time of concentration = 21.02 min. Critical depth = 0.093 (Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Rainfall intensity = 1.774(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.845 CA = 0.634 Subarea runoff = 0.924(CFS) for 0.630(Ac.) Total runoff = 1.124(CFS) Total area = 0.750(Ac.) Depth of flow = Critical depth = 0.123(Ft.), Average velocity = 1.113(Ft/s) 0.112(Ft.) Process from Point/Station 175.000 to Point/Station **** SUBAREA FLOW ADDITION **** 170.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.790 Time of concentration = 21.02 min. Rainfall intensity = 1.774(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.818 CA = 1.226 Subarea runoff = l.OSl(CFS) for 0.750(Ac.) Total runoff = 2.175(CFS) Total area = 1.500(Ac.) Process from Point/Station 180.000 to Point/Station **** SUBAREA FLOW ADDITION **** 170.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (43.0 DU/A or Less ) Impervious value, Ai = 0.800 Sub-Area C Value = 0.790 Time of concentration = 21.02 min. Rainfall intensity = 1.774(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.808 CA = 1.898 Subarea runoff = 1.191(CFS) for 0.850(Ac.) Total runoff = 3.367(CFS) Total area = 2.350(Ac.) Process from Point/Station 170.000 to Point/Station 150.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.350(Ft.) Downstream point/station elevation = 51.900(Ft.) Pipe length = 113.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 10.39(In.) Flow top width inside pipe = 13.84(In.) Critical Depth = 8.87(In.) 3.367(CFS) 15.00(In.) 3.367(CFS) Pipe flow velocity = 3.71(Ft/s) Travel time through pipe = 0.51 min. Time of concentration (TC) = 21.53 min. Process from Point/Station 170.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 150.000 Along Main Stream number: 1 in normal stream number 2 Stream flow area = 2.350(Ac.) Runoff from this stream = 3.367(CFS) Time of concentration = 21.53 min. Rainfall intensity = 1.747(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(l) 3.242 3.367 = 1.000 * 1.000 * 14.92 21.53 1.000 * 0.693 * 2 1 3.242) + 3.367) + Qmax(2) = 0.789 * 1.000 * 1.000 * 1.000 * 2.213 1.747 3.242) + 3.367) + 5.575 5.926 Total of 2 streams to confluence: Flow rates before confluence point: 3.242 3.367 Maximum flow rates at confluence using above data: 5.575 5.926 Area of streams before confluence: 1.990 2.350 Results of confluence: Total flow rate = 5.926(CFS) Time of concentration = 21.528 min. Effective stream area after confluence = 4.340(Ac.) Process from Point/Station 150.000 to Point/Station 185.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.900(Ft.) Downstream point/station elevation = 51.700(Ft.) Pipe length = 75.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 5.926(CFS) Nearest computed pipe diameter = 21.00(In.) Calculated individual pipe flow = 5.926(CFS) Normal flow depth in pipe = 13.24(In.) Flow top width inside pipe = 20.27(In.) Critical Depth = 10.75(In.) Pipe flow velocity = 3.71(Ft/s) Travel time through pipe = 0.34 min. Time of concentration (TC) =21.87 min. Process from Point/Station 190.000 to Point/Station **** SUBAREA FLOW ADDITION **** 185.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (Office Professional ) Impervious value, Ai = 0.900 Sub-Area C Value = 0.850 Time of concentration = 21.87 min. Rainfall intensity = 1.729(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.780 CA = 3.791 Subarea runoff = 0.630(CFS) for 0.520(Ac.) Total runoff = 6.556(CFS) Total area = 4.860(Ac.! Process from Point/Station 185.000 to Point/Station 195.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.700(Ft.) Downstream point/station elevation = 51.070(Ft.) Pipe length = 210.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 6.55S(CFS) Nearest computed pipe diameter = 21.00(In.) Calculated individual pipe flow = 6.556(CFS) Normal flow depth in pipe = 13.64(In.) Flow top width inside pipe = 20.04(In.) Critical Depth = 11.34(In.) Pipe flow velocity = 3.97(Ft/s) Travel time through pipe = 0.88 min. Time of concentration (TC) = 22.75 min. Process from Point/Station 197.000 to Point/Station **** SUBAREA FLOW ADDITION **** 195.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [COMMERCIAL area type ] (General Commercial ) Impervious value, Ai = 0.850 Sub-Area C Value = 0.820 Time of concentration = 22.75 min. Rainfall intensity = 1.686(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.784 CA = 4.193 Subarea runoff = 0.512(CFS) for 0.490(Ac.) Total runoff = 7.068(CFS) Total area = 5.350(Ac.; Process from Point/Station 195.000 to Point/Station 198.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.070 (Ft.) Downstream point/station elevation = 48.500(Ft.) Pipe length = 108.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 7.068(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 7.068(CFS) Normal flow depth in pipe = 9.33(In.) Flow top width inside pipe = 14.55(In.) Critical Depth = 12.76(In.) Pipe flow velocity = 8.81(Ft/s) Travel time through pipe = 0.20 min. Time of concentration (TC) = 22.95 min. End of computations, total study area = 5.350 (Ac.) San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 08/17/06 3153 POINSETTIA COMMONS SYSTEM 200 - PROPOSED CONDITIONS 10 YEAR STORM AUGUST 16, 2006 Hydrology Study Control Information ********** Program License Serial Number 4049 Rational hydrology study storm event year is 10.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.700 24 hour precipitation(inches) = 3.000 P6/P24 = 56.7% San Diego hydrology manual 'C' values used Process from Point/Station 205.000 to Point/Station 210.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.340 Initial subarea total flow distance = 95.000(Ft.) Highest elevation = 57.130(Ft.) Lowest elevation = 56.500(Ft.) Elevation difference = 0.630(Ft.) Slope = 0.663 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.66 %, in a development type of 2.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 11.09 minutes TC = [1.8* (l.l-C)*distance(Ft.)*.5)/(% slope"(l/3)] TC = [1.8* (1.1-0.3400)*( 50.000A.5)/( 0.663^(1/3)]= 11.09 The initial area total distance of 95.00 (Ft.) entered leaves a remaining distance of 45.00 (Ft.) Using Figure 3-4, the travel time for this distance is 1.01 minutes for a distance of 45.00 (Ft.) and a slope of 0.66 % with an elevation difference of 0.30(Ft.) from the end of the top area Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]".385 *60(min/hr) 1.010 Minutes Tt=[(11.9*0.0085*3)/( 0.30)]A.385= 1.01 Total initial area Ti = 11.09 minutes from Figure 3-3 formula plus 1.01 minutes from the Figure 3-4 formula = 12.10 minutes Rainfall intensity (I) = 2.532(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.340 Subarea runoff = 0.043(CFS) Total initial stream area = 0.050(Ac.) Process from Point/Station 210.000 to Point/Station 215.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 56.500 (Ft.) Downstream point elevation = 55.820(Ft.) Channel length thru subarea = 72.000 (Ft.) Channel base width = 0.000 (Ft.) Slope or 'Z' of left channel bank = 25.000 Slope or 'Z' of right channel bank = 25.000 Estimated mean flow rate at midpoint of channel = 0.082(CFS) Manning's 'N' = 0.020 Maximum depth of channel = 1.000 (Ft.) Flow(q) thru subarea = 0.082(CFS) Depth of flow = 0.066 (Ft.), Average velocity = 0.745(Ft/s) Channel flow top width = 3.314(Ft.) Flow Velocity = 0.74(Ft/s) Travel time = 1.61 min. Time of concentration = 13.71 min. Critical depth = 0.058(Ft.) Adding area flow to channel Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.340 Rainfall intensity = 2.336(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.340 CA = 0.048 Subarea runoff = 0.068(CFS) for 0.090(Ac.) Total runoff = O.lll(CFS) Total area = 0.140(Ac.) Depth of flow = 0.074(Ft.), Average velocity = 0.804(Ft/s) Critical depth = 0.066(Ft.) Process from Point/Station 215.000 to Point/Station 225.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.320 (Ft.) Downstream point/station elevation = 53.870(Ft.) Pipe length = 80.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = O.lll(CFS) Nearest computed pipe diameter = 6.00 (In.) Calculated individual pipe flow = O.lll(CFS) Normal flow depth in pipe = 2.11(In.) Flow top width inside pipe = 5.73(In.) Critical Depth = 1.98(In.) Pipe flow velocity = 1.81(Ft/s) Travel time through pipe = 0.74 min. Time of concentration (TC) = 14.45 min. Process from Point/Station 230.000 to Point/Station 225.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 14.45 min. Rainfall intensity = 2.259(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.784 CA = 0.674 Subarea runoff = 1.41KCFS) for 0.720 (Ac.) Total runoff = 1.523(CFS) Total area = 0.860(Ac.) Process from Point/Station 225.000 to Point/Station 235.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.870(Ft.) Downstream point/station elevation = 52.600(Ft.) Pipe length = 254.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.523(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 1.523(CFS) Normal flow depth in pipe = 6.73(In.) Flow top width inside pipe = 11.91(In.) Critical Depth = 6.27(In.) Pipe flow velocity = 3.36(Ft/s) Travel time through pipe = 1.26 min. Time of concentration (TC) = 15.71 min. Process from Point/Station 240.000 to Point/Station 235.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 15.71 min. Rainfall intensity = 2.140(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.816 CA = 1.118 Subarea runoff = 0.870(CFS) for 0.510(Ac.) Total runoff = 2.392(CFS) Total area = 1.370(Ac.) Process from Point/Station 235.000 to Point/Station 245.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.600(Ft.) Downstream point/station elevation = 51.890(Ft.) Pipe length = 142.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 9.33(In.) Flow top width inside pipe = 9.98(In.) Critical Depth = 7.94(In.) Pipe flow velocity = 3.65(Ft/s) Travel time through pipe = 0.65 min. Time of concentration (TC) = 16.36 min. 2.392(CFS) 12.00(In.) 2.392(CFS) Process from Point/Station 350.000 to Point/Station **** SUBAREA FLOW ADDITION **** 245.000 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 16.36 min. Rainfall intensity = 2.085(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.829 CA = 1.500 Subarea runoff = 0.737(CFS) for 0.440(Ac.) Total runoff = 3.129(CFS) Total area = 1.810(Ac.) Process from Point/Station 245.000 to Point/Station **** PIPEFLOW TRAVEL TIME (Program estimated size) **** 255.000 Upstream point/station elevation = 51. 890 (Ft.) Downstream point/station elevation = 51.330(Ft.) Pipe length = 112.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 3.129(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 3.129(CFS) Normal flow depth in pipe = 9.12(In.) Flow top width inside pipe = 14.65(In.) Critical Depth = 8.54(In.) Pipe flow velocity = 4.01(Ft/s) Travel time through pipe = 0.47 min. Time of concentration (TC) = 16.83 min. Process from Point/Station 260.000 to Point/Station 255.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 16.83 min. Rainfall intensity = 2.048(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.837 CA = 1.883 Subarea runoff = 0.728(CFS) for 0.440(Ac.) Total runoff = 3.857(CFS) Total area = 2.250(Ac.) Process from Point/Station 255.000 to Point/Station 265.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.330(Ft.) Downstream point/station elevation = 50.400 (Ft.) Pipe length = 186.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 3.857(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 3.857(CFS) Normal flow depth in pipe = 10.57(In.) Flow top width inside pipe = 13.69(In.) Critical Depth = 9.53(In.) Pipe flow velocity = 4.l7(Ft/s) Travel time through pipe = 0.74 min. Time of concentration (TC) = 17.57 min. Process from Point/Station 270.000 to Point/Station 265.000 **** SUBAREA FLOW ADDITION **** Decimal fraction soil group A = 1.000 .KM Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 [INDUSTRIAL area type ] (General Industrial ) Impervious value, Ai = 0.950 Sub-Area C Value = 0.870 Time of concentration = 17.57 min. Rainfall intensity = 1.991(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.843 CA = 2.327 Subarea runoff = 0.778(CFS) for 0.510(Ac.) Total runoff = 4.634(CFS) Total area = 2.760(Ac.) Process from Point/Station 275.000 to Point/Station **** SUBAREA FLOW ADDITION **** 265.000 = 1 000 0.000 0.000 0.000 Decimal fraction soil group A Decimal fraction soil group B Decimal fraction soil group C Decimal fraction soil group D [LOW DENSITY RESIDENTIAL ] (2.0 DU/A or Less ) Impervious value, Ai = 0.200 Sub-Area C Value = 0.340 Time of concentration = 17.57 min. Rainfall intensity = 1.991(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.829 CA = 2.354 Subarea runoff = 0.054(CFS) for 0.080(Ac.) Total runoff = 4.688(CFS) Total area = 2.840(Ac.) Process from Point/Station 265.000 to Point/Station 280.