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HomeMy WebLinkAboutCT 2019-0001; LA COSTA VILLAS NORTH; PRELIMINARY STORM WATER QUALITY MANAGEMENT PLAN; 2021-06-15PRELIMINARY CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR LA COSTA VILLAS NORTH CT 2019-0001 PUD 2019-0001 ENGINEER OF WORK: NAJARS ENGINEERING BASHAR NAJAR, RE78159 772 JAMACHA RD #157 EL CAJON, CA 92019 PREPARED FOR: FAR SAHBA PREMIER REALTY ASSOCIATES 4858 MERCURY STREET SAN DIEGO, CA 92111 858-888-6420 PREPARED BY: NAJARS ENGINEERING BASHAR NAJAR, RE78159 772 JAMACHA RD #157 EL CAJON, CA 92019 619-971-7514 DATE: JULY 24, 2020 REV. DECEMBER 10, 2020 REV. FEBRUARY 25, 2021 REV. JUNE 15, 2021 C TABLE OF CONTENTS Certification Page Project Vicinity Map FORM E-34 Storm Water Standard Questionnaire Site Information FORM E-36 Standard Project Requirement Checklist Summary of PDP Structural BMPs Attachment 1: Backup for PDP Pollutant Control BMPs Attachment 1a: OMA Exhibit Attachment 1 b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1 c: Harvest and Use Feasibility Screening (when applicable) Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable) Attachment 1 e: Pollutant Control BMP Design Worksheets / Calculations Attachment 2: Backup for PDP Hydromodification Control Measures Attachment 2a: Hydromodification Management Exhibit Attachment 2b: Management of Critical Coarse Sediment Yield Areas Attachment 2c: Geomorphic Assessment of Receiving Channels Attachment 2d: Flow Control Facility Design Attachment 3: Structural BMP Maintenance Thresholds and Actions Attachment 4: Single Sheet BMP (SSBMP) Exhibit C C C CERTIFICATION PAGE Project Name: La Costa Villas North Project ID: CT 2019-0001, PUD 2019-0001 I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs for this project, and that I have exercised responsible charge over the design of the project as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the requirements of the BMP Design Manual, which is based on the requirements of SDRWQCB Order No. R9-2013-0001 (MS4 Permit) or the current Order. I have read and understand that the City Engineer has adopted minimum requirements for managing urban runoff, including storm water, from land development activities, as described in the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable source control and site design 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 SWQMP by the City Engineer is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of storm water BMPs for this project, of my responsibilities for project design. ~< PE78159 Exp09/30/2021 BASHAR NAJAR Print Name NAJARS ENGINEERING Company 07/24/2020 Date PROJECT VICINITY MAP C cityof Carlsbad STORM WATER STANDARDS QUESTIONNAIRE Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov E-34 I INSTRUCTIONS: To address post-development pollutants that may be generated from development projects, the city requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual, refer to the Engineering Standards (Volume 5). This questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY DEVELOPMENT PROJECT' (PDP) requirements. Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. If staff determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than initially assessed by you, this will result in the return of the development application as incomplete. In this case, please make the changes to the questionnaire and resubmit to the city. If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, please seek assistance from Land Development Engineering staff. , completed and signed questionnaire must be submitted with each development project application. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. PROJECT INFORMATION PROJECT NAME: La Costa Villas North PROJECT ID: CT2019-0001 ADDRESS: 400 Gibraltar Street Carlsbad, CA APN: 216-300-05-00 The project is (check one): 1K] New Development D Redevelopment The total proposed disturbed area is: 17A95 tt2 < 0.402 ) acres The total proposed newly created and/or replaced impervious area is: 131305 ft2 ( 0.305 ) acres If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the SWQMP # of the larger development project: Project ID SWQMP#: Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. E-34 Page 1 of 4 REV 02/16 STEP1 TO BE COMPLETED FOR ALL PROJECTS ( o determine if your project is a "development project", please answer the following question: YES NO Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building □ IX] or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)? If you answered "yes" to the above question , provide justification below then go to Step 5, mark the third box stating "my project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant information. Justification/discussion: (e.g. the project includes only interior remodels within an existing building): If you answered "no" to the above Question, the project is a 'development project', go to Step 2. STEP2 TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer the following questions: (;s your project LIMITED to one or more of the following: YES NO 1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria: a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non- erodible permeable areas; □ IX] b) Designed and constructed to be hydraulically disconnected from paved streets or roads; c) Designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets quidance? 2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in □ IX] accordance with the USEPA Green Streets guidance? 3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? □ 00 If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark the second box stating "my project is EXEMPT from PDP ... " and complete applicant information. Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with the USEPA Green Street guidance): C ,f you answered "no" to the above Questions, your project is not exempt from PDP, ao to Step 3. E-34 Page 2 of 4 REV 04/17 STEP3 TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS o determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1 )): _, YES NO 1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, IX! □ and public development projects on public or private land. 2. Is your project a redevelopment project creating and/or replacing 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 □ [XI more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public development proiects on public or private land. 3. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and □ [X] refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). 4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a hillside development project? A hillside □ [XI development project includes development on any natural slope that is twenty-five percent or Qreater. 5. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is □ [XI a land area or facility for the temporary parking or storage of motor vehicles used personally for business or for commerce. 6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious street, road, highway, freeway or driveway surface collectively over the entire project □ [XI site? A street, road, highway, freeway or driveway is any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles. 7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more ,I of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? uDischarging Directly to" includes flow that is conveyed overland a distance of □ [X] 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 comminqled with flows from adiacent lands).* 8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface that supports an automotive repair shop? An automotive repair □ IX! shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC) codes: 5013, 5014, 5541, 7532-7534, or 7536-7539. 9. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes □ IX] RGO's that meet the following criteria: (a) 5,000 square feet or more or {b) a project Average Daily Traffic (ADT) of 100 or more vehicles per dav. 10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land □ 00 and are expected to generate pollutants post construction? 11. Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of impervious surface or (2) increases impervious surface on the property by more than 1 0%? (CMC □ [XI 21.203.040) If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ... " and complete applicant information. If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the second box statinq "Mv project is a 'STANDARD PROJECT' ... " and complete applicant information. E-34 Page 3 of 4 REV 04/17 STEP4 TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP) ONLY ()omplete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)): YES NO Does the redevelopment project result in the creation or replacement of impervious surface in an amount of less than 50% of the surface area of the previously existing development? Complete the percent impervious calculation below: Existing impervious area (A)= 0 sq. ft . □ IX! Total proposed newly created or replaced impervious area (B) = 13,305 sq. ft. Percent impervious area created or replaced (B/A)*100 = 100 % If you answered "yes", the structural BMPs required for PDP apply only to the creation or replacement of impervious surface and not the entire development. Go to step 5, check the first box stating "My project is a PDP ... " and complete applicant information. If you answered "no," the structural BM P's required for PDP apply to the entire development. Go to step 5, check the check the first box statinQ "My project is a PDP ... " and complete applicant information. STEPS CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION !XI My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application. □ My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with 'STANDARD PROJECT' stormwater requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project Requirement Checklist Form E-36" and incorporate low impact development strategies throughout my project. Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations nd exhibits to verify if 'STANDARD PROJECT stormwater requirements apply. D My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual. Applicant Information and Signature Box Applicant Name: Bashar Najar Applicant Title: Engineer Nit?~ Applicant Signature: Date: 12/10/2020 .. • Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) 1mpa1red water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; Habitat Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City. Th . B f; C O I IS ox or itv Use nrv YES NO City Concurrence: □ □ By: Date: Project ID: E-34 Page 4 of 4 REV 04/17 SITE INFORMATION CHECKLIST Proiect Summarv Information Project Name La Costa Villas North Project ID CT 2019-0001, PUD 2019-0001 Project Address Gibraltar St Carlsbad, CA 92009 Assessor's Parcel Number(s) (APN(s)) 216-300-05 Project Watershed (Hydrologic Unit) Carlsbad 904.51 Parcel Area 0.402 Acres (17,495 Square Feet) Existing Impervious Area O Acres (0 Square Feet) (subset of Parcel Area) Area to be disturbed by the project 0.402 Acres (17,495 Square Feet) (Project Area) Project Proposed Impervious Area 0.306 Acres (13,305 Square Feet) (subset of Proiect Area) Project Proposed Pervious Area 0.096 Acres (4,190 Square Feet) (subset of Proiect Area) Note: Proposed Impervious Area+ Proposed Pervious Area= Area to be Disturbed by the Project. This mav be less than the Parcel Area. Description of Existing Site Condition and Drainaae Patterns Current Status of the Site (select all that apply): o Existing development 11 Previously graded but not built out o Agricultural or other non-impervious use ~ Vacant, undeveloped/natural Description/ Additional Information: Existing Land Cover Includes (select all that apply): □ Vegetative Cover ~ Non-Vegetated Pervious Areas o Impervious Areas Description/ Additional Information: Underlying Soil belongs to Hydrologic Soil Group (select all that apply): u NRCS Type A D NRCS Type B 0 NRCS Type C [).{NRCS Type D Approximate Depth to Groundwater (GW): D GW Depth < 5 feet D 5 feet < GW Depth < 1 0 feet 11 1 0 feet < GW Depth < 20 feet D<l GW Depth > 20 feet Existing Natural Hydrologic Features (select all that apply): D Watercourses □Seeps 0 Springs n wetlands !Kl None Description/ Additional Information: Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from the site? At a minimum, this description should answer (1) whether existing drainage conveyance is natural or urban; (2) describe existing constructed storm water conveyance systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]: The existing site features complete barren and undeveloped land with no existing storm water infrastructure. A small portion of the neighboring property to the south drains onto the site and water naturally sheet flows north/northeast onto Gibraltar street. Description of Proposed Site Develooment and Drainaae Patterns Project Description / Proposed Land Use and/or Activities: Project site proposes two condominium residential buildings with a total of 9 units. List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): Impervious areas include the building footprint, sidewalks, retaining wall areas, enclosed trash enclosure, and pavers with impermeable liner. List/describe proposed pervious features of the project (e.g., landscape areas): Pervious areas include landscape and natural slope areas between walls. Does the project include grading and changes to site topography? rK!Yes □No Description/ Additional Information: Grading is necessary to accommodate proposed development Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? IX! Yes □No Description/ Additional Information: The site will feature grate inlets and pipes to convey water to low point on northwest Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply): ~ On-site storm drain inlets o Interior floor drains and elevator shaft sump pumps 5a Interior parking garages ~ Need for future indoor & structural pest control P.51 Landscape/Outdoor Pesticide Use o Pools, spas, ponds, decorative fountains, and other water features o Food service ~ Refuse areas o Industrial processes O Outdoor storage of equipment or materials o Vehicle and Equipment Cleaning o Vehicle/Equipment Repair and Maintenance o Fuel Dispensing Areas o Loading Docks ® Fire Sprinkler Test Water oo Miscellaneous Drain or Wash Water ;){I Plazas, sidewalks, and parking lots Identification of Receivina Water Pollutants of Concern Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable): Water discharged from the project site travels approximately 700 feet east along Gibraltar St before leading into a curb inlet located near the intersection of Romera St. Water travels through City drainage path before discharging at Batiquitos Lagoon and the Pacific