Loading...
HomeMy WebLinkAboutLD21-2040Permit Number: LD21-2040 LD - Onsite Improvements/ Mass & Rough Grading Issued: 02/06/2025 Expired: 10/27/2025 Job Address: Tract Map 37928 Legal Description: City of Temecula - Land Development Division 41000 Main Street - Temecula, CA 92590 Mailing Address: P.O. Box 9033 Temecula, CA 92589-9033 Phone: (951) 308-6395 Fax: (951) 694-6475 ANY NOTICE OR NOTICES REQUIRED TO BE GIVEN PURSUANT TO THIS PERMIT SHALL BE SERVED ON THE OTHER PARTY BY FIRST CLASS MAIL, POSTAGE PREPAID, AT THE FOLLOWING ADDRESS: Decatur Advisors Llc Po Box 2016 Carlsbad, CA 92018 (619) 851-5121 Applicant: Contractor: Description of Work: The City Engineer hereby authorizes the Property Owner and Applicant (if different from Property Owner) (hereinafter collectively referred to a "Permittee") to do the following work including backfilling, compaction, surfacing and/or as outlined in the description of work below: Description: Tract Map 37928 Rough Grading for Planning Area 33A (PA33A) Separate permits required: 1. Haul route permit for the export of material 2. Encroachment permit for ALL work within the City right-of-way 3. Retaining wall permit Earthwork includes 14,000 CY excavation/14,000 CY embankment/0 CY export. Maximum 2:1 slopes. All grading and improvements shall be as specified on the approved plans and per the preliminary soils report. Perform grading in accordance with approved Grading Plans dated . A pre-grading conference is required 48 hours (minimum) in advance of any work done under this permit with the grading contractor and City Inspector. A pre-grade meeting is required 48 hours prior to any work. Permittee shall contact e-mail LDinspections@TemeculaCA.gov to schedule a meeting. Any field changes to the plan shall be approved by the City Engineer. All required permits and inspections by Building and Safety for walls, etc. shall be completed prior to any releases and/or other permits issued or released. Traffic and dust control shall be reviewed and approved by the inspector. Permitee Date City Engineer or Authorized Representative Date 02/06/2025 Page 1 of 1 City of Temecula WATER QUALITY MANAGEMENT PLAN (WQMP) PROJECT NAME & PERMIT NO: Wingsweep PA33A – Tract # 37928 Permit # PA20-0569 LD21-2040 PROJECT ADDRESS: Nicolas Road and Butterfield Stage Road PROJECT APN: 964-460-017 PREPARED BY: Rick Engineering Company 5620 Friars Road San Diego, California 92110 PREPARED FOR: Wingsweep Corporation 38445 Overview Rd Temecula, California 92592 DATE OF WQMP: 04/16/2021 Revised: 06/14/2021 APPROVED BY: APPROVAL DATE: APPROVED BY CITY OF TEMECULA PUBLIC WORKS valerie.ycong 08/04/2022 08/04/2022 08/04/2022 08/04/20 Michael Gentile 6/23/2022 WATER QUALITY MANAGEMENT PLAN FOR WINGSWEEP PLANNING AREA 33A REVISION PAGE JUNE 14, 2021 This Water Quality Management Plan presents a revision to the report titled “Water Quality Management Plan for Wingsweep Planning Area 33A” dated April 16, 2021, pursuant to 1st plan check review comments and minor project design changes. Redline review comments have been addressed and included on a separate document. WQMP 3 Template Date: October 31st, 2018 Preparation Date: June ,14 2021 Step 1: Source Control BMP Checklist Source Control BMPs All development projects must implement source control BMPs 4.2.1 through 4.2.6 where applicable and feasible. See Chapter 4.2 and Appendix E of the City BMP Design Manual for information to implement source control BMPs shown in this checklist. Answer each category below pursuant to the following: • "Yes" means the project will implement the source control BMP as described in Chapter 4.2 and/or Appendix E of the City BMP Design Manual. Discussion / justification must be provided and show locations on the project plans. Select applicable Source Controls in the Source Control BMP summary on the following page. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided. • "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion / justification must be provided. Source Control Requirement Applied? 4.2.1 Prevention of Illicit Discharges into the MS4 X Yes ☐No ☐N/A Discussion / justification: Several of the ultimate intended uses may result in non-stormwater discharges that are not to enter the MS4. Source Control BMPs can be effective in preventing illicit discharges. Source control BMPs include Stenciling On-Site Storm Drains indicating illicit discharges are not permissible, adhering to plazas, sidewalks, and parking lots sweeping and washing requirements, Maintaining Landscaping using minimum or no pesticides. 4.2.2 Storm Drain Stenciling or Signage X Yes ☐No ☐ N/A Discussion / justification: Posted notices that can prevent waste dumping will be employed. 4.2.3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal ☐ Yes ☐No X N/A Discussion / justification: There will be no outdoor materials storage areas associated with this project. 4.2.4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal ☐Yes ☐No X N/A Discussion / justification: There will be no outdoor work areas associated with this project. 4.2.5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal ☐Yes ☐No X N/A Discussion / justification: There will be no trash storage areas associated with this project. 4.2.6 Additional BMPs Based on Potential Sources of Runoff Pollutants ☐Yes ☐No X N/A Discussion / justification. Clearly identify which sources of runoff pollutants are discussed: 4 WQMP Preparation Date: June 14, 2021 Template Date: October 31st, 2018 BH:JR:vs:k.files/Report/17883-J.003 Source Control BMP Summary Select all source control BMPs identified for your project in sections 4.2.1 through 4.2.6 above in the column on the left below. Then select “yes” if the BMP has been implemented and shown on the project plans, “No” if the BMP has not been implemented, or “N/A” if the BMP is not applicable to your project. X SC-A. On-site storm drain inlets X Yes ☐No ☐N/A ☐ SC-B. Interior floor drains and elevator shaft sump pumps ☐Yes ☐No X N/A ☐ SC-C. Interior parking garages ☐Yes ☐No X N/A ☐ SC-D1. Need for future indoor & structural pest control ☐Yes ☐No X N/A X SC-D2. Landscape/outdoor pesticide use X Yes ☐No ☐N/A ☐ SC-E. Pools, spas, ponds, fountains, and other water features ☐Yes ☐No X N/A ☐ SC-F. Food service ☐Yes ☐No X N/A ☐ SC-G. Refuse areas ☐Yes ☐No X N/A ☐ SC-H. Industrial processes ☐Yes ☐No X N/A ☐ SC-I. Outdoor storage of equipment or materials ☐Yes ☐No X N/A ☐ SC-J. Vehicle and equipment cleaning ☐Yes ☐No X N/A ☐ SC-K. Vehicle/equipment repair and maintenance ☐Yes ☐No X N/A ☐ SC-L. Fuel dispensing areas ☐Yes ☐No X N/A ☐ SC-M. Loading docks ☐Yes ☐No X N/A ☐ SC-N. Fire sprinkler test water ☐Yes ☐No X N/A ☐ SC-O. Miscellaneous drain or wash water ☐Yes ☐No X N/A X SC-P. Plazas, sidewalks, and parking lots X Yes ☐No ☐N/A ☐ SC-Q. Large trash generating facilities ☐Yes ☐No X N/A ☐ SC-R. Animal facilities ☐Yes ☐No X N/A ☐ SC-S. Plant nurseries and garden centers ☐Yes ☐No X N/A ☐ SC-T. Automotive facilities ☐Yes ☐No X N/A Note: Show all source control measures applied above on the plan sheets. WQMP 5 Template Date: October 31st, 2018 Preparation Date: June ,14 2021 Step 2: Site Design BMP Checklist Site Design BMPs All development projects must implement site design BMPs SD-A through SD-H where applicable and feasible. See Chapter 4.3 and Appendix E of the City BMP Design Manual for information to implement site design BMPs shown in this checklist. Answer each category below pursuant to the following: • "Yes" means the project will implement the site design BMP as described in Chapter 4.3 and/or Appendix E of the City BMP Design Manual. Discussion / justification must be provided and show locations on the project plans. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided. • "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project site has no existing natural areas to conserve). Discussion / justification must be provided. Site Design Requirement Applied? 4.3.1 Maintain Natural Drainage Pathways and Hydrologic Features ☐ Yes ☐No X N/A Discussion / justification: Post-construction drainage pathways will closely mimic the pre-project conditions in that runoff will generally flow southerly eventually discharging to Santa Gertrudis Creek. However, the site has been previously mass graded and therefore no natural storage reservoirs or natural drainage corridors currently occur. 4.3.2 Conserve Natural Areas, Soils, and Vegetation ☐Yes ☐No X N/A Discussion / justification: The site has been previously mass graded over a decade ago and there is currently no appreciable vegetation present on the site. Several steps have been taken to restore and mimic the benefits provided by the natural vegetation, however. The site will be developed so as to have landscaped areas that mimic the natural vegetation. 4.3.3 Minimize Impervious Area X Yes ☐No ☐N/A Discussion / justification: Impervious surfaces have been minimized per landscape design. Street widths have designed to the minimum widths necessary. 4.3.4 Minimize Soil Compaction X Yes ☐No ☐ N/A Discussion / justification: As mentioned above, the site was previously mass-graded over a decade age and the soil has been compacted. Several steps will be taken to restore and minimize additional soil compaction, however. Protected areas have been identified and will be left undisturbed by the development envelope. The site will be developed so as to have landscaped areas that mimic the natural vegetation, with landscaped areas to be re-tilled and un-compacted to the extent practicable to allow for plant growth, also allowing for greater infiltrative capacity. 4.3.5 Impervious Area Dispersion X Yes ☐No ☐N/A Discussion / justification: The impervious areas will be interspersed by pervious landscaped areas. Where feasible, flow from impervious areas will be routed through pervious areas. 6 WQMP Preparation Date: June 14, 2021 Template Date: October 31st, 2018 BH:JR:vs:k.files/Report/17883-J.003 As roadways will be crowned, the potential to use landscaped medians to collect impervious areas is limited. Residential lots will be designed to sheet flow prior to collection by conveyance systems. 