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 50.400(Ft.) Downstream point/station elevation = 50.020(Ft.) Pipe length = 21.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 4.688(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 4.688(CFS) Normal flow depth in pipe = 9.61(In.) Flow top width inside pipe = 9.59(In.) Critical Depth = 10.79(In.) Pipe flow velocity = 6.96(Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 17.62 min. End of computations, total study area = 2.840 (Ac.) Swale Treatment Flows Worksheet for Trapezoidal Channel Project Description Worksheet Swale Water Qu Flow Element Trapezoidal Cha Method Manning's Formi Solve For Channel Depth Input Data Mannings Coeffic 0.250 Channel Slope 005000 ft/ft Left Side Slope 1.00 H: V Right Side Slope 1.00 H : V Bottom Width 3.00 ft Discharge 0.47 cfs Results Depth 0.55 ft Flow Area 2.0 ft2 Wetted Perimi 4.56 ft Top Width 4.11 ft Critical Depth 0.09 ft Critical Slope 2.103524 ft/ft Velocity 0.24 ft/s Velocity Head 0.00 ft Specific Enerc 0.55 ft Froude Numb 0.06 Flow Type Subcritical Project Engineer: Employee of PDC p:\3153\engr\reports\drain\hydra\sd.fm2 PROJECTDESIGN CONSULTANTS FlowMaster v7.0 [7.0005] 01/18/07 02:56:39 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Cross Section Cross Section for Trapezoidal Channel Project Description Worksheet Flow Element Method Solve For Swale Water Qu Trapezoidal Cha Manning's Formi Channel Depth Section Data Mannings Coeffic 0.250 Channel Slope 005000 ft/ft Depth Left Side Slope Right Side Slope Bottom Width Discharge 0.55 ft 1.00 H :V 1.00 H : V 3.00 ft 0.47 cfs 0.55 ft -3.00 ft~ NTS p:\3153\engr\reports\drain\hydra\sd.fm2 01/18/07 02:43:36 PM © Haestad Methods, Inc. PROJECTDESIGN CONSULTANTS 37 Brookside Road Waterbury, CT 06708 USA Project Engineer: Employee of PDC FlowMaster v7.0 [7.0005] -203-755-1666 Page 1 of 1 Swale 100 Year Storm Conveyance Worksheet for Trapezoidal Channel Project Description Worksheet Swale Storm Conv Flow Element Trapezoidal Chann Method Manning's Formula Solve For Channel Depth Input Data Mannings Coeffic 0.035 Channel Slope 005000 ft/ft Left Side Slope 1.00 H : V Right Side Slope 1.00 H : V Bottom Width 3.00 ft Discharge 7.00 cfs Results Depth 0.85 ft Flow Area 3.3 ft2 Wetted Perimi 5.40 ft Top Width 4.70 ft Critical Depth 0.52 ft Critical Slope 0.026610 ft/ft Velocity 2.15 ft/s Velocity Head 0.07 ft Specific Enerc 0.92 ft Froude Numb< 0.45 Flow Type Bubcritical Project Engineer: Employee of PDC p:\3153\engr\reports\drain\hydra\sd.fm2 PROJECTDESIGN CONSULTANTS FlowMaster v7.0 [7.0005] 01/18/07 02:53:38 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 Cross Section Cross Section for Trapezoidal Channel Project Description Worksheet Flow Element Method Solve For Swale Storm Conv Trapezoidal Chann Manning's FormulE Channel Depth Section Data Mannings Coeffic 0-035 Channel Slope 005000 ft/ft Depth Left Side Slope Right Side Slope Bottom Width Discharge 0.85 ft 1.00 H : V 1.00 H : V 3.00 ft 7.00 cfs 0.85ft -3.00 ft- NTS p:\3153\engr\reports\drain\hydra\sd.fm2 01/18/07 02:56:26 PM © Haestad Methods, Inc. PROJECTDESIGN CONSULTANTS 37 Brookside Road Waterbury, CT 06708 USA Project Engineer Employee of PDC FlowMaster v7.0 [7.0005] t-1 -203-755-1666 Page 1 of 1 APPENDIX 5 Supplemental BMP Information Treatment BMP 30" DIAMETER CAST IRON MANHOLE FRAME AND COVER SUPPLIED BY CDS OR CONTRACTOR REINFORCED CONCRETE TRAFFIC BEARING SLAB SUPPLIED BY CDS 0 CONTRACTOR PSW50 RISER SECTIONS. (AS REQUIRED) PSW50 INLET/OUTLET- ACCESS COVER AND FRAMES REDUCER SECTION AS REQUIRED RISER BARREL LENGTH VARIES PSW50 WEIR BOX COVER LID CDS UNIT TO WEIR BOX CONNECTION JCOLLAR NOT SHOWN , /— PSW50 WEIR BOX1 ' 7 (CUSTOMIZED TO EACH LOCATION) PSW50 SEPARATION CHAMBER TOP PSW50 SEPARATION CHAMBER PSW50 SUMP L ^._ PSW50 ASSEMBLY SUPPLIED BY CDS INLET PIPE BLOCKOUT (CONNECTION COLLAR NOT SHOWN) BLOCKOUT FOR CONNECTION TO OUTLET PIPE COLLAR (CONNECTION COLLAR NOT SHOWN) DIVERSION STRUCTURE SUPPLIED BY CDS OR CONTRACTOR PSYF50_42 fc PSW50_50 ASSEMBLIES, SEE SHEET 2 CDS TECHNOLOGIES PATFNTED CDS PSW50 ASSEMBLY AND DIVERSION STRUCTURE DATE 4/3/01 DRAWN ARDY APPROV. SCALE N.T.S. SHEET 1 Pedestrian Loading CDS Access Cover Not Shown PSW50 Riser, Not Shown Wt=1,250#/Ft. PSW50 Inlet/Outlet Wt=5,360# PSW50 Chamber Top Assembled Weights PSW50_42 = 20,000| PSW50_50 = 23,000# PSW50 Separation Chamber, (Chamber Top Not Shown) PSW50 Sump Wt=4.260# ASSEMBLYDETAIL CDS PSW50 ASSEMBLY GENERIC / TYPICAL INSTALLATION (LEFT HAND UNIT SHOWN) 4' TO 7' TYPICALLY XX'tf INLET PIPE 30" ACCESS COVER (TYPICAL), OTHER ACCESS COVERS AVAILABLE 84'0 MH COVER AND FRAME (TYPICAL), OTHER ACCESS COVERS AVAILABLE DIVERSION CHAMBER POUR CONCRETE CONNECTION COLLARS TO SEAL INLET AND OUTLET PIPES. XX'0 OUTLET PIPE SHT 4 DIVERS! VEIR BLDCKDUT, W=5'-6' H=2'-B' (TYPICAL) t TY FLOW 7 PSV50_4E STORM VATER TREATMENT UNIT TYPICALLY 7' TO 9' " TYPICALLY 14' TO 16'"SHT 4 PLAN VIEW CDS UNIT PSW50_42 9 CFS CAPACITY STORM WATER TREATMENT UNIT NOTES. 1. CREATE SMDDTH SWALE TRANSITION THROUGH DIVERSION BOX WITH SECONDARY CONCRETE POUR IN FIELD TECHNOLOGIES PATENTED PROJECT / DEVELOPMENT NAME CITY & STATE DATE 4/3/01 DRAVN W. STEIN APPRDV. SCALE SHEET GENERIC / TYPICAL INSTALLATION (LEFT HAND UNIT SHOWN) £4'0 HH COVER AND FRAME CTYPICAL), OTHER <tXX'(» OUTLET PIPE CBS MODEL PSV50.4E 9 CFS CAPACITY 30" ACCESS COVER (TYPICAL), OTHER ACCESS ACCESS COVERS AVAILABLE \ VAR VAR ES± VAR ES± VAI ES± IES 4' TO 7'CTYPICAL) XX'0 ~T OUTLET PIPE ft — t3 J3 \\ } : - -. f* |- 4 • | 1 ^^ 1 '' t=- j L- f=a DIVERSION—!L raR] / — "~\/^/^^\VA li V nLv i //A^vyy/ /.j^3>-;)^^2i.^_ ^7T^4' TO r - CTYPICAL) Z ^-SECONDARY 1 1 1 1 I 1 RIESl 1 •. 1 %! t!-HJJ' :fe».KT- POUR TO MATCH INVLKI , IPE INVERT, E1-=X.X'± CONNECTION COLLAR POURED IN FIELDH -11' ALL AROUND . . , 1 r — \~^n 1 ACCESS I rl / COVERS AVAILABLE f" 17\ SHAFT K INTAKE 1 r SEPARATION CHAMBER s *x' 1 VAt JfTi j SUMP 1 1 -. t' ' 1l_ ^i,-.'^^:;:,.- SUMP BOTTOM, / L 4'. EL.=X.X'± TYPICALLY 7' TO 91 TYPICAUY i_i aspr** 9'- "'is'Ss'/ 10" — ' IES r± 14' TO 16'" ELEVATION VIEW CDS UNIT PSW50_42, 9 CFS CAPACITY STORM WATER TREATMENT UNIT TECHNOLOGIES PATENTED PROJECT / DEVELOPMENT NAME CITY & STATE DATE 3/12/00 DRAVN W. STEIN APPRDV. SCALE 1"=5' SHEET 4 GENERIC / TYPICAL INSTALLATION (LEFT HAND UNIT SHOWN) 4' TO 7' TYPICALLY XX'0 INLET PIPE E4'0 MH COVER AND FRAME (TYPICAL), DTHER ACCESS COVERS AVAILABLE DIVERSION CHAMBER POUR CONCRETE CONNECTION COLLARS TO SEAL INLET AND OUTLET PIPES. XX'0 OUTLET PIPE SHT 2 TYPICALLY 14' TO 16' 30" ACCESS COVER (TYPICAL), DTHER ACCESS COVERS AVAILABLE 9' SHT 2j PLAN VIEW CDS UNIT PSW50_50 11 CFS CAPACITY STORM WATER TREATMENT UNIT 1. CREATE SMOOTH SWALE TRANSITION THROUGH DIVERSION BOX WITH SECONDARY CONCRETE POUR IN FIELD TECHNOLOGIES .PATENTED PROJECT / DEVELOPMENT NAME CITY & STATE DATE 3/12/00 DRAVN W. STEIN APPRDV. SCALE SHEET GENERIC / TYPICAL INSTALLATION (LEFT HAND UNIT SHOWN) £4'* MM COVER AND FRAME (TYPICAL), OTHER ACCESS COVERS AVAILABLE t CDS MODEL PSV5D 50 11 CFS CAPACITY 30" ACCESS COVER CTYPICAU, OTHER ACCESS COVERS AVAILABLE SECONDARY POUR TO MATCH INVERT CONNECTION COLLAR POURED IN -11' ALL AROUND ELEVATION VIEW CDS UNIT PS¥50_50, 11 CFS CAPACITY STORM WATER TREATMENT UNIT TECHNOLOGIES PATENTED PROJECT / DEVELOPMENT NAME CITY & STATE DATE 4/3/01 DRAWN W. STEIN APPRDV. SCALE 1"=5' SHEET 6 *" CDS Unit Manufacturer's Hydraulic Calculations 1 <m 1 <m -I <•* -I -I ilWW -I I I I w I •I i l I W REP\2068DR.DOC A-ll 1 I :l Performance Specifications Continuous Deflective Separation Storm Water Treatment Unit The Contractor shall install a precast storm water treatment unit (STWU) in accordance with the notes and details shown on the Drawings and in conformance with these Specifications. The precast storm water treatment units shall be continuous deflective separators (CDS®) unit. The CDS® unit shall be non-mechanical and gravity driven, requiring no external power requirements. The CDS® unit shall come equipped with a stainless steel expanded metal screen having a screen opening of 4700 microns (4.7 mm or 0.185 inches). The separation screen shall be self-cleaning and non-blocking for all flows diverted to it, even when flows within the pipe exceed the CDS® unit's design treatment flow capacity. For this condition, some storm flow bypasses the unit over the diversion weir. Solids Removal Performance Requirements The CDS unit shall be capable of removing suspended and fine solids and shall capture 100% of the fioatables and 100% of all particles equal to or greater than 4.7 millimeter (mm) for all flow conditions up to unit's design treatment flow capacity, regardless of the particle's specific gravity. The CDS® unit shall capture 100% of all neutrally buoyant material greater than 4.7 mm for all flow conditions up to its design treatment flow capacity. There shall be no flow conditions up to the design treatment flow capacity of the CDS® unit in which a flow path through the CDS® unit can be identified that allows the passage of a 4.7-mm or larger neutrally buoyant object. The CDS® unit shall permanently retain all captured material for all flow conditions of the storm drains to include flood conditions. The CDS® unit shall not allow materials that have been captured within the unit to be flushed through or out of the unit during any flow condition to include flood and/or tidal influences. The CDS® unit shall capture 95% of 2350-micron size sand particles (one half the screen opening size), 90% of 1551-micron size sand particles (one third the size of the screen opening) and 50% of 940-micron size sand particles (one fifth the size of the screen opening). There shall be no attenuation of these removal efficiencies or blocking of the screen face as the flow rate increases up to treatment flow capacity of the CDS® unit. The following table lists these required removal efficiencies for a CDS® unit equipped with 4700- micron size screen: D-1 UM> .1 "Im*k 'I .4111 1 <•• -i«• -i -i fl»l -I J I I I IB I 'l II I I :i Performance Specifications Table 1 MEDIUM/FINE SAND SEDIMENT REMOVAL (Indirect Screening - 4700-Micron Screen) Particle Removal Efficiency* Particle Size as percentage of screen opening (%) 100 50 33 20 Screening Removal Efficiency 100% 95% 90% 50% Standard Screen Openings 4700 Micron (0.185-inches) Microns 4700 2350 1551 940 Inches 0.185 0.093 0.061 0.037 Particle Specific Gravity = 2.65 Solids Removal Performance Requirements: (0.095 inches) screen] [For CDS® units equipped with a 2400-micron The CDS unit shall be capable of removing suspended and fine solids and shall capture 100% of the floatables and 100% of all particles greater than 2.4 millimeter for all flow conditions up to its design treatment flow capacity, regardless of the particle's specific gravity. The CDS unit shall capture 100% of all neutrally buoyant material greater than 2.4 millimeters (mm) for all flow conditions up its design treatment flow capacity. There shall be no flow conditions up to the minimum treatment flow capacity in which a flow path through the CDS unit can be identified that allows the passage of a 2.4-millimeter or larger neutrally buoyant object. The CDS unit shall permanently retain all captured material for all flow conditions of the storm drain to include flood conditions. The CDS unit shall not allow materials that have been captured within the unit to be flushed through and/or out of the unit during any flow condition. The CDS unit shall capture 98% of 600-micron size sand particles (one fourth the screen opening size), 80% of 425-micron size sand particles (one twelfth the size of the screen opening) and 42% of 300-micron size sand particles (one twelfth the size of the screen opening). There shall be no blocking of the screen face as the flow rate increases up to the 1 treatment flow capacity. The following table lists these required removal efficiencies for a CDS unit equipped with a 2400-micron size screen: D-2 I 1 1 t 1 -I «* -I I I J Mil I I 11 I •I I J * I I Performance Specifications Table 2 MEDIUM/FINE SEDIMENT REMOVAL (indirect Screening - 2400-Micron Screen) Particle Removal Efficiency* Particle Size (urn) >2400 2400 - 850 850 - 600 600 - 425 425 - 300 300-150 150-75 Particle Removal Efficiency (%) CDS flow rate 28% Capacity (8 l/s) 100 100 100 100 96 76 42 60.7% Capacity (17 l/s) 100 100 100 98 80 42 12 *Particle SG = 2.65 Manufacturers Performance Certificate The manufacturer of the CDS® unit shall submit details and shop drawings of sufficient detail for the Engineer to confirm that no available flow paths exist that would allow the passage of an object greater than 4.7 mm [2.4 mm if a 2400 micron screen is specified]. Additionally, the manufacturer shall submit