Ocean. List any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water bodies: 303(d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs Not applicable. Batiquitos HSA not listed on 303(d) list per Final CA 2018 Integrated Report. Identification of Project Site Pollutants Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix B.6): Also a Receiving Not Applicable to Anticipated from the Water Pollutant of Pollutant the Project Site Project Site Concern Sediment X Nutrients X Heavy Metals X Oroanic Compounds X Trash & Debris X Oxygen Demanding X Substances Oil & Grease X Bacteria & Viruses X Pesticides X Hvdromodification Manaaement ReQuirements Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)? IRl Yes, hydromodification management flow control structural BMPs required. D No, the project will discharge runoff directly to existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. □ No, the project will discharge runoff directly to conveyance channels whose bed and bank are concrete-lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. n No, the project will discharge runoff directly to an area identified as appropriate for an exemption by the WMAA for the watershed in which the project resides. Description/ Additional Information (to be provided if a 'No' answer has been selected above): Critical Coarse Sediment Yield Areas* *This Section only reauired if hvdromodification management reQuirements aoolv Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries? □Yes ~ No, No critical coarse sediment yield areas to be protected based on WMAA maps If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual been performed? u 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite D 6.2.2 Downstream Systems Sensitivity to Coarse Sediment □ 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite LJ No optional analyses performed, the project will avoid critical coarse sediment yield areas identified based on WMAA maps If optional analyses were performed, what is the final result? n No critical coarse sediment yield areas to be protected based on verification of GLUs onsite □ Critical coarse sediment yield areas exist but additional analysis has determined that protection is not required. Documentation attached in Attachment 8 of the SWQMP. D Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit. Discussion/ Additional Information: Flow Control for Post-Project Runoff"' lt"fhis Section onlv reauired if hvdromodification manaaement reauirements aoolv List and describe point(s) of compliance (POCs) for flow control for hydromodification management (see Section 6.3.1 ). For each POC, provide a POC identification name or number correlating to the project's HMP Exhibit and a receiving channel identification name or number correlating to the project's HMP Exhibit. A single point of connection for bio-filtration basin. Has a geomorphic assessment been performed for the receiving channel(s)? ~ No, the low flow threshold is 0.1Q2 (default low flow threshold) D Yes, the result is the low flow threshold is 0.1Q2 u Yes, the result is the low flow threshold is 0.3Q2 o Yes, the result is the low flow threshold is 0.5Q2 If a geomorphic assessment has been performed, provide title, date, and preparer: Discussion/ Additional Information: (optional) Other Site Reauirements and Constraints When applicable, list other site requirements or constraints that will influence storm water management design, such as zoning requirements including setbacks and open space, or City codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements. N/A 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. C cityof Carlsbad Project Name: La Costa Villas North Project ID: cr201s-0001 DWG No. or Building Permit No.: STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Project Information Source Control BMPs Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) 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 and/or Appendix E.1 of the Model BMP Design Manual. Discussion/justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. • "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 may be provided. Source Control Requirement Applied? ( ,SC-1 Prevention of Illicit Discharges into the MS4 !!I Yes □No □ N/A Discussion/justification if SC-1 not implemented: SC-2 Storm Drain Stenciling or Signage ll]Yes □ No □ NIA Discussion/justification if SC-2 not implemented: SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind □Yes □No Ill N/A Dispersal Discussion/justification if SC-3 not implemented: Proposed project site consists of new residential units. It is not anticipated that there will be any pollutant driven material stored outdoors. E-36 Page 1 of 4 Revised 09/16 Source Control Reaulrement (continued) Applied? SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and □Yes D No lil N/A Wind Dispersal Discussion/justification if SC-4 not implemented: 1 Proposed project site consists of new residential units. It is not anticipated that there will be any pollutant driven material stored outdoors. SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal □Yes 0 No Iii NIA Discussion/justification if SC-5 not implemented: Proposed project site consists of new residential units. A common trash enclosure area is not part of the development. Each unit will have trash bins for weekly pick up. SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and identify additional BMPs. (See Table in Aooendix E.1 of BMP Manual for Quidance ). ii On-site storm drain inlets Ill Yes 0 No 0 N/A D Interior floor drains and elevator shaft sump pumps □Yes □No lil N/A ltll Interior parking garages ll!IYes 0 No 0 N/A Ill Need for future indoor & structural pest control ~ Yes □No 0 N/A ii Landscape/Outdoor Pesticide Use Ill Yes 0 No 0 N/A -O Pools, spas, ponds, decorative fountains, and other water features □Yes 0 No l!l N/A \. ) D Food service □Yes ONo [j] NIA Iii Refuse areas Iii Yes □No 0 N/A □ Industrial processes □Yes ONo lil N/A □ Outdoor storage of equipment or materials □Yes 0 No lil N/A D Vehicle and Equipment Cleaning □Yes □No [j] N/A □ Vehicle/Equipment Repair and Maintenance □Yes □No [j] N/A D Fuel Dispensing Areas □Yes ONo l!l N/A D Loading Docks □Yes □No Ii N/A Ii] Fire Sprinkler Test Water Iii Yes ONo Ii N/A [j] Miscellaneous Drain or Wash Water Iii Yes ONo 0 N/A ii Plazas, sidewalks, and oarkino lots Ill Yes □No □ N/A For "Yes" answers, identify the additional BMP per Appendix E.1 . Provide justification for "No" answers. All the potential sources of runoff which were selected as N/A are features which will not be a part of the new develoment, and therefore no additional BMP's will be applicable. There are no proposed interior floor drains, elevator shaft pumps, pools, spas or other water features, food service, communal refuse area, industrial processes, outdoor storage, vehicle maintenance/cleaning, vehicle repair/maintenance, fuel dispensing areas, loading docks, fire sprinkler test water or miscellaneous drain/wash water proposed and/or anticipated at the site. See attached Appendix E checklist for more information on all potential sources identified above as yes. "' E-36 Page 2 of 4 Revised 09/16 Site Design BMPs All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information _, to implement site design BMPs shown in this checklist. 1 Answer each category below pursuant to the following. • "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of the Model BMP Design Manual. Discussion / justification is not required. • "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. • "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be provided. Site Design Requirement I Applied? SD-1 Maintain Natural Drainaae Pathwavs and Hvdrologic Features I II Yes I □ No I □ N/A Discussion/justification if SD-1 not implemented: SD-2 Conserve Natural Areas, Soils, and Vegetation I □ Yes I □ No I lll N/A Discussion/justification if SD-2 not implemented: Note: Will be conserved where applicable but no vegetation or natural areas exist on site. c:~ SD-3 Minimize Impervious Area I II Yes I □ No ID N/A Discussion/justification if SD-3 not implemented: Note: Impervious area is minimized to the best extent possible including the implementation of pervious pavers at the drive isle between units. SD-4 Minimize Soil Compaction I lilYes I D No I □ N/A Discussion/justification if SD-4 not implemented: Note: Will be minimized to the best extent possible, but compaction is required for the building pads. SD-5 Impervious Area Dispersion I □Yes I Iii No I □ N/A Discussion/justification if SD-5 not implemented: Project is maximized to greatest extent and does not allow open space for dispersion before entering storm drain system. (} E-36 Page 3 of 4 Revised 09/16 Site Deslan Reaulrement (continued) I ADolled? SD-6 Runoff Collection I Iii Yes I □ No I □ N/A Discussion/justification if SD-6 not implemented: SD-7 Landscaping with Native or Drought Tolerant Species I Ill Yes I □ No I □ N/A Discussion/justification if SD-7 not implemented: SD-8 Harvesting and Using Precipitation I D Yes I III No ION/A Discussion/justification if SD-8 not implemented: Not feasible per form 1-7 E-36 Page 4 of 4 Revised 09/16 Appendix E: BMP Design Fact Sheets If These Sources Will Be on rhe Project Site ... ... Then Your Project Shall Consider These Source Control RMP~ 1 2 Potential Sowces of Permanent Controls-Show on Runoff Pollutants Drawings A. Onsite storm drain -fil' J ,ocations of inlets. inlets □ Not /\pplicabk 3 Permanent Controls-List in Table and Narrative Mark all inlets with the words "No Dumping! Flows to Bay" or similar. E-3 4 Operational BMPs-lnclude in Table and Narrative Maintain and periodicaJJy repaint or replace inlet markings. Provide storm water pollution prevention information to new site owners, lessees, or opernrors. See applicable operational BMPs in Fact Sheet SC-44, "Drainage System Maintenance," in the CASQA Stormwater Quality Handbooks at '\\'\\'\\'.cabmphandbooks.com. Include the following in lease agreements: "Tenanr shall not allow anyone to discharge anything 10 storm drains or tu store or deposit materials so as to create a potential discharge to storm dr-.uns." February 2016 Appendix E: BMP Design Fact Sheets I fThcse Sources \\'ill Be 011 ihc Project Site · · · ... Then Your Project shall consider These Source Control RMPs 1 Potential Sources of Runoff Pollutants D B. l nterior floor drains and elevat0r shaft sump pumps parking future indoor & structural pest control Not /\ licnblc 2 Permanent Controls-Show on Drawings 3 Permanent Controls-List in Table and Narrative Q State that interior floor drains and elevator shaft sump pumps will be plumbed to sanitar)' sewer. ~ Stare th:it parking g:irnge floor drains will be plumbed to the sanitary sewer or an approved BMP Note building design features that discourage entry of pests. E-4 4 Operational BMPs-Include in Table and Narrative D Inspect and maintain drains to prevent blockages and overflow. Inspect and mruntain drains to prevent blockages and overflow. Provide Integrated Pest Management information to owners, lessees, and operators. February 2016 Appendix E: BMP Design Fact Sheets lfThcsc Sourl·cs Will lk 011 the Projn:t Site ·· · ... Then Your Proj,·et shall consider Thc:sc So urn: Control R\f Ps 1 Potential Sow ces of Runoff Pollutants D2. Landscape/ Outdoor Pesticide Use □ Noc Appticahle 2 Pennanent Controls-Show on Drawings □ Show locations of existing trees or areas of shn1bs and ground cover to be undisturbed and retained. Show self-retaining landscape areas, if any. Show storm water treatment facilities. 3 Pennanent Controls-List in Table and Narrative State that final landscape pllllls will nccomplish all of the follo\\~ng. .fil' Preserve existing drought w leram trees, shrubs, and ground cover to the ma.ximum extent possible. Design landscapin~ co minimize irrigation and runoff, to promote surface infiltration where appropriate, and to minimize the use of fertilizers and pesticides that can contribute to storm water pollution. ¥ W'hcrc landscaped areas arc used ro retain or detain storm water, specify planes that n.re tolerant of periodic saturated soil conditions. Consider using pest-resistant plants, especially adjacent to hardscape. ~ To ensure successful establishment, select plants appropriate ro site soils, slopes, climate, sun, wind, rain, land use, air movement, ecological consistency, and plant interactions. E-5 4 Operational BMPs-lnclude in Table and N arrative Maintain landscaping using minimum or no pesticides. See applicable operational BMPs in Fact Sheet SC-41, ''Building and Grounds Maintenance," in the CASQA Stormwater Quality Handbooks at W'\\'\\'.cabmphanclbooks.com. Provide IPJ\1 information to new owners, lessees and operators. February 2016 Appendix E: BMP Design Fact Sheets If These Sources \'fill Be . I r, • s· ... 1"11<.-n Your Project shall consider Thcst' Sourn· Control Bl\lPs on I IC fOJt.'CI It~• .•• 1 Potential Sources of Runoff Pollutants ~ P. Plazas, sidewalks, nnd parking lots. □ Not 1\pplicable 2 Permanent Controls-Show on Drawings 3 Permanent Controls-List in Table and Narrative E-14 4 Operational BMPs-Include in Table and Narrative ~ Plazas, side'\\'alks, and parking lots shall be swept regularly to prevent the accumulation of litter and debris. Debris frum pressure washing shall be collected to prevent entry into the storm drain system. Washw'llter containing any cleaning agent or degreaser shall be collected and discharged ro the sanirary sewer and not discharged to a storm clrnin. February 2016 SUMMARY OF PDP STRUCTURAL BMPS PDP Structural BMPs All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s). PDP 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 to certify construction of the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the BMP Design Manual). Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet for each structural BMP within the project (copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP). Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated together or separate. Based on the infeasibility to naturally drain and the availability of open space at the low point of the site, a bio-filtration is most feasible for hydromodification and pollutant control. [Continue on next page as necessary.] Structural BMP Summary Information [Copy this page as needed to provide information for each individual proposed structural BMP] Structural BMP ID No. DWG CT 2019-0001, PUD 2019-0001 Sheet No. 2 Type of structural BMP: o Retention by harvest and use (HU-1) n Retention by infiltration basin (INF-1) o Retention by bioretention (INF-2) o Retention by permeable pavement (INF-3) o Partial retention by biofiltration with partial retention (PR-1) ~ Biofiltration (BF-1) o Flow-thru treatment control included as pre-treatmenVforebay 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) LJ Detention pond or vault for hydromodification management o Other (describe in discussion section below) Purpose: o Pollutant control only D Hydromodification control only ll() Combined pollutant control and hydromodification control .J Pre-treatment/forebay for another structural BMP o Other (describe in discussion section below) Discussion (as needed): Due to site and design constraints regarding maximum allowable wall heights at the property frontage setbacks, the Biofiltration basin located at the northeast corner of the project limits has been redesigned as a "two tier" system (BMP lA and BMP 1B), which captures runoff from two DMA's (DMA 1 and DMA 2). BMP lA is designed to capture and treat runoff from DMA 1. BMP 1B is designed to capture and treat runoff from DMA 2. Treated runoff volume from BMP lA and BMP 1B is collected and routed via 6" perforated pipe system which runs through the bottom 18" gravel layer, towards final curb outlet at the City of Carlsbad ROW. ATTACHMENT 1 BACKUP FOR PDP POLLUTANT CONTROL BMPS This is the cover sheet for Attachment 1. Check which Items are Included behind this cover sheet: Attachment Contents Checklist Seauence Attachment 1 a DMA Exhibit (Required) Attachment 1 b Attachment 1 c Attachment 1 d See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24"x36" Exhibit typically required) Tabular Summary of DMAs Showing DMA ID matching DMA Exhibit, OMA Area, and OMA Type (Required)* *Provide table in this Attachment OR on OMA Exhibit in Attachment 1 a Form 1-7, Harvest and Use Feasibility Screening Checklist (Required unless the entire project will use infiltration BMPs) Refer to Appendix B.3-1 of the BMP Design Manual to complete Form 1-7. Form 1-8, Categorization of Infiltration Feasibility Condition (Required unless the project will use harvest and use BMPs) Refer to Appendices C and D of the BMP Design Manual to complete Form 1-8. !Kl Included ~ Included on OMA Exhibit in Attachment 1 a u Included as Attachment 1 b, separate from DMA Exhibit oo Included LJ Not included because the entire project will use infiltration BMPs ~ Included n Not included because the entire project will use harvest and use BMPs Attachment 1 e Pollutant Control BMP Design Kl Included Worksheets / Calculations (Required) Refer to Appendices B and E of the BMP Design Manual for structural pollutant control BMP design guidelines C Use this checklist to ensure the required information has been included on the OMA Exhibit: The DMA Exhibit must identify: D{] Underlying hydrologic soil group D{] Approximate depth to groundwater ~, Existing natural hydrologic features (watercourses, seeps, springs, wetlands) ~: Critical coarse sediment yield areas to be protected (if present) P{] Existing topography and impervious areas ~ Existing and proposed site drainage network and connections to drainage offsite ~ Proposed grading ~ Proposed impervious features ~J Proposed design features and surface treatments used to minimize imperviousness P<1 Drainage management area (OMA) boundaries, DMA ID numbers, and OMA areas (square footage or acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating) ~ Structural BMPs (identify location and type of BMP) Attachment 1 a ! ___ J ' L _______ _ I N 68°34'07" E 100.00 ' ' ' LC, ~· ~ ' ' Lu .. N ~: "1) ' in N • ~ N : :,,: rn § (Jl ' - , 'l, '.c,,-{P0C-1 )' GIBRALTAR STREET • ·,, '" -----------------------, -------------------------· -------------, J ' r r c;--"", .r.:--- i \1 ! : t', I r.:-___ t ':o.. __ _ NAJARs ENGINEERING, INC. 772 JAMA:CHA RD Q157, E:.. CA..!ON, CA 92019 PHONE (519) 971-?SH EMAIL: SG~AJAR@GMAl!..COM ' 0 "' \ ' 1 20' -:J ~ SCALE: 1''= 20' 40' I I I L / ' / / ! ·--J / , / / I PROPOSED rBL:>G. VA.RIES- ► 6" SUB BASE COURSE 1/2" CLEAN 'RACTURED 0 PEN-G?.ADED lr2 ,1\GGREGA TE SUIDUNG i=OOTING?ER :;fiA!L 9 1------------~·-- ', ' ' \ ' ', ' OMA EXHIBIT 400 GIBR'AL TAR STREET OMA 1 OMA 2 TOTAL ....-----~..-----, ---------\ CARLSBAD, CA GEN::RAL INFORM/1.TICN LEGEND: • UNDERL 'rlNG HYJJROLOGIC SOil GROLIP = SOIL TYPE D • • • • • NO EXISTING NATURA:. HYDROLOGIC FEATURES LOCATED WITHIN IMPACT AREA OF PROJECT SlTE (WETLANDS MAP PROVIDED IN SWQMP) PER WMAA MAPPING. NC CCSYA AT PROJECT SITE APPROXIMATE DEPTfl TO GRQIJNDWA TER = >20' THE AREA LABELED (OMA 1) FLOWS TOWARDS THE TOP TIER DF THE INALTRA"llON BASIN, LABELED BMP 1 A THE AREA LABELED (DMA 2) FLOWS TOWARDS THE BOTTOM TIER OF THE INFILTRATION BASIN, LABELED BMP 18 IMPERVIOUS AREA 13,305 SF 0.305 AC DM,t,. SUMMARY TABLE TOTAL AREA PERVIOUS (SF) (SF /AC) 8,414 / 0.193 3,254 9,os, / 0.20s 551 14,495 / 0.401 3,805 IMPERVIOUS (SF) BMP SIZE (SF) 5,004 8,301 13,305 156 ✓ 229 / 385 ✓ PERPENDi'CiJLAR ~ WALL EDGE OVERFLOW WEIR -i 7 1 T•·. ,,.--...,.0' ~ . "' BMP TYPE 8I0-FIL TRA TlON BASIN (BMP 1A) BIO-FIL TRA TlON BASIN (BMP 18) f'=-~7=• . , 1;'1 ! ,..= -l:a'.::..G I . . --I. • • ---.0. /0: ..r--. iSP:.--<-' OVERFLOW SECTIO_N,.__.JPJ\/'->~ RAILING PER LANDSCAPE PLANES • r I L ------------8.7' BASIN--t----------1 .~ .. BAS:: COURSE· 3/4'. WASHED -----FRACTURED OPEN-GRA:iED STOt>CE .i,t57 .A,GGREGATE 2" SEDJING CO~'RSE-1/4" -3/8" -----WASHED F,ACTURED O?EN-GRA:,ED STONE tr89 AGGREGAT:: PINE HALL BRICK RAJNPAVE/.STO.:;,>,~ .. tPAVE OR EOU'AL21/.t" ,•~-tlN, VAi<'IES ◄ fi S .~. GGREGFJE iN OP::NINGS-'tA'AShED ,,,r-,. rn· MIN -----6"' PERfOl~.A.TED DRAIN UN:: W/ UJN. 2% SLOPE UO DETENTIOhc BASIS 1-~✓iPERME/~5LE LNER 14 -"T"""-/M!N 30-l.-t.lL YCPE OR PV::::l C'F-OFF WAL. PER PLANS ~ DRIVEWAY f ! I RAILING PER LANDSCAPE PLANES 7 PROP RETAIN!NG WALL ----1 H=.3.5-fT • CITY ROW----1 CURB OUTLET . • • • 1.67' 2' FREEBOARD i2" TO TG '''ll •'•, ·•., . ', • / 24"x24" BROO S BOX CATCH BA IN CD PERVIOUS PAVERS (PVT) EB BIOFIL TRA TION BASIN SCALE: N. T.S. SCALE: N. I.S. -·--·,---- - OMA 9081 0.208 ···--- ' 1.0' PLANTER 2 SF AC -- 4.0' SIDEWALK - / PRQR l'<ft:TAlNING WALL H=3.5-':.Fl,.IIIAX 7 I J Attachment 1 c Appendix I: Forms and Checklists Harvest and Use Feasibility Checklist Form 1-7 l. ls there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season? IKl Toilet and urinal flushing 1K] Landscape irrigation D Other: _____ _ 2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section B.3.2. fProvide a summary of calculations here] (2.7 X 6) X ((700 X .2) / 0.90) + 0) X 0.015 = 36.4 3. Calculate the DCV using worksheet B.2-1. DCV = 237+ 370=607 __ (cubic feet) 3a. Ts the 36 hour demand greater than or e,1ual to the DCV? r Yes / Y(INo c::> -0. Harvest and use appears to be feasible. Conduct more detailed evaluation and sizing calculations to confirm that DCV can be used at an adequate rate to meet drawdown criteria. 36. Is the 36 hour demand greater than 0.25DCV but less than the full DCV? 7 Yes / I{] No c:::> JJ. Harvest and use may be feasible. Conduct more detailed evaluation and sizing calculations to determine feasibility. Harvest and use may only be able to be used for a portion of the site, or (optionally) the storage may need to be upsized to meet long term capture targets while draining in longer than 36 hours. Is harvest and use feasible based on further evaluation? 7 Yes, refer to Appendix E to select and size harvest and use BMPs. ~ No, select alternate BMPs. 1-2 3c. Ts the 36 hour demand less than 0.25DCV? ~ Yes ~ Harvest and use is considered to be infeasible. February 2016 Attachment 1 d Appendix I: Forms and Checklists Categorization of Infiltration Feasibility Form 1-8 Condition Part J -Full lpfiltration feaeibilicy: Screening Criteria Would infiJtration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria Screening Question Is the es timated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Q uestion shall be based on a comprehensive eYaluation of the factors presented in Appendix C:.2 and Appendix D. Provide basis: Refer to geotechnical report, Project No. Gl-18-12-158. Yes No X 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? T he response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appenclix C.2. Provide basis: Not applicable. No infiltration. Summarize findings of studies; provide reference tO studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. I-3 February 2016 Appendix I: Forms and Checklists Criteri a 3 ----Form 1-8 Page 2 of 4 Screening Question 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? 1he response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Not applicable. No infiltration. Yes No Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 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 shall be based on a comprehensive evaluation of the factors presented in Appendi." C.3. Provide basis: Not applicable. No infiltration. Summarize findings of studies; provide reference to studies, calculations, maps, dala sources, etc. Provide narrative discussion of study/ data source applicability. Part 1 Result * ff all answers to rows 1 -4 arc "Yes" a full infiltration design is potentially feasible. "The feasibility screening category is Full lo.filtration 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 NO ,tc"fo be completed us1ng gathered site informatJon and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or studies mar be required by the City to substantiate findings. I-4 February 2016 Appendix I: Forms and Checklists Form 1-8 Page 3 of 4 Part 2 -Partial Infilttation vs, No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be rca.onably mitigated? Criteria 5 Screening Question Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Refer to geotechnical report, Project No. Gl-18-12-158. Yes No X 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. 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 shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: Not applicable. No infiltration. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why ir was not feasible to mitigate low infiltration rates. 1-5 February 2016 Appendix I: Forms and Checklists Criteria 7 Form 1-8 Page 4 of 4 Screening Question 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 shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Not applicable. No infiltration. Yes No Summari.ze findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was nut fea~ible tu mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Not applicable. No infiltration. 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* 1f all answers from row 5-8 arc 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. :ikTo be completed using gathered site mformatton and best professional Judgment considering the definition of ~IEP in the MS4 Permit. Additional testing and/ or srudies may be required by the City to substantiate findings. February 2016 Attachment 1 e C DMAl Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B.1 DCV DCV is defined as the volume of storm water runoff resulting from the 85th percentile, 24-hr storm event. The following hydrologic method shall be used to calculate the DCV: Where: DCV = C x d X AX 43,560 sf /ac X 1/12 ft/in DCV = 3,630 x C x d x A DCV = Design Capture Volume in cubic feet C = Runoff factor (unitless); refer to section B.1.1 d = 85'h percentile, 24-hr storm event rainfall depth (inches), refer to section B.1.3 r\ = Tributary area (acres) which includes the total area draining to the BMP, including any offsite or onsite areas that comingles with project runoff and drains to the BMP. Refer to Section 3.3.3 for additional guidance. Street redevelopment projects consult Section 1.4.2. B.1.1 Runoff Factor Estimate the area weighted runoff factor for the tributary area to the BMP using runoff factor (from Table B.1-1) and area of each surface type in the tributary area and the following equation: Where: C. = Runoff factor for area X A,= Tributary area X (acres) LCxAx C= LAx These nmoff factors apply to areas receiving direct rainfall only. For conditions in which runoff is ro uted onto a surface from an adjacent surface, see Section B.2 for determining composite runoff factors for these areas. Table B.1-1: Runoff factors for surfaces draining to BMPs -Pollutant Control BMPs Surface Runoff Factor Roofs' 0.90 Concrete or Asphalt' 0.90 Unit Pavers (!!touted)' 0.90 Decomposed Granite 0.30 Cobbles or Crushed A12:llte12"ate 0.30 Amended, Mulched Soils or Landscape 0.10 Compacted Soil (e.g., unpaved parking) 0.30 S11rfo.-,-is rnf'lsidered impervious and could benefit from use of Site Design BMPs and Roofs/Concrete/Unit Pavers = 5004 sf the runoff factor per Section B.2.1. Amended Soils/Landscape= 3410 sf Total Area= 8414 sf B-2 ((5004 X 0.90) + (3410 X 0.10)) / 8414 = 0.576 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Surface Runoff Factor Natural (A Soil) 0.10 Natura] (B Soil) 0.14 Natural (C Soil) 0.23 Natural (D Soil) 0.30 B.1.2 Offline BMPs Diversion flow rates for offline BMPs shall be sized to convey the maximum flow rate of runoff produced from a rainfall intensity of 0.2 inch of rainfall per hour, for each hour of every storm event. The following hydrologic method shall be used to calculate the diversion flow rate for off-line BMPs: Where: Q=CxixA Q = Diversion flow rate in cubic feet per second C = Runoff factor, area weighted estimate using Table B.1-1 i = Rainfall intensity of 0.2 in/hr A = Tributary area (acres) which includes the total area draining to the BMP, including any offsite or onsite areas that comingle with project runoff and drain to the BMP. Refer to Section 3.3.3 for additional guidance. Street redevelopment projects also consult Section 1.4.2. B.1.3 85th Percentile, 24-Hour Storm Event The 85th percentile, 24-hour isopluvial map is provided as Figure B.1 -1. The rainfall depth to estimate the DCV shall be determined using Figure B.1 -1. The methodology used to develop this map is presented below: B.1.3.1 Gage data and calculation of 85th percentile The method of calculating the 85th percentile is to produce a list of values, order them from smallest to largest, and then pick the value that is 85 percent of the way through the list. Only values that are capable of producing run off arc of interest for this purpose. Lacking a legislative definition of rainfall values capable of producing runoff, Flood Control staff in San Diego County have observed that the point at which significant runoff begins is rather subjective, and is affected by land use type and soil moisture. In highly-urbanized areas, the soil has a high impermeability and runoff can begin with as little as 0.02" of rainfall. In rural areas, soil impermeability is significantly lower and even 0.30" of rain on dry soil will frequently not produce significant runoff. For this reason, San Diego County has chosen to use the more objective method of including aU non-zero 24-hour rainfall totals when calculating the 85th percentile. To produce a statistically significant number, only stations with 30 years or greater of daily rainfall records are used. B-3 February 2016 C Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B.1.3.2 Mapping the gage data A collection of 56 precipitation gage points was developed with 85th percentile precipitation values based on multiple years of gage data. A raster surface (grid of cells with values) was interpolated from that set of points. The surface initially did not cover the County's entire jurisdiction. A total of 13 dummy points were added. Most of those were just outside the County boundary to enable the software to generate a surface that covered the entire County. A handful of points were added to enforce a plausible surface. In particular, one point was added in the desert east of Julian, to enforce a gradient from high precipitation in the mountains to low precipitation in the desert. Three points were added near the northern boundary of the County to adjust the surface to reflect the effect of elevation in areas lacking sufficient operating gages. Several methods of interpolation were considered. The method chosen is named by Environmental Systems Research Institute as the Natural Neighbor technique. This method produces a surface that is highly empirical, with the value of the surface being a product of the values of the data points nearest each cell. It does not produce peaks or valleys of surface based on larger area trends, and is free of artifacts that appeared with other methods. B-4 February 2016 San Diego County 85 th Percentile lsopluvials Legend -e5CII PERCUITILE ISOPt.lMAl D INCORPORATED CITY NOTE TM 85Ch pe,centrie ii a 2• hour rainfall Iota! It represema a valle such mat 85'4 cl the observed 24 hour rainf•• 10tats Wll be IHs thenthatvaloe N + ~-0 I l • I 4 '"9-C,,,·•'11-.ii-1.t-, ..,•-•••..,.