4.3.6 Runoff Collection ☐Yes ☐No X N/A Discussion / justification: Rainwater harvest is not considered feasible for this project per worksheet B.3-1 4.3.7 Landscaping with Native or Drought Tolerant Species X Yes ☐No ☐N/A Discussion / justification: It is anticipated that right of way landscaped areas will use drought tolerant and native species and are to be shown on landscape plans. 4.3.8 Harvesting and Using Precipitation ☐Yes ☐No X N/A Discussion / justification: Rainwater harvest is not considered feasible for this project per worksheet B.3-1 Step 3: Construction Stormwater BMP Checklist Minimum Required Standard Construction Stormwater BMPs If you answer “Yes” to any of the questions below, your project is subject to Table 1 on the following page (Minimum Required Standard Construction Stormwater BMPs). As noted in Table 1, please select at least the minimum number of required BMPs 1, or as many as are feasible for your project. If no BMP is selected, an explanation must be given in the box provided. The following questions are intended to aid in determining construction BMP requirements for your project. Note: All selected BMPs below must be included on the BMP plan incorporated into the construction plan sets. 1. Will there be soil disturbing activities that will result in exposed soil areas? (This includes minor grading and trenching.) Reference Table 1 Items A, B, D, and E Note: Soil disturbances NOT considered significant include, but are not limited to, change in use, mechanical/electrical/plumbing activities, signs, temporary trailers, interior remodeling, and minor tenant improvement. X Yes ☐No 2. Will there be asphalt paving, including patching? Reference Table 1 Items D and F X Yes ☐No 3. Will there be slurries from mortar mixing, coring, or concrete saw cutting? Reference Table 1 Items D and F X Yes ☐No 4. Will there be solid wastes from concrete demolition and removal, wall construction, or form work? Reference Table 1 Items D and F X Yes ☐No 5. Will there be stockpiling (soil, compost, asphalt, concrete, solid waste) for over 24 hours? Reference Table 1 Items D and F X Yes ☐No 6. Will there be dewatering operations? Reference Table 1 Items C and D X Yes ☐No 1 Minimum required BMPs are those necessary to comply with the City of Temecula Erosion and Sediment Control Ordinance (Chapter 18.18 et seq.) and the City of Temecula Engineering and Construction Manual (Chapter 18). WQMP 7 Template Date: October 31st, 2018 Preparation Date: June ,14 2021 7. Will there be temporary on-site storage of construction materials, including mortar mix, raw landscaping and soil stabilization materials, treated lumber, rebar, and plated metal fencing materials? Reference Table 1 Items E and F X Yes ☐No 8. Will trash or solid waste product be generated from this project? Reference Table 1 Item F X Yes ☐No 9. Will construction equipment be stored on site (e.g.: fuels, oils, trucks, etc.?) Reference Table 1 Item F ☐Yes X No 10. Will Portable Sanitary Services (“Porta-potty”) be used on the site? Reference Table 1 Item F X Yes ☐No 8 WQMP Preparation Date: June 14, 2021 Template Date: October 31st, 2018 BH:JR:vs:k.files/Report/17883-J.003 Table 1. Construction Stormwater BMP Checklist Minimum Required Best Management Practices (BMPs) CALTRANS SW Handbook 2 Detail  BMP Selected Reference sheet No.’s where each selected BMP is shown on the plans. If no BMP is selected, an explanation must be provided. A. Select Erosion Control Method for Disturbed Slopes (choose at least one for the appropriate season) Vegetation Stabilization Planting 3 (Summer) SS-2, SS-4 ☐ Plan sheet number will be referenced when available Hydraulic Stabilization Hydroseeding2 (Summer) SS-4 X Bonded Fiber Matrix or Stabilized Fiber Matrix 4 (Winter) SS-3 X Physical Stabilization Erosion Control Blanket3 (Winter) SS-7 ☐ B. Select erosion control method for disturbed flat areas (slope < 5%) (choose at least one) Will use erosion control measures from Item A on flat areas also SS-3, 4, 7 ☐ Plan sheet number will be referenced when available Sediment Desilting Basin (must treat all site runoff) SC-2 X Mulch, straw, wood chips, soil application SS-6, SS-8 ☐ 2 State of California Department of Transportation (Caltrans). 2003. Storm Water Quality Handbooks, Construction Site Best Management Practices (BMPs) Manual. March. Available online at: http://www.dot.ca.gov/hq/construc/stormwater/manuals.htm. 3 If Vegetation Stabilization (Planting or Hydroseeding) is proposed for erosion control it may be installed between May 1st and August 15th. Slope irrigation is in place and needs to be operable for slopes >3 feet. Vegetation must be watered and established prior to October 1st. The owner must implement a contingency physical BMP by August 15th if vegetation establishment does not occur by that date. If landscaping is proposed, erosion control measures must also be used while landscaping is being established. Established vegetation must have a subsurface mat of intertwined mature roots with a uniform vegetative coverage of 70 percent of the natural vegetative coverage or more on all disturbed areas. 4 All slopes over three feet must have established vegetative cover prior to final permit approval. WQMP 9 Template Date: October 31st, 2018 Preparation Date: June ,14 2021 Table 1. Construction Stormwater BMP Checklist (continued) Minimum Required Best Management Practices (BMPs) CALTRANS SW Handbook Detail  BMP Selected Reference sheet No.’s where each selected BMP is shown on the plans. If no BMP is selected, an explanation must be provided. C. If runoff or dewatering operation is concentrated, velocity must be controlled using an energy dissipater Energy Dissipater Outlet Protection 5 SS-10 X Plan sheet number will be referenced when available D. Select sediment control method for all disturbed areas (choose at least one) Silt Fence SC-1 X Plan sheet number will be referenced when available Fiber Rolls (Straw Wattles) SC-5 X Gravel & Sand Bags SC-6 & 8 X Dewatering Filtration NS-2 X Storm Drain Inlet Protection SC-10 X Engineered Desilting Basin (sized for 10-year flow) SC-2 ☐ E. Select method for preventing offsite tracking of sediment (choose at least one) Stabilized Construction Entrance TC-1 X Plan sheet number will be referenced when available Construction Road Stabilization TC-2 ☐ Entrance/Exit Tire Wash TC-3 ☐ Entrance/Exit Inspection & Cleaning Facility TC-1 ☐ Street Sweeping and Vacuuming SC-7 ☐ F. Select the general site management BMPs F.1 Materials Management Material Delivery & Storage WM-1 X Plan sheet number will be referenced when available Spill Prevention and Control WM-4 ☐ F.2 Waste Management 6 Waste Management Concrete Waste Management WM-8 X Plan sheet number will be referenced when available Solid Waste Management WM-5 ☐ Sanitary Waste Management WM-9 X Hazardous Waste Management WM-6 ☐ Note: The Construction General Permit (Order No. 2009-0009-DWQ) also requires all projects not subject to the BMP Design Manual to comply with runoff reduction requirements through the implementation of post-construction BMPs as described in Section XIII of the order. 5 Regional Standard Drawing D-40 – Rip Rap Energy Dissipater is also acceptable for velocity reduction. 6 Not all projects will have every waste identified. The applicant is responsible for identifying wastes that will be onsite and applying the appropriate BMP. For example, if concrete will be used, BMP WM-8 must be selected. 10 WQMP Preparation Date: June 14, 2021 Template Date: October 31st, 2018 BH:JR:vs:k.files/Report/17883-J.003 Step 4: Project type determination (Standard or Priority Development Project) Is the project part of another Priority Development Project (PDP)? X Yes ☐ No If so, Standard and PDP requirements apply. Go to Step 4.1 and select “PDP” The project is (select one): X New Development ☐ Redevelopment 7 The total proposed newly created or replaced impervious area is: 210,379 ft2 The total existing (pre-project) impervious area is: 0 ft2 The total area disturbed by the project is: 471,041 ft2 *This area includes DMAs considered self-treating and not draining to BMP, therefore this number will differ from DMA/BMP DCV values. If the total area disturbed by the project is 1 acre (43,560 sq. ft.) or more OR the project is part of a larger common plan of development disturbing 1 acre or more, a Waste Discharger Identification (WDID) number must be obtained from the State Water Resources Control Board. WDID: N/A Discretionary Project Is the project in any of the following categories, (a) through (f)?8 Yes X No ☐ (a) New development projects that create 10,000 square feet or more of impervious surfaces 9(collectively over the entire project site). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land. Yes ☐ No X (b) Redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surfaces). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land. Yes ☐ No X (c) New and redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site), and support one or more of the following uses: (i) Restaurants. This category is defined as a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). (ii) Hillside development projects. This category includes development on any natural slope that is twenty-five percent or greater. (iii) Parking lots. This category is defined as a land area or facility for the temporary parking or storage of motor vehicles used personally, for business, or for commerce. (iv) Streets, roads, highways, freeways, and driveways. This category is defined as any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles. 7 Redevelopment is defined as: The creation and/or replacement of impervious surface on an already developed site. Examples include the expansion of a building footprint, road widening, the addition to or replacement of a structure, and creation or addition of impervious surfaces. Replacement of impervious surfaces includes any activity that is not part of a routine maintenance activity where impervious material(s) are removed, exposing underlying soil during construction. Redevelopment does not include routine maintenance activities, such as trenching and resurfacing associated with utility work; pavement grinding; resurfacing existing roadways; new sidewalks construction; pedestrian ramps; or bike lanes on existing roads; and routine replacement of damaged pavement, such as pothole repair. 