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Home My WebLink AboutPD 2024-0012; CARRILLO ELEMENTARY SCHOOL; PRIORITY DEVELOPMENT PROJET (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP); 2024-10-28Gityof __ ls a STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) TEMPLATE E-35 Development Services Land Development Engineering 1635 Faraday Avenue 442-339-2750 www .carlsbadca.gov E-35 (FOR PDP PROJECTS ONLY) CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR Carrillo Elementary school PROJECT ID: PD 2024-0012 DRAWING No.: (DWG -548-4A) GR No.: 2024-0014 ENGINEER OF WORK: MICHAEL D. SCHWEITZER, P.E. 59658 PREPARED FOR: SWS Engineering, Inc. 1635 Lake San Marcos Drive, Suite 200 San Marcos, California 92078 P: 760-744-0011 DATE: 10/28/2024 REV04/23 b d 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: DMA Exhibit Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1c: Harvest and Use Feasibility Screening (when applicable) Attachment 1d: Infiltration Feasibility Analysis (when applicable) Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations Attachment 1f: Trash Capture BMP Requirements 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 CERTIFICATION PAGE Project Name: Carrillo Elementary School Project ID: PD 2024-0012 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. 59658 Exp. 12-31-25 Engineer of Work's Signature, PE Number & Expiration Date Michael Schweitzer Print Name SWS Engineering, Inc. Company 10/28/2024 Date PROJECT VICINITY MAP VICI NI TY MAP Page 1 of 4 REV E-34 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, “PRIORITY DEVELOPMENT PROJECT (PDP) requirements or not considered a development project. This questionnaire will also determine if the project is subject to TRASH CAPTURE 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. A 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:APN: ADDRESS: The project is (check one): New Development Redevelopment The total proposed disturbed area is:ft2 ( ) acres The total proposed newly created and/or replaced impervious area is:ft2 ( ) 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. This Box for City Use Only City Concurrence: YES NO Date: Project ID: By: Development Services Land DevelopmentEngineering 1635 FaradayAvenue 442-339-2750 www.carlsbadca.gov STORM WATER STANDARDS QUESTIONNAIRE E-34 INSTRUCTIONS: Carrillo Elementary School 2875 Poinsettia Lane, Carlsbad, CA 92009 222-011-11 & 15 149,789 3.44 135,752 3.12 C cityof Carlsbad □ □ [g] □ E-34 Page 2 of 4 REV 0 STEP 1 TO BE COMPLETED FOR ALL PROJECTS To 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 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 6, mark the 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. STEP 2 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: Is 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; OR b)Designed and constructed to be hydraulically disconnected from paved streets or roads; OR c)Designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets guidance? 2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in 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? If you answered “yes” to one or more of the above questions, provide discussion/justification below, then go to Step 6, 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): If you answered “no” to the above questions, your project is not exempt from PDP, go to Step 3. □ ~ □ ~ □ ~ □ ~ E-34 Page 3 of 4 REV 0 * Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodiesdesignated 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. STEP 3 TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS To 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,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 more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public development projects 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 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 development project includes development on any natural slope that is twenty-five percent or greater. 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 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 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 of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? “Discharging Directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).* 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 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 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 day. 10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land 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 10%? (CMC 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, complete the trash capture question. If you answered “no” to all of the above questions, your project is a ‘STANDARD PROJECT’. Go to step 5, complete the trash capture question. □ lg] lg] □ lg] □ □ lg] lg] □ lg] □ lg] □ □ lg] □ lg] lg] □ □ lg] E-34 Page 4 of 4 REV 0 STEP 4 TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP) ONLY Complete 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) = sq. ft. Total proposed newly created or replaced impervious area (B) = sq. ft. Percent impervious area created or replaced (B/A)*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, complete the trash capture question. If you answered “no,” the structural BMP’s required for PDP apply to the entire development. Go to step 5, complete the trash capture question. STEP 5 TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS Complete the question below regarding your Project (SDRWQCB Order No. 2017-0077): YES NO Is the Project within any of the following Priority Land Use (PLU) categories? R-23 (15-23 du/ac), R-30 (23-30 du/ac), PI (Planned Industrial), CF (Community Facilities), GC (General Commercial), L (Local Shopping Center), R (Regional Commercial), V-B (Village-Barrio), VC (Visitor Commercial), O (Office), VC/OS (Visitor Commercial/Open Space), PI/O (Planned Industrial/Office), or Public Transportation Station If you answered “yes”, the ‘PROJECT’ is subject to TRASH CAPTURE REQUIREMENTS. Go to step 6, check the first box stating, “My project is subject to TRASH CAPTURE REQUIREMENTS …” and the second or third box as determined in step 3. If you answered “no”, Go to step 6, check the second or third box as determined in step 3. STEP 6 CHECK THE APPROPRIATE BOX(ES) AND COMPLETE APPLICANT INFORMATION My project is subject to TRASH CAPTURE REQUIREMENTS and must comply with TRASH CAPTURE REQUIREMENTS of the BMP Manual. I understand I must prepare a Storm Water Quality Management Plan (SWQMP). 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. If my project is subject to TRASH CAPTURE REQUIREMENTS, I will submit a TRASH CAPTURE Storm Water Quality Management Plan (TCSWQMP) per E-35A. 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) per E-35 template for submittal at time of application. Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations and exhibits to verify if ‘STANDARD PROJECT’ stormwater requirements apply. 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: Applicant Title: Applicant Signature: Date: 323,128 135,752 42.0 Michael D. Schweitzer CEO/President 10/28/2024 181 □ □ 181 □ □ 181 □ -~ - SITE INFORMATION CHECKLIST Project Summary Information Project Name Project ID Project Address Assessor's Parcel Number(s) (APN(s)) Project Watershed (Hydrologic Unit) Carlsbad 904 Parcel Area ________ Acres (____________ Square Feet) Existing Impervious Area (subset of Parcel Area) ________ Acres (____________ Square Feet) Area to be disturbed by the project (Project Area) ________ Acres (____________ Square Feet) Project Proposed Impervious Area (subset of Project Area) ________ Acres (____________ Square Feet) Project Proposed Pervious Area (subset of Project Area) ________ Acres (____________ Square Feet) Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project. This area includes but is not limited to off-site work including public improvements and temporary disturbance such as vehicle and equipment staging areas, construction worker foot traffic, soil/gravel piles, utility trenches, backfill cuts and slope keyways. Carrillo Elementary School PD 2024-0012 2875 Poinsettia Lane Carlsbad, CA 92009 222-011-11 9.7 524.146 7.4 323.128 3.44 149,789 3.12 135,752 0.32 14,037 Description of Existing Site Condition and Drainage Patterns Current Status of the Site (select all that apply): Existing development Previously graded but not built out 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 Impervious Areas Description / Additional Information: Underlying Soil belongs to Hydrologic Soil Group (select all that apply): NRCS Type A NRCS Type B NRCS Type C NRCS Type D Approximate Depth to Groundwater (GW): GW Depth < 5 feet 5 feet < GW Depth < 10 feet 10 feet < GW Depth < 20 feet GW Depth > 20 feet Existing Natural Hydrologic Features (select all that apply): Watercourses Seeps Springs Wetlands None Description / Additional Information: *HRWHFKQLFDO(YDOXDWLRQE\1LQ\R 0RRUHGDWHG 0D\ The existing project site is an elementary school. Existing landscape, buildings, parking lot and driveways, ✔ ✔ ✔ ✔ ✔ ✔ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ 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 site is an existing elementary school with one parcel area 9.76 ac which about 3.44 ac of the total site (located on the northeast) will be disturbed. The disturbed area consist of existing playground and grass filed. The site slopes range from 0-30%. The project site disturbed runoff drains in the southeasterly direction into the existing onsite storm drain system, then the existing public storm drain system. The runoff from undisturbed north and east slopes bypasses the site via proposed storm drain systems. The proposed series of storm drain systems will convey confluenced onsite treated runoff and slopes bypass runoff in a westerly direction into the existing onsite systems located on the southwest of the site which then discharges into public storm drain system. The site runoff will ultimately drain into San Marcos Creek, then to Batiquitos Lagoon and finally into Pacific Ocean. There is existing impervious area (rooftops areas to be swapped) that commingle with the proposed impervious area within the DMA 1-7 before discharging into proposed biofiltration basin in exchange to the proposed/replaced impervious area (ADA and path of travel and hard court) located on the southwest portion of the site in the parking lot and near the entrance driveway that can not be treated. Description of Proposed Site Development and Drainage Patterns Project Description / Proposed Land Use and/or Activities: List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features): List/describe proposed pervious features of the project (e.g., landscape areas): Does the project include grading and changes to site topography? Yes No Description / Additional Information: Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? Yes No Description / Additional Information: 1.0 PROJECT DESCRIPTION The proposed redevelopment project is a portion of the total 9.76 ac of two parcels that is located southeast of Poinsettia Lane and southwest of Melrose Drive in the City of Carlsbad, California. The redevelopment site consists of playground asphalt replacement, ADA/Path of travel improvement, new artificial turf (impermeable) in place of the existing grass field, and associated storm drain improvements, including inlets, grates, retaining walls and a treatment basin. The drainage study area is 4.97 ac, of which 1.35 ac is undisturbed slopes area that the runoff from them will bypass the disturbed area via proposed storm drain systems into the existing system located on the south portion of the site. The site has a current and future land use of Elementary School (Code 6806). The site impervious feature will be asphalt playground, artificial turf with impermeable liner, ADA and path of travel and hard court. The site pervious features will be biofiltration basin. The proposed disturbed area approximately 3.44 ac will be graded. The proposed disturbed area will be entirely graded, retaining wall will be installed and proposed storm drain systems will bypass the undisturbed slopes runoff and treated runoff (from disturbed area) into onsite existing storm drain system before discharging into public storm drain system as it does in existing condition. Runoff from the existing rooftop area within the DMA 1-7 will be swapped to be treated in exchange to the runoff from the ADA and path of travel and hard court improvement that can not be treated ✔ ✔ □ □ □ □ 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 Interior floor drains and elevator shaft sump pumps Interior parking garages Need for future indoor & structural pest control Landscape/Outdoor Pesticide Use Pools, spas, ponds, decorative fountains, and other water features Food service Refuse areas Industrial processes Outdoor storage of equipment or materials Vehicle and Equipment Cleaning Vehicle/Equipment Repair and Maintenance Fuel Dispensing Areas Loading Docks Fire Sprinkler Test Water Miscellaneous Drain or Wash Water Plazas, sidewalks, and parking lots ✔ ✔ ✔ ✔ ✔ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ Identification of Receiving 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): 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 Identification of Project Site Pollutants Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see Table B.6-1 below): Pollutant Not Applicable to the Project Site Anticipated from the Project Site Also a Receiving Water Pollutant of Concern Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Oil & Grease Bacteria & Viruses Pesticides the proposed site will discharge offsite into the existing public storm drain system located on the southeast portion of the site and then into stream prior to discharge into San Marcos Creek and then Batiquitos Lagoon and ultimately into Pacific Ocean. Lower San Marcos Creek Benthic Community Effects, Indicator Bacteria Effects, Nitorgen, Phosphorus, Selenium, Toxicity Batiquitos Lagoon Toxicity NA Pacific Ocean NA X XX XX X X X X X X TABLE Error! No text of specified style in document.