a "Manufacturers Performance Certificate" certifying that the CDS® unit shall achieve the specified removal efficiencies listed in these specifications. This Manufacturer's Performance Certification of removal efficiencies shall clearly and unequivocally state that the listed removal efficiency shall be achieved throughout the entire treatment flow processed by the CDS® unit with no attenuation of removal efficiency as the flow increase up to the minimum treatment flow capacity specified above. Oil and Grease Removal Performance The CDS® unit is equipped with a conventional oil baffle to capture and retain oil and grease and Total Petroleum Hydrocarbons (TPH) pollutants as they are transported through the storm drain system during dry weather (gross spilis) and wet weather flows. The conventional-oil-baffle-within-a-unitassures-satisfactory oil .and. grease-removaLfrom-typicaL urban storm water runoff. D-3 I I I I II I I I I I I I ht I IIi i 1 I Performance Specifications The CDS® unit shall also be capable of receiving and retaining the addition of Oil Sorbents within their separation chambers. The addition of the oil sorbents can ensure the permanent removal of 80% to 90% of the free oil and grease from the storm water runoff. The addition of sorbents enables increased oil and grease capture efficiencies beyond that obtainable by a conventional oil baffle systems. Sorbent material shall be added in accordance with the "OIL SORBENTS SPECIFICATION", Appendix D, CDS® Technical Manual. Warranty The manufacturer of the CDS® unit shall guarantee the filtration unit free from defects in materials and workmanship for a period one year following installation. Equipment supplied by the manufacturer shall be installed and used only in the particular application for which it was specifically.designed. D-4 TeCHMOLOGfCS ^^•lUllllt"'" BEDS T6CHNOLCX5I€S October 30, 2001 HYDRAULIC CALCULATIONS CONTINUOUS DEFLECTIVE SEPARATOR (CDS) STORM WATER POLLUTION CONTROL UNIT BY CDS TECHNOLOGIES, INC. PROJECT: WATERS END - CARLSBAD, CA ENGINEER: Submitted by: PROJECT DESIGN CONSULTANTS SAN DIEGO, CA Mark Cuneo, P.E. CDS Technologies, Inc. 3950 Long Beach Blvd. Suite 100 Long Beach, CA 90807 _^ CDS Technologies, Inc. • http://www.cdstech.com/ • cds@cdstech.com 3950 Long Beach Blvd. • Suite TOO • Long Beach, CA 90807-5411 • Phone (562) 424-6334 • Fax (562) 424-8336 CDS PROJECT NAME PROJECT NO: <A-/LA ~O 1 - ) S~ S DATE: I Q /Oq /O) BY:SHFFT I OF T€CHNOLOGieS - J ?T" TO ; rn 5: P 1TH , I = O. ^ Ci . a S M.QOCL-... f S> ^ ^O > ^ X > -7 OF 10°) . ^ . OS . T ..... - 07 ni! [CDS TeCHNOLOGieS PROJECT NAME: PROJECT NO: _ BY: * DATE:/Q .SHEET 2-. OF C A- L-^tA fT~ TVHI TXL A- 6-HfT" s* £-SM/\ eg Q VQ 0 (9.O = O. 0. '* ~f-S CDS PROJECT NAME- PROJECT NO: _ BY: M DATE: SHEET OF TeCHNOlCX3l€S O 4" -F -us H. I4~ THC- CDS T6CHNOLOGI€S PROJECT NAME PROJECT NO: BY: M DATE SHEET 4 OE A \ 84) - 34.07 L \ [T- (. CDS PROJECT NAME: PROJECT NO: _ BY: M. DATE: _SHEET._OF 'o T6CHNOLOGI€5 L_ =- <Mt ,tf» *if C V CP3 4.^•+ rs_S.=o.. .01 Pi 34: 07- CDS PROJECT NAME: PROJECT NO: BY: »»\ DATE:Ol T6OHNOLOGI6S 1T->V Ml O - A- 2. - O * ' -TX^^ PC X S t t I i I I t i I i E ; £ : ; i f ; i i S I ! j i i I Submerged Weir Upstream Head Calculations for a Sharp Crested Weir ks = submergence discharge correction factor For sharp crested weirs: Starosolszki Pg 344 or Villmont Equation rWhu,. = 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 ks = 1 0.99 0.98 0.96 0.91 0.93 0.87 0.8 0.7 0.54 0.2 Villmont Eq ks = 1.00 0.99 0.96 0.93 0.89 0.85 0.79 0.71 0.62 0.48 0.00 Assume Select ks from above hu/, hd/, hd,,/hu,, ks Q L C H ft ft cfs ft ft °-53!',', ,VO".83j 109.334EJjJiiiJ1.QJ . 3,08 2.6417 C = 3.08 CDS weirs 2.54 Side weirs ~ ~~>v hu/s <D hd/s t ! t i ft i . i s *t * 5 ! S * « * £« i I i i i t i i i I i i i i i W* BtCT MFC tUMWII »-7UNO D-7U, irw > ir,W1WT • ¥, HAX nU.OVTX nr • INDVMU.I TO KM. MXTAND a/ncr pra actwnc u «•• aunrr pirt PLAN VIEW NOTES: w* HUT t CBS Km.PSV90.4If CTt CAPACITY tvt m covaANB F1WCUN d. 471* MU.MO •OKI 11 Uf I DCTMJ » 10- UWO — MTO f DOT »J» HOU1 Mcos Mtcr/ounrf (J£I COAL HnDOM) L atEATt naaiH SVALX IMOUOI DtvatsnH BK »-T«B rw miracocHT DCTAU. I ,-J ELEVATION VIEW OP UVDtSIM DIVERSION WEIR DETAIL (NO SCALE) SECTION A-A (NO SCALE) CXTCND mmm cu.vnr INLET/OUTLET OPENING DETAIL (NO SCALE) Manufacturer's Reinforcing Steel Drawings REP\2068DR.DOC A-11 ^^•lUIIU""" BEDS TeCHNOlOGICS November 14, 2001 REINFORCING STEEL DRAWINGS CONTINUOUS DEFLECTIVE SEPARATOR (CDS) STORM WATER POLLUTION CONTROL UNIT BY CDS TECHNOLOGIES, INC. PROJECT: WATERS END - CARLSBAD, CA ENGINEER:PROJECT DESIGN CONSULTANTS SAN DIEGO, Submitted by: Mark Cuneo, P.E. CDS Technologies, Inc. 3950 Long Beach Blvd. Suite 100 Long Beach, CA 90807 CDS Technologies, Inc. • http;//www.cdstech.com/ • eds@cdstech.com 3950 Long Beach Blvd. • Suite 100 • Long Beach, CA 90807-5411 • Phone (562) 424-6334 • Fax (562) 424-8336 P50 Riser, Not Shown Wt=1.250#/Ft. P50 Inlet/Outlet, See Sheet 6 Wt=5,360# P50 Chamber Top,See Sheet 5 Assembled Wt 20,000# Screen, Not Shown P50 Separation Chamber, See Sheets 3 and 4 P50 Sump, See Sheet 2 Wt=4,260# DETAIL ASSEMBLY jjSaiBBBIIlW'"" [CDS ' TECHNOLOGIES PATENTED CDS PSW50_42 REINFORCING DETAILS DATE 1/19/99 DRAWN W. SHADEL APPROV. SCALE N.T.S SHEET DETAIL PLAN I 4 1/2" 4'3'-6" •04'-10"- — 04' — 3-D VIEW NOT TO SCALE #4 BARS © EACH WAY SECTION ONE SINGLE WRAP WWF 8X3 - W2.5/3.0 ASTM A 185 OR #3 BARS @ 8"O.C. HORZ. AND #3 BARS O 18" O.C. VERT. i- 3" CLR I. i TM CDS TECHNOLOGIES PATENTED CDS PSW50_42 SUMP REINFORCING DATE 1/19/99 DRAWN W. SHADEL APPROV. SCALE SHEET —^ 1 1 3- <b H. 1 6"|— f h -' * . .. •A -c 1 j— HARDWARE & SCREEN NOT | SHOWN 1 5*- --. "^t^• ; . . *v*/ 4*-\ f o — | — -. A" F" i n" ru • n" ^hU *- \ r-6- #5 GRADE 60 @6" O.C. __» "• ""* —- — ' ' t • ' '^\ •. ' • • ". . 5' \ -.-••' • • • . . < 4 / / D. _l O c CM 1 ^ F BARS @ 6" '96 6-#3 @ 10.5" ALL AROUND DO SECTION 1/2" = 1'-0" SUMP BELOW 00 9'-0" 4'-C ^ >—6-#3 @ 10.5" V ALL AROUND 5'-0" r-6- #5 BARS, TYP. , #3 0 B. I •5'4o"- •4'40"- 48 NOT TO SCALE '96BARS @ 6" 6-#3 0 10.5" ALL AROUND SECTION 1/2" = 1'-0" #5 GRADE 60 @ 6" O.C. TECHNOLOGIES PATENTED CDS PSW50_42 SEPARATION CHAMBER REINFORCING SECTIONS 01/9/01 DRAWN DQP APPROV. SCALE AS SHOWN SHEET PICK POINT 1 GROUP 6: 3-#5 3" THICK TYP. GROUP 5: 3-#5 O 1-1/2" CLR TO BOTTOM OF FORM SPACED O 3" HOOPS AROUND OPENING GROUP 3: 3-#5 REBARS oI CO J. GROUP 1: 3-#5 ON BOTTOM STEEL AROUND OPENING CONFIGURATION GROUP 2: 5-#5 1-1/2" CLR FROM BOTTOM SPACED @3" GROUP 4 : 4-#5 LAID ON TOP OF LOWER #5 BARS PLAN VIEW SCALE: 1/2"=1'-0" 2-#3 @ 2" IN. FROM EDGE FOR CRACK CONTROL NO. OF BARS LENGTHS CO I #3 TOP & BOTTOM #4 AROUND OPENING SEE ABOVE DETAIL A-A SCALE: r=1'-0" B-B -1/2" CLR TYP SCALE: 1/2"=1'-0" GROUP 1 GROUP 2 GROUP 3 GROUP 4 GROUP 5 GROUP 6 3 5 3 4 3 3 2' 3" 5' 6" 6' 0" 6r 6" T 0" T 5" 6' 4" 5' 10" 5' 3" 61 11" 6' 6" 5' 11" 5' 8" 5' 7" 5' 0" 4' 4" 5' 0" 4' 6" 3' 9" REBAR SCHEDULE NOTE: ALL REBARS ARE #5 UNLESS OTHERWISE NOTED CDSTECHNOLOGIES PATENTED CDS PSW50_42 REINFORCING SEPARATION CHAMBER TOP DATE 1/19/99 DRAWN W. SHADEL APPROV. SCALE AS SHOWN SHEET DRILL AND BOND »4 HOVELSIS. REQUIRED (INSTALLED^IN nnj» REINFORCED FDR RISERS 2 WRAPS OF WWF 8X3 - 3.00x2,50 or #3 Bars 6 5' D.C. Horz. and #3 bars 8 18' O.C. Vert. Per ASTM A 185 (NDT SHOWN) DETAIL I4 1/2' TALL JDINT PLAN •5'- SECTION REINFORCE INLET/DUTLET WITH #4 BARS 6 12' DN CENTER, EACH WAY, DR 4*3 BARS 8 6* D.C. EACH WAY, TONGUE 1I u 1^, 1 i1 • • • 4' in*J.U • i DUTLE1 / 1// • • • < IN' i "AKE • • • l\ 1 1 1 1 1 Ini ' _ c* PLACE IN FIELD 12-#4 DDVELS EMBEDDED 4' INTO INLET/OUTLET, PROJECTING OUT 6' [CDS ' TECHNOLOGIES PATENTED CDS PSW50_42 INTAKE REINFORCING DATE 1/19/99 DRAWN V. SHADEL APPRDV. SCALE SHEET 6 9 8 15 1617 18 19 1) FOR REBAR LENGTHS SEE REBAR LEGEND ON SHEET 8 2) FOR SECTION A-A SEE DETAIL ON SHEET 8 A 1-4 \ \ RISER REINFORCEMENT EXTENDED INTO INLET- / / OUTLET AS SHOWN TM CDS TECHNOLOGIES PATENTED CDS PSW50 REINFORCING DIAGRAM IN/OUTLET STRUCTURE DATE 4/30/01 DRAWN CCS APPROV. SCALE NTS SHEET 7 Rebar Legend Note: All Steel Shown Are # 3 @ 6" O.C. (Maximum) 24" 26" 18"1-4) 18' 5) 6) 7) 8) 12" 9)12" 24" 18" 18" 10) 18' 11) 18' 12) 18" 13) 18' 14) 18" 15) 16-19) 18" 18" 24" Total 3 18" SECTION A - A CDS TECHNOLOGIES PATENTED CDS PSW50 REINFORCING DIAGRAM IN/OUTLET STRUCTURE DATE 4/30/01 DRAWN CCS APPROV. SCALE NTS SHEET 8 Vegetated Swale TC-30 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 reduced 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. Design Considerations • Tributary Area • Area Required • Slope • Water Availability Targeted Constituents 0 Sediment A 0 Nutrients • 0 Trash • 0 Metals A 0 Bacteria • 0 Oil and Grease A 0 Organics A Legend (Removal Effectiveness) • Low » High A Medium ASQ January 2003 California Storm water BMP Handbook New Development and Redevelopment w ww .ca bmpha ndbooks.com lof 13 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. m 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 Mew Development and Redevelopment www .ca bmpha ndbooks.com Vegetated Swale TC-30 Construction/Inspection Considerations m 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, krge 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 RunoffProgram (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 .ca bmpha ndbooks.com TC-30 Vegetated Swale Table 1 Grassed swale pollutant removal efficiency data Removal Efficiencies (% Removal) Study Caltrans 2002 Goldberg 1993 Seattle Metro and Washington Department of Ecology 1992 Seattle Metro and Washington Department of Ecology, 1992 Wang et al., 1981 Dorman et al., 1989 Harper, 1988 Kercheret 31,1983 Harper, 1988. Koon, 1995 TSS 77 67.8 60 83 80 98 87 99 81 67 TP 8 4-5 45 29 - 18 83 99 17 39 TN 67 - - - - - 84 99 40 - N03 66 31-4 -25 ~25 - 45 80 99 52 9 Metals 83-90 42-62 2-16 46-73 70-80 37-8l 88-90 99 37-69 -35 to 6 Bacteria -33 -100 -25 -25 - - - - - - Type dry swales grassed channel grassed channel grassed channel dry swale dry swale dry swale dry swale wet swale wet 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 knd use, size of the area serviced, soil type, slope, irnperviousness 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 New Development and Redevelopment www.cabmphandbooks.com January 2003 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 9 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 1) 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%. 2) A design grass height of 6 inches is recommended. 3) Regardless of the recommended detention time, the swale should be not less than 100 feet in length. 4) 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. 5) 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 loo-year storm if it is located "on-line." The side slopes should be no steeper than 3:1 (H:V). 6) 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. 7) 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 .ca bmpha ndbooks.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.corn 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. January 2003 California Stormwater BMP Handbook New Development and Redevelopment www .ca bmpha ndbooks.com 7 of 13 i I i I TC-30 Vegetated Swale Table 2 Swale Cost Estimate (SEWRPC, 1991) Component Mobilization / Demobilization-Light Site Preparation Clearing11 Grubbing General Excavatinrf1 La vel and Till* .. Sites Development Salvaged Topsoil Seed, and Mulch'.. Sa& Subtotal Continganciaa Total Unit Swale Acre ACTS Yd3 Yd3 Yd2 Yd3 - Swale -- Extent 1 0.5 0.25 372 1,210 1,210 1,210 - 1 - Low $107 $2,200 $3,800 .$2.10 10 .20 $0.40 $1.20 -- 2S% -- Unit Cost Moderate $274 $3,800 $5,200 $3.70 $0,35 $roa $2.40 - 25% - High $441 $5,400 $6,600 $5 30 SO, 50 $1 80 53.60 -- 25% - Low $107 41,100 $950 $781 $242 $484 1 1.452 is. ne 11,278 $6,395 Total Cost Moderate $274 $1,900 $1,300 $1,375 $424 $1,210 $2,904 $9,356, $2,347 $11,736 High $441 $2,700 $1,650 $1,972 $605 $1,936 $4,356 $13,660 $3,415 $17,075 Source: (SEWRPC, 1991) Not a: Mobilizaton/demobil ration refers lotha organization and planning involved in establishing a vegetative swale. •Swale has a bottom width of 1,0 foot, a top width of 10 feet wtth 1:3 side slopes, and a 1,000-Toot length, 6 Area cleared - (top width + 10 feet) x swale length, " Area grubbed = (top width x swale length!, "Volume excavated = (0.67xtopwidthx swale depth) x swale length (parabolic cross-section), "Area tilled = (top width + Bfswale deuth?ix swsle length (parabolic cross-section). 3(1op width] ' Area seeded - area cleared x 0,5, 8 Area sodded = area cleared x 0,5. 