8 Applicants should note that any development project that will create and/or replace 10,000 square feet or more of impervious surface (collectively over the entire project site) is considered a new development. WQMP 11 Template Date: October 31st, 2018 Preparation Date: June ,14 2021 12 WQMP Preparation Date: June 14, 2021 Template Date: October 31st, 2018 BH:JR:vs:k.files/Report/17883-J.003 Project type determination (continued) Yes ☐ No X (d) New or redevelopment projects that create and/or replace 2,500 square feet or more of impervious surface (collectively over the entire project site), and discharging directly to an Environmentally Sensitive Area (ESA). “Discharging directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands). Note: ESAs are areas that include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Board and San Diego Water Board; State Water Quality Protected Areas; water bodies designated with the RARE beneficial use by the State Water Board and San Diego Water Board; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. See BMP Design Manual Chapter 1.4.2 for additional guidance. Yes ☐ No X (e) New development projects, or redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface, that support one or more of the following uses: (i) Automotive repair shops. This category is defined as a facility that is categorized in any one of the following SIC codes: 5013, 5014, 5541, 7532-7534, or 7536- 7539. (ii) Retail gasoline outlets (RGOs). This category includes RGOs that meet the following criteria: (a) 5,000 square feet or more or (b) a projected Average Daily Traffic (ADT) of 100 or more vehicles per day. Yes ☐ No X (f) New or redevelopment projects that result in the disturbance of one or more acres of land and are expected to generate pollutants post construction. Note: See BMP Design Manual Chapter 1.4.2 for additional guidance. Does the project meet the definition of one or more of the Priority Development Project categories (a) through (f) listed above? ☐ No – the project is not a Priority Development Project (Standard Project). X Yes – the project is a Priority Development Project (PDP). Further guidance may be found in Chapter 1 and Table 1-2 of the BMP Design Manual. The following is for redevelopment PDPs only: The area of existing (pre-project) impervious area at the project site is: ________________ ft2 (A) The total proposed newly created or replaced impervious area is _______________ ft2 (B) Percent impervious surface created or replaced (B/A)*100: _______________ % The percent impervious surface created or replaced is (select one based on the above calculation): ☐ less than or equal to fifty percent (50%) – only newly created or replaced impervious areas are considered a PDP and subject to stormwater requirements OR ☐ greater than fifty percent (50%) – the entire project site is considered a PDP and subject to stormwater requirements WQMP 13 Template Date: October 31st, 2018 Preparation Date: June ,14 2021 Step 4.1: Water Quality Management Plan requirements Step Answer Progression Is the project a Standard Project, Priority Development Project (PDP), or exception to PDP definitions? To answer this item, complete Step 4 Project Type Determination Checklist, and see PDP exemption information below. For further guidance, see Chapter 1.4 of the BMP Design Manual in its entirety. ☐ Standard Project Standard Project requirements apply, STOP, you have satisfied stormwater requirements. X PDP Standard and PDP requirements apply. Complete Exhibit A “PDP Requirements.” http://temeculaca.gov/wqmpa2 ☐ PDP Exemption Go to Step 4.2 below. Step 4.2: Exemption to PDP definitions Is the project exempt from PDP definitions based on either of the following: ☐ Projects that are only new or retrofit paved sidewalks, bicycle lanes, or trails that meet the following criteria: (i) Designed and constructed to direct stormwater runoff to adjacent vegetated areas, or other non-erodible permeable areas; OR (ii) Designed and constructed to be hydraulically disconnected from paved streets or roads [i.e., runoff from the new improvement does not drain directly onto paved streets or roads]; OR (iii) Designed and constructed with permeable pavements or surfaces in accordance with City of Temecula Guidance on Green Infrastructure; If so: Standard Project requirements apply, AND any additional requirements specific to the type of project. City concurrence with the exemption is required. Provide discussion and list any additional requirements below in this form. STOP, you have satisfied stormwater requirements. ☐ Projects that are only retrofitting or redeveloping existing paved alleys, streets or roads that are designed and constructed in accordance with the City of Temecula Guidance on Green Infrastructure. Complete Exhibit A “PDP Requirements.” Select Green Streets Exemptions where applicable. Discussion / justification, and additional requirements for exceptions to PDP definitions, if applicable: Exhibit A City of Temecula PRIORITY DEVELOPMENT PROJECT REQUIREMENTS ii PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 This page was left intentionally blank. PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS iii Template Date: September 26, 2019 Preparation Date: June 14, 2021 Table of Contents Table of Contents ....................................................................................................................... iii Attachments ............................................................................................................................... iii Preparer's Certification Page ...................................................................................................... v Step 1: Site Information Checklist ......................................................................................... 7 Step 1.1: Description of Existing Site Condition and Drainage Patterns ............................ 7 Step 1.2: Description of Proposed Site Development and Drainage Patterns ................... 8 Step 1.3: Other Site Requirements and Constraints ......................................................... 9 Step 2: Strategy for Meeting PDP Performance Requirements ............................................11 Attachments Attachment 1: Stormwater Pollutant Control BMP Selection Attachment 1a: DMA Exhibit Attachment 1b: 85th percentile 24-hour Isohyetal Map Attachment 1c: Worksheet B.1-1 DCV Attachment 1d: Structural Pollutant Control BMP Checklist(s) Attachment 1e: Attachment 1f: Attachment 2: Hydromodification Control Measures Attachment 2a: Applicability of HMP Requirements Attachment 2b: HMP Exhibit(s) Attachment 2c: Management of Critical Coarse Sediment Yield Areas Attachment 2d: Flow Control Facility Design Attachment 2e: Geomorphic Assessment of Receiving Channels (optional) Attachment 2f: Vector Control Plan (if applicable) Attachment 3: Structural BMP Maintenance Plan Attachment 3a: Structural BMP Maintenance Thresholds and Actions Attachment 3b: Maintenance Agreements / Notifications (when applicable) Attachment 3c: Individual Structural BMP DMA Map book Attachment 4: City of Temecula PDP Structural BMP Verification for DPW Permitted Land Development Projects Attachment 5: Copy of Plan Sheets Showing Permanent Stormwater BMPs Attachment 6: Copy of Project's Drainage Report Attachment 7: Copy of Project's Geotechnical and Groundwater Investigation Report iv PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 This page was left intentionally blank. PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS v Template Date: September 26, 2019 Preparation Date: June 14, 2021 Preparer's Certification Page Project Name: Wingsweep PA33A Permit Application Number: PA20-0569 LD21-2040 PREPARER'S CERTIFICATION I hereby declare that I am the Engineer in Responsible Charge of design of Stormwater best management practices (BMPs) for this project, and that I have exercised responsible charge over the design of the BMPs as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the PDP requirements of the City of Temecula BMP Design Manual, which is a design manual for compliance with local City of Temecula Stormwater and Urban Runoff Management and Discharge Controls Ordinance (Chapter 8.28 et seq.) and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2013-0001 as amended by R9-2015-0001 and R9-2015-0100) requirements for stormwater management. I have read and understand that the City of Temecula has adopted minimum requirements for managing urban runoff, including stormwater, from land development activities, as described in the BMP Design Manual. I certify that this PDP WQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this PDP WQMP by City staff is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of stormwater BMPs for this project, of my responsibilities for project design. Engineer of Work's Signature, PE Number & Expiration Date Print Name Rick Engineering Company 619-291-0707 Company & Phone No. ______________________ Date Engineer's Seal: Brendan Hastie 3-3-22 #65809, Exp. 9/23 vi PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 This page was left intentionally blank. PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS 7 Template Date: September 26, 2019 Preparation Date: June 14, 2021 Step 1: Site Information Checklist Step 1.1: Description of Existing Site Condition and Drainage Patterns Project Watershed (Complete Hydrologic Unit, Area, and Subarea Name with Numeric Identifier; e.g., 902.52 Santa Margarita HU, Pechanga HA, Wolf HSA) 902.00 Santa Margarita HU, 902.40 Auld HA, 2.43 Gertrudis HSA Current Status of the Site (select all that apply): Existing development X Previously graded but not built out Demolition completed without new construction Agricultural or other non-impervious use Vacant, undeveloped/natural Description / Additional Information: The site has been previously mass graded by others. An existing sediment basin is found in the southwest corner of the site. The majority of the runoff from the site flows southwest before being collected in the sediment basin and discharged to Santa Gertrudis creek. Existing Land Cover Includes (select all that apply and provide each area on site): X Pervious Area 10.7 Acres (471,088 Square Feet) ☐ Impervious Areas 0 Acres (0 Square Feet) Description / Additional Information: How is stormwater runoff conveyed from the site? At a minimum, this description should answer: (1) Whether existing drainage conveyance is natural or urban; (2) Is runoff from offsite conveyed through the site? If yes, describe the offsite drainage areas, design flows, and locations where offsite flows enter the project site, and summarize how such flows are conveyed through the site; (3) Provide details regarding existing project site drainage conveyance network, including any existing storm drains, concrete channels, swales, detention facilities, stormwater treatment facilities, natural or constructed channels; and (4) Identify all discharge locations from the existing project site along with a summary of conveyance system size and capacity for each of the discharge locations. Provide summary of the pre-project drainage areas and design flows to each of the existing runoff discharge locations. Reference the Drainage report Attachment for detailed calculations. Describe existing site drainage patterns: The site has been previously mass graded by others. An existing sediment basin is found in the southwest corner of the site, with no current engineered outworks. The majority of the runoff from the site sheet flows southwest before being collected in the sediment basin and discharged to Santa Gertrudis creek. 