-1. Anticipated and Potential Pollutants Generated by Land Use Type General Pollutant Categories Priority Project Categories Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Oil & Grease Bacteria & Viruses Pesticides Detached Residential Development X X X X X X X Attached Residential Development X X X P(1) P(2) P X Commercial Development >one acre P(1) P(1) X P(2) X P(5) X P(3) P(5) Heavy Industry X X X X X X Automotive Repair Shops X X(4)(5) X X Restaurants X X X X P(1) Hillside Development >5,000 ft2 X X X X X X Parking Lots P(1) P(1) X X P(1) X P(1) Retail Gasoline Outlets X X X X X Streets, Highways & Freeways X P(1) X X(4) X P(5) X X P(1) X = anticipated P = potential (1) A potential pollutant if landscaping exists onsite. (2) A potential pollutant if the project includes uncovered parking areas. (3) A potential pollutant if land use involves food or animal waste products. (4) Including petroleum hydrocarbons. (5) Including solvents. Trash Capture BMP Requirements The project GRHVQRWQHHGWRPHHWTrash Capture BMP Requirements (see Section 4.4 of the BMP Design Manual): 1) GXHWRWKHJHQHUDOODQGXVH Description / Discussion of Trash Capture BMPs: Hydromodification Management Requirements Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)? Yes, hydromodification management flow control structural BMPs required. 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. 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 required if hydromodification management requirements apply 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 Appendix H of the manual been performed? H.6.1 Site-Specific GLU Analysis H.7 Downstream Systems Sensitivity to Coarse Sediment H.7.3 Coarse Sediment Source Area Verification 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? 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. Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections H.2, H.3, and H.4 as applicable, and the areas are identified on the SWQMP Exhibit. Discussion / Additional Information: See CCSYA Exhibit ✔ ✔ □ □ □ □ □ □ □ □ □ □ Flow Control for Post-Project Runoff* *This Section only required if hydromodification management requirements apply 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. Has a geomorphic assessment been performed for the receiving channel(s)? No, the low flow threshold is 0.1Q2 (default low flow threshold) Yes, the result is the low flow threshold is 0.1Q2 Yes, the result is the low flow threshold is 0.3Q2 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) POC-1 is located southeast portion of the site where the treated runoff from biofiltration basin discharges into proposed 24" storm drain system prior to discharging into the existing public storm drain system. ✔□ □ □ □ Other Site Requirements 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. 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. Majority of existing development will not be redeveloped. E-36 Page 1 of 4 Revised 0 Development Services Land Development Engineering 1635 Faraday Avenue 442-339-2750 www.carlsbadca.gov STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Project Information Project Name: Project ID: DWG No. or Building Permit No.: Baseline BMPs for Existing and Proposed Site Features Complete the Table 1 - Site Design Requirement to document existing and proposed site features and the BMPs to be implemented for them. All BMPs must be implemented where applicable and feasible. Applicability is generally assumed if a feature exists or is proposed. BMPs must be implemented for site design features where feasible. Leaving the box for a BMP unchecked means it will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided in the area below. The table provides specific instructions on when explanations are required. Table 1 - Site Design Requirement A.Existing Natural Site Features (see Fact Sheet BL-1) 1. Check the boxes below for each existing feature on the site. 1.Select the BMPs to be implemented for each identified feature. Explain why any BMP not selected is infeasible in the area below. SD-G Conserve natural features SD-H Provide buffers around waterbodies Natural waterbodies Natural storage reservoirs & drainage corridors -- Natural areas, soils, & vegetation (incl. trees)-- B.BMPs for Common Impervious Outdoor Site Features (see Fact Sheet BL-2) 1. Check the boxes below for each proposed feature. 2. Select the BMPs to be implemented for each proposed feature. If neither BMP SD-B nor SD-I is selected for a feature, explain why both BMPs are infeasible in the area below. SD-B Direct runoff to pervious areas SD-I Construct surfaces from permeable materials Minimize size of impervious areas Streets and roads Check this box to confirm that all impervious areas on the site will be minimized where feasible. If this box is not checked, identify the surfaces that cannot be minimized in area below, and explain why it is Sidewalks & walkways Parking areas & lots Driveways Patios, decks, & courtyards Hardcourt recreation areas Carrillo Elementary School PD 2024-0012 GR2024-0014 ■■ □ □ □ □ □ □ □ □ □ {'city of Carlsbad □ □ □ □ □ □ □ LI □ LI □ □ □ □ □ □ □ E-36 Page 2 of 4 Revised 0 Other: _______________infeasible to do so. C. BMPs for Rooftop Areas:Check this box if rooftop areas are proposed and select at least one BMP below. If no BMPs are selected, explain why they are infeasible in the area below. (see Fact Sheet BL-3) SD-B Direct runoff to pervious areas SD-C Install green roofs SD-E Install rain barrels D. BMPs for Landscaped Areas: Check this box if landscaping is proposed and select the BMP below SD-K Sustainable Landscaping If SD-K is not selected, explain why it is infeasible in the area below. (see Fact Sheet BL-4) Provide discussion/justification for site design BMPs that will not be implemented (either partially or fully): Baseline BMPs for Pollutant-generating Sources All development projects must complete Table 2 - Source Control Requirement to identify applicable requirements for documenting pollutant-generating sources/ features and source control BMPs. BMPs must be implemented for source control features where feasible. Leaving the box for a BMP unchecked means it will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided in the area below. The table provides specific instructions on when explanations are required. Table 2 - Source Control Requirement A. Management of Storm Water Discharges 1. Identify all proposed outdoor work areas below Check here if none are proposed 2. Which BMPs will be used to prevent materials from contacting rainfall or runoff? (See Fact Sheet BL-5) Select all feasible BMPs for each work area 3. Where will runoff from the work area be routed? (See Fact Sheet BL-6) Select one or more option for each work area SC-A Overhead covering SC-B Separation flows from adjacent areas SC-C Wind protection SC-D Sanitary sewer SC-E Containment system Other Trash & Refuse Storage Materials & Equipment Storage The proposed project site is replacement of the existing playground asphalt new artificial turf in place of the existing grass field, and associated storm drain improvements,including inlets, grates, ADA and path of travel improvement, retaining walls and a biofiltration basin which implementing the BMP SD-B and SD-1 inapplicable and infeasible. All the improvement areas including the existing rooftop within DMA-1 will be routed into proposed biofiltration basin for treatment. The project site is a redevelopment portion of an existing school site that does not propose building Rooftop. The proposed project site consists of playground asphalt replacement, new artificial turf in place of the existing grass field, and associated storm drain improvements, including inlets, grates, ADA and path of travel improvement, retaining walls and a biofiltration basin. Please see the landscaping plan □ □ □ D □ □ □ Iii Iii Iii □ □ □ □ □ □ □ □ □ □ □ □ □ □ E-36 Page 3 of 4 Revised 0 Loading & Unloading Fueling Maintenance & Repair Vehicle & Equipment Cleaning Other: _________________ B. Management of Storm Water Discharges (see Fact Sheet BL-7) Select one option for each feature below: x Storm drain inlets and catch basins …are not proposed will be labeled with stenciling or signage to discourage dumping (SC-F) x Interior work surfaces, floor drains & sumps … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters x Drain lines (e.g. air conditioning, boiler, etc.) … are not proposed will not discharge directly or indirectly to the MS4 or receiving waters x Fire sprinkler test water …are not proposed will not discharge directly or indirectly to the MS4 or receiving waters Provide discussion/justification for source control BMPs that will not be implemented (either partially or fully): Inlets: SWPPP, inlets marked with "No Dumping! Flows to Lagoon" or similar, regular maintenance Pest control: Building design that discourages pest entry, 1PM plan Pesticide use: Landscaping designed/plant selection to minimize need for fertilizers/pesticides Refuse areas: Grading to minimize runoff, provide adequate# of receptacles, regular inspection/repair/trash pick-up Fire sprinkler test water: Drain to sanitary sewer Hardscape/parking lots: Regular sweeping, debris collection to prevent entry into the storm drain system, cleaning agents discharged into sanitary sewer □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ Iii Iii □ Iii □ Iii □ E-36 Page 4 of 4 Revised 0 Form Certification This E-36 Form is intended to comply with applicable requirements of the city’s BMP Design Manual. I certify that it has been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the review of this form by City staff is confined to a review and does not relieve me as the person in charge of overseeing the selection and design of storm water BMPs for this project, of my responsibilities for project design. Preparer Signature: Date: Print preparer name: 10/28/2024 Michael D. Schweitzer ~ j d ~V\ I - 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). PDP’s subject to trash capture requirements must implement trash capture devices (see Chapter 4 of the BMP Design Manual). Storm water pollutant control, flow control for hydromodification management and trash capture can all 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 and trash capture devices, indicate whether pollutant control, trash capture and flow control BMPs are integrated together or separate. [Continue on next page as necessary.] The impervious area was calculated for the redevelopment portion of the site and compared to the total site existing impervious area. Since the proposed impervious area is less than 50% of the existing impervious area, the project is only required to mitigate the proposed development and not the entire site. The project tributary area were delineated and used to calculated the Design Capture Volume (DCV). There is existing impervious area (Swap area: rooftops) that commingle with the proposed impervious area within the DMA 1-7 before discharging into proposed biofiltration basin in exchange to the proposed/replaced impervious area (ADA and path of travel and hard court) located on the southwest portion of the site in the parking lot and near the entrance driveway that can not be treated. The proposed site will incorporate a biofiltration basin in the southeast corner of the site. All the runoff from the improved playground and artificial impermeable turf will drain into biofiltration for treatment prior to discharge into existing public storm drain system via proposed storm drain systems. The proposed BMP will be used to meet water quality pollutant control requirements and Hydromodification control. [Continued from