8 of 13 California Storm water BMP Handbook New Development and Redevelopment www.cabmphandbooks.oom January 2003 i i i I i i i i i i i i Vegetated Swale TC-30 Table 3 Estimated Maintenance Costs fSEWRPC, 1991} Component Lawn Mowing General Lawn Cane Swale Debris and Litter Rsm ova 1 Grass Reseeding with Mulch and Fertilizer Program Administration and Swale Inspection Total UnWCost $0.85/1, 000 ft3/ mowing $9.00 C1, 000 ttV year $0.10 f linear foot /year $0.30 / yd3 $0.1 5 / linear foot /year, plus $26 /inspect on .. Swale Size {Depth and Top Width) 1,5 Foot Depth, One- Foot Bottom Width, 10-FootTopWWth $0.14/linearfoDt S0.18Hinearfoot 50.10 Hir oar foot $0.01 yiinearfoot S0.15/lirearfoot ?0. 58 / linear lool 3-Foot Depth, 3-Foot Bottom Width, 21-Foot Top Width $0.21 /linear foot SO. 26 /linear foot JO. 10 /linear foot $0 01 /linear toot $0.15 /linear foot $ 0.75 Hinsar loot Comment Lewn mainlsnancs area=(top width ->- 1 0 feet) x length . Mow eight times per year Lawn maintenance area = Jtop widfri +• 10 faetj Klengti - Area revegetated eq usls 1 "i of I awn ma inten a nca a rea pa r year Inspect tour times per year - January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 9 of 13 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. 11, pp. 1121-1128. Brown, W., andT. 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 Biqfihration 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. i. 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 SammamishBasins. 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.Oakland, 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. I n 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: Number 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)1379-383. 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^-99-006 http://www.epa.gov/owm/mtb/vegswale.pdf, Office of Water, Washington DC. Wang, T., D. Spyridakis, B. Mar, and R. Horner. 1981. Transport, Deposition and Control of Heavy Metals in Highway Runoff. FHWA-WA-RD-39-io. 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., TX. 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-Ri6. Virginia Transportation Research Council, Charlottesville, VA. Information Resources Maryland Department of the Environment (MDE). 2000. Maryland Stormwater Design Manual. wwrw.mde.state.md.us/environment/wma/storm.waterrnanual. Accessed May 22, 2001. Reeves, E. 1994. Performance and Condition of Biofilters in the Pacific Northwest. Watershed Protection Techniques i(3):ii7-H9. January 2003 California Stormwater BMP Handbook 11 of 13 New Development and Redevelopment www .ca bmpha ndbooks.com TC-30 Vegetated Swale Seattle Metro and Washington Department of Ecology. 1992. Biof&tration Swale Performance. Recommendations and Design Considerations. Publication No. 657. Seattle Metro and Washington Department of Ecology, Olympia, WA. USEPA1993. Guidance Specifying Management Measures for Sources ofNonpoint Pollution in Coastal Waters. EPA-84O-B-92-OO2. 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 lor j-cour (a) Cross $rctiun vfswak »itfc clnrc k sin m. Notali on: L = Lwg* of swale impoundment area per cJitck darn j(t» (fc> Ds = OKSjrth of chock fern (» &s = Bottom sip* of swale {fttfti W = Top vridth o-f dietk dam <ftj WB = Boliom width of ch«ck dam (ft; £»« z Ra^e of horiiomal to vertical cllange in swale si(tB slojx? (ftft'' l>(ittatsii>i»*l View ofsttili if«t>«HI><l«»«I »tt*- January 2003 California Storm water BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 13 of 13 I | Inlet Stenciling and Signage I I I I I I I I I I I I I I I I I I I Storm Drain Stenciling Tips NOTE: You may check out the storm drain stencil and a stenciling kit with the necessary paint, brushes, and other materials from: I Love A Clean San Diego, Inc. 4891 Pacific Highway, Suite 115 San Diego, CA 92110 (619)291-0103 Stencil Placement: The stencil needs to be painted above the storm drain. The stencil message should be readable from the roadside. If the curb is red, paint directly above the red area. f:37$CNO DUMPING GOES TO OCEAN NQTIRENADA- LLEGAALMAk *PIease 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 you to 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. i I TIPS: If painting a rough surface, firmly hold down the stencil and dab (don't brush) the letters and the I 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. I 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. I 1 i I i i i ti Inlet Stenciling and Signage Storm Drain Signage SD-13 Design Objectives Maximize Infiltration Provide Retention Slow Runoff Minimize Impervious Land Coverage r* Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Description ~™ ~~~___»__»__. Waste materials dumped into storm drain inlets can have severe impacts on receiving and ground waters. Posting notices regarding discharge prohibitions at storm drain inlets can prevent waste dumping. Storm drain signs and stencils are highly visible source controls that are typically placed directly adjacent to storm drain inlets. Approach The stencil or affixed sign contains a brief statement that prohibits dumping of improper materials into the urban runoff conveyance system. Storm drain messages have become a popular method of alerting the public about the effects of and the prohibitions against waste disposal. Suitable Applications Stencils and signs alert the public to the destination of pollutants discharged to the storm drain. Signs are appropriate in residential, commercial, and industrial areas, as well as any other area where contributions or dumping to storm drains is likely. Design Considerations Storm drain message markers or placards are recommended at all storm drain inlets within the boundary of a development project. The marker should be placed in clear sight facing toward anyone approaching the inlet from either side. All storm drain inlet locations should be identified on the development site map. Designing Neiv Installations The following methods should be considered for inclusion in the project design and show on project plans: Provide stenciling or labeling of all storm drain inlets and catch basins, constructed or modified, within the project area with prohibitive language. Examples include "NO DUMPING :ASQ January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 1 of 2 SD-13 Storm Drain Signage — DRAINS TO OCEAN" and/or other graphical icons to discourage illegal dumping. • Post signs with prohibitive language and/or graphical icons, which prohibit illegal dumping at public access points along channels and creeks within the project area. Note - Some local agencies have approved specific signage and/or storm drain message placards for use. Consult local agency stormwater staff to determine specific requirements for placard types and methods of application. 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 cbnstruction, and land disturbing activities with structural or impervious surfaces. If the project meets the definition of "redevelopment", then the requirements stated under " designing new installations" above should be included in all project design plans. Additional Information Maintenance Considerations • Legibility of markers and signs should be maintained. If required by the agency with jurisdiction over the project, the owner/operator or homeowner's association should enter into a maintenance agreement with the agency or record a deed restriction upon the property title to maintain the legibility of placards or signs. Placement • Signage on top of curbs tends to weather and fade. • Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms. Supplemental Information Examples m Most MS4 programs have storm drain signage programs. Some MS4 programs will provide stencils, or arrange for volunteers to stencil storm drains as part of their outreach program. Other Resources A Manual for the Standard Urban Stormwater 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 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Storm Water Education I i i I i i f i f i § i f i f : t Think Blue: Top Tips Healthy Yards and Healthy Families JtJefore beginning an outdoor project, locate :he nearest storm drain and take action to protect t from debris. This may require you to sweep the gutter between your project and the storm drain, before starting work. Chemicals, fertilizers, herbicides and pesticides can be harmful to you, your family, Dlant and animal life. 9 Use them sparingly. Read labels carefully and don't apply if the forecast calls for rain. 9 Use mulch instead of herbicides to prevent weeds from growing and to help absorb water. 9 Select drought resistant native plants that con- serve water and prevent runoff. 9 Don't overwater your lawn. Water during the cooler times of day and don't let it run off into the gutter. 9 Drain swimming pools only when chlorine levels are not detected by your swimming pool test kit. 9 Keep your gutters in front of your house clean of leaves and grass cuttings. Sweep up debris instead of hosing down your driveway. Helpful Habits Around the House If you use hazardous substances such as paints, solvents and cleaners, use them sparingly, accord- ing to directions. Store properly to avoid spilling. If you use water-based paints, rinse paint brushes in the sink. For oil-based paints, filter and reuse paint thinner. Dispose of all used paints and materials through a hazardous waste collection program. Never clean brushes or pour paint in the gutter or storm drain. If you use other hazardous substances such as cleaners and solvents, properly dispose through a hazardous waste collection program. Pick up trash and litter around your yard and home. If you're working on a home improvement project, dispose of drywall, concrete and mortar in the trash. Don't rinse concrete or mortar into the street. Sweep up all project debris. Pick up pet waste and dispose in the toilet or in a bag for the trash. Bacteria from pet waste contains harmful bacteria that pollutes our waterways. Remember "Scoop the Poop!" Vehicle and Garage Safety Routinely check your car for leaks and keep it tuned up. Car pooling or using a bicycle for transportation helps reduce pollutants on our streets. Never pour any chemicals or other hazardous substances from cars down a storm drain, on to the ground or leave on driveways or parking lots. When changing fluids from your car, drain into a clean container and seal completely. Take the oil and the oil filter to a used oil collection site. If you spill fluids, contain quickly with rags or kitty litter. Safely dispose at a hazardous waste collection site. If you wash your own car, use a shutoff nozzle on your hose and use detergents and water sparingly. Wash your car on a landscaped surface. Important Resources City of San Diego Household Hazardous Materials Program Information: (619) 235-2111 • Dates and locations of household hazardous waste collections • Locations for recycling motor oil • Information on safe use and storage and substitutes for commonly used household products Poison Control Center: (800) 876-4766 (call 911 in an emergency) Easy Solutions for Keeping Our Creeks, Bays and OceiilGV - :---\.,.:^:*'-;'^^i&?:f", '...