~•-·, ,.,. .. ,, l ..._,. _.,,.;>-·--•~ ,,_...,..,111,,, ,.,,. '°''h• Q ""l _,,_ ,,_,.,,.,,;;11>-'"-•r-•••"i• ~,.-... ,. .• "' ,.. ~;;,111"~···-.......... -.............. ~ ~.,,,.,._._ -· -~ ....,__.,., _,..,., __ _ .:,.:;--::::!:'.;;w~;•;.."'.;'.,.~~-~~ ;;~~=-v..::..•.;::::! :.."..,-.:;. ~~~":"."':---"' ..... "_,_,,._ .. ;;:..;:-..:--.::.;.:..,;.,..:··~-:-=-~-·~ .... <#~--..... ~-·~ .. .,,~ ... _ _. • ., ... , ... ~ .......... l/F'" , . :.... ..... Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Figure B.1-1: 85th Percentile 24-hour Isopluvial Map B-5 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods 8 .2 Adjustments to Account for Site Design BMPs This section provides methods to adjust the DCV (for sizing pollutant control BMPs) as a result of implementing site design BMPs. The adjustments are provided by one of the following two methods: • Adjustment to impervious runoff factor • Adjustment to DCV B.2.1 Adjustment to Impervious Runoff Factor When one of the following site design BMPs is implemented the runoff factor of 0.9 for impervious surfaces identified in Table B.1-1 should be adjusted using the factors listed below and an adjusted area weighted runoff factor shall be estimated following guidance from Section B.1.1 and used to calculate the DCV. • SD-5 Disperse Runoff from impervious area • SD-6A Green roofs • SD-6B Permeable pavement B.2.1.1 Disperse Runoff from Impervious Area (SD-5) Dispersion of impervious areas through pervious areas: The fo!Jowing adjustments are allowed to impervious runoff factors when dispersion is implemented in accordance with the SD-5 fact sheet (Appendix E.3). Adjustments are only credited up to a 4:1 ma.xi.mum ratio of impervious to pervious areas. In order to adjust the runoff factor, the pervious area shall have a minimum width of 10 feet and a maximum slope of 5%. Based on the ratio of impervious area to pervious area and the hydrologic soil group of the pervious area, the adjustment factor from Table B.2-1 shall be multiplied with the unadjusted runoff factor (Table B.1-1) of the impervious area to estimate the adjusted runoff factor for sizing pollutant control BMPs. The adjustment factors in Table B.2-1 are ruJh valid for impervious surfaces that have an unadjusted runoff factor of 0.9. Table B.2-1: Impervious area adjustment factors that accounts for dispersion Pcrvious area Ratio= Impervious arca/Pcrvious arcn hydrologic soil i group <=1 I 2 3 4 A 0.00 0.00 0.23 0.36 B 0.00 0.27 0.42 0.53 C 0.34 0.56 0.67 0.74 D 0.86 0.93 0.97 1.00 B-6 February 2016 C Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Continuous simulation modeling in accordance with Appendix G is required to develop adjustment factors for surfaces that have an unadjusted runoff factor less than 0.9. Approval of adjustment factors for surfaces that have an unadjusted runoff factor less than 0.9 is at the discretion of the City Engineer. The adjustment factors in Table B.2-1 were developed by performing continuous simulations in SWMM with default parameters from Appendix G and impervious to pervious area ratios of 1, 2, 3, and 4. When using adjustment factors from Table B.2-1: • Linear interpolation shall be performed if the impervious to pervious area ratio of the site is in between one of ratios for which an adjustment factor was developed; • Use adjustment factor for a ratio of 1 when the impervious to pervious area ratio is less than 1;and • Adjustment factor is not allowed when the impervious to pervious area ratio is greater than 4, when the pervious area is designed as a site design BMP. Example B.2-1: DMA is comprised of one acre of impervious area that drains to a 0.4 acre hydrologic soil group B pervious area and then the pervious area drains to a BMP. Impervious area dispersion is implemented in the DMA in accordance with SD-5 factsheet. Estimate the adjusted runoff factor for theDMA. • Baseline Runoff Factor per Table B.1-1 = [(1 *0.9+0.4*0.14)/1.4] = 0.68. • Impervious to Pervious Ratio = 1 acre impervious area/ 0.4 acre pervious area = 2.5; since the ratio is 2.5 adjustment can be claimed. • from Table B.2-1 the adjustment factor for hydrologic soil group B and a ratio of 2 = 0.27; ratio of 3 = 0.42. • Linear interpolated adjustment factor for a ratio of 2.5 = 0.27 + {f(0.42 -0.27)/(3-2)1*(2.5-2)} = 0.345. • Adjusted runoff factor for the DlVIA = [(1*0.9*0.345+0.4*0.14)/1.4] = 0.26. • Note only the runoff factor for impervious area is adjusted, there is no change made to the pervious area. B.2.1.2 Green Roofs When green roofs are implemented in accordance with the SD-6A fact sheet (Appendix E.4) the green roof footprint shall be assigned a runoff factor of 0.10 for adjusted runoff factor calculations. B.2.1.3 Permeable Pavement When a permeable pavement is implemented in accordance with the SD-6B fact sheet (Appendix E.5) and it does not have an impermeable liner and has storage greater than the 85th percentile depth below the underdrain, if an underdrain is present, then the footprint of the permeable pavement shall be assigned a runoff factor of 0.10 for adjusted runoff factor calculations. B-7 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Permeable Pavement can also be designed as a structural BMP to treat nm on from adjacent areas. Refer to INF-3 factsheet and Appendix B.4 for additional guidance. B.2.2 Adjustment to DCV When the following site design BMPs are implemented the anticipated volume reduction from these BMPs shalJ be deducted from the DCV to estimate the volume for which the downstream structural BMP should be sized for: • SD-1: Tree welJs • SD-8 Rain barrels B.2.2.1 Tree Wells Tree wells credit volume from tree trenches or boxes (tree BMPs) is a sum of three runoff reduction volumes provided by trees that decrease the required DCV for a tributary area. The following reduction in DCV is allowed per tree based on the mature diameter of the tree canopy, when trees are implemented in accordance with SD-1 fact sheet (Appendix E.2): Mature Tree Canopy Tree Credit Volume (ft1/trcc) Diameter (ft) 5 10 10 40 15 100 20 180 25 290 30 420 Basis for the reduction in DCV: Tree credit volume was estimated based on typical characteristics of tree wells as follows: lt is assumed that each tree and associated trench or box is considered a single BMP, with calculations based on the media storage volume and/ or the individual tree within the tree BMP as appropriate. Tree credit volume is calculated as: B-8 February 2016 C Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods rev= TIV + TCIV + TETV Where: • TCV = Tree credit volume (fr') • nr ·· = Total infiltration volume of all storage layers within tree BMPs (ft3) • TCIV = Total canopy interception volume of all individual trees within tree BMPs (ft') • TETV = Total evapotranspiration volume, sums the media evapotranspiration storage within each tree BMP (ft') Total infiltration volume was calculated as the total volume infiltrated within the BMP storage layers. Infiltration volume was assumed to be 20% of the total BMP storage layer volume, the available pore space in the soil volume (porosity-field capacity). Total canopy interception volume was calculated for all tree wells within the tributary area as the average interception capacity for the entire mature tree total canopy projection area. Interception capacity was determined to be 0.04 inches for all street tree sizes, an average from the findings published by Breuer et al (2003) for coniferous and deciduous trees. Total evapotranspiration volume is the available evapotranspiration storage volume (field capacity -wilting point) within the BMP storage layer media. TE1V is assumed to be 10% of the minimum soil volume. The minimum soil volume as required by SD-1 fact sheet of 2 cubic feet per unit canopy projection area was assumed for estimating reduction in DCV. B.2.2.2 Rain Barrels Rain barrels are containers that can capture rooftop runoff and store it for future use. Credit can be taken for the full rain barrel volume when each barrel volume is smaller than 100 gallons, implemented per SD-8 fact sheet (Appendix E.6) and meet the following criteria: • Total rain barrel volume is less than 0.25 DCV and • Landscape areas arc greater than 30 percent of the project footprint. Credit for harvest and use systems that do not meet the above criteria shall be based on the criteria in Appendix B.3 and HU-1 fact sheet (Appendix E.7). B-9 February 2016 1 2 3 4 5 6 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV Design Capture Volume Worksheet B-2.1 85th percentile 24-hr storm depth from Figure B.1-1 d= 0.588 inches Area tributary to BMP (s) A= 0.193 acres Area weighted runoff factor (estimate using Appendix 0.576 B.1.1 and B.2.1) C= unitless Tree wells volume reduction TCV= 0 cubic-feet Rain barrels volume reduction RCV= 0 cubic-feet Calculate DCV = (3630 x C x d x A) -TCV -RCV DCY= 237 cubic-feet B-10 February 2016 Appendix B: Storm Water Pollutant Control H ydrologic Calc ulations and Sizing Methods Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs Rem:uning DCV after implementing retention BMPs Partial Retention 2 Infiltration rate from Form I-9 if partial infiltration is feasible 3 Allowable drawdown time for ag,s;regate storage below the tinderdrain 4 Depth of runoff that can be infiltrated [Line 2 x Line 3j 5 Aggregate pore space 6 Required depth of gravel below the underdrain [Line 4/ Line SJ 7 Assumed surface area of the biofiltration BMP 8 Media retained pore storage 9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)]/12] x Linc 7 10 DCV that requires biofiltration [Line 1 -Line 9] BMP Parameters 11 Surface Ponding [6 inch minimum, 12 inch maximum] 12 ?-.lcdia Thickness 118 inches minimum], also add mulch layer thickness to this line for sizing calculations 13 Aggregate Storage above underdrain invert (12 inches typical) -use 0 inches for sizing if the aggregate is not over the entire bottom surface area 14 Media available pore space 15 .Media filtration rate to be used for sizing (5 in/hr. with no outlet control; if the filtration is controlled b}' the outlet, use the outlet controlled rate) Baseline Calculations 16 Allowable Routing Time for sizing 17 Depth filtered during storm [ Line 15 x Linc 16] 18 Depth of Detention Storage [Une 11 + (Line 12 x Line 14) + (Line 13 x Line 5)1 19 Total Depth Treated [Line 17 + Line 18] Option 1 -Biofilter 1.5 times the DCV 20 Required biofiltcrccl volume 11 .5 x Linc 1 0j 21 Required Footprint [Line 20/ Linc 19] x 12 Option 2 -Store 0.75 of remaining DCV in pores and ponding 22 Required Storage (surface+ pores) Volume [0.75 x Line 10] 23 Required Footprint [Une 22/ Une 18] x 12 Footprint of the BMP 24 Area draining to the BMP 25 Adjusted Runoff Factor for drainage area (Refer to Appendix 8 .1 and B.2) 26 Minimum 13MP Footprint [Linc 24 x Linc 25 x 0.03] 27 Footprint of the BMP = Ma.ximum(Minimum(Linc 21, Llne 23), Llne 26) 0 in/hr. 36 hours 0 inches 0.40 in/in 0 inches 155 sq-ft 0.1 in/in 27.125 cubic-feet 2 I 0.1810508 cubic-feet 12 ,,-inches 21 / inches inches 12 ✓ 0.2 in/in 5 in/hr. 6 hours 30 inches inches 21 5 1 inches 315.2715762 cubic-feet 74.18154733 sq-ft 157 .6357881 cubic-feet 90.07759319 sq-ft 8414 sq-ft 0.575588305 145.29 sq-ft 145 sq-ft Note: fjnc 7 is used to estimate the amount ofvo]umc retained by the B~JP. Upd:ttc assumed surfa~ca in Linc 7 until its c9uivalent to the rc9uircd biofilttation footprint (either Linc 21 or Llnc 23) I OMA 1 flows to BMP 1A which Is sized at 156 sf > 145 sf B-26 February 2016 DMA2 C Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B.1 DCV DCV is defined as the volume of storm water runoff resuJting &om the 85th percentile, 24-hr storm event. The following hydrologic method shall be used to calcuJate the DCV: Where: DCV = C x d X AX 43,560 sf /ac x 1/12 ft/in DCV = 3,630 X C x d x A DCV = Design Capture Volume in cubic feet C = Runoff factor (unitless); refer to section 13.1.1 d = 85th percentile, 24-hr storm event rainfall depth (inches), refer to section B.1.3 A = Tributary area (acres) which includes the total area draining to the BMP, including any offsite or onsite areas that comingles with project runoff and drains to the BMP. Refer to Section 3.3.3 for additional guidance. Street redevelopment projects consult Section 1.4.2. B.1.1 Runoff Factor Estimate the area weighted runoff factor for the tributary area to the BMP using runoff factor (from Table B.1 -1) and area of each surface type in tl1e tributary area and the following equation: Where: C. = Runoff factor for area X A,= Tributary area X (acres) l:CxAx C = l:Ax These runoff factors apply to areas receiving direct rainfall only. For conditions in which runoff is routed onto a surface from an adjacent surface, see Section B.2 for determining composite runoff factors for these areas. Table B.1-1: Runoff factors for surfaces draining to BMPs -Pollutant Control BMPs Surface Runoff Factor Roofs1 0.90 Concrete or Asphalt1 0.90 Unit Pavers ({l!outed)1 0.90 Decomposed Granite 0.30 Cobbles or Crushed A!:!"