8 PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 Step 1.2: Description of Proposed Site Development and Drainage Patterns Project Description / Proposed Land Use and/or Activities: Planning Area 33A (PA33A) provides for the development of 15 single family residential dwelling units, and one street. The drainage pattern will mimic existing conditions drainage, flowing generally southwest before being collected in a Biofiltration BMP and discharged to Santa Gertrudis Creek. Proposed Land Cover Includes (select all that apply and provide each area on site): Existing to Remain X Pervious Area 1.5 Acres (67,411 Square Feet) ☐ Impervious Areas _______ Acres (_______ Square Feet) Existing to Be Replaced ☐ Pervious Area _______ Acres (_______ Square Feet) ☐ Impervious Areas _______ Acres (_______ Square Feet) Newly Created X Pervious Area 4.4 Acres 193,298 Square Feet) X Impervious Areas 4.8 Acres 210,379 Square Feet) Total X Pervious Area 5.9 Acres (260,709 Square Feet) X Impervious Areas 4.8 Acres (210,379 Square Feet) Description / Additional Information: List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): The proposed site will consist of one street with curbs and 15 detached residential units. List/describe proposed pervious features of the project (e.g., landscape areas): The proposed site will consist of 15 detached residential units with landscaped yard areas, and one (1) Biofiltration BMP area. Describe any grading or changes to site topography: Proposed grading changes will mimic drainage patterns of existing conditions. PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS 9 Template Date: September 26, 2019 Preparation Date: June 14, 2021 Provide details regarding the proposed project site drainage conveyance network, including storm drains, concrete channels, swales, detention facilities, stormwater treatment facilities, natural or constructed channels, and the method for conveying offsite flows through or around the proposed project site. Identify all discharge locations from the proposed project site along with a summary of the conveyance system size and capacity for each of the discharge locations. Provide a summary of pre- and post-project drainage areas and design flows to each of the runoff discharge locations. Reference the drainage study for detailed calculations. Describe proposed site drainage patterns: The proposed project site drainage will consist of curb and gutter conveyance directing flow to the Biofiltration basin located in the southwest corner of the project site. The Biofiltration basis will be sized for water quality treatment, hydromodification management, detention requirements. Since there is an existing graded sediment basin, the proposed biofiltration basin will occupy the same space, therefore preserving the point of discharge to Santa Gertrudis Creek. Step 1.3: Other Site Requirements and Constraints When applicable, list other site requirements or constraints that will influence stormwater management design, such as zoning requirements including setbacks and open space, or local codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements. 10 PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed. PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS 11 Template Date: September 26, 2019 Preparation Date: June 14, 2021 Step 2: Strategy for Meeting PDP Performance Requirements PDPs must implement BMPs to control pollutants in stormwater that may be discharged from a project (see Chapter 5). PDPs subject to hydromodification management requirements must implement flow control BMPs to manage hydromodification (see Chapter 6). Both stormwater pollutant control and flow control can be achieved within the same BMP(s). Projects triggering the 50% rule must address stormwater requirements for the entire site. Structural BMPs must be verified by the City at the completion of construction. This may include requiring the project owner or project owner's representative and engineer of record to certify construction of the structural BMPs (see Chapter 1.12). Structural BMPs must be maintained into perpetuity, and the City must confirm the maintenance (see Chapter 7). Provide a narrative description of the general strategy for pollutant control and flow control at the project site in the box below. This information must describe how the steps for selecting and designing stormwater pollutant control BMPs presented in Chapter 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected). For projects requiring flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated or separate. At the end of this discussion, provide a summary of all the BMPs within the project including the type and number. 12 PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 Describe the general strategy for BMP implementation at the site. Following direction from the City of Temecula BMP Design Manual, one (1) Biofiltration basin is proposed for the pollutant control requirements of the project. The DCV was calculated using the County of San Diego Automated Stormwater Pollutant Control Worksheet (Version 1.3). The worksheets show the proposed design satisfy the Annual Retention Requirements and effectively treats captured stormwater. The Biofiltration basin will be sized to address Hydromodification management as well as Detention requirements. There is one (1) proposed Biofiltration basin; BMP 33. In addition, three (3) site design BMPs have been implemented on-site. 1. 4.3.3 Minimize directly connected impervious area In order to minimize the impervious footprint of the project, site streets and sidewalks have been designed to the minimum widths necessary. 2. 4.3.5 Disperse impervious areas In order to disconnect impervious surfaces, roof runoff will be directed to pervious areas before discharging to storm drain conveyance where feasible. 3. 4.3.7 Landscape with native or drought tolerant species It is anticipated that right of way landscaped areas will use drought tolerant and other native species and are to be shown on landscape plans. (Continue on following page as necessary.) PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS 13 Template Date: September 26, 2019 Preparation Date: June 14, 2021 Description of structural BMP strategy continued (Page reserved for continuation of description of general strategy for structural BMP implementation at the site) (Continued from previous page) 14 PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 ATTACHMENT 1 STORMWATER POLLUTANT CONTROL BMP SELECTION Indicate which Items are Included behind this cover sheet: Attachment Sequence Contents Checklist Special Considerations for Redevelopment Projects (50% Rule) see chapter 1.7 and Step 4 of Appendix A.1. ☐ Less than or equal to fifty percent (50%) ☐ Greater than fifty percent (50%) Refer to Figure 5-1: Stormwater Pollutant Control BMP Selection Flow Chart Attachment 1a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this form. See Chapter 3.3.3 for guidance X Included ☐ Entire project is designed with Self-Mitigating and De-Minimis DMAs. The project is compliant with Pollution Control BMP sizing requirements. STOP * Attachment 1b Figure B.1-1: 85th Percentile 24-hour Isohyetal Map with project location X Included Attachment 1c Worksheet B.2-1 DCV 1 X Included Attachment 1d Applicable Site Design BMP Fact Sheet(s) from Appendix E X Included ☐ Entire project is designed with Self-Retaining DMAs. The project is compliant with Pollution Control BMP sizing requirements. STOP * Attachment 1e Structural Pollutant Control BMP Checklist(s) X Included Attachment 1f Is Onsite Alternative Compliance proposed?2 X No ☐ Yes - Include WQE worksheets Attachment 1g Offsite Alternative Compliance Participation Form - Pollutant Control Refer to Figure 1-3:Pathways to Participating in Offsite Alternative Compliance Program X Full Compliance Onsite ☐ Partial Compliance Onsite with Offsite Alternative Compliance or Full Offsite Alternative Compliance. Document onsite structural BMPs and complete - Pollutant Control Offsite Alternative Compliance Participation Form, and - WQE worksheets * If this box is checked, the remainder of Attachment 1 does not need to be filled out. 1 All stormwater pollutant control worksheets have been automated and are available for download at: https://www.sandiegocounty.gov/content/sdc/dpw/watersheds/DevelopmentandConstruction/BMP_Design_Manual. html 2 Water Quality Equivalency Guidance and automated worksheets for Region 9: http://www.projectcleanwater.org/water-quality-equivalency-guidance/ PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS 15 Template Date: September 26, 2019 Preparation Date: June 14, 2021 Attachment 1a: DMA Exhibit Checklist See Chapter 3.3.3 for guidance X Point(s) of Compliance X Project Site Boundary X Project Disturbed Area Footprint X Drainage management area (DMA) boundaries, DMA ID numbers, DMA areas (square footage or acreage), DMA