&/':"?:% www.Thinkbluesd.org The CITY OF SAN DIEGO thanks the following partners for their generous support of the Think Blue program: San Diego Port District Caltrans Port of San Diego www.portofsandlego.org This information will be made available in alternative formats upon request. Printed on recycled paper. TP-171 110/01) When it rains or when water flows out of yards, it flows directly into Storm drains.You've probably seen storm drains on our San Diego streets. Many people think that everything that flows into a storm drain gets treated, just like wastewater in a sewer system, but actually these two systems are not connected. Everything that flows down into a storm drain goes untreated directly into our creeks, bays, lagoons and ultimately the ocean. Storm water can consist of pesticides, fertilizers, pet waste, litter, oil and other automobile fluids, soil erosion and household chemicals. Some of these pollutants flow into storm drains unintentionally, but many items are carelessly thrown directly into storm drains. The Clean Water Act prohibits disposal of wastes and pollutants into creeks, bays, lakes and oceans. These pollutants have harmful effects on recreational areas, waterways and wildlife. Some of San Diego's most popular beaches have been closed because of storm water pollutants. Ultimately, storm water pollution harms all of us because we depend on our waterways for recreation and to support San Diego's tourist industry. By preventing pollution from occurring in our homes, neighborhoods and businesses, we can protect our environment and our families' health and safety. You and your family play an important role in storm water pollution prevention. This brochure provides you with easy and inexpensive tips to prevent pollutants from entering storm drains in the first place. If everyone makes a few simple changes, we can help protect our San Diego lifestyle and environment. "Think Blue" means preventing pollution before it reaches our waterways. Caltrans i|2|jt<jrm. water pollu^i^pr&vehtion |i||j|||cir,«i: referral to.'ywl|'local hazardous ^»|tcoll§0tion pMpam .call: ' ..' Port of San Diego www.portofsandiego.org www.ThinkbIuesd.org i i II I i li i i i i i I i f i f i f i f i f hink Blue: Consejos Utiles Jardines Sanos y Familias Sanas JLos productos quimicos, fertllizantes, M'bicidas y pesticidas pueden ser daninos tanto para ;ted como para su farnilia, y tambien para las plantas y limales. Hay otras forrnas de mantener a su jardin verde n tener que usar substancias toxicas. Si tiene que usar pesticidas o fertilizantes, uselos con moderacion. Lea las etiquetas detalladamente y no aplique una substancia si hay pronosticos de lluvia. Use desechos organicos en vez de herbicidas para prevenir que crezcan las hierbas malas y para ayudar a absorber el agua. Seleccione plantas naturales de la region que son resistentes a la falta de agua las cuales conservan agua y previenen el escurrimiento. No riegue demasiado su jardin. Riegue durante las horas rnas frescas del dia y no deje escurrir el agua por el desague. Drene su alberca solamente cuando el nivel de cloro no es detectado en su equipo de deteccion de cloro para albercas. Mantenga los desagues enfrente de su casa limpios y de sin hojas y recortes de pasto. Barra la basura de la entrada a su garaje en vez de echarle agua con la manguera. Habitos Utiles en el Hogar Si usa substancias peligrosas tales como pinturas, solventes y limpiadores, uselos en pequenas cantidades, de acuerdo a las instrucciones. Guardelos correctainente para evitar que se derramen. Si usa pinturas a base de agua, enjuague las brochas en el fregadero. Para pinturas a base de aceite, limpie la brocha con adelgazador de pintura, cuelelo y vuelva a usarlo. Tire todas las pinturas y materiales a traves de un programa de recoleccion de desechos peligrosos. Nunca limpie las brochas ni tire pintura por el desague pluvial. Si usa otras substancias peligrosas tales como limpiadores y solventes, llevelos a un lugar de recoleccion de desechos peligrosos. Recoja la basura y los desechos en su jardin y casa. Si esta remodelando su casa, tire el concrete, muros de yeso y mortero a la basura. No enjuague el concrete o mortero a la calle. Recoja los desechos de mascotas y tirelos al excusado o pongalos en una bolsa en la basura. La bacteria de los desechos animates es dafiina y contamina a nuestras vias acuaticas. Seguridad de Sus Vehiculos y Garaje Periodicamente revise su vehiculo para ver que no tenga fugas y mantengalo afinado. El usar un sistema de transporte publico o usar su bicicleta ayuda a reducir los contaminantes en nuestrascalles. Nunca vierta productos quimicos u otras substancias peligrosas de los vehiculos por los desagues pluviales, en el suelo, ni en los estacionamientos o entradas de garaje. Al cambiar los fluidos de su vehiculo, drenelos en un recipiente limpio y cierrelo completamente. Lleve el aceite y el filtro del aceite a un sitio de recoleccion de aceite. Si derrama algun fluido, use trapos o arena sin usar en donde van al bano los gatos (kitty litter) inmediatamente para contenerlo. Tire la arena y los trapos contaminados en un sitio de recoleccion de desechos peligrosos. Si usted lava su vehiculo, use una manguera con boquilla de cierre para el agua y use poco detergente y agua. Recursos Importantes Information del Programa de Materiales Peligrosos Domesticos de la Ciudad de San Diego:(619) 235-2111 • Fechas y sitios para la recoleccion de desechos domesticos peligrosos • Sitios para el reciclaje de aceite automotor • Informacion respecto al uso y almacenamiento adecuado de productos domesticos de limpieza y sus sustitutos Centre de Control de Envenenamientos: (800) 876-4766 (llame al 911 en caso de una emergencia) www.Thinkbluesd.org El programa THINK BLUE de la Ciudad de San Diego desea agradecer a los siguientes patrocinadores por su apoyo tan generoso al programa THINK BLUE: San Diego Port District Port of San Diego www.portofsandiego.org Caltrans • sBM^V "«~ ns<~s,*-4^^H^Hr Soluciones Faeiles par a Esta in/be;nacjon esfara disponible en formates atternstivos al solicitarlo. Imprest) en papel reciclado. TP-171 (11/01) i 'I I 1 I t i i i i i Cuando llueve o cuando el agua corre de nuestros jardines, fluye directamente a los desag es pluviales. Probablemente ha visto estos desag es pluviales en las calles de San Diego.Muchas personas piensan que todo lo que fluye a los desag es pluviales pasa por un proceso de tratamiento, de la misma manera que se tratan a las aguas negras en un sistema de drenaje. Sin embargo, estos dos sistemas en realidao no est n conectados. Todo lo que fluye a un desag e pluvial va directamente y sin tratamiento a nuestros riachuelos, bah as, lagunas y finalmente al mar. El agua de escurrimiento puede tener pesticidas, fertilizantes, desechos de mascotas, basura, aceite y otro fluidos de autom vil, erosi n de la tierra as como productos qu micos dom sticos. Algunos de estos contaminantes entran a los desag es pluviales no intencionalmente, pero muchos de ellos son tirades, sin pensar, directamente a los desag es pluviales. La Ley de Aguas Limpias proh be tirar basura y productos contaminantes a los riachuelos, bah as, lagos y mares. Estos productos contaminantes tienen efectos da inos para las reas de recreo, v as acu ticas y vida silvestre. Algunas de las playas m s populares de San Diego han tenido que ser cerradas debido a los contaminantes provenientes de los desag es pluviales. A fin de cuentas, la contaminaci n que proviene de los desag es pluviales nos da a a todos puesto que dependemos de las v as acu ticas para la diversi n as como para atraer al turismo a San Diego. Si podemos prevenir que la contaminaci n ocurra en nuestros hogares, vecindarios y negocios, podemos ayudar a proteger a nuestro medio ambiente y a la salud y segurioad de nuestras familias. listed y su familia juegan un papel importante para evitar la contaminaci del agua que entra a los desag es pluviales. Este folleto le proporciona algunos consejos f ciles y econ micos para evitar que las substancias peligrosas entren a los desag es pluviales. Si todos efectuamos algunos cambios sencillos, podemos ayudar a proteger nuestro estilo de vida y nuestro medio ambiente en San Diego. Think Blue significa el evitar la contaminaci n antes de que llegue a nuestras v as acu ticas. n Cal trans Port of San Diego www.portofsandiego.org roli-informaci6n"aceS5M'"tl,e la ^"^ iitfieidii de aguas p acerca de su cai de recoledcMh'de desecho www.Thinkbluesd.org • 1-8884-652 619-235 Be a Clean Water Otorm water pollution is a problem that affects all of us. With a growing population of more than 1.2 million residents and approximately 237 square miles of urbanized development, keep- ing our waters clean from pollutants has become increasingly difficult. With more than 39,000 storm drain structures, and over 900 miles of storm drain pipes and channels to clean and maintain, we need your help. When it rains, water flows over our streets and yards and carries the pollutants it picks up into the storm drains. The problem is that storm drains are not connected to the wastewater treatment plant. So, what's in the streets flows directly into our creeks, lakes, rivers and the ocean, untreated. Last year, too many of our beaches and bays were closed or posted as unsafe for swimming. As our Mayor has said, "this is more than an inconve- nience; it is a civic embarrassment." But, as a City resident, you can make a difference. By becoming a Clean Water Leader, both on the job and in your community, you can help make our beaches and bays free of pollution. When you're at home, share your knowledge with neighbors and family. As you drive to work, be aware of any illegal discharges. And, if you do see an illegal discharge, report it. In the City of San Diego you can call (619) 235- 1000. Or, if you see an illegal discharge outside of the City of San Diego, you can call the regional hotline at 1 -888-THINK-BLue. By working together we can make a difference. Whether at home or at work, by adopting some simple Best Management Practices (BMPs), you can stop pollutants from being generated and enter- ing our storm drain system. • Use dry clean-up methods for spills and outdoor cleaning. Vacuum, sweep, and use rags or dry absorbants. • Properly label, store and dispose of hazardous wastes. • Rake, sweep-up, and place all debris (dust, litter, sediment, etc.) from your yard or near your property into a trash can. • Use a mop where water is needed. As you perform your daily activities be proac- tive. Assess the activity from a stormwater pol- lution point-of-view and ask yourself; "does this activity, directly or indirectly, generate pollu- tion?" And, "how can I get the job done and pre- vent debris from entering into the storm drain collection system?" Here are some general guidelines you can use at home or on the job: The 3 Cs LrOntrol: Locate the nearest storm drain(s) and take measures to ensure nothing will enter or discharge into them. This may require you to sweep-up and place debris & sedi- ment in a trash can prior to beginning the work activity. Contain: isolate your work area, to prevent any potential flow or discharge from leaving the area. rapture: Onceyou have completed a job, be sure to clean-up the area. If there is sediment, sweep it up. If there are liquids, ab- sorb it or vacuum it up with a wet-vac. Remember, what you leave behind can potentially be discharged into the storm drain. CITY or SAN DEEGO TTiis infinmarion is Sea lider del programa de limpia La contaminaciOn de las aguas pluviales es un problema que nos afecta a todos. Con una poblacion creciente de mas de 1'200,000 residentes y aproximadamente 237 millas cuadradas (610 km2) de zonas urbanizadas, mantener nuestras aguas libres de contaminantes se vuelve cada vez mas diffcil. Con mas de 39,000 colectores de aguas pluviales y mas de 900 millas (1,450 km) de canales y tuberias que mantener para el desagtie de aguas pluviales, necesitamos su ayuda. Cuando llueve, el agua fluye por nuestras calles y patios y deposita en los colectores de aguas piuviales los contaminantes que arrastra. El problema es que los colectores de aguas pluviales no estan conectados a la planta de tratamiento de aguas residuales. Por lo tanto, todo lo que se encuentre tirado en las calles fluye directamente a nuestros arroyos, lagos, n'os y al mar, sin recibir tratamiento alguno, Muchas de nuestras playas y bahfas fueron clausuradas el ano pasado o seles cotocaron letreros advirtiendo el riesgo de nadar en ellas. Como nuestras autoridades municipales han dicho, "Esto es mas que una molestia; es una verguenza civica". Pero, como residents de !a ciudad, usted puede ayudar a cambiar esta vergonzosa situacion. Ai sumarse al programa de agua limpia, tanto en el trabajo como en su comunidad, podrS contribuir a librar nuestras playas y bahfas de la contaminacion. En casa, comparta sus conocimientos con vecinos y familiares. Camino al trabajo, este pendiente de descargas ilegales de agua. Si ve una descarga ilicita, d6 parte a las autoridades correspondientes. En la ciudad de San Diego, puede llamar al (619) 235-1000. 0, si se da cuenta de alguna descarga ilegal fuera de la ciudad de San Diego, llame a la linea directa regional, 1-888-THINK-BLUE (1-888-844-6525). Para maypres informes, visite la pSgina en Internet www,thinkbluesd:org. Tanto en el hogar como en el trabajo, usted puede impedir la generacion de contaminantes y su descarga al drenaje de aguas pluviales. S6lo tiene que poner en practice las senclllas medidas sefialadas a continuaci6n: • Para limpiar derrames y areas exteriores, utilice aspiradora, escoba, trapos u otros materiales absorbentes secos. • Identifique claramente con etiquetas los desperdicios nocivos y almacenelos o desechelos correctamente. • Con un rastrillo o escoba, recoja todos los desechos (polvos, basura, sedimentos, etc.) que se encuentren en su patio o cerca de su casa o edificio y depositelos en un bote de basura. • Use un trapeador cuando se requiera el uso de agua para limpiar. Realice sus activldades cotidianas con conciencia ecologica. Vea las cosas desde el punto de vista de la posible contaminaci6n de las aguas pluviales. Preguntese, "Directa o indirectamente, ^genera esta actividad contaminacion?" Y, ",;,C6mo puedo realizaresta tarea de manera que evite la descarga de desperdicios al sistema de captacidn de aguas pluviales?" Las siguientes son algunas recomendaciones generates que puede aplicar en casa o en el trabajo. Las tres C C LrOntfOle: Localice las coladeras para aguas pluviales mas cercanas y haga lo necesario para impedir que se descargue en ellas materias extranas. Para ello, podrfa ser necesario barrer y colocar la basura y sedimentos en un bote de basura antes de comenzar sus actividades de trabajo. ontenga: area de trabajo para impedir que cualquier flujo o descarga saiga del area. -apte: Una vez terminado un trabajo, no se olvide de limpiar bien el lugar. Si qued6 algun sedimento, barralo. Si quedan liquidos, absorbalos o aspfrelos con una aspiradora para liquidos. Recuerde que lo que deje en e) suelo podrfa acabar descargandose a la tuberfa para aguas pluviales. a mfamtaa'tm SF i- ** Impervious Surfaces: ^ ' Cleaning Sidewalks, Pavements, Patios, Parking Lots & Driveways «H | When it rains or when water flows out of yards or over pavement, it flows directly into storm drains. Many people mistakenly believe this water gets "cleaned" before reaching waterways. .