{l!eQ"ate 0.30 Amended, Mulched Soils or Landscape 0.10 Compacted Soil (e.g., unpaved parkin{l) 0.30 S11~forr i~ rnnsidercd impervious and could benefit from use of Site Design BMPs and Roofs/Concrete/Unit Pave rs = 8301 sf rhe runoff factor per Section B.2.1. Amended Soils/Landscape= 780 sf Total Area= 9081 sf B-2 February 2016 {(8301 X 0.90) + (780 X 0.10)} / 9081 = 0.831 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Surface Runoff Factor Natural (A Soil) 0.10 Natural (B Soil) 0.14 Natural (C Soil) 0.23 Natural (D Soil) 0.30 B.1.2 Offline BMPs Diversion flow rates for offline BMPs shall be sized to convey the maximum flow rate of runoff produced from a rainfall intensity of 0.2 inch of rainfall per hour, for each hour of every storm event. The following hydrologic method shall be used to calculate the diversion flow rate for off-line BMPs: Where: Q=CxixA Q = Diversion flow rate in cubic feet per second C = Runoff factor, area weighted estimate using Table B.1-1 i = Rainfall intensity of 0.2 in/hr A = Tributary area (acres) which includes the total area draining to the BMP, including any offsite or onsite areas that comingle with project runoff and drain to the BMP. Refer to Section 3.3.3 for additional guidance. Street redevelopment projects also consult Section 1.4.2. B.1.3 85th Percentile, 24-Hour Storm Event The 85th percentile, 24-hour isopluvial map is provided as Figure B.1-1 . The rainfall depth to estimate the DCV shall be determined using Figure B.1-1 . The methodology used to develop this map is presented below: B.1.3.1 Gage data and calculation of 85th percentile The method of calculating the 85th percentile is to produce a list of values, order them from smallest to largest, and then pick the value that is 85 percent of the way through the list. Only values that are capable of producing run off arc of interest for this purpose. Lacking a legislative definition of rainfall values capable of producing runoff, Flood Control staff in San Diego County have observed that the point at which significant runoff begins is rather subjective, and is affected by land use type and soil moisture. In highly-urbanized areas, the soil has a high impermeability and runoff can begin with as little as 0.02" of rainfall. In rural areas, soil impermeability is significantly lower and even 0.30" of rain on dry soil will frequently not produce significant runoff. For this reason, San Diego County has chosen to use the more objective method of including all non-zero 24-hour rainfall totals when calculating the 85th percentile. To produce a statistically significant number, only stations with 30 years or greater of daily rainfall records are used. B-3 February 2016 C C Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods B.1.3.2 Mapping the gage data A collection of 56 precipitation gage points was developed with 85th percentile precipitation values based on multiple years of gage data. A raster surface (grid of cells with values) was interpolated from that set of points. The surface initially did not cover the County's entire jurisdiction. A total of 13 dummy points were added. Most of those were just outside the County boundary to enable the software to generate a surface that covered the entire County. A handful of points were added to enforce a plausible surface. In particular, one point was added in the desert east of Julian, to enforce a gradient from high precipitation in the mountains to low precipitation in the desert. Three points were added near the northern boundary of the County to adjust the surface to reflect the effect of elevation in areas lacking sufficient operating gages. Several methods of interpolation were considered. The method chosen is named by Environmental Systems Research Institute as the Natural Neighbor technique. This method produces a surface that is highly empirical, with the value of the surface being a product of the values of the data points nearest each cell. It does not produce peaks or valleys of surface based on larger area trends, and is free of artifacts that appeared with other methods. B-4 February 2016 San Diego County 85 th Percentile lsopluvials ~•,i., • Legend -&5ltl PERCENTILE ISOPllMAI. D INCClllf'ORATEDCITY NOTE The 85Ch ~ is a 241 hour raW'lfall lotal ti repreNMS a veUI IUCh mat 8Siw-d the ob'Mfved 24 hcU' rant .. toe.ii WII be len tnan that vatue N + n._ru--._______-0 1 ::' • I I • ~,, __ ..., ......... , ..... •~fl' • ..,. ... . . --··- Appendix B: Storm Water Pollutant Control H ydrologic Calculations and Sizing Methods .. Figure B.1-1: 85th Percentile 24-hour Isopluvial Map B-5 February 2016 Appendix B: Storm Water Pollutant Control H ydrologic Calculations and Sizing Methods B.2 Adjustments to Account for Site Design BMPs This section provides methods to adjust the D CV (for sizing poUutant control B~fPs) as a result of implementing site design BMPs. The adjustments are provided by one of the fo llowing two methods: • Adjustment to impervious runoff factor • Adjustment to D CV B.2.1 Adjustment to Impervious Runoff Factor \'(/hen one of the following site design BMPs is implemented the runoff factor of 0.9 for impervious surfaces identified in T able B.1-1 should be adjusted using the factors listed below and an adjusted area weighted runoff factor shall be estimated following guidance from Section B.1 .1 and used to calculate the D CV. • SD-5 Disperse Runoff from impervious area • SD-6A Green roofs • SD -6B Permeable pavement 8.2.1.1 Disperse Runoff from Impervious Area (SD-5) Dispersion of impervious areas through pervious areas: The following adjustments are allowed to impervious runoff factors when dispersion is implemented in accordance with the SD-5 fact sheet (Appendix E.3). Adjustments are only credited up to a 4:1 maximum ratio of impervious to pervious areas. In order to adjust the runoff factor, the pervious area shall have a minimum width of 10 feet and a maximum slope of 5%. Based on the ratio of impervious area to pervious area and the hydrologic soil group of the pervious area, the adjustment factor from Table B.2-1 shall be multiplied with the unadjusted runoff factor (Table B.1-1) of the impervious area to estimate the adjusted runoff factor for sizing pollutant control BMPs. The adjustment factors in Table B.2-1 are ~ valid for impervious surfaces that have an unadjusted runoff factor of 0.9. Table B.2-1: Impervious area adjustment factors that accounts for dispersion Pcrvious area Ratio = Impervious arca/Pcrvious area hydrologic soil group <=1 : 2 3 4 A 0.00 0.00 0.23 0.36 B 0.00 0.27 0.42 0.53 C 0.34 0.56 0.67 0.74 D 0.86 0.93 0.97 1.00 B-6 February 2016 C Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Continuous simulation modeling in accordance with Appendix G is required to develop adjustment factors for surfaces that have an unadjusted runoff factor less than 0.9. Approval of adjustment factors for surfaces that have an unadjusted runoff factor less than 0.9 is at the discretion of the City Engineer. The adjustment factors in Table B.2-1 were developed by performing continuous simulations in SWMM with default parameters from Appendix G and impervious to pcrvious area ratios of 1, 2, 3, and 4. When using adjustment factors from Table B.2-1: • Linear interpolation shall be performed if the impervious to pervious area ratio of the site is in between one of ratios for which an adjustment factor was developed; • Use adjustment factor for a ratio of 1 when the impervious to pervious area ratio is less than 1;and • Adjustment factor is not allowed when the impervious to pervious area ratio is greater than 4, when the pervious area is designed as a site design BMP. Example B.2-1: DMA is comprised of one acre of impervious area that drains to a 0.4 acre hydrologic soil group B pervious area and then the pervious area drains to a BMP. Impervious area dispersion is implemented in the Dl\1A in accordance with SD-5 factsheet. Estimate the adjusted runoff factor for the DMA. • Baseline Runoff Factor per Table B.1-1 = [(1*0.9+0.4*0.14)/1.4) = 0.68. • Impervious to Pervious Ratio = 1 acre impervious area/ 0.4 acre pervious area = 2.5; since the ratio is 2.5 adjustment can be claimed. • From Table B.2-1 the adjustment factor for hydrologic soil group Band a ratio of 2 = 0.27; ratio of 3 = 0.42. • Linear interpolated adjustment factor for a ratio of 2.5 = 0.27 + {[(0.42 -0.27)/(3-2)1*(2.5-2)} = 0.345. • Adjusted runoff factor for the D1-'IA = [(1 *0.9*0.345+0.4*0.14)/1.4) = 0.26. • Note only the runoff factor for impervious area is adjusted, there is no change made to the perv1ous area. B.2.1.2 Green Roofs When green roofs are implemented in accordance with the SD-6A fact sheet (Appendix E.4) the green roof footprint shall be assigned a runoff factor of 0.10 for adjusted runoff factor calculations. 8.2.1.3 Permeable Pavement \X'hen a permeable pavement is implemented in accordance with the SD-6B fact sheet (Appendix E.5) and it docs not have an impermeable liner and has storage greater than the 85th percentile depth below the underdrain, if an underdrain is present, then the footprint of the permeable pavement shall be assigned a runoff factor of 0.10 for adjusted runoff factor calculations. B-7 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Permeable Pavement can also be designed as a structural BMP to treat run on from adjacent areas. Refer to INF-3 factsheet and Appendix B.4 for additional guidance. B.2.2 Adjustment to DCV When the following site design BMPs are implemented the anticipated volume reduction from these BMPs shall be deducted from the DCV to estimate the volume for which the downstream structural BMP should be sized for: • SD-1: Tree wells • SD-8 Rain barrels B.2.2.1 Tree Wells Tree wells credit volume from tree trenches or boxes (tree B:MPs) is a sum of three runoff reduction volumes provided by trees that decrease the required DCV for a tributary area. The following reduction in DCV is allowed per tree based on the mature diameter of the tree canopy, when trees are implemented in accordance with SD-1 fact sheet (Appendix E .2): Mature Tree Canopy Tree Credit Volume (ft3 /tree) Diameter (ft) 5 10 10 40 15 100 20 180 25 290 30 420 Basis for the reduction in DCV: Tree credit volume was estimated based on typical characteristics of tree wells as follows: It is assumed that each tree and associated trench or box is considered a single BMP, with calculations based on the media storage volume and/ or the individual tree within the tree BMP as appropriate. Tree credit volume is calculated as: B-8 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods TCV = TIV + TCIV + TETV Where: • TCI / = Tree credit volume (ft3) • TH·'= Total infiltration volume of all storage layers within tree BMPs (ft3) • TCIV = Total canopy interception volume of all individual trees within tree BMPs (fr') • 1ETV = Total evapotranspiration volume, sums the media evapotranspiration storage within each tree BMP (ft) Total infiltration volume was calculated as the total volume infiltrated within the BMP storage layers. Infiltration volume was assumed to be 20% of the total BMP storage layer volume, the available pore space in the soil volume (porosity-field capacity). Total canopy interception volume was calculated for all tree wells within the tributary area as the average interception capacity for the entire mature tree total canopy projection area. Interception capacity was determined to be 0.04 inches for all street tree sizes, an average from the findings published by Breuer et al (2003) for coniferous and deciduous trees. Total evapotranspiration volume is the available evapotranspiration storage volume (field capacity -wilting point) within the BMP storage layer media. TE1V is assumed to be 10% of the minimum soil volume. The minimum soil volume as required by SD-1 fact sheet of 2 cubic feet per unit canopy projection area was assumed for estimating reduction in DCV. B.2.2.2 Rain Barrels Rain barrels are containers that can capture rooftop runoff and store it for future use. Credit can be taken for the full rain barrel volume when each barrel volume is smaller than 100 gallons, implemented per SD-8 fact sheet (Appendix E.6) and meet the following criteria: • Total rain barrel volume is less than 0.25 DCV and • Landscape areas arc greater than 30 percent of the project footprint. Credit for harvest and use systems that do not meet the above criteria shall be based on the criteria in Appendix B.3 and HU-1 fact sheet (Appendix E.7). B-9 February 2016 1 2 3 4 5 6 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV Design Capture Volume Worksheet B-2.1 85th percentile 24-h r storm depth from Figure B.1-1 d= 0.588 inches Area tributary to BMP (s) A= 0.208 acres Area weighted runoff factor (estimate using Appendix 0.831 B.1.1 and B.2.1) C= unitless Tree wells volume reduction T CV= 0 cubic-feet Rain barrels volume reductio n RCV= 0 cubic-feet Calculate D CV = (3630 x C x d x A) -TCV -RCV D CY= 370 cubic-feet B-10 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs Remaining DCV after implementing retention BMPs Partial Retention 2 Infiltration rate from Form I-9 if partial infiltration is feasible 3 Nlowable drawdown time for aggregate storage below the underdrain 4 Depth of runoff that can be infiltrated (Line 2 x Line 3) 5 Aggregate pore space 6 Required depth of gravel below the underdrain [Line 4/ Line SJ 7 Assumed surface area o f the biofiltration BMP 8 Media retained pore storage 9 Volume retained by BMP [!Linc 4 + (Line 12 x Line 8)]/121 x Line 7 10 DCV that requires bio filtration [Line 1 -Llne 9] BMP Parameters 11 Surface Ponding [6 inch minimum, 12 inch maximum] 12 Media Thickness [18 inches minimum], also add mulch layer thickness to this line for sizing calculations 13 Aggregate Storage above underdrain invert (12 inches typical) -use 0 inches for sizing if the aggreb>ate is not oYer the entire bottom surface area 14 Media available pore space 15 Media filtration rate to be used for sizing (5 in/hr. with no outlet control; if the filtration is controlled by the outlet, use the outlet controlled rate) Baseline Calculations 16 Allowable Routing Time for sizing 17 Depth filtered during storm 11 .ine 15 x Line 16) 18 D epth of Detention Storage [Line 11 + (Line 12 x Line 14) + (Line 13 x Llne 5)] 19 Total Depth Treated [Line 17 + Line 181 Option 1 -Biofilter 1.5 times the DCV 20 Required biofiltered volume [1.5 x Llne 10] 21 Required Footprint (Tjne 20/ Line 19] x 12 Option 2 -Store O. 75 of remaining DCV in pores and ponding 22 Required Storage (surface+ pores) Volume [0.75 x Line 10] 23 Required Footprint [Line 22/ Line 181 x 12 Footprint of the BMP 24 Area draining to the BMP 25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and B.2) 26 Minimum BMP Footprint {Line 24 x Line 25 x 0.03] 27 Footprint of the BMP = Maximum(1'linimurn(Linc 21, Linc 23), Line 26) 0 in/hr. 36 hours 0 inches 0.40 in/in 0 inches 155 sq-fr 0.1 in/in 27.125 cubic-feet 342. 