land use and pollutants of concern, and DMA type (i.e., drains to structural BMP, self-retaining, self-mitigating, or de-minimis) Note on exhibit de-minimis areas and discuss reason they could not be included in Step 1.3 per section 5.2.2 of the manual. Include offsite areas receiving treatment to mitigate Onsite Water Quality Equivalency. X Include summary table of worksheet inputs for each DMA. X Include description of self-mitigating areas. X Potential pollutant source areas and corresponding required source control BMPs (see Chapter 4, Appendix E.1, and Step 3.5) X Proposed Site Design BMPs and surface treatments used to minimize imperviousness. Show sections, details, and dimensions of site design BMP’s per chapter 5.2.3 (tree wells, dispersion areas, rain gardens, permeable pavement, rain barrels, green roofs, etc.) N/A Proposed Harvest and Use BMPs X Underlying hydrologic soil group (Web Soil Survey) X Existing natural hydrologic features (watercourses, seeps, springs, wetlands, pond, lake) X Existing topography and impervious areas X Proposed grading and impervious areas. If the project is a subdivision or spans multiple lots show pervious and impervious totals for each lot. X Existing and proposed site drainage network and connections to drainage offsite X Potable water wells, onsite wastewater treatment systems (septic), underground utilities X Structural BMPs (identify location, structural BMP ID No., type of BMP, and size/detail) X Approximate depth to groundwater at each structural BMP X Approximate infiltration rate and feasibility (full retention, partial retention, biofiltration) at each structural BMP N/A Critical coarse sediment yield areas to be protected and or conveyed through the project site, if applicable. X Temporary Construction BMPs. Include protection of source control, site design and structural BMPs during construction. PA 33A 32 33116210 11 1 1 9 0 1 1 9 0 1 1 9 0 X X X 1180 X 1185 1185 1 1 8 5 CONC X X X 1190 119 0 1190 1190 1190 1190 X X X X X X X X X SHADOW X DENSE TREES X 1195 1195 119 5 119 5 1195 1195 1195 1195 DENSE TREES X X DENSE TREES X X X MHX 12 0 0 1200 1200 1200 1 2 0 0 12 0 0 1200 1200 1200 1200 X X X X X X X X X 1205 12 0 5 1205 1205 1205 1 2 0 5 1205 1205 1205 1205 1205 1205 1205 X X X X X X ASPH 1206 12 0 6 MHX X X X X X X X X X X P BX X MHX X X DENSE TREES ASPH 1208 12 0 8 X X MHX X PB X X PBX X X MHX 1210 1210 1210 1210 12 10 1210 12 10 12 10 1 2 10 X PBX X MHX X 12 12 MHX PBX X X X PBX X X X X X X MHX X X MHX X CONC X X X X MHX MHX X MHX X X P B X X X P B X X X X X X PB X X X CONC 12 15 X X X X X X MHX X CONC X X X X 1215 1215 12 15 1215 12 15 12 15 X PB X MHX X X X X X PB X X X X ASPH X X 12 16 X 12 16 X X 12 2 0 X 1225 1210 1215 1220 PA 33A DAYLIGHT LINE DAYLIGHT LINE EXIST LOT LINE SEPARATE PLAN EX 48" SD PER EXIST LOT LINE DAYLIGHT LINE DAYLIGHT LINE DAYLIGHT LINE EXIST LOT LINE SEPARATE PLAN EX 48" SD PER EXIST LOT LINE DAYLIGHT LINE 50' 50' REC. 4-21-2006 DOC. NO. 2006-0290814 OF DEDICATION PER IRREVOCABLE OFFER REC. 5-17-2006 DOC. NO. 2006-0359397 OF DEDICATION PER IRREVOCABLE OFFER DMA 33 SANTA GERTRUDIS CREEK NICOLAS ROAD DMA 33-1 DMA 33-2 DMA 33-3 10.7 AC 4.7 AC. 3.1 AC. 0.8 AC. SC-A 1206.51205.81204.9 1208.2 1208.0 1207.7 1207.0 1206.21205.31204.4 7 9 8 10 111213 1203.4 14 15 1202.5 1 1202.80 2 1203.2 3 1204.1 4 5 6 EX EASEMENT 1206.51205.81204.9 1208.2 1208.0 1207.7 1207.0 1206.21205.31204.4 7 9 8 10 111213 1203.4 14 15 1202.5 1 1202.80 2 1203.2 3 1204.1 4 5 6 EX EASEMENT SC-P DMA 33-6 DMA 33-9 DMA 33-7 0.5 AC 0.8 AC. SC-D2 SC-D2 #33 SC-D2 DMA 33-4.1 SC-D2 0.1 AC. 0.1 AC. DMA 33-8 SC-P DMA 33-5 POC 1 0.8 AC. 0.3 AC. DMA 33-4.2 0.3 AC1295 1 1 9 5 119 5 1200 1200 1200 1 2 0 0 1 1 9 5 120 0 1 2 0 0 1205 1205 1205 1205 1205 1205 1205 1 2 0 5 1205 1205 1210 1 2 1 0 1210 12 10 12 10 12 10 12 10 12 10 1210 1210 1215 1215 12 15 1215 1215 1220 1215 SUMMARY DMA PA33AWINGSWEEP DMA (SF) AREA (AC) AREA TYPESLANDUSE/SURFACE %IMPERVIOUS (SF) BMPTO DRAINING AREAS IMPERVIOU (AC) BMPTO DRAINING AREAS IMPERVIOU (SF) BMPTO DRAINING AREA PERVIOUS (AC) BMPTO GDRAININ AREA PERVIOUS (AC) BMPTO GDRAININ AREA 33-1 135439 3.1 RESIDENTIALDETACHED 47%63,656 1.5 71,783 1.6 3.1 33-2 35903 0.8 SURFACE/SIDEWALKROAD 100%35,903 0.8 0 0.0 0.8 33-3 203517 4.7 RESIDENTIALDETACHED 47%95,653 2.2 107,864 2.5 4.7 33-4.1 15167 0.3 BMP WQ PONDING SURFACE 100%15,167 0.3 0 0.0 0.3 33-4.2 13651 0.3 SLOPEVEGETATED 0%0 0.0 13,651 0.3 0.3 33-5 34279 0.8 SLOPEVEGETATED SELF-MITIGATING ----- 33-6 23650 0.5 SLOPEVEGETATED SELF-MITIGATING ----- 33-7 5449 0.1 SLOPEVEGETATED SELF-MITIGATING ----- 33-8 4033 0.1 SLOPEVEGETATED SELF-MITIGATING ----- 33-9 AREA) TOTALIN INCLUDED(NOT SLOPEVEGETATED SELF-TREATING R9-2013-0076 NO. CERTIFICATION QUALITY WATER 401SECTION ACT WATER CLEAN PER IMPROVEMENTSCHANNEL =Totals 471088 10.7 52%210,379 4.8 193,298 4.4 9.2 SUMMARY BMP DESIGN SITEIMPLEMENTED DESCRIPTION LOCATIONSTYPICAL 4.3.3 AREA IMPERVIOUSMINIMIZE TRAILS DG STREET,PRIVATE ALONG AREASSIDEWALK 4.3.5 DISPERSION AREAIMPERVIOUS LOTSRESIDENTIAL 4.3.7 SPECIESTOLERANT DROUGHT ORNATIVE WITHLANDSCAPING PLANSLANDSCAPING PER SLOPES,VEGETATED LOTS,RESIDENTIAL INFORMATION ADDITIONAL FOR WQMP THE OF 2 STEP TO REFERNOTE: # 7 NOTES STORM WATER MANAGEMENT BMP LEGEND 0 2 - M A R - 2 0 2 2 1 3 : 0 1 C : \ R I C K \ P r o j e c t s \ C _ R I V _ G \ 1 7 8 8 3 \ 1 7 8 8 3 - J _ P A 3 3 A \ Wa t e r R e s \ S D C o r p S t d s 2 0 0 5 . d s c r i p t C : \ R I C K \ P r o j e c t s \ C _ R I V _ G \ 1 7 8 8 3 \ 1 7 8 8 3 - J _ P A 3 3 A \ Wa t e r R e s \ 1 7 8 8 3 J _ P A 3 3 A w q m p 0 1 . d g n NOT FOR CONSTRUCTION - EXHIBIT FOR WATER QUALITY MANAGEMENT PLAN ONLY DMA 2 BMP LOCATION OF PROPOSED BIOFILTRATION 27.6 AC DMA AREA BOUNDARY DRAINAGE MANAGEMENT AREA (DMA) DMA ID BMP ID 1SHT OF 1 PLANNING AREA PER SPECIFIC PLAN c 2 0 2 0 Ric k E n g in e e rin g C o m p a n y J-17883-E POC 1 POINT OF COMPLIANCE FLOWPATH PLANNING AREA 33A WINGSWEEP PROPERTY FOR PLAN EXHIBIT WATER QUALITY MANAGEMENT Revised: March 2, 2022 Revised: June 14, 2021 Date: April 16, 2021 60 0 60 SCALE: 1" = 60' 120 NOT ENCOUNTER GROUNDWATER. 6. GEOTECHNICAL BORING TO A DEPTH OF 51.5' DID SEDIMETN YIELD AREA. 5. SITE LOCATION IS OUTSIDE OF CRITICAL COARSE GEOTECHNICAL REPORT INDICATES 0.03 IN/HR. 4. APPROXIMATE INFILTRATION RATE AT BMP PER CALCULATING RUNOFF COEFFICIENTS 3. HYDROLOGIC SOIL GROUP TYPE "D" USED FOR PROPERTY PLANNING AREA 33A. 2. THIS WQMP EXHIBIT COVERS THE WINGSWEEP DESIGN MANUAL. QUALITY REQUIREMENTS OF THE CITY OF TEMECULA BMP THIS EXHIBIT ADDRESSES THE PERMANENT STORM WATER 1. SIZES OF THE POLLUTANT CONTROL BMPs SHOWN ON WQMP SUMBITTAL LD20-1160 ADDRESSED BY A SEPARATE NOTE: NICOLAS ROAD PHASE STREETS ELEMENTS BY NICOLAS ROAD GREEN NOTE: DRIVEWAY TREATED July 2018 B-3 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Figure B.1-1: 85th Percentile 24-hour Isohyetal Map Approximate Project Location Category # Description i ii iii iv v vi vii viii ix x Units 0 Drainage Basin ID or Name DMA 33 unitless 1 Basin Drains to the Following BMP Type Biofiltration unitless 2 85th Percentile 24-hr Storm Depth 0.70 inches 3 Design Infiltration Rate Recommended by Geotechnical Engineer 0.024 in/hr 4 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 210,379 sq-ft 5 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30)sq-ft 6 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10)sq-ft 7 Natural Type A Soil Not Serving as Dispersion Area (C=0.10)sq-ft 8 Natural Type B Soil Not Serving as Dispersion Area (C=0.14)sq-ft 9 Natural Type C Soil Not Serving as Dispersion Area (C=0.23)sq-ft 10 Natural Type D Soil Not Serving as Dispersion Area (C=0.30) 193,298 sq-ft 11 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels? No No No No No No No yes/no 12 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft 13 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft 14 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft 15 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft 16 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14)sq-ft 17 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23)sq-ft 18 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft 19 Number of Tree Wells Proposed per SD-A # 20 Average Mature Tree Canopy Diameter ft 21 Number of Rain Barrels Proposed per SD-E # 22 Average Rain Barrel Size gal 23 Does BMP Overflow to Stormwater Features in Downstream Drainage? No No No No No No No No No No unitless 24 Identify Downstream Drainage Basin Providing Treatment in Series unitless 25 Percent of Upstream Flows Directed to Downstream Dispersion Areas percent 26 Upstream Impervious Surfaces Directed to Dispersion Area (Ci=0.90) 0 0 0 0 0 0 0 0 0 0 cubic-feet 27 Upstream Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 0 0 0 0 0 0 0 0 0 0 cubic-feet 28 Total Tributary Area 403,677 0 0 0 0 0 0 0 0 0 sq-ft 29 Initial Runoff Factor for Standard Drainage Areas 0.61 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 30 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 31 Initial Weighted Runoff Factor 0.61 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 32 Initial Design Capture Volume 14,364 0 0 0 0 0 0 0 0 0 cubic-feet 33 Total Impervious Area Dispersed to Pervious Surface 0 0 0 0 0 0 0 0 0 0 sq-ft 34 Total Pervious Dispersion Area 0 0 0 0 0 0 0 0 0 0 sq-ft 35 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a ratio 36 Adjustment Factor for Dispersed & Dispersion Areas 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ratio 37 Runoff Factor After Dispersion Techniques 0.61 n/a n/a n/a n/a n/a n/a n/a n/a n/a unitless 38 Design Capture Volume After Dispersion Techniques 14,364 0 0 0 0 0 0 0 0 0 cubic-feet 39 Total Tree Well Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet 40 Total Rain Barrel Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet 41 Final Adjusted Runoff Factor 0.61 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 42 Final Effective Tributary Area 246,243 0 0 0 0 0 0 0 0 0 sq-ft 43 Initial Design Capture Volume Retained by Site Design Elements 0 0 0 0 0 0 0 0 0 0 cubic-feet 44 Final Design Capture Volume Tributary to BMP 14,364 0 0 0 0 0 0 0 0 0 cubic-feet Worksheet B.1-1 General Notes: False False False Automated Worksheet B.1-1: Calculation of Design Capture Volume (V1.3) A. Applicants may use