<•« The sewer system and the storm water conveyance system (drains, inlets and catch basins) are separate; they are not connected. Sewer water gets treated, but everything that washes *"* into the storm drain goes untreated directly into our rivers, creeks, bays and ocean. This causes beach closures and postings due to contamination. Releasing pollutants into the storm — water conveyance system is a violation of the City Municipal Code (43.0301). I "*** | We all like clean public areas, but High Pressure Washing and Hosing Down of sidewalks not only contributes to ocean pollution, but wastes one of our most valuable resources - Water. It's not the water that's a problem. It's the pollutants it picks-up off of surfaces that are. In the City of San Diego, Hjgft Pressure Washing or Hofiijg Down surfaces in the public right-of-way will only be allowed when the following Storm Water Best Management Practices are used: Before beginning to wash impervious surfaces, sweep and pick up the debris or trash in w., the area being washed, and in the curbside between the activity and downstream storm drain inlet(s). Properly dispose of the debris. Storm drain inlet(s) must be protected from the water flow and the pollutants it carries. w • Locate the nearest downstream storm drain inlet before beginning work. Cover the inlet with fabric cloth and weigh it down with gravel bags. The debris caught in the fabric cloth can then I be thrown in the trash. Hosing pavement in a parking lot and letting it leave the site is not allowed. Water used to clean gas stations, automotive repair, driveway, street or any surface where motor vehicles I are parked or driven must be recaptured (wet-vacuumed or mopped) and properly disposed of. Sweep-up and properly dispose of all sediments that accumulate as a result of the activity. Disinfectants, solvents, and other household chemicals used to aid in the cleaning process iiJW must be recaptured (mopped up or wet vacuumed) before hosing down. „,, I Dry clean up methods (vacuum, sweep, and absorbents) are recommended for spills and I outdoor cleaning. Where water is needed, use a mop. If hosing down is desired, follow the *«* Best Management Practices listed above. «* Dispose of mop water into the sanitary sewer system. That means down the sink drain, not the storm drain. MM I High pressure washing or hosing of private property must be contained, recaptured and property disposed. Direct the water into planters, don't allow it to wash into the storm drain inlet. - I M - I Other fact Sheets that may pertain to your activities: Be A Clean Water Leader: Control, Contain & Capture; Spills; Dumpsters, and Restaurants. Adopt these behaviors and help Clean up our beaches and bays. Think Blue, San Diego. For more information, call (619) 235-1000, or log on to: www.thinkbluesd.org (03/05/02) i i i i i i i Car Washing When it rains or when water flows out of yards or over pavement, it flows directly into storm drains. Many people mistakenly believe this water gets "cleaned" before reaching waterways. The sewer system and the storm water conveyance systems (drains, inlets, and catch basins) are separate; they are not connected. Sewer water gets treated, but everything that washes into the storm water conveyance system goes untreated directly into our rivers, creeks, bays and ocean. This causes beach closures and postings due to contamination. Releasing pollutants into the storm water collection system is a violation of the City Municipal Code, (43.0301). Whether you are at home, work, or play, there are ways that residents and businesses alike can Think Blue" and prevent pollutants from reaching our waterways. Most of us don't think of our car as a source of beach pollution- but it is. The reality is vehicles are a necessity today, and we don't have a lot of choice about that. However, we can be more environmentally responsible and choose the method(s) of caring for and washing our vehicles in an ocean friendly way. Car washing is a pollution problem because many metals and automotive fluids are washed off with the soapy water, travel down the gutter collecting more street pollutants, then enter our storm water conveyance system and spill into our waterways and bays. Residential/Non-Commercial Vehicles: The Municipal Code allows for the washing of residential vehicles for non-commercial purposes. While washing of your vehicle is allowed, washing-off pollutants from your vehicle such as paint, oils, sediment, debris and such like pollutant(s) is illegal. This is why we encourage that you wash your personal vehicle without creating runoff. When washing is done at home, pollution can be minimized by washing the vehicle on the lawn or over a landscaped area to absorb the liquid and limit runoff from your property. Or, limit runoff by using a bucket and rag to wash your car and a control nozzle on your hose to rinse the car. By actively reducing the amount of water used you are not only protecting our ocean, but helping to conserve water and reducing your water bill. Charity Washes: may be conducted as long as they are staged in a manner which avoids or minimizes the discharge of pollutants- soap, sediment, water that may be contaminated from automotive fluids and residues. Start by locating all storm drain inlets on, near or downstream of the wash site and sweeping up all sediment and debris in the area prior to washing the vehicles. On the day of the event, place sandbags or other blocking devices in front of the inlets to prevent wash water from entering the storm drain conveyance system. Any remaining standing wash water is to be swept or wet-vacuumed into a landscaped area or into the sanitary sewer system. We recommend the site and inlets be swept at the end of the wash event. Illegal Washing Activities: Car dealerships, auto detailers, rental agencies and other automotive rsfated businesses that wash vehicles for commercial purposes must prevent the dirty water from entering the storm water conveyance system. All washing activity for commercial purposes must control, contain and capture the wash water before it leaves the site and/or enters a storm drain or a conveyance system. Failure to do so is illegal. Washing of all vehicles (residential and commercial) that carry items or substances that have a potential to discharge the following pollutants: paint, oils, sediment, yard waste, construction debris, chemicals, hazardous wastes and other pollutants—is illegal. Adopt these behaviors and help Clean up our beaches and bays. Think BlU9, San Diego. For more information, call (619) 235-1000, or log on to: www.thinkbluesd.org (03/05/02) I I I Automotive Fluids When it rains or when water flows out of yards or over pavement, it flows directly into storm drains. Many people mistakenly believe this water gets "cleaned" before reaching waterways. (The sewer system and the storm water conveyance systems (drains, inlets, and catch basins) are separate; they are not connected. Sewer water gets treated, but everything that washes into the storm water conveyance system goes untreated directly into our rivers, creeks, bays _ and ocean. This causes beach closures and postings due to contamination. Releasing • pollutants into the storm water collection system is a violation of the City Municipal Code, ™ (43.0301). Whether you are at home, work, or play there are ways that residents and businesses alike can "Think Blue" and prevent pollutants from reaching our waterways. I I I I I Most of us don't think of our car as a source of beach pollution- but it is. The reality is vehicles are a necessity today, and we don't have a lot of choice about that. However, we can be more environmentally responsible and choose the method(s) of caring for and repairing our vehicles in a more ocean friendly way. Many automotive fluids - Motor Oil, Anti-Freeze, Transmission Fluids, De-Greasers, Solvents and the like are hazardous wastes. They are hazardous to you and me and toxic to our environment. No one wants to swim in them. So, make sure to prevent them from entering our storm water conveyance system. Automotive Maintenance and Repair: When making repairs or performing minor maintenance on your vehicle, make sure you have protected the sidewalk, curb, street and gutter from repair fluids before beginning work. Identify the nearest storm drain and take steps to protect it from the fluids. When changing fluids, collect the substance and other automotive materials in seal able containers. Mark the containers. Never mix different substances in one container. Store the ri containers in a secure location out of reach of children, animals and out of contact with water. Where to Take the Pollutants: _j| Motor oil, Oil filters, anti-freeze and non-leaking auto batteries are accepted at the City of San H Diego Used Oil and Filters Collection Events. Call (619) 235-2105 for event information. For other automotive fluids such as transmission and brake fluids, de-greasers, solvents and •fl the like, call the City's Household Hazardous Materials Program (619) 235-2111, to make an HH appointment to drop-off the pollutants. ^m Leaking Vehicles: If your vehicle is leaking fluids, please make repairs as soon as possible. A Bl short-term, immediate solution is to put an oil drip pan with absorbent materials under your ^^ vehicle wherever it is parked (work, home and other destinations). Until the repair is made, you must capture the leak and prevent fluids from reaching the street or gutter where it can be •£ carried into the storm drain conveyance system and into our waterways and beaches. Other Fact sheets that may pertain to your activities: Cleaning Impervious Surfaces (High Pressure Washing); Be A Clean Water Leader: Control, Contain & Capture; Spills; and Car Washing. Adopt these behaviors and help Clean up our beaches and bays. Think Blue, San Diego. For more information, call (619) 235-1000, or log on to: www.thinkbluesd.org (03/05/02) County of San Diego - Water Quality Program - RESIDENTIAL BEST MANAGEMENT PRACTICES Page 1 of 3 Search : i- 1sss* - I •5»»^- I - I - i I I I i i t i i ENVIRONMENTAL HEALTH Beach & Bay Water Quality Contact Us Contaminated Property Current Events DEH Goals Educational Materials Flies, Mosquitos, & Rats Forms & Applications Frequently Asked Qiiistions Hazardous Materials Housing Inspections & Permits Jobs in OEH Landfills Project Clean Water Public Records Public Swimming Pools Radiation Safety Restaurants & Markets Septic Systems Spills & Releases Stormwater Toxic Waste Underground Storage Tanks Water Wells Water Quality Program RESIDENTIAL BEST MANAGEMENT PRACTICES Is Stormwater from my home polluted? Several activities that you do at your home have the potential to pollute runoff. Potential pollutants from homes include oil, grease and other petroleum hydrocarbons, heavy metals, litter and debris, animal wastes, solvents, paint and masonry wastes, detergents and other cleaning solutions, and pesticides and fertilizers. How you manage your home impacts the ocean, even if you live several miles from the beach. Everything that exits your property will eventually run into the ocean. The sources of residential pollutants include household toxics, litter and debris, and runoff from car washing, pool and spa care, lawn maintenance and on-site domestic sewage treatment systems. It is very important to properly manage and dispose of household toxics to keep your family safe and to prevent pollutants to runoff. Did you know that oil and grease from automotive maintenance; paint, masonry and cleaning wastes from home repairs and maintenance; pesticides and fertilizers from garden care are all considered household toxics? Oil and grease wastes from leaking car engines and maintenance and repair activities may contain a wide variety of toxic hydrocarbon compounds and metals at varying concentrations, and that exposure may be toxic to aquatic plants and organisms. Other wastes may be poured into storm drains or pollute runoff from maintenance activities conducted by .homeowners, including paint and masonry wastes, solvents, detergents from car wash activities, residues from carpet cleaning and pool and spa care. Call the Household Toxics Hotline, for free disposal options available in your area. Residents in the unincorporated areas may call 1(877) R-l Earth or 1(877) 713-2784. From all other cities call 1(800) Clean Up. Household Toxics Improper disposal of household toxics into Stormwater ... 