7745204 cubic-feet 12 inches inches 21 inches 12 0.2 in/in 5 in /hr. 6 hours 30 inches inches 21 51 inches 514.1617806 cubic-feet 120. 9792425 sq-ft 257.0808903 cubic-feet 146.9033659 sq-ft 9081 sq-ft 0.831296113 226.470 sq-ft 226 sq-ft Note: Une 7 is used ro estimate the amount of volume retained by the BMP. Update assumed surface area in Linc 7 until its equivalent to the required biofiltrarion footprint (either Linc 21 or Linc 23) I OMA 2 flows to BMP 18 which is sized at 229 sf > 226 sf B-26 February 2016 DRAWDOWN TIME Water Quality Drawdown Time Results Pond: Biofilter 1 Days 1 2 3 4 5 Maximum Stage: Pond: Surface Biofilter 1 Days 1 2 3 4 5 Maximum Stage: Stage(feet) 0.000 0.000 0.000 0.000 0.000 Percent of Total Run Time NIA NIA NIA NIA NIA 3.250 Drawdown Time: 00 09:05:10 Stage(feet) NIA NIA NIA NIA NIA Percent of Total Run Time NIA NIA NIA NIA NIA 1.000 Drawdown Time: Less than 1 day DRAWDOWN CALCULATIONS FROM SOHM MODEL SURFACE PONDING DRAWDOWN OF LESS THAN 24 HOURS MET HydroMod_GN 6/15/2021 1 :35:27 PM Page 13 A TT AC HM ENT 2 BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES [This is the cover sheet for Attachment 2.) Indicate which Items are Included behind this cover sheet: Attachment Contents Checklist Seauence Attachment 2a Hydromodification Management ~ Included Exhibit (Required} See Hydromodification Management Exhibit Checklist on the back of this Attachment cover sheet. Attachment 2b Management of Critical Coarse !Kl Exhibit showing project drainage Sediment Yield Areas (WMM Exhibit boundaries marked on WMM is required, additional analyses are Critical Coarse Sediment Yield optional) Area Map (Required) See Section 6.2 of the BMP Design Optional analyses for Critical Coarse Manual. Sediment Yield Area Determination LJ 6.2.1 Verification of Geomorphic Landscape Units Onsite □ 6.2.2 Downstream Systems Sensitivity to Coarse Sediment 116.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite Attachment 2c Geomorphic Assessment of Receiving Ki Not performed Channels (Optional) LJ Included See Section 6.3.4 of the BMP Design Manual. Attachment 2d Flow Control Facility Design and ~ Included Structural BMP Drawdown Calculations (Required) See Chapter 6 and Appendix G of the BMP Desian Manual C Use this checklist to ensure the required information has been included on the Hydromodification Management Exhibit: The Hydromodification Management Exhibit must identify: □ Underlying hydrologic soil group LJ Approximate depth to groundwater r-1 Existing natural hydrologic features ( watercourses, seeps, springs, wetlands) r-: Critical coarse sediment yield areas to be protected (if present) [l Existing topography □ Existing and proposed site drainage network and connections to drainage offsite u Proposed grading LJ Proposed impervious features LJ Proposed design features and surface treatments used to minimize imperviousness 1 i Point(s) of Compliance (POC) for Hydromodification Management n Existing and proposed drainage boundary and drainage area to each POC (when necessary, create separate exhibits for pre-development and post-project conditions) LJ Structural BMPs for hydromodification management (identify location, type of BMP, and size/detail) Attachment 2a :== ~ Ul I • I GIBRALTAR STREET I ··----~~<-··-···--·--· -• ·-., ~.... ~ .. , .. ,_'>, ... "' ·~. . , ____ .. -•· -··----, . ., ..... , ... . ----.... . .. _,, ___ , .. . ----------.----- • ' lj 1, 1 "' I ' N ;LC)' ·"in ~ ' -N , ' . (/) ·Y, ·-(POC1) '· -.:.,-- r I \ ·. \' ' \ \ . . ','.-. . . ,_. . . ' ---------------------' .• ---------- ~7 I , . I J [~--'U'.,, f-i---. ' ~ i t' ' ·,, ~ · .... , [ ____ t "'---- - NAJARS ENGINEERING,. INC. 772 JAMACHA f11) #15,, E'.L CAJON, CA 92{;,19 PHONE (61'9) 971-7514 EMAIL; ISC;NMAR@CMAILCOM ' _J r I L_J 0 ~ "" \ \ I I ·._ ..... ,<;,_, 20' 40' SCALE: 1''= 20' I I [ I- 0::: . I ::) 0 .. -0 i . I N " w f 0::: w t .7 ., ' I I / -----, , L , / I PROPOSED rBLDG. /,:' SUB c-ASE COURSE 1/2" CLEAN FRACWRD OPEN-"GRA.DED #2 AGG!:?EGA1E BJ:DUNG FOOll'ING PER DETAIL 9 ____ ,,..,..-------' ', ' ', \ ', ' ' ', ' ' ----~------ ----.... "\ ' ' . '\\ \,._ \ •. ', OMA 1 OMA 2 TOTAL HYDROMODIFICA TION EXHIBIT GENERAL INFORMATION • lJNDERL YlNG HYDROLOGIC SOil GROUP = SOIL TYPE D 400 GIBRALTAR STR'EET CARLSBAD,CA LEGEND: • NO EXISTING NATURAL HYDROLOGIC FEATURES LOCATED WITHIN IMPACT AREA OF IMPERVIOUS AREA 13,305 SF 0.305 AC PROJoCT SITE (WETLANDS MAP PROVIDED IN SWQMP) • PER WMAA 11.APP:iNG, NO CCSYA AT PROJECT SITE • APPROXIMATE DcPTH TO GROUNDWATER = >20' • '1iE AREA LABELED (OMA 1) FlDWS TOWARDS TrlE TOP TIER OF THE INFllTRAllON BASIN, LABEL!D BMP 1 A r ----- • THE AREA LABELED (OMA 2) FLOWS TOW~.RDS THE BOTTOM TIER OF THE INflL TRA TIO~ B~.SIN, LABELED BMP 18 I DMA 9081 0.208 2 SF AC . . -. -. -. . . . . . . . . . -. . L --··-- TOTAL AREA (SF /AC) 8,414 / 0.193 9,081 / 0.208 14,495 / 0.401 DMA SUMMARY TABLE PERVI0US (SF) IMPERVIOUS (SF) BMP SIZE (SF) 3,254 551 3,805 3" PEA GRA V£l FILTER COURSE 01/ER 15" GRA\/El 3• MIN. GRA \/EL BELOW PERI'. PIPE 12" GRA \IEL ABOVE PERF. PIPE IE 5,004 8,301 13,305 156 229 I 385 PERPENDICULAR """-.__ WALL EDGE T" OVERFLOW WEIR 7 1 T· 1.0· :::§ :,a in .,; I I 6" CLEAN OUT ~ I • • • OVERFL OW SECTION 1 j ., BMP TYPE BIO-FILTRATION BASIN (SMP 1A) BIO-Fil TRA 110N BASIN (BMP 18) 6" PERF. PIPE 3" PEA GRA VEl I'll TER COURSE OVER 15" GRAVEL 3" MIN. GRA VEl BELOW PERF. PIPE 12" GRAVEL A.80\/E PERF. PIPE IE RAILING PER '\ lANOSCAPE PLANES '\ 1.0' PLANTER --7 I --J 1.67' 4.0' 8.7' BASIN-----------· 0 -~----I SIDEWALK ' :J 4" BASE COURSE -3/4'· 'JVA5HED _____ FRACTURED OPEN-G'1ADED ST:>NE 1:/. 57 .t.DG~ EGA TE 2" BEDDING COURSE-1 /t..'' -3/8'' '•\',"',SHED FR,ti.,CT JRED OP:'N-GRADE:D STONE #89 AGGREGATE PII\.~ HALL BRIC.< RAIN?AVE/STOR,vF·t.VE OR EQIJA~ 2'/4" ,V,IN. # 8 AGGREGATE iN O?E-NJNGS--'>",/ASHED ..._ __ 6"' PERFORATED DRAIN UNE ',".// .V,!N. 2% SLO.~E TO DETENTION' 3ASIN IMPERMEA6:._E Ll'i:::'-R (M1N 30-Mll HDPE OR PVC) 18" MIN l '----r---' CUT-OFF WAI_L PER PLANS ---- RAILING PER LANDSCAPE PLANES PROP RETAINING WALL ----i H=3.5-fT CITY ROW----1 CURS OUTLET . . 2' FRSEBOARD 12· TO TG 24"x24" BROOKS ! BOX CATCH BASIN 3" Pf.A GRA \IEL FIUTIER ri ~I~, ~I~. 1 ii 1 1 COURSE 0\/ER 15" i-, ::. GRAVEL 12" GflA VEL A.BOVE PERF. PIPE IE • . <fiNt~HEO '•CRP.,DE'' . PERVIQLJ!S PAVERS (PVT) EB BIOFIL TRA TION BASIN SCALE: N. T.S. SCALE: N.T.S. ------------------------ Attachment 2b r legend -RegionalWMAA Streams Watetshed Boundaries [~~J Municipal Boundaries Rive is & Streams Potential Critic a l Coaise Sediment Yield Are as Project Location Potential Critic al CoaISe Sedim.ent Yield Areas Regional San Diego County Watersheds / 1 Santa Margarita River 14 CanollCanyon Creek ' . !\ ~-------------~\\ 15 16 Rose Creek San Diego River f-------+------------------------, -.....,,\, 17 Sycamore Creek 19 San Vicente Creek 20 ForesterCreek 21 Cho Ila s Creek 22 SweetwaterRiver-Reach 1 , "1 LJ ' }--------+-----------------------------, 23 SweetwaterRiver-Reach 2 24 Otay River 25 Jamul/ Dulzura Creek 26 'Iljuana River MilesO 5 10 Geosyntec t> RICK . \ ,Jk I~ :' ~ J 15 a Exhibit Date : Se pt. 8, 2014 consultants ENC.ill\1-J ·_l<.]N(i COMPANY Attachment 2d SDHM3.l PROJECT REPORT General Model Information Project Name: Site Name: Site Address: City: Report Date: Gage: Data Start: Data End: Timestep: Precip Scale: Version Date: HydroMod_GN 6/15/2021 OCEANSID 10/01/1959 09/30/2004 Hourly 1.000 2020/03/12 POC Thresholds Low Flow Threshold for POC1: High Flow Threshold for POC1: HydroMod_GN 10 Percent of the 2 Year 1 O Year 6/15/2021 1 :35:20 PM Page 2 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre D,Dirt,Steep 0.402 Pervious Total 0.402 Impervious Land Use acre Impervious Total 0 Basin Total 0.402 Element Flows To: Surface lnterflow HydroMod_GN Groundwater 6/15/2021 1 :35:20 PM Page 3 Mitigated Land Use Basin 2 Bypass: No GroundWater: No Pervious Land Use acre A,NatVeg,Moderate 0.09676 Pervious Total 0.09676 l~ervious Land Use acre I PERVIOUS-FLAT 0.304866 Impervious Total 0.304866 Basin Total 0.401626 Element Flows To: Surface lnterflow Groundwater Surface Biofilter 1 Surface Biofilter 1 HydroMod_GN 6/15/2021 1 :35:20 PM Page4 Routing Elements Predeveloped Routing HydroMod_GN 6/15/2021 1 :35:20 PM Pages Mitigated Routing Biofilter 1 Bottom Length: Bottom Width: Material thickness of first layer: Material type for first layer: Material thickness of second layer: Material type for second layer: 38.50 ft. 10.00 ft. 0.25 Mulch 1.5 ESM Material thickness of third layer: Material type for third layer: Underdrain used Underdrain Diameter (feet): Orifice Diameter (in.): 1.5 GRAVEL 0.667 1.75 0 Offset (in.): Flow Through Underdrain (ac-ft.): 10.542 10.792 97.68 Total Outflow (ac-ft.): Percent Through Underdrain: Discharge Structure Riser Height: 1 ft. Riser Diameter: 24 in. Element Flows To: Outlet 1 Outlet 2 Biofilter Hydraulic Table Stage(feet) 0.0000 0.0491 0.0982 0.1472 0.1963 0.2454 0.2945 0.3435 0.3926 0.4417 0.4908 0.5399 0.5889 0.6380 0.6871 0.7362 0.7852 0.8343 0.8834 0.9325 0.9816 1.0306 1.0797 1.1288 1.1779 1.2269 1.2760 1.3251 1.3742 HydroMod_GN Area(ac.) 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 0.0088 Volume(ac-ft.) Discharge(cfs) lnfilt(cfs) 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 0.0003 0.0000 0.0000 0.0004 0.0000 0.0000 0.0006 0.0000 0.0000 0.0007 0.0000 0.0000 0.0008 0.0000 0.0000 0.0010 0.0000 0.0000 0.0011 0.0000 0.0000 0.0012 0.0000 0.0000 0.0014 0.0000 0.0000 0.0015 0.0000 0.0000 0.0016 0.0000 0.0000 0.0018 0.0000 0.0000 0.0019 0.0000 0.0000 0.0020 0.0000 0.0000 0.0021 0.0000 0.0000 0.0023 0.0000 0.0000 0.0024 0.0000 0.0000 0.0025 0.0000 0.0000 0.0027 0.0000 0.0000 0.0028 0.0000 0.0000 0.0029 0.0000 0.0000 0.0031 0.0000 0.0000 0.0032 0.0000 0.0000 0.0033 0.0000 0.0000 0.0034 0.0000 0.0000 0.0036 0.0000 0.0000 0.0037 0.0000 0.0000 6/15/2021 1 :35:20 PM Page6 1.4233 0.0088 0.0038 0.0000 0.0000 1.4723 0.0088 0.0040 0.0000 0.0000 1.5214 0.0088 0.0041 0.0000 0.0000 C 1.5705 0.0088 0.0042 0.0000 0.0000 1.6196 0.0088 0.0044 0.0000 0.0000 1.6686 0.0088 0.0045 0.0000 0.0000 1.7177 0.0088 0.0046 0.0000 0.0000 1.7668 0.0088 0.0048 0.0000 0.0000 1.8159 0.0088 0.0050 0.0000 0.0000 1.8650 0.0088 0.0052 0.0000 0.0000 1.9140 0.0088 0.0053 0.0000 0.0000 1.9631 0.0088 0.0055 0.0000 0.0000 2.0122 0.0088 0.0057 0.0000 0.0000 2.0613 0.0088 0.0059 0.0000 0.0000 2.1103 0.0088 0.0061 0.0000 0.0000 2.1594 0.0088 0.0062 0.0000 0.0000 2.2085 0.0088 0.0064 0.0000 0.0000 2.2576 0.0088 0.0066 0.0000 0.0000 2.3067 0.0088 0.0068 0.0000 0.0000 2.3557 0.0088 0.0070 0.0000 0.0000 2.4048 0.0088 0.0071 0.0000 0.0000 2.4539 0.0088 0.0073 0.0000 0.0000 2.5030 0.0088 0.0075 0.0000 0.0000 2.5520 0.0088 0.0077 0.0000 0.0000 2.6011 0.0088 0.0079 0.0000 0.0000 2.6502 0.0088 0.0080 0.0000 0.0000 2.6993 0.0088 0.0082 0.0000 0.0000 2.7484 0.0088 0.0084 0.0000 0.0000 2.7974 0.0088 0.0086 0.0000 0.0000 C 2.8465 0.0088 0.0088 0.0000 0.0000 2.8956 0.0088 0.0089 0.0000 0.0000 2.9447 0.0088 0.0091 0.0000 0.0000 2.9937 0.0088 0.0093 0.0000 0.0000 3.0428 0.0088 0.0095 0.0000 0.0000 3.0919 0.0088 0.0097 0.0000 0.0000 3.1410 0.0088 0.0098 0.0000 0.0000 3.1901 0.0088 0.0100 0.0000 0.0000 3.2391 0.0088 0.0102 0.0000 0.0000 3.2882 0.0088 0.0106 0.0000 0.0000 3.3373 0.0088 0.0111 0.0000 0.0000 3.3864 0.0088 0.0115 0.0000 0.0000 3.4354 0.0088 0.0119 0.0000 0.0000 3.4845 0.0088 0.0124 0.0000 0.0000 3.5336 0.0088 0.0128 0.0000 0.0000 3.5827 0.0088 0.0132 0.0000 0.0000 3.6318 0.0088 0.0137 0.0000 0.0000 3.6808 0.0088 0.0141 0.0000 0.0000 3.7299 0.0088 0.0145 0.0000 0.0000 3.7790 0.0088 0.0150 0.0000 0.0000 3.8281 0.0088 0.0154 0.0000 0.0000 3.8771 0.0088 0.0158 0.0000 0.0000 3.9262 0.0088 0.0163 0.0000 0.0000 3.9753 0.0088 0.0167 0.0000 0.0000 4.0244 0.0088 0.0171 0.0000 0.0000 C 4.0735 0.0088 0.0176 0.0000 0.0000 4.1225 0.0088 0.0180 0.0000 0.0000 4.1716 0.0088 0.0184 0.0000 0.0000 4.2207 0.0088 0.0189 0.0000 0.0000 HydroMod_GN 6/15/2021 1 :35:20 PM Page 7 ___ , ___ ,.,"~ ~ ..,~ ---· ~-~-"~- C 4.2698 4.3188 4.3679 0.0088 0.0193 0.0088 0.0197 0.0088 0.0202 Biofilter Hydraulic Table 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)To Amended(cfs)lnfilt(cfs) 4.3679 0.0088 0.0202 0.0000 0.0000 0.0000 4.4170 0.0088 0.0206 0.0000 0.0000 0.0000 4.4661 0.0088 0.0210 0.0000 0.0000 0.0000 4.4170 0.0088 0.0205 0.0000 0.0817 0.0000 HydroMod_GN 6/15/2021 1 :35:20 PM Page 8 Surface Biofilter 1 Element Flows To: Outlet 1 Outlet 2 Biofilter 1 HydroMod_GN 6/15/2021 1 :35:20 PM Page9 Analysis Results POC 1 (121 ,... • 0 0.19 V ~ (117 0 J II. 015 013 ------• ---111:.. 111:·3 111:·2 111:·1 I 10 100 " "' P•ro.