previous page – This page is reserved for continuation of description of general strategy for structural BMP implementation at the site.] Structural BMP Summary Information [Copy this page as needed to provide information for each individual proposed structural BMP] Structural BMP ID No. DWG _________ Sheet No. __________ Type of structural BMP: Retention by harvest and use (HU-1) Retention by infiltration basin (INF-1) Retention by bioretention (INF-2) Retention by permeable pavement (INF-3) Dry Wells (INF-4) Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1) Proprietary Biofiltration (BF-3) Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) Detention pond or vault for hydromodification management Trash capture device Other (describe in discussion section below) Purpose: Pollutant control only Hydromodification control only Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP Trash Capture Other (describe in discussion section below) Discussion (as needed): ZLWKQXWULHQWVHQVLWLYHPHGLD%) IMP-1 548-4A 13, 15, 19 ✔ ✔ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ □ 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 Sequence Contents Checklist Attachment 1a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24”x36” Exhibit typically required) Included Attachment 1b Tabular Summary of DMAs Showing DMA ID matching DMA Exhibit, DMA Area, and DMA Type (Required)* *Provide table in this Attachment OR on DMA Exhibit in Attachment 1a Included on DMA Exhibit in Attachment 1a Included as Attachment 1b, separate from DMA Exhibit Attachment 1c Form K-7, Harvest and Use Feasibility Screening Checklist (Required unless the entire project will use infiltration BMPs) Refer to Appendix B of the BMP Design Manual to complete Form K-7. Included Not included because the entire project will use infiltration BMPs Attachment 1d Infiltration Feasibility Analysis (Required unless the project will use harvest and use BMPs) Refer to Appendix D of the BMP Design Manual. Included Not included because the entire project will use harvest and use BMPs Attachment 1e Pollutant Control BMP Design Worksheets / Calculations (Required) Refer to Appendices B, E, and I of the BMP Design Manual for structural pollutant control and significant site design BMP design guidelines Included Attachment 1f Trash Capture BMP Design Calculations Refer to Appendices J of the BMP Design Manual for Trash capture BMP design guidelines Included Not included because the entire project is not subject to trash capture requirements ✔ ✔ ✔ ✔ ✔ ✔ □ □ □ □ □ □ □ □ □ □ Use this checklist to ensure the required information has been included on the DMA Exhibit: The DMA Exhibit must identify: Underlying hydrologic soil group Approximate depth to groundwater Existing natural hydrologic features (watercourses, seeps, springs, wetlands) Critical coarse sediment yield areas to be protected (if present) Existing topography and impervious areas Existing and proposed site drainage network and connections to drainage offsite Proposed grading Proposed impervious features Proposed design features and surface treatments used to minimize imperviousness Drainage management area (DMA) boundaries, DMA ID numbers, and DMA 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) Tabular DMA Summary ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔□ □ □ □ □ □ □ □ □ □ □ □ Us e t h e f o l l o w i n g t a b l e f o r T a b u l a r D M A S u m m a r y '0$ZLOOEHVZDSSHGZLWK'0$7KHDUHDVIRU'0$LVDOUHDG\LQFOXGHGLQ'0$ '0$ 879 ,03IRU '0$ %)IRU '0$ 32&IRU '0$ DMA-1 DMA-2 DMA-3 DMA-4 DMA-5 DMA-6 DMA-7 DMA-8 DMA-9 DMA-10 0.15 0.09 0.47 0.22 0.62 0.21 1.83 1.35 0.62 0.57 0.15 0.09 0.44 0.22 0.62 0.21 1.54 0 0.62 0.54 100 100 94 100 100 100 84 0 100 100 C C C C C C C C C C 1-7 BYPASS SWAP SWAP 1-7 3.58 3.26 91 C 0.84 6,879 1-7 POC-1 Worksheet B-1: Tabular Summary of DMAs •~"Irf',a,,. .... """;,11n11ra, 11111lllJl',f~ II '\WiTI°":''l:311lffil B :"klt. V Impervious Area DCV DMA Unique Area Weighted Treated By (BMP Pollutant Control Drains to Identifier (acres) Area %Imp HSG Runoff (cubic ID) Type (POC ID) (acres) Coefficient feet) ... , 1111111 ..... 111111t',f!\I ,111n•11r.■■ 111a l1.11( 1w11r;10lln1J11 ,:..,.-11-.'!111111 UJl..-,11 IIJ.'\l,IIIJ1'1IUJ~· a•r;1■u1~a,, Total DMA Total Area Total DCV Impervious Weighted Total Area No. of No. ofDMAs Area Area %Imp Runoff (cubic Treated (acres) POCs (acres) (acres) Coefficient feet) Where: DMA" Drainage Management Area; Imp " Imperviousness; HSG" Hydro logic Soil Group; DCV" Design Capture Volume; BMP:. Best Management P cdce; POC " Point of compliance; ID " identifier; No. " Number ATTACHMENT 1a DM A - 9 A ( S W A P ) T O B E T R E A T E D 14, 7 2 6 S F DM A - 1 0 ( S W A P ) N O T T O B E T R E A T E D 24,8 4 3 S F BIOFILTRATION BASIN BOTTOM AREA: 5,583 SF TOP AREA: 8,208 SF DMA-9B (SWAP) TO BE TREATED 12,400 SF POC-1 DATE: Feb 26, 25 10:46am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2024\Project Files\24-172\PROD\Reports\WQMP\24-172_DMA Map.dwg DMA MAP CARRILLO ELEMENTARY SHCOOL FOR (1 OF 2) ' , VICINITY MAP NOT TO SCALE , , BLDG BLDG , 1 /:~~E7;"; r \ A ~ D!..cnG LOG !/TTL ~~-~-:ti! ,,#i---!JD-J INLET ;:.. --q}/~ ~--. ..... ' BLDG AC I AC t-1---i-'--J--// • ~-~~ I : I AC\< f '- 'V i !:? . .~~=· . :, BLDG 0 POOL 0 C •• BLDG GRASS BLDG ?:;~~~~ ::-a;,= -=~ 55 ~ 91,i = = 0 .,mu-=-'--~~i.:::: --;:= --=--- TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES BLDG BLDG ~ASS \ 50 25 BLDG WALL 1sws N WALL DMA IMP # AREA (SF) 1 6,579 2 3,915 3 20,452 4 1 9,387 5 26,881 6 8,964 7 79,809 8 58,841 A+B * 27,126 1 O* 24,843 LEGEND -------- "c" > 5 & < 10' MAJOR BASIN BOUNDARY FLOW PATH SOIL TYPE GROUNDWATER TABLE PER SOIL REPORT BY NINYO & MOORE DATED MAY 17, 2024 -No EXISTING NATURAL HYDROLOGIC FEATURES (WATERCOURSES, SEEPS, SPRINGS, WETLANDS) -No CRITICAL COARSE SEDIMENT YIELD AREAS TO BE PROTECTED -No PROPOSED DESIGN FEATURES AND SURFACE TREATMENTS USED TO MINIMIZE IMPERVIOUSNESS CONG V-0/Y SYMBOL ............ ., .............. ~ ~ ~ ~ ~ ~ ~ ~ DESCRIPTION LANDSCAPE (BIOFIL TRATION) IMPERVIOUS ASPH IMPERVIOUS CONC IMPERVIOUS TURF IMPERVIOUS (CONC) IMPERVIOUS (ASPH) SWAP AREAS TABULAR SUMMARY OF DMAs IMPERVIOUS AREA (SF) 6,579 3,915 19,083 9,387 26,881 8,964 67,141 0 27,126 24,843 % IMP 100 100 93 100 100 100 84 100 100 100 HSG C C C C C C C C C C AREA WEIGHTED RUNOFF COEFFICIENT 0.84 VOLUME (DCV) 6,952 TREATMENT SYSTEM BF-1 (BIOFILTRATION) BYPASS THE SITE SWAP-TO BE TREATED SWAP-NOT TO BE TREATED *EXISTING ROOFS (DMA 9A+9B) WILL BE SWAPPED TO BE TREATED IN EXCHANGE WITH THE COMBINED MULTIPLE DISTURBED AREAS (DMA-10) THAT CAN NOT BE TREATED NOTE: TOTAL PROPOSED DISTURBED AREA: DMAs (3+4+5+7+10) - EXITING UNDISTURBED AREA (GRAY HATCH) WITHIN THE DMAS TOTAL PROPOSED NEWLY CREA TED /REPLACED IMPERVIOUS AREA = 149,789 SF = 135,752 SF 0 50 100 150 SWS ENGINEERING, INC. CIVIL ENGINEERJNG • LAND PLANNING • SURVEYING -----------SCALE IN FEET GRAPHIC SCALE 1635 Lake San Marcos Drive, Suite 200 San Marcos, CA 92078 P: 760-744-0011 F: 760-744-0046 • "' .., " RESTRICTOR PLATE ELEVATION PLAN NTS DATE: Feb 26, 25 10:48am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2024\Project Files\24-172\PROD\Reports\WQMP\24-172_DMA Map.dwg DMA MAP CARRILLO ELEMENTARY SHCOOL FOR DMA MAP (2 OF 2) TABLE: BIOFILTRATION SOIL MEDIA (BSM) SAND 60-80% BY VOLUME TOPSOIL 0-20% BY VOLUME COMPOST 20% BY VOLUME i-------~ BASIN TOP (8,028 SF)-------" 2'x2' RISER OUTLET STRUCTURE TOP ELEV: 264.92' BERM: PLAN VIEW FOR ELV 3.5' TALL CHAIN LINK FENCE BERM: PLAN VIEW FOR LOCA Tl ON BASIN BOTTOM (ELV: 264.42') 'v BASIN TOP ELEV 266.42' 100-YR STORAGE DEPTH 3" MULCH (264.17') 18" MEDIA (262.67') WITH A MIN 5" IN/HR PER "BIOFILTRATION SOIL MEDIA (BSM) TABLE" 3'' FILTER WASH SAND (26242) ' =11 •. ;I J 11 3" FILTER PEA GRAVEL -------1 ( 2 6 2. 1 7') ---.--+---------c;t+F- 33" GRAVEL SAND (259.42') 3/4 IN CRUSH ROCK j 6" PER FORA TED Pl PE (3" FROM THE BOTTOM) IMP-1: - Tf I -=1 ~I 0 , I I TREATMENT IS AT THE BOTTOM = 5,583 SF BASIN TOP AREA = 8,028 SF 'v 3.83" ORIFICE (259.79') TREATMENT AT i----BOTTOM AREA ------i ( 5,583) 24" 2' SURFACE DEPTH 3: 1 SIDE SLOPE 6" WO DEPTH PLANTS AND GRASS HMP STORAGE DEPTH 1: 1 EXCAVATED SIDE SLOPE EXISTING GROUND IMPERVIOUS LINER 30 MIL PVC OR EQUIV. CONTRACTOR TO SUBMIT PRODUCT DATA TO ENGINEER OF RECORD FOR APPROVAL PRIOR TO CONSTRUCTION. OUTLET PIPE (259.54') NOTE: ELEVATIONS SHOWN HERE REFERENCE DATUM NGVD29 BIOFIL TRATION FACILITY DETAIL (IMP-1) 4'' PVC SCREW CAP RIM IS 12" ABOVE -~ GRADE ?--- 4" NON PER FORA TED2.___j_--~~--~ STANDPIPE WATER TIGHT CAP ON TERMINAL END OF PIPE (] 000000 000000 USE 45· WYE AND FITTING OR EQUIVALENT DIRECTION CLEANOUT TO CONNECT UNDERDRAIN TO STANDPIEP 3" MULCH 18" MEDIA 3" FILTER WASH SAND 3"FILTER PEAS GRAVEL 33" GRAVEL SAND CONNECT PIPE TO DOWNSTREAM SYSTEM 6" PERFORATED UNDERDRAIN Scale: NTS ,n, 1~ " . . . . . . . . . . RESTRICTOR PLATE (SEE BELOW) APPROVED CORROSION RESISTANT CONCRETE ANCHORS (4X) WITH PLATE WASHERS PERF PIPE BEHIND 2x2 RISER CONTINUOUS BEAD OF SEALANT WALL AROUND RESTRICTOR PLATE PERIMETER 12"---I 2" 1 l--1 ~-,- 2 "1 g" ORIFICE (SEE BELOW) BIOFILTRATION BASIN ADHERED TO CONCRETE WITH APPROVED ADHESIVE (LOCTITE EPOXY-HEAVY DUTY) AND VESTIL CONCRETE WEDGE ANCHOR BOLTS (MODLE # AS-125 (1/2" DIA, 5" DEPTH) SEE RESTRICTOR PLATE E_EVATION 3.83" FLOW-CONTROL ORIFICE 259. 79' RISER BOTTOvl PER DETAIL AND CHA I GRAVEL PER BIOFILTRATION DETAIL GRAVEL STORAGE \ IU'~:l..&:~...!d.""-'! --I=~-3" GR A VE L BASE IMPERMEABLE LINER PER BIOFIL TRATION DETAIL BIOFILTRATION PLATE & ORIFICE DETAIL {IMP-1) Scale: NTS ;'; •• 00 00 OUTLET 00 2'x2' RISER ~ ,--' 00 ' L STRUCTURE 00 / ., .. .. -C .. •• .. Fl OW US, . ~ . . . . . . . . " OUTLET PIPE f . . . . . . . PLATE FLO~ ..... '-...._ RESTRICTED ,· , f / ',c' ' /,_-' BIOFILTRATION C.O. DETAIL (IMP-1) BIOFILTRATION OUTLET DETAIL (IMP-1) Scale: NTS Scale: NTS NOTE: ELEVATIONS SHOWN HEREON ARE IN THE CITY OF CARLSBAD DATUM (NGVD29) SWS ENGINEERING, INC. CIVIL ENGINEERJNG • LAND PLANNING • SUR VE YING 1635 Lake San Marcos Drive, Suite 200 San Marcos, CA 92078 P: 760-744-0011 F: 760-744-0046 • "' .., " ATTACHMENT 1c 1.Is there a demand for harvested water ( check all that apply) at the project site that is reliably present duringthe wet season?D Toilet and urinal flushingD Landscape irrigationD 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 providedin Section B.3.2.3.Calculate the DCV using worksheet B-2.1.DCV = ____ (cubic feet) 3a. Is the 36 hour demand greater than or equal to the DCV? □ Yes / □No c:::> 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 than0.25DCV but less than the full DCV?□Yes / □No c:::> 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? D Yes, refer to Appendix E to select and size harvest and use BMPs. □No, select alternate BMPs.1-26 3c. Is the 36 hour demand less than 0.25DCV? □Yes,().Harvest and use is considered to be infeasible. February 2016 Form I-7 ATTACHMENT 1d Appendix I: Forms and Checklists I-3 February 2016 Categorization of Infiltration Feasibility Condition Form I-8 Part 1 - Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria Screening Question Yes No 1 Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. Appendix I: Forms and Checklists I-4 February 2016 Form I-8 Page 2 of 4 Criteri a Screening Question Yes No 3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 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 Appendix C.3. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. Part 1 Result * If all answers to rows 1 - 4 are “Yes” a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration If any answer from row 1-4 is “No”, infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a “full infiltration” design. Proceed to Part 2 *To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or studies may be required by the City to substantiate findings. Appendix I: Forms and Checklists I-5 February 2016 Form I-8 Page 3 of 4 Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria Screening Question Yes No 5 Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability 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: 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. Appendix I: Forms and Checklists I-6 February 2016 Form I-8 Page 4 of 4 Criteria Screening Question Yes No 7 Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. Part 2 Result* If all answers from row 5-8 are yes then partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration. If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. *To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or studies may be required by the City to substantiate findings. Appendix D: Geotechnical Engineer Analysis D-1 Jan. 2024 Appendix D Geotechnical Engineer Analysis Analysis of Infiltration Restrictions This section is only applicable if the analysis of infiltration restrictions is performed by a licensed engineer practicing in geotechnical engineering. The SWQMP Preparer and Geotechnical Engineer must work collaboratively to identify any infiltration restrictions identified in Table D.1-1 below. Upon completion of this section, the Geotechnical Engineer must characterize each DMA as Restricted or Unrestricted for infiltration and provide adequate support/discussion in the geotechnical report. A DMA is considered restricted when one or more restrictions exist which cannot be reasonably resolved through site design changes. Table D.1-1: Considerations for Geotechnical Analysis of Infiltration Restrictions Restriction Element Is Element Applicable? (Yes/No) Mandatory Considerations BMP is within 100’ of Contaminated Soils BMP is within 100’ of Industrial Activities Lacking Source Control BMP is within 100’ of Well/Groundwater Basin BMP is within 50’ of Septic Tanks/Leach Fields BMP is within 10’ of Structures/Tanks/Walls BMP is within 10’ of Sewer Utilities BMP is within 10’ of Groundwater Table BMP is within Hydric Soils BMP is within Highly Liquefiable Soils and has Connectivity to Structures BMP is within 1.5 Times the Height of Adjacent Steep Slopes (≥25%) County Staff has Assigned “Restricted” Infiltration Category Optional Considerations BMP is within Predominantly Type D Soil BMP is within 10’ of Property Line BMP is within Fill Depths of ≥5’ (Existing or Proposed) BMP is within 10’ of Underground Utilities BMP is within 250’ of Ephemeral Stream Other (Provide detailed geotechnical support) Result Based on examination of the best available information, I have not identified any restrictions above.  