this worksheet to calculate design capture volumes for up to 10 drainage areas User input must be provided for yellow shaded cells, values for all other cells will be automatically generated, errors/notifications will be highlighted in red and summarized below. Upon completion of this worksheet, proceed to the appropriate BMP Sizing worksheet(s). Dispersion Area, Tree Well & Rain Barrel Inputs (Optional) Standard Drainage Basin Inputs Results Tree & Barrel Adjustments Initial Runoff Factor Calculation Dispersion Area Adjustments Treatment Train Inputs & Calculations False 16 PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS Preparation Date: June 14, 2021 Template Date: September 26, 2019 Attachment 1e: Structural Pollutant Control BMP Checklist Provide the following items for each Structural BMP selected Refer to Figure 5-2: Stormwater Pollutant Control Structural BMP Selection Flow Chart DMA ID No. 33 Structural BMP ID No. 33 Construction Plan Sheet No. TBD X Worksheet B.3-1 Structural BMP Feasibility: Project-Scale BMP Feasibility Analysis X Worksheet C.4-1: Categorization of Infiltration Feasibility Condition Refer to Appendices C and D to complete. ☐ Not included because the entire project will use harvest and use BMPs X Worksheet D.5-1 Infiltration & partial retention Safety Factor Structural BMP Selection and Design (Chapter 5.5) complete an include the applicable worksheet(s) found in appendix B and design criteria checklists from the associated fact sheets found in appendix E for selected Structural BMP(s): ☐ Worksheet B.6-1 - Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) ☐ Retention by harvest and use (HU-1) ☐ Continuous simulation Model ☐ Worksheet B.4-1 ☐ Infiltration basin (INF-1) ☐ Bioretention (INF-2) ☐ Permeable pavement (INF-3) X Worksheet B.5-1 ☐ Biofiltration with partial retention (PR-1) X Biofiltration (BF-1) X Biofiltration with Nutrient Sensitive Media Design (BF-2) X Identification and Narrative of Receiving Water Pollutants of Concern ☐ Proprietary Biofiltration (BF-3) ☐ Appendix F checklist ☐ Identification and Narrative of Receiving Water Pollutants of Concern X Worksheet B.5-3 Minimum Footprint ☐ Worksheet B.5-4 Biofiltration + Storage X Selected BMPs have been designed to address the entire DCV. The DMA is compliant with Pollution Control BMP sizing requirements. STOP * ☐ Other (describe in discussion section below) ☐ Worksheet B.6-1 - Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below) ☐ Describe in discussion section below why the remaining BMP size could not fit on site. ☐ Identification and Narrative of Receiving Water Pollutants of Concern ☐ Selection of Flow-Thru Treatment Control BMPs with high or medium effectiveness ☐ FT-1 Vegetated swales ☐ FT-2 Media Filters ☐ FT-3 Sand Filters ☐ FT-4 Dry Extended Detention Basin ☐ FT-5 Proprietary flow-thru treatment control ☐ Pollutant Control Offsite Alternative Compliance Participation form ☐ Water Quality Equivalency Worksheets20 PRIORITY DEVELOPMENT PROJECT (PDP) REQUIREMENTS 17 Template Date: September 26, 2019 Preparation Date: June 14, 2021 Purpose: ☐ Pre-treatment/forebay for another structural BMP ☐ Pollutant control only ☐ Combined pollutant control and hydromodification control (see Attachment 2) ☐ Other (describe in discussion section below) Who will certify construction of this BMP? Provide name and contact information for the party responsible to sign BMP verification forms (See Chapter 1.12 of the BMP Design Manual) Who will be the final owner of this BMP? X HOA ☐ Property Owner ☐ City ☐ Other (describe) Who will maintain this BMP into perpetuity? X HOA ☐ Property Owner ☐ City ☐ Other (describe) Discussion (as needed): (Continue on subsequent pages as necessary) * If this box is checked, Worksheet B.6-1 does not need to be filled out. Category # Description Value Units 0 Design Capture Volume for Entire Project Site 14,364 cubic-feet 1 Proposed Development Type Residential unitless 2 Number of Residents or Employees at Proposed Development 60 # 3 Total Planted Area within Development 200,000 sq-ft 4 Water Use Category for Proposed Planted Areas Low unitless 5 Is Average Site Design Infiltration Rate ≤0.500 Inches per Hour?Yes yes/no 6 Is Average Site Design Infiltration Rate ≤0.010 Inches per Hour?No yes/no 7 Is Infiltration of the Full DCV Anticipated to Produce Negative Impacts? Yes yes/no 8 Is Infiltration of Any Volume Anticipated to Produce Negative Impacts? No yes/no 9 36-Hour Toilet Use Per Resident or Employee 1.86 cubic-feet 10 Subtotal: Anticipated 36 Hour Toilet Use 112 cubic-feet 11 Anticipated 1 Acre Landscape Use Over 36 Hours 52.14 cubic-feet 12 Subtotal: Anticipated Landscape Use Over 36 Hours 239 cubic-feet 13 Total Anticipated Use Over 36 Hours 351 cubic-feet 14 Total Anticipated Use / Design Capture Volume 0.02 cubic-feet 15 Are Full Capture and Use Techniques Feasible for this Project? No unitless 16 Is Full Retention Feasible for this Project? No yes/no 17 Is Partial Retention Feasible for this Project? Yes yes/no Result 18 Feasibility Category 4 1, 2, 3, 4, 5 Worksheet B.3-1 General Notes: H. PDPs participating in an offsite alternative compliance program are not held to the feasibility categories presented herein. Capture & Use Inputs Automated Worksheet B.3-1: Project-Scale BMP Feasibility Analysis (V1.3) C. Feasibility Category 1: Applicant must implement capture & use, retention, and/or infiltration elements for the entire DCV. D. Feasibility Category 2: Applicant must implement capture & use elements for the entire DCV. E. Feasibility Category 3: Applicant must implement retention and/or infiltration elements for all DMAs with Design Infiltration Rates greater than 0.50 in/hr. B. Negative impacts associated with retention may include geotechnical, groundwater, water balance, or other issues identified by a geotechnical engineer and substantiated through completion of Form I-8. Infiltration Inputs G. Feasibility Category 5: Applicant must implement standard lined biofiltration BMPs sized at ≥3% of the effective impervious tributary area for all DMAs with Design Infiltration Rates of 0.010 in/hr or less. Applicants may also be permitted to implement reduced size and/or specialized biofiltration BMPs provided additional criteria identified in "Supplemental Retention Criteria for Non-Standard Biofiltration BMPs" are satisfied. A. Applicants may use this worksheet to determine the types of structural BMPs that are acceptable for implementation at their project site (as required in Section 5 of the BMPDM). User input should be provided for yellow shaded cells, values for all other cells will be automatically generated. Projects demonstrating feasibility or potential feasibility via this worksheet are encouraged to incorporate capture and use features in their project. F. Feasibility Category 4: Applicant must implement standard unlined biofiltration BMPs sized at ≥3% of the effective impervious tributary area for all DMAs with Design Infiltration Rates of 0.011 to 0.50 in/hr. Applicants may be permitted to implement lined BMPs, reduced size BMPs, and/or specialized biofiltration BMPs provided additional criteria identified in "Supplemental Retention Criteria for Non-Standard Biofiltration BMPs" are satisfied. Calculations C-11 July 2018 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1: Categorization of Infiltration Feasibility Condition Categorization of Infiltration Feasibility Condition Worksheet C.4-1 Part 1 - Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Note that it is not necessary to investigate each and every criterion in the worksheet if infiltration is precluded. Instead a letter of justification from a geotechnical professional familiar with the local conditions substantiating any geotechnical issues will be required. Criteria Screening Question Yes No 1 Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. Percolation testing performed and test results included in : Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. X X Percolation rates below 0.5 in/hr based on testing performed in: Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. C-12 July 2018 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1 Page 2 of 4 Criteria Screening Question Yes No 3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.3. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.3. Part 1 Result* If all answers to rows 1 - 4 are “Yes” a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration If any answer from row 1-4 is “No”, infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a “full infiltration” design. Proceed to Part 2 *To be completed using gathered site information and best professional judgment considering the definition of MEP in the Regional MS4 Permit. Additional testing and/or studies may be required by City staff to substantiate findings. X Provide basis: Groundwater was not encountered within the depth explored of 51.5', boring logs included in: Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. X Provide basis: Groundwater was not encountered within the depth explored of 51.5' per: Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. C-13 July 2018 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1 Page 3 of 4 Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria Screening Question Yes No 5 Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. X Provide basis: Percolation/infiltration testing has yielded an average infiltration rate of 0.11in/hr. Soil is not impermeable, however the infiltration rate is low. Testing performed in: Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. X Proposed infiltration areas are away from cut/fill slopes, retaining walls, are located +10' from high groundwater level and are not near utilities. C-14 July 2018 Appendix C: Geotechnical and Groundwater Investigation Requirements Worksheet C.4-1 Page 4 of 4 Criteria Screening Question Yes No 7 Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question must be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. Part 2 Result* If all answers from row 5-8 are yes then partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration. If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. *To be completed using gathered site information and best professional judgment