-nt "Tlm• El:ac:o••cl•nu 0,U, j-------------~IOOJI C~ I 2 ) 10 20 3) )0 I~ IC J,.l 16 11 "90 I + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0.402 Total Impervious Area: 0 Mitigated Land use Totals for POC #1 Total Pervious Area: 0.09676 Total Impervious Area: 0.304866 Flow Frequency Method: Cunnane Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.118212 5 year 0.189257 10 year 0.250657 25 year 0.321755 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.079633 5 year 0.157 411 1 O year 0.243614 25 year 0.316664 HydroMod_GN 6/15/2021 1 :35:20 PM Page 10 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.1310 22 17 77 Pass 0.1318 22 17 77 Pass 0.1326 22 17 77 Pass 0.1334 22 17 77 Pass 0.1342 22 17 77 Pass 0.1350 20 17 85 Pass 0.1358 19 17 89 Pass 0.1367 19 16 84 Pass 0.1375 17 16 94 Pass 0.1383 17 16 94 Pass 0.1391 17 16 94 Pass 0.1399 17 16 94 Pass 0.1407 17 16 94 Pass 0.1415 17 15 88 Pass 0.1423 17 15 88 Pass 0.1431 17 15 88 Pass 0.1439 17 15 88 Pass 0.1447 17 15 88 Pass 0.1455 17 15 88 Pass 0.1464 17 14 82 Pass 0.1472 17 14 82 Pass 0.1480 17 13 76 Pass 0.1488 17 13 76 Pass 0.1496 17 13 76 Pass 0.1504 17 13 76 Pass 0.1512 17 13 76 Pass 0.1520 17 12 70 Pass 0.1528 17 11 64 Pass 0.1536 17 11 64 Pass 0.1544 17 11 64 Pass 0.1552 17 11 64 Pass 0.1561 17 11 64 Pass 0.1569 17 11 64 Pass 0.1577 16 11 68 Pass 0.1585 16 11 68 Pass 0.1593 16 10 62 Pass 0.1601 16 10 62 Pass 0.1609 16 10 62 Pass 0.1617 16 10 62 Pass 0.1625 16 10 62 Pass 0.1633 16 10 62 Pass 0.1641 16 10 62 Pass 0.1649 16 10 62 Pass 0.1657 16 10 62 Pass 0.1666 16 10 62 Pass 0.1674 16 10 62 Pass 0.1682 16 10 62 Pass 0.1690 16 10 62 Pass 0.1698 16 10 62 Pass 0.1706 16 10 62 Pass 0.1714 15 10 66 Pass 0.1722 14 10 71 Pass 0.1730 14 10 71 Pass HydroMod_GN 6/15/2021 1 :35:27 PM Page 11 0.1738 14 10 71 Pass 0.1746 14 10 71 Pass 0.1754 12 10 83 Pass \ 0.1763 12 10 83 Pass 0.1771 12 10 83 Pass 0.1779 12 10 83 Pass 0.1787 11 10 90 Pass 0.1795 11 10 90 Pass 0.1803 11 10 90 Pass 0.1811 10 10 100 Pass 0.1819 10 10 100 Pass 0.1827 10 10 100 Pass 0.1835 10 10 100 Pass 0.1843 10 9 90 Pass 0.1851 10 9 90 Pass 0.1859 9 8 88 Pass 0.1868 9 7 77 Pass 0.1876 9 7 77 Pass 0.1884 9 7 77 Pass 0.1892 9 7 77 Pass 0.1900 9 7 77 Pass 0.1908 8 7 87 Pass 0.1916 8 7 87 Pass 0.1924 8 7 87 Pass 0.1932 8 7 87 Pass 0.1940 8 7 87 Pass 0.1948 8 7 87 Pass 0.1956 8 7 87 Pass 0.1965 8 7 87 Pass C 0.1973 8 7 87 Pass 0.1981 8 7 87 Pass 0.1989 8 7 87 Pass 0.1997 8 7 87 Pass 0.2005 8 7 87 Pass 0.2013 8 7 87 Pass 0.2021 8 7 87 Pass 0.2029 8 7 87 Pass 0.2037 8 7 87 Pass 0.2045 8 7 87 Pass 0.2053 8 7 87 Pass 0.2062 8 7 87 Pass 0.2070 7 6 85 Pass 0.2078 7 6 85 Pass 0.2086 7 6 85 Pass 0.2094 7 6 85 Pass 0.2102 7 6 85 Pass 0.2110 7 6 85 Pass HydroMod_GN 6/15/2021 1 :35:27 PM Page 12 Water Quality Drawdown Time Results Pond: Biofilter 1 Days 1 2 3 4 5 Maximum Stage: Pond: Surface Biofilter 1 Days 1 2 3 4 5 Maximum Stage: HydroMod_GN Stage(feet) 0.000 0.000 0.000 0.000 0.000 Percent of Total Run Time N/A N/A N/A N/A N/A 3.250 Drawdown Time: 00 09:05:10 Stage(feet) N/A N/A N/A N/A N/A Percent of Total Run Time N/A N/A N/A N/A N/A 1.000 Drawdown Time: Less than 1 day 6/15/2021 1 :35:27 PM Page 13 Model Default Modifications Total of O changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. HydroMod_GN 6/15/2021 1 :35:27 PM Page 14 Appendix Predeveloped Schematic HydroMod_GN 6/15/2021 1 :35:27 PM Page 15 Mitigated Schematic HydroMod_GN Basin 2 .40ac 1 6/15/2021 1 :35:27 PM Page 16 Predeveloped UGI File RUN GLOBAL WWHM4 START model simulation 1959 10 01 OUTPUT LEVEL RUN INTERP RESUME 0 RUN 1 END GLOBAL FILES END 2004 09 30 3 0 UNIT SYSTEM 1 <File> <Un#> <-ID-> <-----------File Name------------------------------>*** WDM 26 MESSU 25 END FILES 27 28 30 OPN SEQUENCE INGRP PERLND COPY DISPLY END INGRP END OPN SEQUENCE DISPLY DISPLY-INFOl HydroMod GN.wdm PreHydroMod GN.MES PreHydroMod-GN.L61 PreHydroMod-GN.L62 POCHydroMod=GNl.dat 33 501 1 INDELT 00:60 # -#<----------Title----------->***TRAN PIVL DIGl FILl PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFOl END DISPLY COPY TIMESERIES # -# NPT 1 1 501 1 END TIMESERIES END COPY GENER OPCODE NMN 1 1 # # OPCD *** END OPCODE PARM # # END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS # -# 33 D,Dirt,Steep 1 END GEN-INFO *** Section PWATER*** ACTIVITY Unit-systems User t -series in out 1 1 1 Printer Engl Metr 2 7 0 *** *** *** <PLS >*************Active Sections***************************** # -# ATMP SNOW PWAT SEO PST PWG PQAL MSTL PEST NITR PHOS TRAC*** 33 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # -# ATMP SNOW PWAT SEO PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 33 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO HydroMod_GN 6/15/2021 1 :35:28 PM Page 17 C PWAT-PARMl <PLS > PWATER variable monthly parameter value flags *** # -# CSNO RTOP UZFG VCS vuz VNN VIFW VIRC VLE INFC HWT *** 33 0 1 1 1 0 0 0 0 1 1 0 END PWAT-PARMl PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # -# ***FOREST LZSN INFILT LSUR SLSUR KVARY 33 0 2.2 0.02 75 0.15 2.5 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # -# ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP 33 0 0 2 2 0 0.05 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 # -# CEPSC UZSN NSUR INTFW IRC LZETP 33 0 0.6 0.017 1 0.3 0 END PWAT-PARM4 MON-LZETPARM <PLS > PWATER input info: Part 3 *** # -# JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 33 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 END MON-LZETPARM MON-INTERCEP <PLS > PWATER input info: Part 3 *** # -# JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 33 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 END MON-INTERCEP PWAT-STATEl <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # -# *** CEPS 33 0 END PWAT-STATEl END PERLND IMPLND GEN-INFO SURS 0 <PLS ><-------Name-------> # -# END GEN-INFO *** Section IWATER*** ACTIVITY uzs IFWS 0.01 0 Unit-systems Printer User t-series Engl Metr in out LZS 0.4 *** *** *** AGWS 0.01 <PLS >*************Active # -# ATMP SNOW IWAT SLD END ACTIVITY Sections***************************** IWG IQAL *** PRINT-INFO <ILS >********Print-flags ******** PIVL PYR # -# ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARMl <PLS > IWATER variable monthly parameter value flags *** # -# CSNO RTOP VRS VNN RTLI *** END IWAT-PARMl IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # -# *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 HydroMod_GN 6/15/2021 1 :35:28 PM AGWRC 0.915 AGWETP 0.05 *** *** *** *** GWVS 0 Page 18 C IWAT-PARM3 <PLS > !WATER input info: Part 3 *** # -# ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATEl <PLS >***Initial conditions at start of simulation # -# *** RETS SURS END IWAT-STATEl END IMPLND SCHEMATIC <-Source-> <Name> # Basin l*** PERLND 33 PERLND 33 ******Routing****** END SCHEMATIC NETWORK <--Area--> <-factor-> 0.402 0.402 <-Target-> <Name> # COPY 501 COPY 501 MBLK Tbl# 12 13 *** *** <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name># #<-factor->strg <Name> # # <Name>## *** COPY 501 OUTPUT MEAN 1 1 12.1 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name># #<-factor->strg <Name> # # <Name>## *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits # -#<------------------><---> END GEN-INFO *** Section RCHRES*** ACTIVITY Unit Systems User T-series in out Printer Engl Metr LKFG *** *** *** <PLS >*************Active Sections***************************** # -# HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS >*****************Print-flags******************* PIVL PYR # -# HYDR ADCA CONS HEAT SEO GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARMl RCHRES # -# Flags for each HYDR Section VC Al A2 A3 ODFVFG for each FG FG FG FG possible exit **** ***** END HYDR-PARMl HYDR-PARM2 # -# FTABNO LEN DELTH *** *** ODGTFG for each possible exit * * * * * STCOR KS *** FUNCT for each possible exit *** DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # -# *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES HydroMod_GN 6/15/2021 1 :35:28 PM Page 19 C SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> <Name> # <Name> # WDM 2 PREC WDM 2 PREC WDM 1 EVAP WDM 1 EVAP END EXT SOURCES SsysSgap<--Mult-->Tran tern strg<-factor->strg ENGL 1 ENGL 1 ENGL 1 ENGL 1 <-Target vols> <Name> # # PERLND 1 999 IMPLND 1 999 PERLND 1 999 IMPLND 1 999 <-Grp> EXTNL EXTNL EXTNL EXTNL <-Member-> <Name> # # PREC PREC PETINP PETINP *** *** EXT TARGETS <-Volume-> <-Grp> <Name> # <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name># #<-factor->strg <Name> # <Name> tern strg strg*** COPY 501 OUTPUT END EXT TARGETS MEAN 1 1 12.1 WDM 501 FLOW ENGL REPL MASS-LINK <Volume> <Name> MASS-LINK <-Grp> <-Member-><--Mult--> <Name># #<-factor-> 12 PERLND PWATER END MASS-LINK SURO 12 MASS-LINK 13 PERLND PWATER IFWO END MASS-LINK 13 END MASS-LINK END RUN HydroMod_GN 0.083333 0.083333 <Target> <Name> COPY COPY 6/15/2021 1 :35:28 PM <-Grp> <-Member->*** <Name>##*** INPUT MEAN INPUT MEAN Page 20 Mitigated UGI File RUN GLOBAL WWHM4 START model simul ation 1959 10 01 OUTPUT LEVEL RUN INTERP RESUME 0 RUN 1 END GLOBAL FILES END 2004 09 30 3 0 UN I T SYSTEM 1 <File> <Un#> <-ID-> <-----------File Name------------------------------>*** *** WDM 26 MESSU 25 END FILES 27 28 30 OPN SEQUENCE INGRP PERLND IMPLND RCHRES RCHRES COPY COPY DISPLY HydroMod GN.wdm MitHydroMod GN .MES MitHydroMod-GN.L61 MitHydroMod-GN.L62 POCHydroMod=GNl.dat 2 1 1 2 1 501 1 INDELT 00:60 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFOl # -#<----------Title----------->***TRAN PIVL DIGl FILl PYR DIG2 FIL2 YRND 1 Surface Bi ofilter 1 MAX END DISPLY-INFOl END DISPLY COPY TIMESERIES # -# NPT 1 1 501 1 END TIMESERIES END COPY GENER OPCODE NMN 1 1 # # OPCD *** END OPCODE PARM *** # It K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS # -It 2 A,NatVeg,Moderate 1 END GEN-INFO *** Section PWATER*** ACTIVITY Unit-systems User t-series in out 1 1 1 Printer Engl Metr 27 0 *** *** *** 1 2 30 9 <PLS > ************* Active Sections ***************************** It -# ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 2 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags***************************** PIVL PYR HydroMod_GN 6/15/2021 1 :35:28 PM Page 21 # -# ATMP SNOW PWAT SEO PST PWG PQAL MSTL PEST NITR PHOS TRAC 2 0 0 4 0 0 0 0 0 0 0 0 0 END PRINT-INFO PWAT-PARMl <PLS > PWATER variable monthly parameter value flags *** # -# CSNO RTOP UZFG vcs vuz VNN VIFW VIRC VLE INFC 2 0 1 1 1 0 0 0 0 1 1 END PWAT-PARMl PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # -# ***FOREST LZSN INFILT LSUR SL SUR 2 0 3.8 0.07 80 0.1 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # -# ***PETMAX PETMIN INFEXP INFILD DEEPFR 2 0 0 2 2 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 # -# CEPSC UZSN NSUR INTFW 2 0 0.6 0.04 1 END PWAT-PARM4 MON-LZETPARM <PLS > PWATER input info: Part 3 *** # -# JAN FEB MAR APR MAY JUN JUL AUG SEP 2 0.4 0.4 0.4 0.4 0.6 0.6 0.6 0.6 0.6 END MON-LZETPARM MON-INTERCEP <PLS > PWATER input info: Part 3 *** # -# JAN FEB MAR APR MAY JUN JUL AUG SEP 2 0.1 0.1 0.1 0.1 0.06 0.06 0.06 0.06 0.06 END MON-INTERCEP PWAT-STATEl <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) # -# *** CEPS 2 END PWAT-STATEl END PERLND IMPLND GEN-INFO 0 SURS 0 <PLS ><-------Name-------> # -# 1 IMPERVIOUS-FLAT END GEN-INFO *** Section IWATER*** ACTIVITY uzs 0.01 Unit-systems User t-series in out 1 1 1 IFWS 0 Printer Engl Metr 27 0 0 IRC 0.3 OCT 0.4 OCT 0.1 RUN LZS 0.4 *** *** *** HWT 0 *** KVARY 2.5 BASETP 0.05 LZETP 0 NOV DEC 0.4 0.4 NOV DEC 0.1 0.1 21 *** AGWS 0.01 <PLS >*************Active Sections***************************** # -# ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # -# ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARMl <PLS > IWATER variable monthly parameter value flags *** # -# CSNO RTOP VRS VNN RTLI *** HydroMod_GN 6/15/2021 1 :35:28 PM ********* 1 9 AGWRC 0.915 AGWETP 0.05 *** *** *** *** GWVS 0 Page 22 \ 1 0 0 0 0 1 END IWAT-PARMl IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # -# *** LSUR SLSUR NSUR RETSC 1 100 0.05 O.Oll 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # -# ***PETMAX PETMIN 1 0 0 END IWAT-PARM3 IWAT-STATEl <PLS > *** # -# *** 1 Initial conditions at start of simulation RETS SURS END IWAT-STATEl END IMPLND SCHEMATIC <-Source-> <Name> # Basin 2*** PERLND 2 PERLND 2 IMPLND 1 ******Routing****** PERLND 2 IMPLND 1 PERLND 2 RCHRES 1 RCHRES 2 RCHRES 1 END SCHEMATIC NETWORK 0 0 <--Area--> <-factor-> 0. 0968 0.0968 0.3049 0.09676 0.304866 0.09676 1 1 1 <-Target-> <Name> # RCHRES 1 RCHRES 1 RCHRES 1 COPY 1 COPY 1 COPY 1 RCHRES 2 COPY 501 COPY 501 MBLK *** Tbl# *** 2 3 5 12 15 13 8 16 17 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> <Name> # <Name># #<-factor->strg <Name> # # <Name>## COPY 501 OUTPUT MEAN 1 1 12.1 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> <Name> # <Name># #<-factor->strg <Name> # # <Name>## END NETWORK RCHRES GEN-INFO RCHRES Name Nexits # -#<------------------><---> 1 Surface Biofilte-004 2 2 Biofilter 1 1 END GEN-INFO *** Section RCHRES*** ACTIVITY Unit Systems User T-series in out 1 1 1 1 1 1 Printer Engl Metr LKFG 28 0 1 28 0 1 <PLS > ************* Active Sections ***************************** # -# HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS >*****************Print-flags******************* PIVL PYR HydroMod_GN 6/15/2021 1 :35:28 PM *** *** *** *** *** *** *** Page 23 C # - 1 # HYDR ADCA CONS HEAT SED 0 0 GQL OXRX NUTR PLNK PHCB PIVL PYR 9 9 ********* 4 0 0 0 0 0 0 0 0 1 2 4 0 0 0 0 0 0 0 0 1 END PRINT-INFO HYDR-PARMl RCHRES Flags for each HYDR Section # -# VC Al A2 A3 ODFVFG for each FG FG FG FG possible exit * * * * * * * * * 1 0 1 0 0 2 0 1 0 0 END HYDR-PARMl HYDR-PARM2 # -# FTABNO 4 5 0 0 0 4 0 0 0 0 LEN DELTH *** *** ODGTFG for each possible exit * * * * * 0 0 0 0 0 0 0 0 0 0 STCOR KS *** FUNCT for each possible exit *** 2 2 2 2 2 2 2 2 2 2 DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.01 0.0 0.0 0.0 0.0 2 2 0.01 0.0 0.0 0.0 0.0 END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # -# *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2 0 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 2 68 4 Depth Area Volume Outflowl Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)*** 0.000000 0.008838 0.000000 0.000000 0.048538 0.008838 0.000129 0.000000 0.097077 0.008838 0.000257 0.000000 0.145615 0.008838 0.000386 0.000000 0.194154 0.008838 0.000515 0.000000 0.242692 0.008838 0.000644 0.000000 0.291231 0.008838 0. 000772 0.000000 0.339769 0.008838 0.000901 0.000515 0.388308 0.008838 0.001030 0.000754 0.436846 0.008838 0. 001158 0.001059 0.485385 0.008838 0.001287 0.001439 0.533923 0.008838 0.001416 0.001655 0.582462 0.008838 0.001544 0.001900 0.631000 0.008838 0.001673 0.002447 0.679538 0.008838 0.001802 0.003086 0.728077 0.008838 0.001931 0.003823 0.776615 0.008838 0.002059 0.004662 0.825154 0.008838 0.002188 0.005608 0.873692 0.008838 0.002317 0.006665 0.922231 0.008838 0.002445 0.006858 0.970769 0.008838 0.002574 0.007036 1.019308 0.008838 0.002703 0.007837 1.067846 0.008838 0.002831 0.009129 1.116385 0.008838 0.002960 0.010545 1.164923 0.008838 0.003089 0.012088 1.213462 0.008838 0.003218 0.013762 1.262000 0.008838 0.003346 0.014841 1.310538 0.008838 0.003475 0.015570 1.359077 0.008838 0.003604 0.016741 1.407615 0.008838 0.003732 0.017516 1.456154 0.008838 0.003861 0.019602 1.504692 0.008838 0.003990 0.021832 1.553231 0.008838 0.004118 0.024209 HydroMod_GN 6/15/2021 1 :35:28 PM Page 24 <¼ ,_ ..... o •• ~·· ' ~ 1.601769 0.008838 0.004247 0.026735 1.650308 0.008838 0.004376 0.026832 1.698846 0.008838 0.004505 0.029411 1.747385 0.008838 0.004633 0.032237 r 1.795923 0.008838 0.004811 0.032241 1.844462 0.008838 0.004989 0.035223 1.893000 0.008838 0.005167 0.036338 1.941538 0.008838 0.005345 0.036895 1.990077 0.008838 0.005523 0.038282 2.038615 0.008838 0.005701 0.039913 2. 087154 0.008838 0.005879 0.042687 2 .135692 0.008838 0.006058 0.045873 2.184231 0.008838 0.006236 0.049140 2.232769 0.008838 0.006414 0.052345 2.281308 0.008838 0.006592 0.055433 2.329846 0.008838 0.006770 0.058390 2.378385 0.008838 0.006948 0.061219 2.426923 0.008838 0.007126 0.063928 2.475462 0.008838 0.007304 0.066529 2.524000 0.008838 0.007482 0.069032 2. 572538 0.008838 0.007660 0.071447 2.621077 0.008838 0.007838 0.073782 2. 669615 0.008838 0.008016 0.076045 2. 718154 0.008838 0.008194 0.078242 2.766692 0.008838 0.008372 0.081694 2.815231 0.008838 0.008550 0.081694 2.863769 0.008838 0. 008728 0.081694 2.912308 0.008838 0.008906 0.081694 2. 960846 0.008838 0.009084 0.081694 3.009385 0.008838 0.009262 0.081694 3.057923 0.008838 0.009440 0.081694 3.106462 0.008838 0.009618 0.081694 3.155000 0.008838 0.009796 0.081694 3.203538 0.008838 0.009974 0.081694 3.250000 0.008838 0. 