Unrestricted Based on examination of the best available information, I have identified one or more restrictions above.  Restricted Table D.1-1 is divided into Mandatory Considerations and Optional Considerations. Mandatory No No No No No No Yes No No No N/A Yes No Yes No No Yes, expansive soils X D.1 Appendix D: Geotechnical Engineer Analysis D-2 Jan. 2024 Considerations include elements that may pose a significant risk to human health and safety and must always be evaluated. Optional Considerations include elements that are not necessarily associated with human health and safety, so analysis is not mandated through this guidance document. All elements presented in this table are subject to the discretion of the Geotechnical Engineer if adequate supporting information is provided. Applicants must evaluate infiltration restrictions through use of the best available data. A list of resources available for evaluation is provided in Section B.2 5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com August 23, 2024 Project No. 108822013 Ms. Tova Corman San Marcos Unified School District 255 Pico Avenue, Suite 100 San Marcos, California 92069 Subject: Responses to Geotechnical Report Review Comments and Supplemental Recommendations Carrillo Elementary School 2875 Poinsettia Lane, Carlsbad, California Dear Ms. Corman: As requested, we have prepared this letter providing our responses to the City of Carlsbad geotechnical report review comments letter dated August 4, 2024 regarding our geotechnical evaluation for the Carrillo Elementary School Field Turf Replacement project dated May 17, 2024. Our responses are included herein. In addition to the comment responses provided below, at the request of the project civil engineer, we are providing supplemental recommendations for the replacement flexible pavements for fire lanes and pedestrian sidewalks in the western parking lot and driveway entrance to the school campus. The recommendations provided in this letter are considered supplementary and the previous recommendations, findings, and conclusions presented in the original report (Ninyo & Moore, 2024a) and addendum (Ninyo & Moore, 2024b) remain applicable and valid. Comment 1: Please provide a statement addressing the potential impact of the proposed project on adjacent off-site properties from a geotechnical standpoint. Response: Provided the recommendations in the referenced report (Ninyo & Moore, 2024a) and addendum (Ninyo & Moore, 2024b) are incorporated into the design and construction of the proposed project, the proposed project is not anticipated to adversely impact the adjacent off-site properties. JVin90&,v\OOl"'e Geotechnical & Environmental Sciences Consultants Ninyo & Moore | 2875 Poinsettia Lane, Carlsbad, California | 108822013 | August 23, 2024 Comment 2: With respect to possible dewatering that may be performed by the contractor to facilitate the proposed earthwork and construction of the French drain system, please provide a discussion addressing the potential impact of dewatering on the existing adjacent school structures and/or city ROW (Poinsettia Lane and Melrose Drive) bounding the project site. Please provide recommendations as necessary to address possible dewatering and prevent adverse impact to existing structures/improvements and city ROW bounding the subject site. Response: Dewatering measures, if needed to facilitate the construction operations for the proposed project, are anticipated to result in relatively minor drawdown of the perched water conditions at the site. Due to the potential for a limited amount of drawdown, settlements from potential dewatering measures are anticipated to be negligible. Accordingly, we do not anticipate that site dewatering efforts for the proposed project to adversely impact existing onsite structures or the and adjacent Right-of-Way (ROW) improvements. Comment 3: Please clarify the recommendations for the frequency of testing to confirm that the specifications for the cement treated soil (CTS) are being met during the proposed earthwork construction. Response: We recommend that 1 field density test be performed for every 5,000 square feet of cement treated soil (CTS) subgrade or fraction thereof, with no less than 2 field density tests being performed per day of placement. Additionally, the cement application rate should be periodically monitored during the application process. Due to no specific compressive strength recommendation for this project, we do not consider the performance of unconfined compressive strength testing to be needed. Comment 4: Please provide the type of pipe (Sch. 40 PVC, etc.) that is recommended for the proposed French drain system. Response: From a geotechnical standpoint, we recommend that the piping for the French drain system consists of Schedule 40 polyvinyl chloride (PVC) pipe or an equivalent. Pipe material and specifications should be further evaluated by the project civil engineer. Comment 5: Please provide a summary list of the geotechnical observations/testing services that should be provided during the construction of this project. Response: We recommend that the geotechnical observations/testing services during construction include the following: •Geologic/engineering field services to evaluate the suitability of remedial excavations,temporary cut slopes, and foundation excavations including drilled pier foundationexcavations. 2 Ninyo & Moore | 2875 Poinsettia Lane, Carlsbad, California | 108822013 | August 23, 2024 • Field observation and in-place density testing during grading operations including such items as general site work, trench backfill, retaining wall backfill, CTS subgrade preparation, subgrade preparation, and pavement construction. • Laboratory testing of the soils used during the earthwork and paving operations. FLEXIBLE FIRE LANE PAVEMENT – WESTERN PARKING LOT Based on our discussions with the project civil engineer, we understand that portions of the existing asphalt concrete (AC) fire lane in the western parking lot are to be reconstructed. For the design of the new reconstructed AC fire lane, we have used an assumed design R-value of 5 and a Traffic Index (TI) 7 for the basis of the preliminary design. The R-value of 5 is based on the information presented in the original site geotechnical report (Kleinfelder, 1998) for the school development that also used a design R-value of for the site pavements. The preliminary recommended flexible pavement section is presented in Table 1 below. Table 1 – Preliminary Flexible Pavement Sections for Western Parking Lot Fire Lane Traffic Index (Pavement Usage) Design R-Value Asphalt Concrete Thickness (inches) Aggregate Base Thickness (inches) 7 (Fire Lanes) 5 4 15 As indicated, the section assumes a TI of 7.0 for the fire lane. If traffic loads are different from those assumed, the pavement design should be re-evaluated. We recommend that the upper 12 inches of subgrade soils and the layer of aggregate base materials be compacted to a relative compaction of 95 percent relative density as evaluated by the current version of ASTM International (ASTM) D 1557. New fire lanes that are constructed in accordance with the recommendations provided herein are considered to be an all-weather surface that can support 72,000 pounds of vehicle loading and HS-20 loading conditions PEDESTRIAN SIDEWALKS - WESTERN PARKING LOT Exterior pedestrian concrete sidewalks should be 4 inches in thickness and should be reinforced with No. 3 reinforcing bars placed at 24 inches on-center both ways. A vapor retarder is not needed for exterior pedestrian concrete sidewalks. To reduce the potential manifestation of cracks to exterior concrete flatwork due to movement of the underlying soil, we recommend that the sidewalks be installed with crack-control joints at an appropriate spacing as designed by the civil engineer. This assumes that the sidewalks are underlain by subgrade soils that possess a very low to low expansion index (i.e., an expansion index of 50 or less). The subgrade soils 3 Ninyo & Moore | 2875 Poinsettia Lane, Carlsbad, California | 108822013 | August 23, 2024 should be scarified to a depth of 8 inches, moisture conditioned to generally at or slightly above the laboratory optimum moisture content, and compacted to a relative compaction of 90 percent as evaluated by ASTM D 1557. In the event that expansive, clayey soils (i.e., expansion index of 50 or more, as evaluated by ASTM D 4829) are exposed at the subgrade elevation, the upper 12 inches of expansive soil subgrade should be removed and replaced with materials that possess a very low to low expansion index (i.e., an expansion index of 50 or less) that are moisture conditioned to generally at or slightly above the laboratory optimum moisture content and compacted to a relative compaction of 90 percent as evaluated by ASTM D 1557. The removals, if needed, should extend beyond the edge of the sidewalk for a horizontal distance of 1 foot or more. We appreciate the opportunity to be of service. Respectfully submitted, NINYO & MOORE Christopher T. Frank Senior Staff Engineer Jeffrey T. Kent, PE, GE Principal Engineer CTF/JTK/mp Attachment: References LL 4 Ninyo & Moore | 2875 Poinsettia Lane, Carlsbad, California | 108822013 | August 23, 2024 REFERENCES City of Carlsbad, 2024, Geotechnical Report Review, Cabrillo Elementary School Playfield Repair, (1st Review), Project ID PD2024-0012, Grading Permit No. GR2024-0014: dated August 4. Kleinfelder, 1998, Geotechnical Investigation and Geologic/Seismic Hazards Study for Rancho Carrillo School, San Marcos Unified School District, Carlsbad, California, Kleinfelder Job No. 51-4816-001: dated August 3. Ninyo & Moore, 2024a, Update Geotechnical Evaluation, Field Turf Replacement, Carrillo Elementary School, 2875 Poinsettia Lane, Carlsbad, California, Project No. 108822013: dated May 17. Ninyo & Moore, 2024b, Addendum to Geotechnical Evaluation, Supplemental Pavement Recommendations, Carrillo Elementary School, 2875 Poinsettia Lane, Carlsbad, California, Project No. 108822013: dated August 13. 5 ATTACHMENT 1e Legoland :::alifornia Resort 0 " ~ ' i.t $ <i "'-"' 0.5 -1,, ,, Jf' 'o 0 Av1ara Golf Club 1/ ,. .,,1 ' J I Avia Oaks Midd8 ·, I a, .,~os D< Batri u1to Logo on •w s ' ~~•eu dla•B\vd/ 0 """ 0 '.i \ .~~ 7 '" "', J , ~~ .. "' , ' . S t ' , T I , Buena Vista Park Sh:acbwrOge Golf Club ~f'/3 ftj\'f.> L"~ 85TH PERCENT ISOPLUVIA LS: CONTOUR 6.40 ] INCHES \ ~ Zoom to 0.64 .429ff -Carillo ES: 0.63 in Omni la Costa & Golf Club f J)-\1(! (j <a <:Jf:>va. <evante St la Costa Canyon Hgh ~ t; Cerro De las Postt:; I ~ , ' I ~ ' . : ' r I I Sa9e Hill Preserve ~ ,,, o,., .. , -1>q B -<-" :s<' '= t 0 "' ( Sa.nGIS Bureau of Land Ma.nag ~m;nt. Eui, riERE, G.armin. INCREMENT~ USGS METIi ... ":I. LUI•· .,,,,,... Ma, C j \ ' ,, •, I -----, ~M ~ 'l('. □:O, , , ' ' I ' ' ~ C 0 j C ' • ' ,. ' ' H '; -, ,--~~ /\ ,, , \ \ , C j j • • 0 0 ., \ Q ", ' (' r ~Q ·11 " NIDA Et,IC\t1/>.S = c;0 I ' \ ' 0 C , 0 0 0 o MS4 Outfall Discharge Monitoring Station Inventory: I • 0 n o 51, • -. • Highest Priority Non-storm Water Persistent Flow with Unit ID Persistent Flow Not Persistent Flow Other Outfalls: • • ·- Carlsbad MS4 Outfall Other MS4 or Private Outfall Inlet to MS4 ~ MS4 Pipe Owned/Maintained by the City of Carlsbad MS4 Channel Owned/Maintained by the City of Carlsbad ~ MS4 Pipe NOT Owned/Maintained by the City of Carlsbad MS4 Channel NOT Owned/Maintained by the City of Carlsbad Non-impaired Receiving Waters Impaired Receiving Waters Hydrologic Sub-areas: --- I 904.21 904.31 904.4 904.51 904.61 • ( \ • \ ) C " )-, ,r G ~ ~ ~ D r-r , Cl ,., C ~ , 904.4 " 8 y--, \ C ,. /~ , • , ' • • , ,' • ' _, ~ C n co: c 0 , ,~ I I ' I • \\ '\f -~~ • --; ~ . \ C / I ' ;· ; I I ~-1 , ! ' , , ' , , • C 904.31 0 \ ' ' ' , U Cl % , e Q Q . \ C \ II J , " " i _,, ~s • ...,,,,1-' ,) . 