considering the definition of MEP in the Regional MS4 Permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings. X Groundwater not encountered within the upper 51.5', boring logs: Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. X Based on low infiltration rate and depth to groundwater. Rates and depth to groundwater: Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, project no. 12673.001, dated June 30, 2020. Appendix D: Approved Infiltration Rate Assessment Methods D-19 July 2018 Worksheet D.5-1: Factor of Safety and Design Infiltration Rate Worksheet Factor of Safety and Design Infiltration Rate Worksheet Worksheet D.5-1 Factor Category Factor Description Assigned Weight (w) Factor Value (v) Product (p) p = w x v A Suitability Assessment Soil assessment methods 0.25 Predominant soil texture 0.25 Site soil variability 0.25 Depth to groundwater / impervious layer 0.25 Suitability Assessment Safety Factor, SA = p B Design Level of pretreatment/ expected sediment loads 0.5 Redundancy/resiliency 0.25 Compaction during construction 0.25 Design Safety Factor, SB = p Combined Safety Factor, Stotal= SA x SB Observed Infiltration Rate, inch/hr, Kobserved (corrected for test-specific bias) Design Infiltration Rate, in/hr, Kdesign = Kobserved / Stotal Supporting Data 2 3 2 1 2 2 3 0.50 0.75 0.50 0.25 1.00 0.5 0.75 2.00 2.25 4.50 0.11 (average) 0.024 Briefly describe infiltration test and provide reference to test forms: Infiltration tests performed in general accordance with procedures of Section 2.3 of the Riverside County Flood Control and Water Conservation District Design Handbook. Results included in : Geotechnical Evaluation Report (Update), Wingsweep Entitlement, PA-10, PA-12 and PA-33A, City of Temecula, California, by Leighton and Associates, Inc., project no. 12673.001, dated June 30, 2020. Category # Description i ii iii iv v vi vii viii ix x Units 0 Drainage Basin ID or Name DMA 33 - - - - - - - - - sq-ft 1 Design Infiltration Rate Recommended by Geotechnical Engineer 0.024 - - - - - - - - - in/hr 2 Effective Tributary Area 246,243 - - - - - - - - - sq-ft 3 Minimum Biofiltration Footprint Sizing Factor 0.030 - - - - - - - - - ratio 4 Design Capture Volume Tributary to BMP 14,364 - - - - - - - - - cubic-feet 5 Is Biofiltration Basin Impermeably Lined or Unlined? Unlined unitless 6 Provided Biofiltration BMP Surface Area 14,750 sq-ft 7 Provided Surface Ponding Depth 6 inches 8 Provided Soil Media Thickness 27 inches 9 Provided Depth of Gravel Above Underdrain Invert 11 inches 10 Diameter of Underdrain or Hydromod Orifice (Select Smallest) 2.50 inches 11 Provided Depth of Gravel Below the Underdrain 3 inches 12 Volume Infiltrated Over 6 Hour Storm 177 0 0 0 0 0 0 0 0 0 cubic-feet 13 Soil Media Pore Space Available for Retention 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 unitless 14 Gravel Pore Space Available for Retention 0.40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 15 Effective Retention Depth 2.55 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches 16 Calculated Retention Storage Drawdown (Including 6 Hr Storm) 56 0 0 0 0 0 0 0 0 0 hours 17 Volume Retained by BMP 3,311 0 0 0 0 0 0 0 0 0 cubic-feet 18 Fraction of DCV Retained 0.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 19 Portion of Retention Performance Standard Satisfied 0.33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 20 Fraction of DCV Retained (normalized to 36-hr drawdown) 0.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 21 Design Capture Volume Remaining for Biofiltration 11,778 0 0 0 0 0 0 0 0 0 cubic-feet 22 Max Hydromod Flow Rate through Underdrain 0.3098 n/a n/a n/a n/a n/a n/a n/a n/a n/a CFS 23 Max Soil Filtration Rate Allowed by Underdrain Orifice 0.91 n/a n/a n/a n/a n/a n/a n/a n/a n/a in/hr 24 Soil Media Filtration Rate per Specifications 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 in/hr 25 Soil Media Filtration Rate to be used for Sizing 0.91 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 in/hr 26 Depth Biofiltered Over 6 Hour Storm 5.44 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 inches 27 Soil Media Pore Space Available for Biofiltration 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 unitless 28 Effective Depth of Biofiltration Storage 15.80 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 inches 29 Drawdown Time for Surface Ponding 6 0 0 0 0 0 0 0 0 0 hours 30 Drawdown Time for Effective Biofiltration Depth 17 0 0 0 0 0 0 0 0 0 hours 31 Total Depth Biofiltered 21.24 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 inches 32 Option 1 - Biofilter 1.50 DCV: Target Volume 17,667 0 0 0 0 0 0 0 0 0 cubic-feet 33 Option 1 - Provided Biofiltration Volume 17,667 0 0 0 0 0 0 0 0 0 cubic-feet 34 Option 2 - Store 0.75 DCV: Target Volume 8,834 0 0 0 0 0 0 0 0 0 cubic-feet 35 Option 2 - Provided Storage Volume 8,834 0 0 0 0 0 0 0 0 0 cubic-feet 36 Portion of Biofiltration Performance Standard Satisfied 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 37 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements? Yes - - - - - - - - - yes/no 38 Overall Portion of Performance Standard Satisfied 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ratio 39 This BMP Overflows to the Following Drainage Basin - - - - - - - - - - unitless 40 Deficit of Effectively Treated Stormwater 0 n/a n/a n/a n/a n/a n/a n/a n/a n/a cubic-feet Worksheet B.5-1 General Notes: False Retention Calculations Automated Worksheet B.5-1: Sizing Lined or Unlined Biofiltration BMPs (V1.3) False BMP Inputs False Biofiltration Calculations A. Applicants may use this worksheet to size Lined or Unlined Biofiltration BMPs (BF-1, PR-1) for up to 10 basins. User input must be provided for yellow shaded cells, values for blue cells are automatically populated based on user inputs from previous worksheets, values for all other cells will be automatically generated, errors/notifications will be highlighted in red/orange and summarized below. BMPs fully satisfying the pollutant control performance standards will have a deficit treated volume of zero and be highlighted in green. False False False False Result False False BF-1 Biofiltration E-120 July 2018 E.18 BF-1 Biofiltration Location: 43rd Street and Logan Avenue, San Diego, California Biofiltration (Biofiltration with underdrain) facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Biofiltration with underdrain facilities are commonly incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because these types of facilities have limited or no infiltration, they are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and plant uptake. Typical biofiltration with underdrain components include:  Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips)  Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap)  Shallow surface ponding for captured flows  Side slope and basin bottom vegetation selected based on expected climate and ponding depth  Non-floating mulch layer (Optional)  Media layer (planting mix or engineered media) capable of supporting vegetation growth  Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer  Aggregate storage layer with underdrain(s) Description MS4 Permit Category Biofiltration Manual Category Biofiltration Applicable Performance Standard Pollutant Control Flow Control Primary Benefits Treatment Volume Reduction (Incidental) Peak Flow Attenuation (Optional) BF-1 Biofiltration E-121 July 2018  Impermeable liner or uncompacted native soils at the bottom of the facility  Overflow structure Typical plan and Section view of a Biofiltration BMP BF-1 Biofiltration E-122 July 2018 Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un-lined to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered runoff. This configuration is considered to provide biofiltration treatment via flow through the media layer. Storage provided above the underdrain within surface ponding, media, and aggregate storage is considered included in the biofiltration treatment volume. Saturated storage within the aggregate storage layer can be added to this design by raising the underdrain above the bottom of the aggregate storage layer or via an internal weir structure designed to maintain a specific water level elevation. Integrated storm water flow control and pollutant control configuration. The system can be designed to provide flow rate and duration control by primarily providing increased surface ponding and/or having a deeper aggregate storage layer above the underdrain. This will allow for significant detention storage, which can be controlled via inclusion of an outlet structure at the downstream end of the underdrain. Siting Criteria Intent/Rationale □ Placement observes geotechnical recommendations regarding potential hazards (e.g., slope stability, landslides, liquefaction zones) and setbacks (e.g., slopes, foundations, utilities). Must not negatively impact existing site geotechnical concerns. □ An impermeable liner or other hydraulic restriction layer is included if site constraints indicate that infiltration or lateral flows should not be allowed. Lining prevents storm water from impacting groundwater and/or sensitive environmental or geotechnical features. Incidental infiltration, when allowable, can aid in pollutant removal and groundwater recharge. □ Contributing tributary area shall be ≤ 5 acres (≤ 1 acre preferred). Bigger BMPs require additional design features for proper performance. Contributing tributary area greater than 5 acres may be allowed at the discretion of the City Engineer if the following conditions are met: 1) incorporate design features (e.g. flow spreaders) to minimizing short circuiting of flows in the BMP and 2) incorporate additional design features requested by the City Engineer Design Adaptations for Project Goals Recommended Siting Criteria BF-1 Biofiltration E-123 July 2018 Siting Criteria Intent/Rationale for proper performance of the regional BMP. □ Finish grade of the facility is ≤ 2%. Flatter surfaces reduce erosion and channelization within the facility. BMP Component Dimension Intent/Rationale Freeboard ≥ 2 inches Freeboard provides room for head over overflow structures and minimizes risk of uncontrolled surface discharge. Surface Ponding ≥ 6 and ≤ 12 inches Surface ponding capacity