016896 0.081694 C END FTABLE 2 FTABLE 1 26 5 Depth Area Volume Outflowl Outflow2 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (cfs) (ft/sec) (Minutes)*** 0.000000 0.008838 0.000000 0.000000 0.000000 0.048538 0.008838 0.000429 0.000000 0.044560 0.097077 0.008838 0.000858 0.000000 0.054871 0.145615 0.008838 0.001287 0.000000 0. 056313 0.194154 0.008838 0.001716 0.000000 0.057755 0.242692 0.008838 0.002145 0.000000 0.059197 0.291231 0.008838 0.002574 0.000000 0.060638 0.339769 0.008838 0.003003 0.000000 0.062080 0.388308 0.008838 0.003432 0.000000 0.063522 0.436846 0.008838 0.003861 0.000000 0.064964 0.485385 0.008838 0.004290 0.000000 0.066406 0.533923 0.008838 0.004719 0.000000 0.067848 0.582462 0.008838 0.005148 0.000000 0.069290 0.631000 0.008838 0.005577 0.000000 0.070732 0.679538 0.008838 0.006006 0.000000 0.072174 0.728077 0.008838 0.006435 0.000000 0.073616 0.776615 0.008838 0.006864 0.000000 0.075058 0.825154 0.008838 0.007293 0.000000 0.076500 0.873692 0.008838 0. 007722 0.000000 0.077942 0.922231 0.008838 0.008151 0.000000 0.079383 0.970769 0.008838 0.008580 0.000000 0.080825 1.019308 0.008838 0.009009 0.056961 0.081694 1.067846 0.008838 0.009438 0.374816 0.081694 1.116385 0.008838 0.009867 0.841169 0.081694 1.164923 0.008838 0.010296 1.416114 0.081694 C 1.167000 0.008838 0.010314 2.077905 0.081694 END FTABLE 1 END FTABLES EXT SOURCES HydroMod_GN 6/15/2021 1 :35:28 PM Page 25 <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tern strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC C✓ WDM 1 EVAP ENGL 1 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 1 IMPLND 1 999 EXTNL PETINP WDM 2 PREC ENGL 1 RCHRES 1 EXTNL PREC WDM 1 EVAP ENGL 0.5 RCHRES 1 EXTNL POTEV WDM 1 EVAP ENGL 0.7 RCHRES 2 EXTNL POTEV END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tern strg strg*** RCHRES 2 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL RCHRES 2 HYDR STAGE 1 1 1 WDM 1001 STAG ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1002 STAG ENGL REPL RCHRES 1 HYDR 0 1 1 1 WDM 1003 FLOW ENGL REPL COPY 1 OUTPUT MEAN 1 1 12.1 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 12.1 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name>##*** MASS-LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2 MASS-LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3 MASS-LINK 5 C IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5 MASS-LINK 8 RCHRES OFLOW OVOL 2 RCHRES INFLOW IVOL END MASS-LINK 8 MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 MASS-LINK 16 RCHRES ROFLOW COPY INPUT MEAN END MASS-LINK 16 MASS-LINK 17 RCHRES OFLOW OVOL 1 COPY INPUT MEAN END MASS-LINK 17 END MASS-LINK C END RUN HydroMod_GN 6/15/2021 1 :35:28 PM Page 26 Predeveloped HSPF Message File HydroMod_GN 6/15/2021 1 :35:28 PM Page 27 Mitigated HSPF Message File ERROR/WARNING ID: 238 1 The continuity error reported below is greater than 1 part in 1000 and is therefore considered high. Did you specify any "special actions "? If so, they could account for it. Relevant data are: DATE/TIME: 1962/6/30 24: 0 RCHRES 1 RELERR -1.0000 Where: STORS STOR 0.00000 0.0000E+O0 MATIN MATDIF 0.00000 2.0176E-12 RELERR is the relative error (ERROR/REFVAL). ERROR is (STOR-STORS) -MATDIF. REFVAL is the reference value (STORS+MATIN). STOR is the storage of material in the processing unit (land-segment or reach/reservior) at the end of the present interval. STORS is the storage of material in the pu at the start of the present printout reporting period. MATIN is the total inflow of material to the pu during the present printout reporting period. MATDIF is the net inflow (inflow-outflow) of material to the pu during the present printout reporting period. ERROR/WARNING ID: 238 1 The continuity error reported below is greater than 1 part in 1000 and is therefore considered high. Did you specify any "special actions"? If so, they could account for it. Relevant data are: DATE/TIME: 1963/6/30 24: 0 RCHRES 1 RELERR -1.000E+00 Where: STORS STOR 0.00000 0.0000E+00 MATIN MATDIF 0.00000 l.5243E-12 RELERR is the relative error (ERROR/REFVAL). ERROR is (STOR-STORS) -MATDIF. REFVAL is the reference value (STORS+MATIN). STOR is the storage of material in the processing unit (land-segment or reach/reservior) at the end of the present interval. STORS is the storage of material in the pu at the start of the present printout reporting period. MATIN is the total inflow of material to the pu during the present printout reporting period. MATDIF is the net inflow (inflow-outflow) of material to the pu during the present printout reporting period. ERROR/WARNING ID: 238 1 The continuity error reported below is greater than 1 part in 1000 and is therefore considered high. Did you specify any "special actions''? If so, they could account for it. Relevant data are: HydroMod_GN 6/15/2021 1 :35:28 PM Page 28 DATE/TIME: 1975/5/31 24: 0 RCHRES 1 RELERR -1.000E+00 Where: STORS STOR 0.00000 0.0000E+00 MATIN MATDIF 0.00000 6.0928E-12 RELERR is the relative error (ERROR/REFVAL). ERROR is (STOR-STORS) -MATDIF. REFVAL is the reference value (STORS+MATIN). STOR is the storage of material in the processing unit (land-segment or reach/reservior) at the end of the present interval. STORS is the storage of material in the pu at the start of the present printout reporting period. MATIN is the total inflow of material to the pu during the present printout reporting period. MATDIF is the net inflow (inflow-outflow) of material to the pu during the present printout reporting period. ERROR/WARNING ID: 238 1 The continuity error reported below is greater than 1 part in 1000 and is therefore considered high. Did you specify any "special actions"? If so, they could account for it. Relevant data are: DATE/TIME: 1976/6/30 24: 0 RCHRES 1 RELERR -1.000E+00 Where: STORS STOR 0.00000 0.0000E+00 MATIN MATDIF 0.00000 7.6951E-12 RELERR is the relative error (ERROR/REFVAL). ERROR is (STOR-STORS) -MATDIF. REFVAL is the reference value (STORS+MATIN). STOR is the storage of material in the processing unit (land-segment or reach/reservior) at the end of the present interval. STORS is the storage of material in the pu at the start of the present printout reporting period. MATIN is the total inflow of material to the pu during the present printout reporting period. MATDIF is the net inflow (inflow-outflow) of material to the pu during the present printout reporting period. ERROR/WARNING ID: 238 1 The continuity error reported below is greater than 1 part in 1000 and is therefore considered high. Did you specify any "special actions''? If so, they could account for it. Relevant data are: DATE/TIME: 1977/7/31 24: 0 RCHRES 1 RELERR -1.000E+00 ("" Where: STORS STOR 0.00000 0.0000E+00 MATIN MATDIF 0.00000 7.7188E-12 RELERR is the relative error (ERROR/REFVAL). ERROR is (STOR-STORS) -MATDIF. HydroMod_GN 6/15/2021 1 :35:28 PM Page 29 C REFVAL is the reference value (STORS+MATIN). STOR is the storage of material in the processing unit (land-segment or reach/reservior) at the end of the present interval. STORS is the storage of material in the pu at the start of the present printout reporting period. MATIN is the total inflow of material to the pu during the present printout reporting period. MATDIF is the net inflow (inflow-outflow) of material to the pu during the present printout reporting period. The count for the WARNING printed above has reached its maximum. If the condition is encountered again the message will not be repeated. HydroMod_GN 6/15/2021 1 :35:28 PM Page 30 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by: Clear Creek Solutions, Inc. 2005-2021; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1 (866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com HydroMod_GN 6/15/2021 1 :35:28 PM Page 31 C ATTACHMENT 3 Structural BMP Maintenance Information Use this checklist to ensure the required information has been included in the Structural BMP Maintenance Information Attachment: Preliminary Design/Planning/CEQA level submittal: Attachment 3 must identify: O<J Typical maintenance indicators and actions for proposed structural BMP(s) based on Section 7.7 of the BMP Design Manual BMP manual table used to describe general maintenance. Final Design level submittal: Attachment 3 must identify: n Specific maintenance indicators and actions for proposed structural BMP(s). This shall be based on Section 7. 7 of the BMP Design Manual and enhanced to reflect actual proposed components of the structural BMP(s) □ How to access the structural BMP(s) to inspect and perform maintenance LJ Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds) u Manufacturer and part number for proprietary parts of structural BMP(s) when applicable LJ Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level posts or other markings shall be included in all BMP components that will trap and store sediment, trash, and/or debris, so that the inspector may determine how full the BMP is, and the maintenance personnel may determine where the bottom of the BMP is. If required, posts or other markings shall be indicated and described on structural BMP plans.) c Recommended equipment to perform maintenance 1 1 When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management TABLE 7-2. Maintenance Indicators and Actions for Vegetated BMPs Typical Maintenance Maintenance Actions -Indicator(s) for.Vegetated 8MPs . . -· ... -· . . -. ··-· --. . -.. . . -. ... ----- Accumulation of sediment, litter, or Remove and properly dispose of accumulated materials, without debris damage to the vegetation. Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans. Overgtawn vegetation Mow or trim as appropriate, but not less than the design height of the vegetation per original plans when applicable (e.g. a vegetated swale may require a minimum vegetation height). Erosion due to concentrated irrigation Repair/ re-seed/ re-plant eroded areas and adjust the irrigation flow system. Erosion due to concentrated storm Repair/ re-seed/ re-plant eroded areas, and make apptapriate water runoff flow corrective measures such as adding erosion control blankets, adding stone at flow entry points, or minor re-grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the City Engineer shall be contacted prior to any additional repairs or reconstruction. Standing water in vegetated swales used Make appropriate corrective measures such as adjusting .irrigation for pretreatment and/or site design system, removing obstructions of debris or invasive vegetation, BMPs loosening or replacing top soil to allow for better infiltration, or minor re-grading for proper drainage. lf the issue is not corrected by restoring the BMP to the original plan and grade, the City Engineer shall be contacted pnor to any additional repairs or reconstruction. Standing water In bioretention, Make appropriate corrective measures such as biofiltration with partial retention, or inspecting/unclogging orifice opening, adjusting irrigation system, biofiltration areas, or flow-through removing obstructions of debris or invasive vegetation, clearing planter boxes* for longer than 96 hours underdrains (where applicable), or repairing/replacing clogged or following a storm event"'* compacted soils. Obstructed inlet or outlet structure Clear obstructions. Damage to structural components such Repair or replace as applicable. as weirs, inlet or outlet structures **These BMPs typically include a surface ponding layer as part of their function which may take 96 hours to drain following a storm event. A TT AC HM ENT 4 City standard Single Sheet BMP (SSBMP) Exhibit [Use the City's standard Single Sheet BMP Plan.] C ·---· -... ,_ APN, 216-300-06 L□T, 399 MAP, 006600 , . J.~ --ac, --rnM --co.~-· -:JM ..-ro:../ND 0£8A.::;, & CAP STA,"1,PE[, _ 11 "LS 5668 ,-AT ?H()P_ ,.,O,"!ivi:..'~ --""-\-·----- 3 3 ' __::,,_;;~··--,._ -·----·- 'L. - I . I J-,, , Ii; '" I -1 ··. I . . . . . ··---~-------- \ \ \ \ \ \ \ \ l'PN, 216-30 05 L □T, 400 MAP, 00660 . ----..... ,--··" ... . ----·"' -----.:.-----: ~ s - AP~, 2'.6-3( LCT, '. t'.AP, 160G (FF=96 25) PARTY RESPONSIBLE FOR MAINTENANCE: NAME: ADDRESS: PHONE NO.: 400 GIBRALTAR ST F ARAMARZ SAHBA 3525 DEL MAR HEIGHTS RD STE 724 SAN DIEGO, CA 92130 PLAN PREPARED BY: NAME: COMPANY: ADDRESS: BASHAR NAJAR NAJARS ENGINEERING 772 JAMACHA RD #157 EL CAJON, CA 92019 PHONE NO.: 619-971-7514 SIGNAllJRE No 78159 09/30/21 CfV\\. BMP CONSTRUCTION AND INSPECTION NOTES: THE EOW WILL VERIFY THAT PERMANENT BMPS ARE CONSTRUCTED AND OPERATING IN COMPLIANCE WITH THE APPLICABLE REQUIREMENTS. PRIOR TO OCCUPANCY THE EOW MUST PROVIDE: 1. PHOTOGRAPHS OF THE INSTALLATION OF PERMANENT BMPS PRIOR TO CONSTRUCTION, DURING CONSTRUCTION, AND AT FINAL INSTALLATION. 2. A WET STAMPED LETTER VERIFYING THAT PERMANENT BMPS ARE CONSTRUCTED AND OPERATING PER THE REQUIREMENTS OF THE APPROVED PLANS. 3. PHOTOGRAPHS TO VERIFY THAT PERMANENT WATER QUALITY TREATMENT SIGNAGE HAS BEEN INSTALILED. PRIOR TO RELEASE OF SECURITIES, THE DEVELOPER IS RESPONSIBLE FOR ENSURING THE PERMANENT BMPS HA VE NOT BEEN REMOVED OR MODIFIED BY THE NEW HOMEOWNER OR HOA WITHOUT THE APPROVAL OF THE CITY ENGINEER. BMP NOTES: 1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S RECOMMENDATIONS OR THESE PLANS. 2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER. 3. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER. 4. NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTION STAFF HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION AND INSTALLATION. 5. REFER TO MAINTENANCE AGREEMENT DOCUMENT. 6. SEE PROJECT SWMP FOR ADDITIONAL INFORMATION. BMP TABLE BMP BMP TYPE SYMBOL CASQA QUANTITY DRAWING ID # NO. NO. HYDROMODIFICATION & TREATMENT CONTROL 0 BIOFILTRATION ' TC-32 385 SF. CT 2019-0001 AREA ' ! PUD 2019-001 HYDROMODIFICATION ® WET VAULT @] MP-50 1 EA. CT 2019-0001 PUD 2019-001 SOURCE CONTROL 0 TRASH rn SD-32 1 EA. CT 2019-0001 ENCLOSURE PUD 2019-001 0 STENCILS NO DUMPING CT 2019-0001 DR~tlO SD-13 19 EA. PUD 2019-001 SHEET INSPECTION MAINTENANCE NO.(S) FREQUENCY FREQUENCY 2 QUARTERLY SEMI-ANNUALL) 2 TWICE PER TWICE PER YEAR YEAR 2 QUARTERLY AS NEEDED 2 QUARTERLY AS NEEDED ---------------+-------<,----+--+---< I SHEET I CITY OF CARLSBAD I SHEETS I ::;::::::::::;::;::::.,'.::::::::::::;::::=E::;:N::::;G::;:I N=E;::::E::;:Rl;::N=G;::D::::E:::P=A=R=TM=E::::N=T==::::..:===! SINGLE SHEET BMP SITE PLAN 0 1 o' 20· SCALE: 1 "= 1 0' DA TE INl11AL DATE INl11AL DATE INl11AL ENGINEER OF WORK REVISION DESCRIPTION OlHER APPROVAL a1Y APPROVAL LA COSTA VILLAS NORTH 400 GIBRALTAR CARLSBAD, CA 92009 APPROVED: ENGINEERING MANAGER DWN BY: .......,GN"'--1 CHKD BY: ~6~N~_, RVWD BY: RN 63912 RCE JASON S. GELDERT 9/30/22 EXPIRES DATE PROJECT NO. CT 2019-0001 PUD 2019-001