12 .At..G.o. RD ,r--'----------/, L, '--------_, -' I , I , , , I ;· -'---.J' 1 , ... ' ' 0 . , "l ~ C ~ q ea.,□ ,i._? !le l'r ......_ ¼ C ~ i'l ~ ~ Cl • .. /-1 '"t--J . . ~ . 8€rri.._,// ( ., •~) " ~ ~□-!J -~ \ 4......:.,,-.., ) 0 ' 904.51 .. , I t, C • , a e • ' ,J>,V·-: r _______ C" .'" i ), ,✓ t.-,ci ~ . r; p -; ) -i--~~ ~~ ~~ ~ ~ c©"" • l o • n -.,. , " ~, □ .. j w;d/1 ' ~ . • 1 "----{ . t IC DE 1.JJS C ~r 1 \ . , i '~ -.....---,, - I ! .._·_, --·-----=---· ·: -.J I -------------~ ··-~-. }-.--~),i f § r_ Ji ,· :! T ~ .. ,, --,, l . • -s, ~ 1~ t:-' I --....______,_-......J '}-.... J, 0 C a an orres on -ra1na e reas ■ ■ ■ , C 0 0 r Feet 1,000 0.25 Miles 2,000 0.5 -\ • ' I ( r \ r--- , ,..___ Category # Description i Units 1 Drainage Basin ID or Name DMA-1-7 unitless 2 85th Percentile 24-hr Storm Depth 0.63 inches 3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 141,950 sq-ft 4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30)sq-ft 5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10)sq-ft 6 Natural Type A Soil Not Serving as Dispersion Area (C=0.10)sq-ft 7 Natural Type B Soil Not Serving as Dispersion Area (C=0.14)sq-ft 8 Natural Type C Soil Not Serving as Dispersion Area (C=0.23)14,037 sq-ft 9 Natural Type D Soil Not Serving as Dispersion Area (C=0.30)sq-ft 10 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels?No yes/no 11 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft 12 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft 13 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft 14 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft 15 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14)sq-ft 16 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23)sq-ft 17 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft 18 Number of Tree Wells Proposed per SD-A # 19 Average Mature Tree Canopy Diameter ft 20 Number of Rain Barrels Proposed per SD-E # 21 Average Rain Barrel Size gal 22 Total Tributary Area 155,987 sq-ft 23 Initial Runoff Factor for Standard Drainage Areas 0.84 unitless 24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 unitless 25 Initial Weighted Runoff Factor 0.84 unitless 26 Initial Design Capture Volume 6,879 cubic-feet 27 Total Impervious Area Dispersed to Pervious Surface 0 sq-ft 28 Total Pervious Dispersion Area 0 sq-ft 29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a ratio 30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 ratio 31 Runoff Factor After Dispersion Techniques 0.84 unitless 32 Design Capture Volume After Dispersion Techniques 6,879 cubic-feet 33 Total Tree Well Volume Reduction 0 cubic-feet 34 Total Rain Barrel Volume Reduction 0 cubic-feet 35 Final Adjusted Runoff Factor 0.84 unitless 36 Final Effective Tributary Area 131,029 sq-ft 37 Initial Design Capture Volume Retained by Site Design Elements 0 cubic-feet 38 Final Design Capture Volume Tributary to BMP 6,879 cubic-feet False False Automated Worksheet B.1: Calculation of Design Capture Volume (V2.0) Dispersion Area, Tree Well & Rain Barrel Inputs (Optional) Standard Drainage Basin Inputs Results Tree & Barrel Adjustments Initial Runoff Factor Calculation Dispersion Area Adjustments No Warning Messages Category # Description i Units 1 Drainage Basin ID or Name DMA-1-7 unitless 2 85th Percentile Rainfall Depth 0.63 inches 3 Predominant NRCS Soil Type Within BMP Location C unitless 4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Restricted unitless 5 Nature of Restriction n/a unitless 6 Do Minimum Retention Requirements Apply to this Project? Yes yes/no 7 Are Habitable Structures Greater than 9 Stories Proposed? No yes/no 8 Has Geotechnical Engineer Performed an Infiltration Analysis? No yes/no 9 Design Infiltration Rate Recommended by Geotechnical Engineer in/hr 10 Design Infiltration Rate Used To Determine Retention Requirements 0.000 in/hr 11 Percent of Average Annual Runoff that Must be Retained within DMA 1.5% percentage 12 Fraction of DCV Requiring Retention 0.01 ratio 13 Required Retention Volume 69 cubic-feet False False Automated Worksheet B.2: Retention Requirements (V2.0) Advanced Analysis Basic Analysis Result No Warning Messages Category # Description i 1 Drainage Basin ID or Name DMA-1-7 2 Design Infiltration Rate Recommended 0.000 3 Design Capture Volume Tributary to BMP 6,879 4 Is BMP Vegetated or Unvegetated? Vegetated 5 Is BMP Impermeably Lined or Unlined? Lined 6 Does BMP Have an Underdrain? Underdrain 7 Does BMP Utilize Standard or Specialized Media? Standard 8 Provided Surface Area 5,583 9 Provided Surface Ponding Depth 6 10 Provided Soil Media Thickness 24 11 Provided Gravel Thickness (Total Thickness) 36 12 Underdrain Offset 3 13 Diameter of Underdrain or Hydromod Orifice (Select Smallest) 3.83 14 Specialized Soil Media Filtration Rate 15 Specialized Soil Media Pore Space for Retention 16 Specialized Soil Media Pore Space for Biofiltration 17 Specialized Gravel Media Pore Space 18 Volume Infiltrated Over 6 Hour Storm 0 19 Ponding Pore Space Available for Retention 0.00 20 Soil Media Pore Space Available for Retention 0.05 21 Gravel Pore Space Available for Retention (Above Underdrain) 0.00 22 Gravel Pore Space Available for Retention (Below Underdrain) 0.40 23 Effective Retention Depth 2.40 24 Fraction of DCV Retained (Independent of Drawdown Time) 0.16 25 Calculated Retention Storage Drawdown Time 120 26 Efficacy of Retention Processes 0.18 27 Volume Retained by BMP (Considering Drawdown Time) 1,245 28 Design Capture Volume Remaining for Biofiltration 5,634 29 Max Hydromod Flow Rate through Underdrain 0.8692 30 Max Soil Filtration Rate Allowed by Underdrain Orifice 6.73 31 Soil Media Filtration Rate per Specifications 5.00 32 Soil Media Filtration Rate to be used for Sizing 5.00 33 Depth Biofiltered Over 6 Hour Storm 30.00 34 Ponding Pore Space Available for Biofiltration 1.00 35 Soil Media Pore Space Available for Biofiltration 0.20 36 Gravel Pore Space Available for Biofiltration (Above Underdrain) 0.40 37 Effective Depth of Biofiltration Storage 24.00 38 Drawdown Time for Surface Ponding 1 39 Drawdown Time for Effective Biofiltration Depth 5 40 Total Depth Biofiltered 54.00 41 Option 1 - Biofilter 1.50 DCV: Target Volume 8,451 42 Option 1 - Provided Biofiltration Volume 8,451 43 Option 2 - Store 0.75 DCV: Target Volume 4,226 44 Option 2 - Provided Storage Volume 4,226 45 Portion of Biofiltration Performance Standard Satisfied 1.00 46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements? Yes 47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor) 1.00 48 Deficit of Effectively Treated Stormwater 0 Retention Calculations Automated Worksheet B.3: BMP Performance (V2.0) False False BMP Inputs Biofiltration Calculations False False False False Result False False No Warning Messages ATTACHMENT 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 Sequence Contents Checklist Attachment 2a Hydromodification Management Exhibit (Required) Included See Hydromodification Management Exhibit Checklist on the back of this Attachment cover sheet. Attachment 2b Management of Critical Coarse Sediment Yield Areas (WMAA Exhibit is required, additional analyses are optional) See Section 6.2 of the BMP Design Manual. Exhibit showing project drainage boundaries marked on WMAA Critical Coarse Sediment Yield Area Map (Required) Optional analyses for Critical Coarse Sediment Yield Area Determination Appendix H.6.1 Verification of Geomorphic Landscape Units Onsite Appendix H.7 Downstream Systems Sensitivity to Coarse Sediment Attachment 2c Geomorphic Assessment of Receiving Channels (Optional) See Section 6.3.4 of the BMP Design Manual. Not performed Included Attachment 2d Flow Control Facility Design and Structural BMP Drawdown Calculations (Required) See Chapter 6 and Appendix G of the BMP Design Manual Included □ □ □ □ □ □ □ 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 Approximate depth to groundwater Existing natural hydrologic features (watercourses, seeps, springs, wetlands) Critical coarse sediment yield areas to be protected (if present) Existing topography Existing and proposed site drainage network and connections to drainage offsite Proposed grading Proposed impervious features Proposed design features and surface treatments used to minimize imperviousness Point(s) of Compliance (POC) for Hydromodification Management Existing and proposed drainage boundary and drainage area to each POC (when necessary, create separate exhibits for pre-development and post-project conditions) Structural BMPs for hydromodification management (identify location, type of BMP, and size/detail) □ □ □ □ □ □ □ □ □ □ □ □ ATTACHMENT 2a BASIN-1 3.62 AC (SW A P ) T O B E T R E A T E D 14, 7 2 6 S F (SW A P ) N O T T O B E T R E A T E D 23,6 6 7 S F (SWAP) TO BE TREATED 12,400 SF U N D I S T U R B E D S L O P E (B Y P A S S I N P O S T C O N D I T I O N ) 1. 3 5 A C POC-1 DATE: Feb 26, 25 10:43am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2024\Project Files\24-172\PROD\Reports\WQMP\24-172_PRE HMP Map.dwg PRE HMP MAP CARRILLO ELEMENTARY SCHOOL FOR LEGEND ------- -------- Hell > 5 & < 10' I ___ I MAJOR BASIN BOUNDARY FLOW PATH SOIL TYPE GROUNDWATER T NINYO & MOORE ABLE PER SOIL REPOR DATED MAY 17 T BY , 2024 SWAP AREAS -No EXISTING NA WETLANDS) TURAL HYDROLOGIC F -No CRITICAL COA EATURES (WATERCOUR -:Pi:~6i~~~s~E~T5N s~~l~~1s~~~ 1REAS TO BE PRDTE:s, SEEPS, SPRINGS, 50 25 0 '.sws: N 50 SCALE IN GRAPHIC s6A~~T 100 150 URFACE TREATMENTS~~ED TO MINIMIZE pQINSEfllA LN LEO CARILLO RANCH PARK VICINITY MAP NOT TO SCALE SWSEN " CmcENe<N GJNEERJNG I 1635 Lale San Marcos D . LAN□ PuNmNo , NC. EERING • San Marcos, CA 92078 nve, Suite 200 • Su•vrnNc P: 760-744-0011 F· 760 · -744-0046 • "' ,., .. POC-1 DM A - 1 0 ( S W A P ) N O T T O B E T R E A T E D 23,6 6 7 S F DM A - 9 A ( S W A P ) T O B E T R E A T E D 14, 7 2 6 S F BIOFILTRATION BASIN BOTTOM AREA: 5,583 SF TOP AREA: 8,208 SF DMA-9B (SWAP) TO BE TREATED 12,400 SF (1 OF 2) DATE: Feb 26, 25 10:49am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2024\Project Files\24-172\PROD\Reports\WQMP\24-172_POST HMP Map.dwg POST HMP MAP CARRILLO ELEMENTARY SCHOOL FOR ' , VICINITY MAP NOT TO SCALE , , BLDG BLDG , 1 /:~~E7;"; r \ A ~ D!..cnG LOG !/TTL ~~-~-:_tlli ,,#i---!JD-J INLET ;:.. --q}/~ ~--. ..... ' BLDG AC I AC t-1---i-'--J--// • ~-~~ I : I AC\< f '- 'V i !:? . .~~=· . :, BLDG 0 POOL 0 C •• BLDG GRASS BLDG ?:;~~~~ ::-a;,= -=~ 55 ~ 91,i = = 0 .,mu-=-'--~~i.:::: --;:= --=--- TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES TREES BLDG BLDG ~ASS \ 50 25 BLDG WALL 1sws N WALL DMA IMP # AREA (SF) 1 6,579 2 3,915 3 20,452 4 1 9,387 5 26,881 6 8,964 7 79,809 8 58,841 A+B * 27,126 1 O* 24,843 LEGEND -------- "c" > 5 & < 10' MAJOR BASIN BOUNDARY FLOW PATH SOIL TYPE GROUNDWATER TABLE PER SOIL REPORT BY NINYO & MOORE DATED MAY 17, 2024 -No EXISTING NATURAL HYDROLOGIC FEATURES (WATERCOURSES, SEEPS, SPRINGS, WETLANDS) -No CRITICAL COARSE SEDIMENT YIELD AREAS TO BE PROTECTED -No PROPOSED DESIGN FEATURES AND SURFACE TREATMENTS USED TO MINIMIZE IMPERVIOUSNESS CONG V-0/Y SYMBOL DESCRIPTION LANDSCAPE (BIOFIL TRATION) IMPERVIOUS ASPH IMPERVIOUS CONC IMPERVIOUS TURF IMPERVIOUS (CONC) IMPERVIOUS (ASPH) SWAP AREAS TABULAR SUMMARY OF DMAs IMPERVIOUS AREA (SF) 6,579 3,915 19,083 9,387 26,881 8,964 67,141 0 27,126 24,843 % IMP 100 100 93 100 100 100 84 100 100 100 HSG C C C C C C C C C C AREA WEIGHTED RUNOFF COEFFICIENT 0.84 VOLUME (DCV) 6,952 TREATMENT SYSTEM BF-1 (BIOFILTRATION) BYPASS THE SITE SWAP-TO BE TREATED SWAP-NOT TO BE TREATED *EXISTING ROOFS (DMA 9A+9B) WILL BE SWAPPED TO BE TREATED IN EXCHANGE WITH THE COMBINED MULTIPLE DISTURBED AREAS (DMA-10) THAT CAN NOT BE TREATED NOTE: TOTAL PROPOSED DISTURBED AREA: DMAs (3+4+5+7+10) - EXITING UNDISTURBED AREA (GRAY HATCH) WITHIN THE DMAS TOTAL PROPOSED NEWLY CREA TED /REPLACED IMPERVIOUS AREA = 149,789 SF = 135,752 SF 0 50 100 150 SWS ENGINEERING, INC. CIVIL ENGINEERJNG • LAND PLANNING • SURVEYING -----------SCALE IN FEET GRAPHIC SCALE 1635 Lake San Marcos Drive, Suite 200 San Marcos, CA 92078 P: 760-744-0011 F: 760-744-0046 • "' .., " RESTRICTOR PLATE ELEVATION PLAN NTS (2 OF 2) DATE: Feb 26, 25 10:50am by:massy.fatini FILE:C:\Users\massy.fatini\DC\ACCDocs\SWS Engineering\2024\Project Files\24-172\PROD\Reports\WQMP\24-172_POST HMP Map.dwg POST HMP MAP CARRILLO ELEMENTARY SCHOOL FOR TABLE: BIOFILTRATION SOIL MEDIA (BSM) SAND 60-80% BY VOLUME TOPSOIL 0-20% BY VOLUME COMPOST 20% BY VOLUME i-------~ BASIN TOP (8,028 SF)-------" 2'x2' RISER OUTLET STRUCTURE TOP ELEV: 264.92' BERM: PLAN VIEW FOR ELV 3.5' TALL CHAIN LINK FENCE BERM: PLAN VIEW FOR LOCA Tl ON BASIN BOTTOM (ELV: 264.42') 'v BASIN TOP ELEV 266.42' 100-YR STORAGE DEPTH 3" MULCH (264.17') 18" MEDIA (262.67') WITH A MIN 5" IN/HR PER "BIOFILTRATION SOIL MEDIA (BSM) TABLE" 3'' FILTER WASH SAND (26242) ' =11 •. ;I J 11 3" FILTER PEA GRAVEL -------1 ( 2 6 2. 