2/21/2003 County of San Diego - Water Quality Program - RESIDENTIAL BEST MANAGEMENT PRACTICES Page 2 of 3 Pesticides and Fertilizers can endanger aquatic habitat. For example, using excessive amounts of pesticides and fertilizers during landscape maintenance can contribute 'nutrients, such as nitrogen and phosphorus, and toxic organic substances, such as organophosphates and carbamates, into stormwater. Toxic materials can damage aquatic life and nutrients can result in excessive algae growth in waterways, leading to cloudiness and a reduced level of dissolved oxygen available to aquatic life. And unionized ammonia (nitrogen form) can kill fish. Litter and Debris Beach Closure sign Human pathogens It is also important to properly disposal of litter and debris, including cigarette butts and green waste (leaves and grass clippings from landscape maintenance activities). Decaying organic matter reduces the amount of dissolved oxygen available to aquatic life. Litter and debris can plug up storm drains and reduce the aesthetic quality of the receiving waters Human pathogens (bacteria, parasites and viruses) can also pollute run off! Common sources of human pathogens are improperly managed pet wastes and on- site domestic sewage treatment systems. High levels of coliform bacteria in stormwater, which are used as an indicator of fecal contamination and the potential presence of pathogens, may eventually contaminate waterways and lead to beach closures. Decomposition of pet wastes discharged to receiving waters also demand a high level of oxygen, which reduces the amount of dissolved oxygen available to aquatic life. I I I I You can help control runoff pollution by doing the following: • Do not dispose of liquids or other materials to the storm drain system • Report illegal dumping of any substance (liquids, trash, household toxics) to the County's toll free, 24-hour hotline 1-888-846-08OO • Utilize the County Household Toxics Program for disposal of household toxics. Residents in the unincorporated areas may call 1(877) R-l Earth or 1 (877) 713-2784. From all other cities call 1(800) Clean Up. • Keep lawn clippings and other landscaping waste out of gutters and streets by placing it with trash for collection or by composting it • Clean up and properly dispose of pet waste. It is best to flush pet waste. Alternatives to flushing are placing into trash or burying it in your yard (at least 3-ft deep). • Observe parking restriction for street sweeping. • Wash automobiles at car washes or on pervious surfaces (lawns) to keep wash water out of the storm drain system. • Avoid excessive or improper use or disposal of fertilizers, pesticides, herbicides, fungicides, cleaning solutions, and automotive and paint products. • Use biodegradable, non-toxic, and less toxic alternative products to the extent possible. • Cover garbage containers and keep them in good repair. • Sweep sidewalks instead of hosing down. • Water lawn properly to reduce runoff. ProieGts\2236-La%20Mesa%20Autocourt\County%20o... 2/21/2003 I 1 I :ounty of San Diego - Water Quality Program - RESIDENTIAL BEST MANAGEMENT PRACTICES Page 3 of 3 If you have questions or would like additional information, call the County Stormwater hotline at (619) 338-2048 or toll-free 1(888) 846-0800. Comments/Suggestions? swdutveh@sdcoyntv.ca.gov ; Visit Son Diego | Dalr-.g Business | Departments & Services A to 2 | pn-Line Services | Jobs | Disclaimers Proiects\2236-La%20Mesa%20Autocourt\County%20o... 2/21/2003 Integrated Pest Management Principles January 2OO7 Title Publ. Publ. No. Date No. Pgs. Title Annual Bluegrass rev. 4/03 7464 3 Anthracnose rev. 10/03 7420 4 Ants rev. 04/05 7411 6 Aphids rev. 5/00 7404 4 Apple Scab rev. 8/01 7413 3 Bark Beetles rev. 4/04 7421 4 Bed Bugs rev. 9/02 7454 2 Bee and Wasp Stings rev. 2/03 7449 3 Bermudagrass rev. 9/02 7453 4 Bordeaux Mixture 11/00 7481 3 Boxelder Bug 5/04 74114 3 Brown Recluse and Other Recluse Spiders 1/00 7468 4 California Ground Squirrel rev. 1/02 7438 5 California Oakworm rev. 6/00 7422 4 Carpenter Ants rev. 11/00 7416 2 Carpenter Bees rev. 2/04 7417 2 Carpenterworm 1/03 74105 4 Carpet Beetles rev. 4/01 7436 4 Chickweeds 4/06 74129 4 Clearwing Moths rev. 4/04 7477 6 Cliff Swallows rev. 7/05 7482 4 Clothes Moths rev. 12/00 7435 3 Clovers 11/01 7490 3 Cockroaches 11/99 7467 6 Codling Moth rev. 12/05 7412 6 Common Groundsel 5/06 74130 3 Common Knotweed 12/00 7484 2 Common Purslane rev. 10/03 7461 3 Conenose Bugs rev. 11/02 7455 3 Cottony Cushion Scale rev. 12/03 7410 3 Crabgrass rev. 9/02 7456 4 Creeping Woodsorrel and Bermuda Buttercup rev. 1/02 7444 4 Dallisgrass 11/01 7491 3 Damping-off Diseases in the Garden 8/06 74132 2 Dandelions rev. 7/06 7469 3 Delusory Parasitosis rev. 8/03 7443 2 Deer 6/04 74117 3 Dodder 1/02 7496 4 Drywood Termites rev. 9/02 7440 6 Earwigs 9/02 74102 2 Elm Leaf Beetle rev. 2/04 7403 6 Eucalyptus Longhorned Borers rev. 1/00 7425 4 Eucalyptus Redgum Lerp Psyllid rev. 1/06 7460 4 Eucalyptus Tortoise Beetle 1/03 74104 4 Field Bindweed rev. 4/03 7462 4 Publ. Publ. No. Date No. Pgs. Fire Blight rev. 10/03 7414 3 Fleas rev. 11/00 7419 4 Flies rev. 4/04 7457 4 Fruittree Leafroller on Ornamental and Fruit Trees 3/00 7473 3 Fungus Gnats, Shore Flies, Moth Flies, and March Flies rev. 8/01 7448 4 Giant Whitefly 5/06 7400 3 Glassy-winged Sharpshooter 1/07 7492 4 Grasshoppers 9/02 74103 2 Green Kyllinga rev. 4/03 7459 3 Hackberry Woolly Aphid rev. 6/05 74111 3 Head Lice rev. 8/01 7446 4 Hiring a Pest Control Company 3/06 74125 4 Hobo Spider 5/06 7488 4 Hoplia Beetle 9/02 7499 2 Horsehair Worms rev. 12/03 7471 2 House Mouse rev. 11/06 7483 5 Kikuyugrass rev. 4/03 7458 3 Lace Bugs rev. 8/06 7428 4 Lawn Diseases: Prevention and Management 1/02 7497 8 Lawn Insects rev. 3/03 7476 6 Leaf Curl rev. 12/00 7426 2 Lizards 10/04 74120 2 Lyme Disease in California 12/00 7485 3 Mallows 3/06 74127 3 Millipedes and Centipedes 3/00 7472 3 Mistletoe rev. 2/06 7437 3 Moles 5/04 74115 3 Mosquitoes 2/98 7451 3 Mushrooms and Other Nuisance Fungi in Lawns 9/02 74100 4 Nematodes 8/01 7489 5 Nutsedge rev. 4/03 7432 4 Oak Pit Scales rev. 1/04 7470 2 Oleander Leaf Scorch 6/06 7480 3 Olive Fruit Fly 12/03 74112 4 Opossum 4/05 74123 4 Pantry Pests rev. 9/02 7452 4 Perennial Pepperweed 10/04 74121 4 Pesticides: Safe and Effective Use in the Home and Landscape 4/06 74126 6 Phytophthora Root and Crown Rot in the Garden 10/06 74133 3 Pitch Canker 2/03 74107 5 Plantains 6/00 7478 3 (Continued on page 2) 5 1 PDFs of these Pest Notes and HTML versions with color photos are available online at www.ipm.ucdavis.edu. UC^IPM For other ANR publications, go to www.anrcatalog.ucdavis.edu. UNIVERSITY OF CALIFORNIA • AGRICULTURE AND NATURAL RESOURCES Page 1 of 2 January 2OO7 Title Publ. Date Publ. No. No. Pes. 7433 4 (continued from page 1) Pocket Gophers rev. 1/02 Poison Oak rev. 5/01 Powdery Mildew on Fruits and Berries 11/01 Powdery Mildew on Ornamentals 11/01 Powdery Mildew on Vegetables rev. 11/01 Psyllids rev. 5/01 Puncturevine 3/06 Rabbits rev. 1/02 Raccoons 6/04 Rats 7431 7494 7493 7406 1/03 Rattlesnakes 6/04 Redhumped Caterpillar 3/00 Red Imported Fire Ant 4/01 Roses in the Garden and Landscape: Cultural Practices and Weed Control rev. 7/03 Roses in the Garden and Landscape: Diseases and Abiotic Disorders rev. 10/03 Roses in the Garden and Landscape: Insect and Mite Pests and Beneficials 9/99 Russian Thistle 12/00 Scales rev. 4/01 Scorpions 8/03 Sequoia Pitch Moth rev. 3/04 Skunks 7/04 Silverfish and Firebrats 3/00 Snails and Slugs rev. 5/03 Sooty Mold 3/03 Spider Mites rev. 12/00 Spiders rev. 5/00 Spotted Spurge rev. 1/02 Sudden Oak Death in California 4/02 Sycamore Scale rev. 12/00 Termites rev. 5/01 Thrips rev. 5/01 Tree Squirrels 4/05 Voles (Meadow Mice) rev. 1/02 Walnut Husk Fly rev. 12/00 Weed Management in Landscapes rev. 8/01 Weed Management in Lawns 1/04 Whiteflies rev. 9/02 Wild Blackberries rev. 4/02 Windscorpion 11/01 Wood-boring Beetles in Homes rev. 11/00 Wood Decay Fungi in Landscape Trees 3/03 7466 7486 7408 74110 7479 74118 7475 7427 74108 7405 7442 7498 7409 7415 7429 74122 7439 7430 7441 74113 7401 7434 7495 7418 74109 7423 6 74128 3 7447 5 74116 3 74106 8 74119 4 7474 2 7487 3 7465 4 7463 3 7445 4 Woodpeckers Wood Wasps and Horntails Yellowjackets and Other Social Wasps- Yellow Starthistle 6/0574124 3 . rev. 12/00 7407 2 ....rev. 8/01 7450 4 ... rev. 7/03 7402 4 UC^IPM PDFs of these Pest Notes and HTML versions with color photos are available online at www.ipm.ucdavis.edu. For other ANR publications, go to www.anrcatalog.ucdavis.edu. UNIVERSITY OF CALIFORNIA • AGRICULTURE AND NATURAL RESOURCES Page 2 of 2 6 APPENDIX 6 Discussion of Feasible BMP Treatment Options The following is a discussion of the treatment BMP options considered. The owner and the design team have weighed the recommended BMP options from each category before selecting the primary treatment BMP system for the project, which can be found in Selected Treatment BMPs in Section 4. 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 Poinsettia Commons and the proposed site plan, detention basins are not a feasible option for treating the storm water runoff from this project. 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 pavers with the added feature of permeability. The notched design creates voids between the pavers 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. • 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.3 2 http://www.uni-groupusa.org/uni-eco-.htm, brochures 3 http://www.invisiblestructures.com/GV2/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.4 • 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.5 Recommended Infiltration Option The presence of soil type D in portions of the Poinsettia Commons Project does not provide the required infiltration rate required for infiltration basins. Additionally, site design constraints make infiltration an infeasible option including proximity to retaining walls, proximity to slopes, and impervious area layout. 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.6 A wet pond is (not) an option for this project (due to space constraints, drainage area requirements, and recent reports of vector problems associated with wet ponds). Filtration Systems Filtration systems include biofilters, sand and organic filters, and proprietary devices. 4 http://www.invisiblestructures.com/GP2/grasspave.htm, brochures5 http://www.sspco.org/geoblock.html6 National Menu of Best Management Practices for Storm Water Phase II, US EPA 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.7 • 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 boxes8 or Filterra catch basins9: 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. • 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. Sand and Organic Filters For sand and organic filtration systems, there are five basic storm water filter designs: 7 CASQA, California Stormwater BMP Handbook, New Development and Redevelopment 8 Stormwater Management Manual, September 2002 9 Prince George's County, Maryland, Department of Environmental Resources, Programs and Planning Division 10 Prince George's County, Maryland, Department of Environmental Resources, Programs and Planning Division • 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.11 • 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, 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 11 EPA 832-F-99-007 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 types12: • Fabric Filter Bag Design o 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. o 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 o 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. o AquaGuard: AquaGuard works by initially capturing sediment and trash and debris, and then combats dissolved oil, nutrients and metals through a filter 12 http://www.epa.gov/regionl/assistance/ceitts/stormwater/techs media. AquaGuard compares to others by being easy to handle, i.e. no special lifting equipment for filter removal. o 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.13 o 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.14 Recommended Filtration Option Depending on the proposed site drainage patterns, biofiltration may be applicable to this project. Buffer strips and bioretention areas 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 volume using less than 1% of the urban landscape. TABLE 8. POLLUTANT REMOVAL RATES FOR BIORETENTION SYSTEMS Metals (copper, lead, zinc) 99% Total Phosphorus 80% Total Nitrogen 40% Coliform Bacteria 80% Oil and Grease 95% Total Suspended Solids 95% SOURCE: Prince George's County, Maryland, Department of Environmental Resources, Programs and Planning Division. 