lowers subsurface storage requirements. Deep surface ponding raises safety concerns. Surface ponding depth greater than 12 inches (for additional pollutant control or surface outlet structures or flow-control orifices) may be allowed at the discretion of the City Engineer if the following conditions are met: 1) surface ponding depth drawdown time is less than 24 hours; and 2) safety issues and fencing requirements are considered (typically ponding greater than 18” will require a fence and/or flatter side slopes) and 3) potential for elevated clogging risk is considered. Recommended BMP Component Dimensions BF-1 Biofiltration E-124 July 2018 BMP Component Dimension Intent/Rationale Ponding Area Side Slopes 3H:1V or shallower Gentler side slopes are safer, less prone to erosion, able to establish vegetation more quickly and easier to maintain. Mulch ≥ 3 inches Mulch will suppress weeds and maintain moisture for plant growth. Aging mulch kills pathogens and weed seeds and allows the beneficial microbes to multiply. Media Layer ≥ 18 inches A deep media layer provides additional filtration and supports plants with deeper roots. Standard specifications shall be followed. For non-standard or proprietary designs, compliance with F.1 ensures that adequate treatment performance will be provided. Underdrain Diameter ≥ 6 inches Smaller diameter underdrains are prone to clogging. Cleanout Diameter ≥ 6 inches Properly spaced cleanouts will facilitate underdrain maintenance. BF-1 Biofiltration E-125 July 2018 Biofiltration with underdrain must meet the following design criteria. Deviations from the below criteria may be approved at the discretion of the City Engineer if it is determined to be appropriate: Design Criteria Intent/Rationale Surface Ponding □ Surface ponding is limited to a 24-hour drawdown time. Surface ponding limited to 24 hours for plant health. Surface ponding drawdown time greater than 24-hours but less than 96 hours may be allowed at the discretion of the City Engineer if certified by a landscape architect or agronomist. Vegetation □ Plantings are suitable for the climate and expected ponding depth. A plant list to aid in selection can be found in Appendix E.26. Plants suited to the climate and ponding depth are more likely to survive. □ An irrigation system with a connection to water supply should be provided as needed. Seasonal irrigation might be needed to keep plants healthy. Mulch (Optional or Mandatory – Dependent on jurisdiction) □ A minimum of 3 inches of well-aged, shredded hardwood mulch that has been stockpiled or stored for at least 12 months is provided. Mulch will suppress weeds and maintain moisture for plant growth. Aging mulch kills pathogens and weed seeds and allows the beneficial microbes to multiply. Media Layer □ Media maintains a minimum filtration rate of 5 in/hr over lifetime of facility. An initial filtration rate of 8 to 12 in/hr is recommended to allow for clogging over time; the initial filtration rate should not exceed 12 inches per hour. A filtration rate of at least 5 inches per hour allows soil to drain between events. The initial rate should be higher than long term target rate to account for clogging over time. However an excessively high initial rate can have a negative impact on treatment performance, therefore an upper limit is needed. □ Media is a minimum 18 inches deep, meeting either of these two media specifications: Section F.3 Biofiltration Soil Media (BSM) or specific jurisdictional guidance. A deep media layer provides additional filtration and supports plants with deeper roots. Design Criteria and Considerations BF-1 Biofiltration E-126 July 2018 Design Criteria Intent/Rationale Alternatively, for proprietary designs and custom media mixes not meeting the media specifications, the media meets the pollutant treatment performance criteria in Section F.1. Standard specifications shall be followed. For non-standard or proprietary designs, compliance with F.1 ensures that adequate treatment performance will be provided. □ Media surface area is 3% of contributing area times adjusted runoff factor or greater. Unless demonstrated that the BMP surface area can be smaller than 3%. Greater surface area to tributary area ratios: a) maximizes volume retention as required by the MS4 Permit and b) decrease loading rates per square foot and therefore increase longevity. Adjusted runoff factor is to account for site design BMPs implemented upstream of the BMP (such as rain barrels, impervious area dispersion, etc.). Refer to Appendix B.2 guidance. □ Where receiving waters are impaired or have a TMDL for nutrients, the system is designed with nutrient sensitive media design (see fact sheet BF-2). Potential for pollutant export is partly a function of media composition; media design must minimize potential for export of nutrients, particularly where receiving waters are impaired for nutrients. Filter Course Layer □ A filter course is used to prevent migration of fines through layers of the facility. Filter fabric is not used. Migration of media can cause clogging of the aggregate storage layer void spaces or subgrade. Filter fabric is more likely to clog. □ Filter course is washed and free of fines. Washing aggregate will help eliminate fines that could clog the facility and impede infiltration. □ Filter course calculations assessing suitability for particle migration prevention have been completed. Gradation relationship between layers can evaluate factors (e.g., bridging, permeability, and uniformity) to determine if particle sizing is appropriate or if an intermediate layer is needed. Aggregate Storage Layer □ Class 2 Permeable per Caltrans specification 68- 1.025 is recommended for the storage layer. Washing aggregate will help eliminate fines that could clog the aggregate storage BF-1 Biofiltration E-127 July 2018 Design Criteria Intent/Rationale Washed, open-graded crushed rock may be used, however a 4-6 inch washed pea gravel filter course layer at the top of the crushed rock is required. layer void spaces or subgrade. □ The depth of aggregate provided (12-inch typical) and storage layer configuration is adequate for providing conveyance for underdrain flows to the outlet structure. Proper storage layer configuration and underdrain placement will minimize facility drawdown time. Inflow, Underdrain, and Outflow Structures □ Inflow, underdrains and outflow structures are accessible for inspection and maintenance. Maintenance will prevent clogging and ensure proper operation of the flow control structures. □ Inflow velocities are limited to 3 ft/s or less or use energy dissipation methods. (e.g., riprap, level spreader) for concentrated inflows. High inflow velocities can cause erosion, scour and/or channeling. □ Curb cut inlets are at least 12 inches wide, have a 4-6 inch reveal (drop) and an apron and energy dissipation as needed. Inlets must not restrict flow and apron prevents blockage from vegetation as it grows in. Energy dissipation prevents erosion. □ Underdrain outlet elevation should be a minimum of 3 inches above the bottom elevation of the aggregate storage layer. A minimal separation from subgrade or the liner lessens the risk of fines entering the underdrain and can improve hydraulic performance by allowing perforations to remain unblocked. □ Minimum underdrain diameter is 6 inches. Smaller diameter underdrains are prone to clogging. □ Underdrains are made of slotted, PVC pipe conforming to ASTM D 3034 or equivalent or corrugated, HDPE pipe conforming to AASHTO 252M or equivalent. Slotted underdrains provide greater intake capacity, clog resistant drainage, and reduced entrance velocity into the pipe, thereby reducing the chances of solids migration. □ An underdrain cleanout with a minimum 6-inch diameter and lockable cap is placed every 250 to 300 feet as required based on underdrain length. Properly spaced cleanouts will facilitate underdrain maintenance. □ Overflow is safely conveyed to a downstream storm drain system or discharge point Size overflow structure to pass 100-year peak flow for on-line infiltration basins and water quality Peak flow for off-line basins. Planning for overflow lessens the risk of property damage due to flooding. BF-1 Biofiltration E-128 July 2018 To design biofiltration with underdrain for storm water pollutant control only (no flow control required), the following steps should be taken: 1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio. 2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas. 3. Use the sizing worksheet presented in Appendix B.5 to size biofiltration BMPs. Control of flow rates and/or durations will typically require significant surface ponding and/or aggregate storage volumes, and therefore the following steps should be taken prior to determination of storm water pollutant control design. Pre-development and allowable post-project flow rates and durations should be determined as discussed in Chapter 6 of the manual. 1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slopes, and the recommended media surface area tributary ratio. 2. Iteratively determine the facility footprint area, surface ponding and/or aggregate storage layer depth required to provide detention storage to reduce flow rates and durations to allowable limits. Flow rates and durations can be controlled from detention storage by altering outlet structure orifice size(s) and/or water control levels. Multi-level orifices can be used within an outlet structure to control the full range of flows. 3. If biofiltration with underdrain cannot fully provide the flow rate and duration control required by this manual, an upstream or downstream structure with significant storage volume such as an underground vault can be used to provide remaining controls. 4. After biofiltration with underdrain has been designed to meet flow control requirements, calculations must be completed to verify if storm water pollutant control requirements to treat the DCV have been met. Normal Expected Maintenance. Biofiltration requires routine maintenance to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health; maintain Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only Conceptual Design and Sizing Approach when Storm Water Flow Control is Applicable Maintenance Overview