1 7') ---.--+---------c;t+F- 33" GRAVEL SAND (259.42') 3/4 IN CRUSH ROCK j 6" PER FORA TED Pl PE (3" FROM THE BOTTOM) IMP-1: - Tf I -=1 ~I 0 , I I TREATMENT IS AT THE BOTTOM = 5,583 SF BASIN TOP AREA = 8,028 SF 'v 3.83" ORIFICE (259.79') TREATMENT AT i----BOTTOM AREA ------i ( 5,583) 24" 2' SURFACE DEPTH 3: 1 SIDE SLOPE 6" WO DEPTH PLANTS AND GRASS HMP STORAGE DEPTH 1: 1 EXCAVATED SIDE SLOPE EXISTING GROUND IMPERVIOUS LINER 30 MIL PVC OR EQUIV. CONTRACTOR TO SUBMIT PRODUCT DATA TO ENGINEER OF RECORD FOR APPROVAL PRIOR TO CONSTRUCTION. OUTLET PIPE (259.54') NOTE: ELEVATIONS SHOWN HERE REFERENCE DATUM NGVD29 BIOFIL TRATION FACILITY DETAIL (IMP-1) 4'' PVC SCREW CAP RIM IS 12" ABOVE -~ GRADE ?--- 4" NON PER FORA TED2.___j_--~~--~ STANDPIPE WATER TIGHT CAP ON TERMINAL END OF PIPE (] 000000 000000 USE 45· WYE AND FITTING OR EQUIVALENT DIRECTION CLEANOUT TO CONNECT UNDERDRAIN TO STANDPIEP 3" MULCH 18" MEDIA 3" FILTER WASH SAND 3"FILTER PEAS GRAVEL 33" GRAVEL SAND CONNECT PIPE TO DOWNSTREAM SYSTEM 6" PERFORATED UNDERDRAIN Scale: NTS ,n, 1~ " . . . . . . . . . . RESTRICTOR PLATE (SEE BELOW) APPROVED CORROSION RESISTANT CONCRETE ANCHORS (4X) WITH PLATE WASHERS PERF PIPE BEHIND 2x2 RISER CONTINUOUS BEAD OF SEALANT WALL AROUND RESTRICTOR PLATE PERIMETER 12"---I 2" 1 l--1 ~-,- 2 "1 g" ORIFICE (SEE BELOW) BIOFILTRATION BASIN ADHERED TO CONCRETE WITH APPROVED ADHESIVE (LOCTITE EPOXY-HEAVY DUTY) AND VESTIL CONCRETE WEDGE ANCHOR BOLTS (MODLE # AS-125 (1/2" DIA, 5" DEPTH) SEE RESTRICTOR PLATE E_EVATION 3.83" FLOW-CONTROL ORIFICE 259. 79' RISER BOTTOvl PER DETAIL AND CHA I GRAVEL PER BIOFILTRATION DETAIL GRAVEL STORAGE \ IU'~:l..&:~...!d.""-'! --I=~-3" GR A VE L BASE IMPERMEABLE LINER PER BIOFIL TRATION DETAIL BIOFILTRATION PLATE & ORIFICE DETAIL {IMP-1) Scale: NTS ;'; •• 00 00 OUTLET 00 2'x2' RISER ~ ,--' 00 ' L STRUCTURE 00 / ., .. .. -C .. •• .. Fl OW US, . ~ . . . . . . . . " OUTLET PIPE f . . . . . . . PLATE FLO~ ..... '-...._ RESTRICTED ,· , f / ',c' ' /,_-' BIOFILTRATION C.O. DETAIL (IMP-1) BIOFILTRATION OUTLET DETAIL (IMP-1) Scale: NTS Scale: NTS NOTE: ELEVATIONS SHOWN HEREON ARE IN THE CITY OF CARLSBAD DATUM (NGVD29) SWS ENGINEERING, INC. CIVIL ENGINEERJNG • LAND PLANNING • SUR VE YING 1635 Lake San Marcos Drive, Suite 200 San Marcos, CA 92078 P: 760-744-0011 F: 760-744-0046 • "' .., " ATTACHMENT 2b ATTACHMENT 2c N/A ATTACHMENT 2d 1 SWMM ANALYSIS FLOW DURATION CURVE ANALYSIS Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing Factors www.sandiegocounty.gov/stormwater G-35 Effective January 1, 2019 Figure G.2-2: Rainfall Basin Map Table G.2-1: Runoff factors for surfaces draining to BMPs for Hydromodification Sizing Factors Method Surface Runoff Factor Roofs 1.0 Concrete 1.0 Pervious Concrete 0.10 Porous Asphalt 0.10 Grouted Unit Pavers 1.0 Solid Unit Pavers on granular base, min. 3/16 inch joint space 0.20 Crushed Aggregate 0.10 Turf block 0.10 Amended, mulched soils 0.10 Landscape 0.10 ; I , I I ~ i EXPLANATI ON I -Precipitation Contours g. Lake Woh~ord • ~ L" Basm I indbergh Basl'I i OceanstdeB l • asm l -s Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing Factors www.sandiegocounty.gov/stormwater G-4 Effective September 15, 2020 download the appropriate rainfall record from the Project Clean Water website and load it into the software program. Both the pre-development and post-project model simulation period shall encompass the entire rainfall record provided in the approved rainfall data set. Scaling the rainfall data is not permitted. G.1.3.2 Potential Evapotranspiration Project applicants preparing continuous simulation models shall select a data set from the sources described below to represent potential evapotranspiration. For HSPF users, this parameter may be entered as an hourly time series. The hourly time series that was used to develop the BMP Sizing Calculator parameters is provided on the project clean water website and may be used for hydromodification management studies in San Diego. For SDHM users, the hourly evaporation data set is pre-loaded into the program. HSPF users may download the evaporation record from the Project Clean Water website and load it into the software program. For HSPF or SWMM users, this parameter may be entered as monthly values in inches per month or inches per day. Monthly values may be obtained from the California Irrigation Management Information System "Reference Evapotranspiration Zones" brochure and map (herein "CIMIS ETo Zone Map"), prepared by California Department of Water Resources, dated January 2012. The CIMIS ETo Zone Map is available from www.cimis.gov, and is provided in this Appendix as Figure G.1-2. Determine the appropriate reference evapotranspiration zone for the project from the CIMIS ETo Zone Map. The monthly average reference evapotranspiration values are provided below in Table G.1-1. Figure G.1-2: California Irrigation Management Information System "Reference Evapotranspiration Zones" SAN BERNARDINO t 9 117! R 17 V E R S D I E G 0 16 D E 16 M P E R 18 EL CENTRO t 18 A L Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing Factors www.sandiegocounty.gov/stormwater G-6 Effective January 1, 2019 Table G.1-1: Monthly Average Reference Evapotranspiration by ETo Zone (inches/month and inches/day) for use in SWMM Models for Hydromodification Management Studies in San Diego County CIMIS Zones 1, 4, 6, 9, and 16 (See CIMIS ETo Zone Map) January February March April May June July August September October November December Zone in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month 1 0.93 1.4 2.48 3.3 4.03 4.5 4.65 4.03 3.3 2.48 1.2 0.62 4 1.86 2.24 3.41 4.5 5.27 5.7 5.89 5.58 4.5 3.41 2.4 1.86 6 1.86 2.24 3.41 4.8 5.58 6.3 6.51 6.2 4.8 3.72 2.4 1.86 9 2.17 2.8 4.03 5.1 5.89 6.6 7.44 6.82 5.7 4.03 2.7 1.86 16 1.55 2.52 4.03 5.7 7.75 8.7 9.3 8.37 6.3 4.34 2.4 1.55 January February March April May June July August September October November December Days 31 28 31 30 31 30 31 31 30 31 30 31 Zone in/day in/day in/day in/day in/day in/day in/day in/day in/day in/day in/day in/day 1 0.030 0.050 0.080 0.110 0.130 0.150 0.150 0.130 0.110 0.080 0.040 0.020 4 0.060 0.080 0.110 0.150 0.170 0.190 0.190 0.180 0.150 0.110 0.080 0.060 6 0.060 0.080 0.110 0.160 0.180 0.210 0.210 0.200 0.160 0.120 0.080 0.060 9 0.070 0.100 0.130 0.170 0.190 0.220 0.240 0.220 0.190 0.130 0.090 0.060 16 0.050 0.090 0.130 0.190 0.250 0.290 0.300 0.270 0.210 0.140 0.080 0.050 2 INTRODUCTION: The approach used to model the proposed school redevelopment project site in the city of Carlsbad using the Environmental Agency (EPA) Storm Water Management Model 5.1 (SWMM). SWMM models were prepared for the pre and post-development conditions at the project site to determine if the proposed LID treatment basins have sufficient volume to meet Hydromodification Management Plan (HMP) requirements. The Diego Regional Water Quality Control board (SDRWQCB) established these requirements in the final HMP, dated March 2011, prepared for the County of San Diego by Brown and Caldwell, as modified by the HMP dated January 2024 per City of Carlsbad BMP Design Manual. SWMM MODEL DEVELOPMENT The proposed project site consists of playground asphalt replacement, new artificial turf in place of the existing grass field, and associated storm drain improvements, including inlets, grates, retaining walls and a treatment basin. The project site is a 4.97-acre portion of one parcel of a total area 9.76 acres that is located southeast of Poinsettia Lane and southwest of Melrose Drive in the City of Carlsbad, California. The site has a current and future land use of Elementary School. SWMM models were prepared for this study, one for pre-development and one for post-development conditions. One Point of Compliance (POC-1) has been identified at the southeast portion of site where the site treated runoff discharges into stream river via proposed storm drain systems, as shown on the Pre and Post-development HMP maps. For both SWMM models, flow duration curves were prepared for POC-1 to determine if the proposed HMP facility is sufficient to meet the current HMP requirements. Table 1.0 summarizes the contributing area for POC-1 in pre and post-development conditions. TABLE 1.0 POC Pre-Dev Area (ac) Post-Dev Area (ac) 1 4.97 4.97 The inputs required to develop SWMM models include rainfall, watershed characteristics, and Integrated Management Practices (IMP) configurations. The Oceanside gauge from the Project Clean Water website was used for this study, since it is the most representative of the project site precipitation due to elevation and proximity of the project site. Evaporation for the site was modeled using average monthly values from City of Carlsbad BMP Design Manual Appendices, Table G.1-1. 3 HMP MODELING PROPOSED CONDITION POC-1 POC-1 has been identified on the southeast portion of the project site where the site treated runoff drains into proposed storm drain systems located on the southeast portion of the site prior to discharging into existing storm drain system and then into stream river and ultimately lower San Marcos Creek. The biofiltration basin (IMP 1) is responsible for handling hydromodification requirements for POC-1. The biofiltration basin has been designed with a uniform total of surface depth of 24-inch (ponding 6- inch for WQ). IMP is comprised of a 3-inch mulch layer, 18-inch layer of amended soil (a highly sandy, organic rich compost with an infiltration rate of 5 in/hr), 6-inch of filter course and 33 inch gravel layer for additional detention (see underground layers depth below¹). Below the gravel layer, the basin is lined to prevent infiltration into the underlying soil. Flow will discharge from basins via a low flow orifice outlet set at the bottom, 3 inch from bottom of the gravel. A riser structures will be constructed that peak flows can be safely discharged to the receiving storm drain systems. The area and depth used in SWMM model is deferent than what is shown on the “Biofiltration Value Table” because of limitation of SWMM software (volume used in SWMM model is equivalent to what will be constructed). TABLE 1.1- Summary of Existing Condition for POC-1 DMA Tributary Area, A(ac) Impervious Percentage, IP Basin-1 4.97 0% ABLE 1.2- Summary of Developed Condition for POC-1 DMA Tributary Area, A(ac) Impervious Percentage, IP 1 - 8 4.97 99% The biofiltration basin is modeled using the biofiltration LID module within SWMM. The biofiltration module can model the underground gravel, underdrain with an orifice plate, amended soil layer, and a surface pond up to the elevation of the invert of the spillway. It should be noted that detailed outlet location and elevations will be shown on the construction plans based on the recommendations of this study. Underground layers depth: 3” Mulch 18” Soil 6” Filter Course 33” gravel Total = 60” 4 BMP MODELING FOR HMP PURPOSES * The Green Ampt data’s for Soil C are selected for this site. FLOW DURATION CURVE COMPARISON The flow Duration Curve (FDC) were compared at the project’s POCs by exporting the hourly runoff time result from the SWMM to a spreadsheet. For each POC, the FDC was compared between 10% of the existing condition Q2 up to the existing condition Q10. Q2 and Q10 were determined by the statistics analysis report exported to spreadsheet from the SWMM model, which is based on the Weibull Plotting Positions. The runoff time series was also exported from the SWMM model to a spreadsheet to calculate flow durations. The range between 10% of Q2 and Q10 was divided into 100 equal time intervals; the number of hours that each flow rate was exceeded was counted from the hourly series. Additionally, the intermediate peaks with a return period “i” were obtained (Qi with i=3 to 9). For the purpose of the plot, the values were presented as percentage of time exceeded for each flow rate. FDC comparison for each POC is illustrated in the following Figure-1. As can be seen in Figures 1, the FDCs for the proposed condition with the HMP facilities are within 110% of the curve for the existing condition in both peak flow and duration. The additional runoff volume generated from developing the site will be released to the storm drain system at a flow rate below the 10% Q2 lower threshold. Additionally, the project will not increase peak flow rates between the Q2 and the Q10. 