1 http://www.biocleanenvironmental.net 14 http://www.kristar.com The multi-chamber treatment train has space requirements that cannot be shared with other uses (e.g., parking, driveways, sidewalks, etc.). 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, sidewalks, etc.). Therefore, permeable pavement may be applicable to this project as well. TABLE 9. POLLUTANT REMOVAL RATES FOR POROUS/PERMEABLE PAVEMENTS Lead 50-98% Zinc 62-99% Copper 42% Cadmium 33% Total Suspended Solids 95% SOURCE: Stormwater Magazine May/June 2003 Issue. Surface sand and media filters as well as the multi-chamber treatment train have space requirements that make them unappealing for this project site. However, 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. TABLE 10. POLLUTANT REMOVAL RATES FOR PERIMETER SAND FILTER SYSTEMS Metals (iron, lead, zinc) 45% Total Organic Carbon 48% Total Phosphorus 33% Biochemical Oxygen Demand 70% Total Nitrogen 21% Fecal Coliform 76% Total Kjeldahl Nitrogen 46% Total Suspended Solids 70% SOURCE: Galli, 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.15 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). TABLE 11. POLLUTANT REMOVAL RATES FOR GRATE INLET SKIMMER Box Oil and Grease 90-99% Chromium 89% Iron 98-99% Total Phosphorus 37% Aluminum 98-99% Nickel 57-86% Total Nitrogen 24% Lead 73-93% Zinc 92-97% Total Suspended Solids 73% Copper 93-97% Soap (-4)-(-62)% 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 test results. Therefore, the best type of filtration system for Poinsettia Commons is a biofiltration system. 15 Correspondence with the City of Dana Point, the City of Encinitas, and the City of Santa Monica 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 types16: • BaySaver®: The BaySaver Stormwater Treatment System meets regulations for non-point source pollution control. The system operates using gravity flow and density differences to remove oils, fine suspended solids, and floatables (trash and other debris) from stormwater runoff. • Bio Clean Nutrient Separating Baffle Box17: 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. 16 http://www.epa.gov/region 1 /assistance/ceitts/stormwater/techs 17 http://www.biocleanenvironmental.net/ • 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. The BaySaver and the Bio Clean Baffle Box are the most economical. The CDS unit and Vortechs unit have the smallest footprints. Therefore, the CDS unit would be the best hydrodynamic separator for Poinsettia Commons due to its small footprint. APPENDIX 7 References References 1. City of Carlsbad, City of Carlsbad Standard Urban Storm Water Mitigation Plan, Storm Water Standards 2. San Diego Regional Water Quality Control Board, Water Quality Control Plan for the San Diego Basin (Basin Plan) and Amendments, March 1997 3. San Diego Regional NPDES Storm Water Permit (Order Number 2001-01, NPDES Number CAS0108758), February 2001 4. NPDES General Permit for Storm Water Discharges Associated with Construction Activity Water Quality Order 99-08-DWQ, March 2003 5. 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 6. 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 7. Final Carlsbad Watershed Urban Runoff Management Program FY 03/04 Annual Report, January 2005 8. Project Design Consultants, Drainage Report - Poinsettia Commons, November 2006 9. California Stormwater Quality Association, Stormwater Best Management Practice Handbook - New Development and Redevelopment, January 2003 10. National Menu of Best Management Practices for Storm Water Phase II, US EPA 11. Correspondence with the City of Dana Point, the City of Encinitas, and the City of Santa Monica 12. Protocol for Developing Pathogen TMDLs, US EPA 13. 2002 Aquashield, Inc. 14. 2003 Stormwater Management Inc. 15. AbTech Industries 16. Bio Clean Environmental Services, Inc. 17. Bowhead Manufacturing Co. 18. CDS Technologies, Inc. 19. Comm Clean 20. Hydro International 21. Invisible Structures, Inc. 22. Kristar Enterprises, Inc. 23. Soil Stabilization Products Company, Inc. 24. Stormceptor Technical Manual, Rinker Materials, January 2003 25. Stormwater Magazine May/June 2003 Issue 26. Ultra Tech International, Inc. 27. UNI-GROUP U.S.A. 28. Vortechnics Design Manual, 2004 8 APPENDIX 8 Excerpts from Vernal Pool Study ^ 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 (aes) m Ver. 2.0 Release Date: 06/01/2005 License ID 1509 M Analysis prepared by: ** Project Design Consultants 701 B Street, Suite 800 «"» San Diego, CA 92101 (619) 235-6471 t************************* DESCRIPTION OF STUDY ********************** Poinsettia Station JN-2541 Calculations for existing conditons of all Waters End and Poinsettia Properties discharging at the NCTD and Poinsettia Lane intersection per request by US Fish and Wildlife FILE NAME: POIN100.DAT TIME/DATE OF STUDY: 08:37 01/18/2007 USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 100.00 6-HOUR DURATION PRECIPITATION (INCHES) = 2.500 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE =0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *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. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (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: 1. Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) 2. (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 100.00 IS CODE = 22 >»»RATIONAL METHOD INITIAL SUBAREA ANALYSIS<«« OPEN BRUSH GOOD COVER RUNOFF COEFFICIENT = .3500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 81 USER SPECIFIED Tc(MIN.) = 13.200 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.522 SUBAREA RUNOFF(CFS) = 0.62 TOTAL AREA(ACRES) = 0.50 TOTAL RUNOFF(CFS} = 0.62 FLOW PROCESS FROM NODE 100.00 TO NODE 101.00 IS CODE = 51 >»»COMPUTE TRAPEZOIDAL CHANNEL FLOW<«« >»»TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <«« ELEVATION DATA: UPSTREAM(FEET) = 54.80 DOWNSTREAM(FEET) = 46.20 CHANNEL LENGTH THRU SUBAREA(FEET) = 2700.00 CHANNEL SLOPE = 0.0032 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 0.030 MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 500.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.127 OPEN BRUSH GOOD COVER RUNOFF COEFFICIENT = .3500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 81 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 25.65 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.88 AVERAGE FLOW DEPTH(FEET) = 1.77 TRAVEL TIME(MIN-) = 15.65 Tc(MIN.) = 28.85 SUBAREA AREA(ACRES) = 64.50 SUBAREA RUNOFF(CFS) = 48.01 AREA-AVERAGE RUNOFF COEFFICIENT = 0.350 TOTAL AREA(ACRES) = 65.00 PEAK FLOW RATE(CFS) = 48.39 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 2.80 FLOW VELOCITY(FEET/SEC.) = 3.40 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 101.00 = 2700.00 FEET. END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 65.00 TC(MIN.) = 28.85 PEAK FLOW RATE(CFS) = 48.39 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 (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 (619) 235-6471 ************************** DESCRIPTION OF STUDY ************************** * Poinsettia Station JN-2541 Calculations for existing conditons * * of all Waters End and Poinsettia Properties discharging at the NCTD * * and Poinsettia Lane intersection per request by US Fish and Wildlife * ************************************************************************** FILE NAME: POIN2.DAT TIME/DATE OF STUDY: 11:31 01/22/2007 USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 2.00 6-HOUR DURATION PRECIPITATION (INCHES) = 1.200 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE =0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *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. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (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: 1. Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) 2. (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 100.00 IS CODE = 22 >»»RATIONAL METHOD INITIAL SUBAREA ANALYSIS«<« OPEN BRUSH GOOD COVER RUNOFF COEFFICIENT = .3500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 81 USER SPECIFIED Tc(MIN.) = 13.200 2 YEAR RAINFALL INTENSITY ( INCH/HOUR) = 1.690 SUBAREA RUNOFF (CFS) = 0.30 TOTAL AREA (ACRES) = 0.50 TOTAL RUNOFF (CFS) =0.30 FLOW PROCESS FROM NODE 100.00 TO NODE 101.00 IS CODE = 51 »>»COMPUTE TRAPEZOIDAL CHANNEL FLOW<«« >»»TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) ««< ELEVATION DATA: UPSTREAM (FEET) = 54.80 DOWNSTREAM (FEET) = 46.20 CHANNEL LENGTH THRU SUBAREA(FEET) = 2700.00 CHANNEL SLOPE = 0.0032 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 0.030 MANNING'S FACTOR = 0.030 MAXIMUM DEPTH (FEET) = 500.00 2 YEAR RAINFALL INTENSITY ( INCH/HOUR) = 0.934 OPEN BRUSH GOOD COVER RUNOFF COEFFICIENT = .3500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 81 TRAVEL TIME COMPUTED USING ESTIMATED FLOW (CFS) = 11.50 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY (FEET/SEC. ) = 2.26 AVERAGE FLOW DEPTH (FEET) = 1.01 TRAVEL TIME(MIN.) = 19.92 Tc(MIN.) = 33.12 SUBAREA AREA (ACRES) = 64.50 SUBAREA RUNOFF(CFS) = 21.08 AREA-AVERAGE RUNOFF COEFFICIENT = 0.350 TOTAL AREA(ACRES) = 65.00 PEAK FLOW RATE (CFS) = 21.24 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 1.54 FLOW VELOCITY (FEET/SEC. ) = 2.73 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 101.00 =2700.00 FEET. END OF STUDY SUMMARY: TOTAL AREA (ACRES) = 65.00 PEAK FLOW RATE (CFS) = 21.24 TC(MIN.) =33.12 END OF RATIONAL METHOD ANALYSIS «M> 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 (aes) Ver. 2.0 Release Date: 06/01/2005 License ID 1509 Analysis prepared by: Project Design Consultants ** 701 B Street, Suite 800 m San Diego, CA 92101 (619) 235-6471 ************** DESCRIPTION OF STUDY ************************** * Poinsettia Station JN-2541 Calculations for existing conditons * * of all Waters End and Poinsettia Properties discharging at the NCTD * * and Poinsettia Lane intersection per request by US Fish and Wildlife * ************************************************************************** FILE NAME: POIN10.DAT TIME/DATE OF STUDY: 09:54 01/22/2007 USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: 2003 SAN DIEGO MANUAL CRITERIA USER SPECIFIED STORM EVENT(YEAR) = 10.00 6-HOUR DURATION PRECIPITATION (INCHES) = 1.700 SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *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. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (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: 1. Relative Flow-Depth = 0.00 FEET as (Maximum Allowable Street Flow Depth) - (Top-of-Curb) 2. (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 100.00 IS CODE = 22 >»»RATIONAL METHOD INITIAL SUBAREA ANALYSIS<«« OPEN BRUSH GOOD COVER RUNOFF COEFFICIENT = .3500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 81 USER SPECIFIED Tc(MIN.) = 13.200 10 YEAR RAINFALL INTENSITY (INCH/HOUR) = 2.395 SUBAREA RUNOFF (CFS) = 0.42 TOTAL AREA (ACRES) = 0.50 TOTAL RUNOFF (CFS) = 0.42 FLOW PROCESS FROM NODE 100.00 TO NODE 101.00 IS CODE = 51 >»»COMPUTE TRAPEZOIDAL CHANNEL FLOW<«« >»»TRAVELTIME THRU SUBAREA (EXISTING ELEMENT) <«« ELEVATION DATA: UPSTREAM(FEET) = 54.80 DOWNSTREAM(FEET) = 46.20 CHANNEL LENGTH THRU SUBAREA(FEET) = 2700.00 CHANNEL SLOPE = 0.0032 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 0.030 MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 500.00 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 1.384 OPEN BRUSH GOOD COVER RUNOFF COEFFICIENT = .3500 SOIL CLASSIFICATION IS "D" S.C.S. CURVE NUMBER (AMC II) = 81 TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 16.86 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.54 AVERAGE FLOW DEPTH(FEET) = 1.32 TRAVEL TIME(MIN-) = 17.69 Tc(MIN.) = 30.89 SUBAREA AREA(ACRES) = 64.50 SUBAREA RUNOFF(CFS) = 31.24 AREA-AVERAGE RUNOFF COEFFICIENT = 0.350 TOTAL AREA(ACRES) = 65.00 PEAK FLOW RATE(CFS) = 31.48 END OF SUBAREA CHANNEL FLOW HYDRAULICS: DEPTH(FEET) = 2.04 FLOW VELOCITY(FEET/SEC.) = 3.05 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 101.00 = 2700.00 FEET. END OF STUDY SUMMARY: TOTAL AREA(ACRES) = 65.00 TC(MIN.) = 30.89 PEAK FLOW RATE(CFS) = 31.48 END OF RATIONAL METHOD ANALYSIS