5 DRAWDOWN TIME To ensure compliance with the 96 hour toral drawdown requirements and 24 hour surface ponding drawdown requirement per current City of Carlsbad BMP Design Manual Appendicies, drawdown calculation are provided below in this report. Please see the calculations (Elevation Discharge and Drawdown Summary). SUMMARY This study has demonstrated that the proposed biofiltration basin with gravel storage layer provided within the Carillo Elemenaray Shcool project are sufficient to meet the current HMP criteria and the respective orifice and outlet structure, are incorporated as specified within the proposed project site. KEY ASSUMPTIONS 1. The biofiltration basin is lined in order to prevent infiltration into the underlying soil. ELEVATION‐DISCHARGE CALCULATOR DISCHARGE THRU UNDERDRAIN ORIFICE WEIR FLOW (1‐'D‐1' inches) ORIFICE FLOW ('D' inches and over)DMA‐1 INPUT Orifice Diameter, D = 3.8300 inches Underground Storage = 36" CALCULATE Weir Equation, Q = 3.0WH1.5 Orifice Equation, Q = 0.61A(2gH)0.5 ELEVATION (in) DISCHARGE (cfs) EFFECTIVE HEIGHT H (in) ORIFICE AREA (sq ft) WEIR LENGTH (ft) 1 0.0202 Bottom of Storage 1.000 0.0000 0.28 2 0.0651 2.000 0.0000 0.32 3 0.0986 3.000 0.0000 0.26 4 0.1633 2.085 0.0800 0.00 5 0.1986 3.085 0.0800 0.00 6 0.2285 4.085 0.0800 0.00 7 0.2549 5.085 0.0800 0.00 8 0.2789 6.085 0.0800 0.00 9 0.3009 7.085 0.0800 0.00 10 0.3215 8.085 0.0800 0.00 11 0.3408 9.085 0.0800 0.00 12 0.3590 10.085 0.0800 0.00 13 0.3764 11.085 0.0800 0.00 14 0.3930 12.085 0.0800 0.00 15 0.4090 13.085 0.0800 0.00 16 0.4243 14.085 0.0800 0.00 17 0.4391 15.085 0.0800 0.00 18 0.4534 Ave Storage 16.085 0.0800 0.00 19 0.4673 17.085 0.0800 0.00 20 0.4808 18.085 0.0800 0.00 21 0.4939 19.085 0.0800 0.00 22 0.5067 20.085 0.0800 0.00 23 0.5192 21.085 0.0800 0.00 24 0.5313 22.085 0.0800 0.00 25 0.5432 23.085 0.0800 0.00 26 0.5549 24.085 0.0800 0.00 27 0.5663 25.085 0.0800 0.00 28 0.5774 26.085 0.0800 0.00 29 0.5884 27.085 0.0800 0.00 30 0.5992 28.085 0.0800 0.00 31 0.6097 29.085 0.0800 0.00 32 0.6201 30.085 0.0800 0.00 33 0.6304 31.085 0.0800 0.00 34 0.6404 32.085 0.0800 0.00 35 0.6503 33.085 0.0800 0.00 36 0.6601 Top of Storage 34.085 0.0800 0.00 37 0.6697 35.085 0.0800 0.00 38 0.6792 36.085 0.0800 0.00 39 0.6885 37.085 0.0800 0.00 40 0.6977 38.085 0.0800 0.00 41 0.7068 39.085 0.0800 0.00 42 0.7158 40.085 0.0800 0.00 43 0.7247 41.085 0.0800 0.00 44 0.7335 42.085 0.0800 0.00 45 0.7421 43.085 0.0800 0.00 46 0.7507 44.085 0.0800 0.00 47 0.7591 45.085 0.0800 0.00 48 0.7675 Ave soil 46.085 0.0800 0.00 49 0.7758 47.085 0.0800 0.00 50 0.7840 48.085 0.0800 0.00 51 0.7921 49.085 0.0800 0.00 52 0.8001 50.085 0.0800 0.00 53 0.8081 51.085 0.0800 0.00 54 0.8160 52.085 0.0800 0.00 55 0.8237 53.085 0.0800 0.00 56 0.8315 54.085 0.0800 0.00 57 0.8391 55.085 0.0800 0.00 58 0.8467 56.085 0.0800 0.00 59 0.8542 57.085 0.0800 0.00 60 0.8617 Top of Mulch 58.085 0.0800 0.00 Drawdown Calculation Summary Carrillo ES Biofiltration IMP‐1 Surface Average Discharge Rate cfs 0.926 Ponding Depth in 18 Bottom Area sf 5142 Top Area sf 7410 Drawdown Time hr 2.8 Soil Layer Average Discharge Rate cfs 0.7675 Thickness in 24 Area sf 5593 Porosity 0.4 Field Capacity 0.2 Drawdown Time hr 0.8 Gravel Layer Average Discharge Rate cfs 0.4534 Thickness in 36 Area sf 5593 Porosity 0.4 Drawdown Time hr 4.1 TOTAL DRAWDOWN TIME hr 7.7 6 'ii, .... u -:it 0 u: 4.000 3.500 3.000 2.500 2.000 1.500 1.000 0.500 0.000 0.D°lo I I I I I -- 0.D°lo Flow Duration Curve [Pre vs. Post (Mitigated)] =,..., ~" L i"""""'o, \. -, l '\ ', 11 "\ .. ,.,. \.. "' ,1 l"' '""" ~ ""-- .... r-,,..... I 0.0% % Time Exceeding -Pre-project Q -Post-project (Mitigated) Q I I I .... ~~ ..... 'r· 0.1% 1.0% 7 Q2 to Q10 Comparison Table‐ POC‐1 Return Period Existing Condition (cfs) Mitigated Condition (cfs) Reduction, Exist - Mitigated (cfs) 2-year 1.882 0.941 0.941 3-year 2.377 1.160 1.217 4-year 2.470 1.739 0.731 5-year 2.549 1.894 0.655 6-year 2.647 2.251 0.396 7-year 2.900 2.572 0.328 8-year 3.048 2.773 0.275 9-year 3.297 2.969 0.327 10-year 3.582 3.187 0.395 8 Lower Flow Threshold: 10% 0.1xQ2 (Pre): 0.1882 cfs Q10 (Pre): 3.5818 cfs # of Ordinates: 99 Incremental Q (pre) 0.0343 cfs Total Houly Data: 499320 hours Interval Pre‐project Flow (cfs) Pre‐Project Hours Pre‐project % Time Exceeding Post‐Project Hours Post‐project % Time Exceeding Percentage Pass?Fail 1 0.188 432 0.1% 464 0.09% 107 pass 2 0.222 388 0.1% 399 0.08% 103 pass 3 0.257 362 0.1% 348 0.07% 96 pass 4 0.291 330 0.1% 296 0.06% 90 pass 5 0.325 313 0.1% 261 0.05% 83 pass 6 0.360 295 0.1% 217 0.04% 74 pass 7 0.394 268 0.1% 177 0.04% 66 pass 8 0.428 248 0.0% 161 0.03% 65 pass 9 0.462 227 0.0% 140 0.03% 62 pass 10 0.497 218 0.0% 130 0.03% 60 pass 11 0.531 195 0.0% 110 0.02% 56 pass 12 0.565 185 0.0% 101 0.02% 55 pass 13 0.600 175 0.0% 93 0.02% 53 pass 14 0.634 158 0.0% 89 0.02% 56 pass 15 0.668 154 0.0% 80 0.02% 52 pass 16 0.702 143 0.0% 77 0.02% 54 pass 17 0.737 138 0.0% 73 0.01% 53 pass 18 0.771 133 0.0% 68 0.01% 51 pass 19 0.805 128 0.0% 62 0.01% 48 pass 20 0.840 118 0.0% 53 0.01% 45 pass 21 0.874 107 0.0% 51 0.01% 48 pass 22 0.908 102 0.0% 47 0.01% 46 pass 23 0.942 98 0.0% 43 0.01% 44 pass 24 0.977 97 0.0% 38 0.01% 39 pass 25 1.011 90 0.0% 36 0.01% 40 pass 26 1.045 86 0.0% 35 0.01% 41 pass 27 1.079 80 0.0% 33 0.01% 41 pass 28 1.114 76 0.0% 32 0.01% 42 pass 29 1.148 72 0.0% 30 0.01% 42 pass 9 30 1.182 66 0.0% 26 0.01% 39 pass 31 1.217 64 0.0% 26 0.01% 41 pass 32 1.251 60 0.0% 23 0.00% 38 pass 33 1.285 60 0.0% 23 0.00% 38 pass 34 1.319 53 0.0% 21 0.00% 40 pass 35 1.354 50 0.0% 21 0.00% 42 pass 36 1.388 50 0.0% 20 0.00% 40 pass 37 1.422 47 0.0% 19 0.00% 40 pass 38 1.457 45 0.0% 19 0.00% 42 pass 39 1.491 42 0.0% 18 0.00% 43 pass 40 1.525 42 0.0% 18 0.00% 43 pass 41 1.559 40 0.0% 18 0.00% 45 pass 42 1.594 40 0.0% 18 0.00% 45 pass 43 1.628 40 0.0% 18 0.00% 45 pass 44 1.662 39 0.0% 18 0.00% 46 pass 45 1.696 39 0.0% 18 0.00% 46 pass 46 1.731 39 0.0% 17 0.00% 44 pass 47 1.765 37 0.0% 15 0.00% 41 pass 48 1.799 37 0.0% 15 0.00% 41 pass 49 1.834 37 0.0% 14 0.00% 38 pass 50 1.868 35 0.0% 13 0.00% 37 pass 51 1.902 33 0.0% 13 0.00% 39 pass 52 1.936 32 0.0% 13 0.00% 41 pass 53 1.971 31 0.0% 12 0.00% 39 pass 54 2.005 30 0.0% 12 0.00% 40 pass 55 2.039 27 0.0% 12 0.00% 44 pass 56 2.074 26 0.0% 12 0.00% 46 pass 57 2.108 26 0.0% 12 0.00% 46 pass 58 2.142 26 0.0% 12 0.00% 46 pass 59 2.176 25 0.0% 12 0.00% 48 pass 60 2.211 25 0.0% 12 0.00% 48 pass 61 2.245 25 0.0% 11 0.00% 44 pass 62 2.279 25 0.0% 9 0.00% 36 pass 63 2.314 22 0.0% 9 0.00% 41 pass 64 2.348 22 0.0% 9 0.00% 41 pass 65 2.382 21 0.0% 9 0.00% 43 pass 66 2.416 20 0.0% 9 0.00% 45 pass 67 2.451 18 0.0% 9 0.00% 50 pass 68 2.485 15 0.0% 9 0.00% 60 pass 10 69 2.519 15 0.0% 9 0.00% 60 pass 70 2.553 12 0.0% 9 0.00% 75 pass 71 2.588 11 0.0% 9 0.00% 82 pass 72 2.622 11 0.0% 9 0.00% 82 pass 73 2.656 11 0.0% 9 0.00% 82 pass 74 2.691 11 0.0% 9 0.00% 82 pass 75 2.725 11 0.0% 8 0.00% 73 pass 76 2.759 11 0.0% 8 0.00% 73 pass 77 2.793 11 0.0% 8 0.00% 73 pass 78 2.828 10 0.0% 7 0.00% 70 pass 79 2.862 9 0.0% 7 0.00% 78 pass 80 2.896 9 0.0% 7 0.00% 78 pass 81 2.931 8 0.0% 7 0.00% 88 pass 82 2.965 8 0.0% 7 0.00% 88 pass 83 2.999 8 0.0% 7 0.00% 88 pass 84 3.033 8 0.0% 7 0.00% 88 pass 85 3.068 8 0.0% 7 0.00% 88 pass 86 3.102 7 0.0% 7 0.00% 100 pass 87 3.136 7 0.0% 6 0.00% 86 pass 88 3.170 6 0.0% 6 0.00% 100 pass 89 3.205 6 0.0% 6 0.00% 100 pass 90 3.239 6 0.0% 6 0.00% 100 pass 91 3.273 6 0.0% 6 0.00% 100 pass 92 3.308 6 0.0% 6 0.00% 100 pass 93 3.342 6 0.0% 6 0.00% 100 pass 94 3.376 6 0.0% 6 0.00% 100 pass 95 3.410 6 0.0% 6 0.00% 100 pass 96 3.445 6 0.0% 6 0.00% 100 pass 97 3.479 6 0.0% 4 0.00% 67 pass 98 3.513 5 0.0% 4 0.00% 80 pass 99 3.548 5 0.0% 4 0.00% 80 pass 100 3.582 5 0.0% 4 0.00% 80 pass 11 SWMM Input Data in Input Format (Existing & Proposed Models) 12 PRE-DEV INPUT (POC-1) [TITLE] ;;Pr oject Title/Notes [OPTIONS] ;;Option FLOW_UNITS I NF! L TRA TION F LOW_ROUTING LINK_OFFSETS MIN_SLOPE AL LOW_PONDI NG SKI P_STEADY_STATE START_DATE START_TIME REPORT_START_DATE REPORT_START_TIME END_DATE END_TIME SWEEP _START SWEEP _END DRY_DAYS REPORT_STEP WET_STEP DRY_STEP ROUTING_STEP RULE_STEP I NERTIAL_DAMPI NG NORMAL_FLOW_LIMITED FORCE_MAIN_EQUATION VARIABLE_STEP LENGTHENI NG_STEP MIN_SURFAREA MAX_TRIALS HEAD_TOLERANCE SYS_FLOW_TOL LAT _FLOW_ TOL MINIMUM_STEP THREADS Value CFS GREEN_AMPT KI NWAVE DEPTH 0 NO NO 08/28/1951 05:00:00 08/28/1951 05:00:00 05/23/2008 23:00:00 01/01 12/31 0 01 :00:00 00 :15:00 04 :00:00 0 :01:00 00 :00:00 PARTIAL BOTH H-W 0 .75 0 12.557 8 0 .005 5 5 0 .5 1 13 [ EVAPORATION] ;;Dat a Source Paramet ers " MONTHLY DRY_ONLY 0.06 0.08 0.110 0.15 0.17 0.19 0.19 0.18 0.15 0.11 0.08 0.06 NO [ RAIN GAGES] ; ; Name " Format Int erval SCF Sou rce Oceanside INTENSITY 1:00 1.0 TIMESERI ES Oceansi de [SUBCATCHMENTS] ;;Name Rai n Gage Out l et Area %Imperv " -------- Basin-1 Oceanside POC-1 3.62 0 Sl opes Oceanside POC-1 1.35 0 [SUBAREAS] l-lidt h %Slope CurbLen ---------------- -------- 592 1.5 0 549 50 0 ;;Subcat chment N-Imperv N-Pe rv S-Imperv S-Perv Pct Zero Rout e To Pct Rout ed " ------------------------ ---------- ---------- ---------- Basin-1 0.012 0.15 0.05 0.1 25 OUTLET Sl opes 0.012 0.15 0.05 0.1 25 OUTLET [INFILTRATION] ; ; Subcat chment Paraml Param2 Param3 Param4 Param5 " ------------------------ ---------- ---------- ---------- ---------- Basin-1 6.0 0.075 0.31 7 0 Sl opes 6.0 0.075 0.31 7 0 [OUTFALLS] ;;Name Elevat ion Type St age Dat a Gat ed Rout e To " POC-1 0 FREE NO [TIMESERIES ] ;;Name Dat e Ti me Val ue " Oceanside FILE "Z: \Project s\2023 \23-221 \PROD\Report s\t,/QMP\Sl-l~Y.l\oceansi de . dat " SnowPack --------- 14 [REPORT) ;;Reporting Opt i ons SUBCATCHMENTS ALL NODES ALL LINKS ALL [TAGS) [MAP) DIMENSIONS -966 .709 0.000 10966 .709 10000 .000 Uni ts None (COORDINATES) ; ; Node X-Coo rd Y-Coord " ------------------------------------------· POC-1 -320.277 513 .999 (VERTICES) ;;Li nk X-Coo rd Y-Coord " ------------------------------------------· (Pol ygons) ;;Subcatchment X-Coo rd Y-Coord " ------------------------------------------· Basi n-1 -417.902 564. 511 Basi n-1 -366.141 564. 511 Basi n-1 -363.004 611. 566 Basi n-1 -417.902 613 .135 Sl opes -291.280 637 .002 Sl opes -265.384 583 .810 Sl opes -267.600 576.364 Sl opes -299.329 615.655 Sl opes -341.147 594.484 Sl opes -345.171 600 .958 (SYMBOLS) ; ; Gage X-Coo rd Y-Coord " ------------------------------------------· Oceanside -361.142 645.822 15 POST-DEV INPUT (POC-1) 16 [TITLE] ;;Project Tit le/Notes [OPTIONS ] ; ;Opt i on Va lue F LOl•I_UNITS CFS INFILTRATION GREEN_AMPT F LOl•I_ROUTING KINWAVE LINK_OFFSETS DEPTH MIN_SLOPE 0 ALLOl•I_PONDING NO SKIP_STEADY_STATE NO START_DATE 08/28/1951 START_TIME 05:00:00 REPORT_START_DATE 08/28/1951 REPORT_START_TIME 05:00:00 END_DATE 05/23/2008 END_TIME 23:00:00 SHEEP_START 01/01 SHEEP_END 12/31 DRY_DAYS 0 REPORT_STEP 01:00:00 WET_STEP 00:15:00 DRY_STEP 04:00:00 ROUTING_STEP 0:01 :00 RULE_STEP 00:00:00 INERTIAL_DAMPING PARTIAL NORMAL_F LOl·I_ LIMITED BOTH FORCE_MAIN_EQUATION H-W VARIABLE_STEP 0.75 LENGTHEN ING_STEP 0 MIN_SURFAREA 12.566 ~IAX_ TRIALS 8 HEAD_ TOLERANCE 0.005 SYS_FLOl·I_TOL 5 LAT_FLOl·I_TOL 5 MINIMUM_STEP 0.5 THREADS 4 17 ( EVAPORATION] ; ; Data Source " MONTHLY Pa rameter s .06 .08 .11 .15 .17 .19 .19 .18 .15 .11 .08 .06 DRY_ONLY NO [RAINGAGES] ; ; Name " Oceanside (SUBCATCHMENTS] ; ; Name " -------------- DMA-1 BF-1 DMA-2 DMA-3 DMA-8-Sl opes DMA-4 DMA-5 DMA-6 DMA-7 (SUBAREAS] ;;Subcatchment " -------------- DMA-1 BF-1 DMA-2 DMA-3 DMA-8-Sl opes DMA-4 DMA-5 DMA-6 DMA-7 [INFILTRATION] ;;Subcatchment " -------------- DMA -1 BF-1 DMA -2 DMA -3 DMA -8-Sl opes DMA -4 DMA -5 DMA -6 DMA -7 Format Interval SCF Source INTENSITY 1:00 1.0 TIMESERIES Oceanside Rai n Gage Outlet Area %Imperv Width %Slope Cu rbl en SnowPack ---------------- -------------------------------- -------- -------- ----------------- Oceanside BF-1 0.153 100 33 0.5 0 Oceanside POC-1 0.128168 0 10 0 0 Oceanside BF-1 0.09 100 37 0.5 0 Oceanside BF-1 0.49 94 91 1.5 0 Oceanside POC-1 1.35 0 549 50 0 Oceanside BF-1 0.22 100 35 1.5 0 Oceanside BF-1 0.58 100 84 1.5 0 Oceanside BF-1 0.25 100 106 0.5 0 Oceanside BF-1 1. 712 84 211 1.5 0 N-Imperv N-Perv S-Imperv S-Perv PctZero RouteTo PctRouted ---------- ---------- ------------------------------ ---------- ---------- 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET 0.012 0.15 0.05 0.1 25 OUTLET Pa raml Param2 Param3 Param4 Param5 ---------- ---------- ------------------------------ 6 0.075 0.31 7 0 1.5 0.3 0.33 7 0 6 0.075 0.31 7 0 6 0.075 0.31 7 0 6 0.075 0.31 7 0 6 0.075 0.31 7 0 6 0.075 0.31 7 0 6 0.075 0.31 7 0 6 0.075 0.31 7 0 18 [LID_CONTROLS] ; ; Name Type/Layer " ------------------------ BF-1 BC BF-1 SURFACE BF-1 SOIL BF-1 STORAGE BF-1 DRAIN [ LID _USAGE] ;;Subcatchment LID Process FromPerv " BF-1 BF-1 100 [OUTFALLS] Parameter s ---------- 18 0.0 24 0.4 36 0.67 0.8805 0 Number Area 1 5583 .00 ; ; Name Elevation Type Stage Dat a " POC-1 [TIMESERIES] ; ; Name " 0 Date FREE Time Value 0 0.2 0 3 l-li dth 0 Gated NO 0 0.1 0 6 InitSat 0 5 5 0 Route To Fromi mp 100 5 0 ToPerv 0 1.5 Rpt File Drai nTo POC-1 Oceansi de FI LE "C: \Users \massy. fat ini \DC\ACCDocs \Sl-lS Engineer ing\2024 \Project Files \24-172\PROD\Repor t s \t,/QMP\Sl-l~Y.l\oceansi de Rai ngauge \oceanside .dat" [REPORT] ;;Reporting Opt ions INPUT YES SUBCATCHMENTS ALL NODES ALL LINKS ALL [TAGS] 19 [MAP] DIMENSIONS -129 .191 -319 .762 933 .945 189.693 Uni ts Feet [COORDI NATES] ; ; Node X-Coord Y-Coord " POC-1 355.694 -215 .355 [VERTICES J ; ; Li nk X-Coord Y-Coord " I --------------------------------------------· [Polygons ] ; ; Subcatchment X-Coord Y-Coord " --------------------------------------------· DMA-1 46,961 98.357 DMA-1 48,206 49 ,807 DMA-1 -28.355 46,694 DMA-1 -33.334 94 ,623 BF-1 307.887 -101 .129 BF-1 338.103 -102.363 BF-1 335.020 -132.579 BF-1 302.336 -131 .963 DMA-2 156.828 98.883 DMA-2 162.735 56,444 DMA-2 97.368 57 .678 DMA-2 94,584 98.261 DMA-3 296.512 109 .878 DMA-3 298.978 45 ,128 DMA-3 219,428 45 ,744 DMA-3 216.961 108 .028 DMA-8-Slopes 747,271 -16 .977 DMA-8-Slopes 751 .745 -75 .875 DMA-8-Slopes 675.700 -78 .111 DMA-8-Slopes 677.191 -20.705 DMA-4 417,439 107 .149 DMA-4 418.930 55 .707 DMA-4 350.341 54 ,961 DMA-4 348.104 110 .876 DMA-5 457.526 110 .184 DMA-5 534 .086 108 .316 DMA-5 538,443 55 ,409 DMA-5 460 .015 54 ,164 DMA-5 457.526 101 ,470 DMA-6 630.503 109 .250 DMA-6 636. 728 60 . 699 DMA-6 570. 748 60 .077 DMA-6 570. 748 111.117 DMA-7 729.783 115 ,475 DMA-7 735.385 58.210 DMA-7 651 .977 53 .852 DMA-7 650.110 116 .097 [SYMBOLS] ;;Gage X-Coord Y-Coord " Oceanside 333.927 166.524 20 PRE-DEVELOPMENT CONDITION (POC-1) Oceanside eJ ' ' ' . '•,POC-1 .. Slopes " 21 Outfall POC-1 a Property Value Name POC-1 Rain Gage Oceanside a X-Coordinate -320.277 Property Value Y-Coordinate 513.999 Name Oceanside Description X-Coordinate -361.1 42 Tag Y-Coordinate 645.822 Inflows NO Description Treatment NO Tag Invert El. 0 Rain Format INTENSITY Tide Gate NO Time Interval 1:00 Route To Snow Catch Factor 1.0 Type FREE Data Source TIMESERIES Fixed Outfall TIME SERIES: Fixed Stage 0 -Series Name Oceanside Tidal Outfall DATAFILE: Curve Name • -File Name • Time Series Outfall -Station ID • Series Name • -Rain Units IN 22 Subcatchment Basin-1 II I Property [value I Name /Basin-1 ...I t ..... ,,. X-Coordinate -391.237 Y·Coordinate 588.431 Description Tag Rain Gage Oceanside Outlet POC-1 Area 3.62 Width 592 %Slope 1.5 %Imperv 0 N-lmperv 0.012 N-Perv 0.15 Dstore-lmperv 0.05 Dstore·Perv 0.1 %Zero-lmperv 25 Subarea Routing OUTLET Percent Routed 100 Infiltration Data GREEN_AMPT Groundwater NO Snow Pack -LID Controls 0 Infiltration Editor X Land Uses 0 Infiltration M ethod I GREEN_AMPT vi Initial Buildup NONE Property Value Curb Length 0 Suction Head 6.0 N-Perv Pattern Conductivity 0.07S .. Initial Deficit Dstore Pattern 0.31 lnfil. Pattern I Soil capillary suction head (inches or mm) I 23 Subcatchment Slopes ■ Property Value Name Slopes X-Coordinate 1-301.652 Y-Coordinate 1601.379 Description I Tag I Rain Gage 10ceanside Outlet 1 POC-1 Area I 1.35 Width I S49 %Slope 150 %1mperv 10 N-lmperv 10.012 N-Perv 10.15 Dstore-lmperv 10.05 Dstore-Perv 10.1 %Zero-lmperv 125 Su ba rea Routing 10UTLET Percent Routed I 100 Infiltration Data 1 GREEN_AMPT Groundwater 1NO Snow Pack I I Infiltration Editor X LID Controls 10 land Uses 10 Infiltration Method I GREEN_AMPT vi Initial Buildup 1NONE Property Value Curb length 10 Suction Head 6.0 N-Perv Pattern I Conductivity 0.075 Dstore Pattern Initial Deficit 0.31 I lnfil. Pattern I I Soil capillary suction head (inches or mm) 24 POST-DEVELOPMENT CONDITION (POC-1) DMA (1‐7) drain into BF (biofiltration) where an orifice control will be installed inside the catch basin to discharge the flow per design. Flow coefficient “C” is calculated using the selected orifice size and used in SWMM LID control Editor: DMA 1‐7 Cg 0.61 DIAMETER 3.830 AREA 5583 C* 0.8805 *C = Cg (605/ALID) (πD2/8) √(g/6) per Section G.1.5.3.4 of Appendix G of the County of San Diego BMP Design Manual dated January 2, 2024 Oceanside 121 \,_ _______ ... --··· ·._poc-1·-· ... 25 Subcatchment DMA-1 a I Property Name DMA-1 X-Coordinate 8.369 ¥-Coordinate 172.370 Description Tag Rain Gage Oceanside Outlet l BF-1 Area 0.153 Width 33 %Slope 0.5 %1mperv 1,00 N-lmperv 0.012 --N-Perv 0.15 Dstore-lmperv 0.05 Dstore•Perv 10.1 %Zero·lmperv 25 Subarea Routing OUTLET Percent Routed 100 Infiltration Data JGREEN_AMPT .. ·I Groundwater NO Snow Pack I Infiltration Editor X LI D Controls 0 Jo Infiltration Metl-od I GREEN_AMPT vi Land Uses Property Value Initial Buildup NONE lo Suction Head 6 Curb Length Conductivity 0.075 N-Perv Pattern l11ilie1IDt:fic.il 0.31 Dstore Pattern I lnfil. Pattern Soil capillary suction head (inches or mm) I 26 Subcatchment DMA-2 ■ I Property I Value Name DMA-2 X-Coordinate 127.879 Y-Coordinate 77.817 ' Description Tag Rain Gage Oceanside Outlet BF-1 ' Area 0.09 Width 37 %Slope 0.5 %1mperv 100 ' N-lmperv 0.012 --N-Perv 0.1 5 Dstore-lmperv 0.05 Dstore-Perv 0.1 ' %Zero-lmperv 25 Subarea Routing OUTLET Percent Routed 100 Infiltration Data !GREEN_AMPT i ... 1 Groundwater NO -Snow Pack Infiltration Editor X LID Controls 0 Infiltration Method I GREEN_AMPT vi Land Uses 0 ' I Property Value Initial Buildup NONE Suction Head 6 Curb Length 0 Conductivity 0.075 N-Perv Pattern Initial Deficit 0.31 Dstore Pattern ' I lnfil. Pattern Soil capillary suction head (inches or mm) II 27 Subcatchment DMA-3 a I Property Value Name DMA-3 -X-Coordinate 257.970 ¥-Coordinate 77.195 Description -Tag -Rain Gage Oceanside Outlet BF-1 Are.a 0.49 Width 91 -%Slope 1.5 %1mperv 94 N-lmperv 0.012 -N-Perv 0.15 -Dstore.-lmperv 0.05 Dstore-Perv 0.1 %Zero-lmperv 25 -Subarea Routing OUTLET -Percent Routed 100 Infiltration Data ! jGREEN_AMPT Groundwater NO -Snow Pack -Infiltration Editor X LID Controls 0 Infiltration M ethod I GREEN_AMPT vi Land Uses 0 Initial Buildup NONE Property Value -Suction Head 6 Curb Length 0 -Conductivity 0.075 N-Perv Pattern l11ilie1IDt:fic.il 0.31 Dstore P attem lnfil. Pattern Soil capillary suction head (inches or m11) I 28 Subcatchment DMA-4 a I Property I value Name DMA-4 X-Coordinate 383.704 Y-Coordinate 82.173 Description Tag _7 Rain Gage Oceanside Outlet BF-1 Area 0.22 Width 135 %Slope 1.5 %1mperv 100 N-lmperv 0.012 N-Perv 7 0.1 5 Dstore-lmperv 0.05 Dstore-Perv 0.1 %Zero-lmperv 25 Subarea Routing 7 o uTLET Pe.rcent Routed 100 Infiltration Data jGREEN_AMPT ... Groundwater NO Snow Pack _7 Infiltration Editor X LID Controls 0 Infiltration Method I GREEN_AMPT vi Land Uses 0 Property Value Initial Buildup NONE 7 0 Suction Head 6 Curb Length Conductivity 0.075 N-Perv Pattern l11ilie1IDt:fic.il 0.31 Dstore Pattern lnfil. Pattern Soil capillary suction head (inches or mm) I 29 Subcatchment DMA-5 a Property Va lue Name DMA-5 X-Coordinate 489.519 ¥-Coordinate 85.909 Description Tag Rain Gage Outlet Area Width %Slope % lmperv N-lmperv N-Perv Dstore-lmperv Dstore-Perv %Zero-lmperv Subarea Routing Perce.nt Routed Infiltration Data Groundwater Snow Pack LID Controls Land Uses Initial Buildup Curb Length N-Perv Pattern Dstore Pattern lnfil. Pattern Ocean side BF-1 0.58 84 1.5 100 0.012 0.15 0.05 0.1 25 OUTLET 100 jGREEN_AMPT NO 0 0 NONE 0 Infiltration Editor X Infiltration Method I GREEN_AMPT Property Value Suction Head 6 Conductivity 0.075 l11ilie1IDt:fic.il 0.31 Soil capillary suction head (inches or mm) 30 Subcatchment DMA-6 II I Property !Value I Name DMA-6 X-Coordinate _1_602.182 Y-Coordinate 85.286 Description L Tag Rain Gage --!Oceanside Outlet BF-1 Area fo.25 Width 106 % Slope _1_0.s %1mperv 100 N-lmperv 10,012 N-Perv 0.1 5 Dstore-1 mperv 10.05 Dstore-Perv 0.1 %Zero-lmperv 25 Sub area Routing OUTLET Percent Routed 100 Infiltration Data iGREEN AMPT : -.. · I Grou ndwater NO Snow Pack Infiltration Editor X LID Controls 10 -Infiltration M ethod I GREEN_AMPT vi Land Uses 0 Property Value Initial Bu ildu p NONE Suction Head 6 Curb Length 0 Conductivity 0.075 N-P erv Pattern Initial Deficit 0.3 1 Dstore Pattern lnfil. Pattern I Soil capillary suction head (inches or m11) 31 Subcatchment OMA· 7 a I Property Value Name DMA-7 ~ X-Coordinate 691.814 - Y-Coordinate 85.909 Description Tag -Rain Gage Ocean side -Outlet BF-1 Area 1.712 -Width 21 1 %Slope 1.) - %1mperv 84 N-lmperv 0.012 N-Perv 0.15 -Dstore-lmperv 0.05 -Dstore-Perv 0.1 %Zero-lmperv 25 -Subarea Routing OUTLET -Percent Routed 100 Infiltration Data GREEN_AMPT ... Groundwater NO Snow Pack -Infiltration Editor X LID Controls 0 -Infiltration M ethod I GREEN_AMPT vi Land Uses 0 Initial Buildup NONE Property Value Suction Head 6 Curb Length 0 Conductivity 0.075 N-Perv Pattern Initial Deficit -0.3 1 Dstore Pattern I nfil. Pattern I Soil capillary suction head (inches or m11) 32 Subcatchment DMA-8-Slopes a I Property I value Name §DMA-8-Slopes t,.._,.. ... ,,..,..,,..,.. .... ,.. .... ,.. .... ,.. .... ,.. .... ,.. .... ,.. .... ,...,., .. X-Coordinate 712.977 Y-Coordinate -47.917 Description Tag _7 Rain Gage Oceanside Outlet POC-1 Area 1.35 Width 1549 %Slope so %1mperv 0 N-lmperv 0.012 N-Perv 7 0.1 5 Dstore-lmperv 0.05 Dstore-Perv 0.1 %Zero-lmperv 25 Subarea Routing 7 o uTLET Pe.rcent Routed 100 -Infiltration Data GREEN_AMPT Groundwater NO Snow Pack _7 Infiltration Editor X LID Controls 0 Infiltration Method I GREEN_AMPT vi Land Uses 0 Property Value Initial Buildup NONE 7 0 Suction Head 6 Curb Length Conductivity 0.075 N-Perv Pattern l11ilie1IDt:fic.il 0.31 Dstore Pattern lnfil. Pattern Soil capillary suction head (inches or mm) I 33 Subcatchment BF-1 ■ I Property Value Name BF-1 X-Coordinate 320.837 Y-Coordinate -117.009 Description Tag Rain Gage Oceanside Outlet POC-1 Area 0.128168 Width 10 % Slope 0 -%1mperv 0 N-lmperv 0.012 N-Perv 0.1 5 Dstore-lmperv 0.05 Dstore-Perv 0.1 %Zero-lmperv 25 Subarea Routing OUTLET Percent Routed 100 Infiltration Data GREEN_AMPT ... Groundwater NO Snow Pack Infiltration Editor X LID Controls 1 Infiltration Method GREEN_AMPT V Land Uses 0 Property Value Initial Buildup NONE Suction Head 1.5 Cu rb Length 0 Conductivity 0.3 N-Perv Pattern Initial Deficit 0.33 Dstore Pattern lnfil. Pattern Soil capillary suction head (inches or mm) I 34 The treatment area is at the bottom which is 5,583 sf LID Usage Editor X LID Control Name 0 LID Occupies Full Subcatchment Area of Each Unit (sq ft or sq m) 15583.00 Number of Units I, IF-3 % of Subcatchment Occupied 100.0 Surface Width per Unit (ft or m) lo % Initially Saturated lo % of Impervious Area Treated 1,00 % of Pervious Area Treated 1,00 Send Drain Flow To: Detailed Report File (Optional) (Leave blank to use subcatchment outlet) 0 Return al I Outflow to Pervious Area OK Cancel I I Help 35 LID Control Editor X LID Control Editor X Control Name: 1ai Surface Soil Storage Drain Control Name: 1ai Surface Soil Storage Drain I Bio-Retention Cell vi Berm Height 1,s LID Type: I Bio-Retention Cell vi Thickness 124 LID Type: (in. or mm) (in. or mm) Vegetation Volume 10.0 Porosity 10.4 Fraction (volume fraction) Surface Roughness lo ~ Field Capacity 10.2 (Mannings n) (volume fraction) Soil Surface Slope lo Wilting Point 10.1 (volume fraction) Storage =o (percent) fl Drain,. D Conductivity Is (in/hr or mm/hr) Conductivity Is Slope •Optional •Optional Suction Head 1,.s (in. or mm) OK I I Cancel I I Help OK I I Cancel I I Help LID Control Editor X LID Control Editor X Control Name: lliDII Surface Soil Storage Drain Control Name: lliDII Surface Soil Storage Drain LID Type: I Bio-Retention Cell vi Thickness 136 LID Type: I Bio-Retention Cell vi Flow Coefficient" 10.ssos (in. or mm) Void Ratio 10.67 Flow Exponent 10 (Voids/ Solids) Offset (in or mm) 13 Sttpag• Rate 10 (in/hr or mm/hr) Clogging Factor 10 Soil Open Level (in or mm) 10 I -Storage Storag~ ' 10 I D J1 Drain* Closed level (in or mm) Control Curve vi Drain Advisor •Optional •Optional •Flow is in in/hr or mm/hr, use O if there is no drain. L OK I l Cancel l I Help OK Cancel Help 36 Summary Files from the SWMM Model 37 PRE-DEV OUTPUT (POC-1) EPA STORM WATER MANAGEMENT MODEL -VERSION 5 ,1 (Build 5 ,1 ,015) ********************************************************* NOTE: The sunmary statistics displayed i n t his report are based on results found at every computational time step, not just on results from each reporting time step, ********************************************************* **************** Analys i s Options **************** Flow Units ,. , , , , , , , , , , , , , CFS Process Models : Rainfall/Runoff , , , , , , , , YES RDII , , , , .. , , , , , , , , , , , , , NO Snowmelt ,. , , , , , , , , , , , , , NO Groundwater , , , , , , , , , , , , NO Flow Routing , , , , , , , , , , , NO Water Quality , , , , , , , , , , NO Inf iltration Method , , , , , , GREEN_AMPT Starting Date , , , , , , , , , , , , 08/28/1951 05:00:00 Ending Date .,,,,,,,,,,,,, 05/23/2008 23:00:00 Antecedent Ory Days , , , , , , 0.0 Repor t Time Step , , , , , , , , , 01 :00:00 Wet Time Step , , , , , , , , , , , , 00:15:00 Dry Time Step , , , , , , , , , , , , 04 :00:00 ************************** Runoff Quantity Continuity ************************** Tu l ol Pn :t..iµil o l i u11 , , , , , , Evaporation loss , , , , , , , , , Inf iltration loss , , , , , , , , Surface Runoff , , , , , , , , , , , Final Storage , , , , , , , , , , , , Continuity Err or(%) , , , , , Volume acre -feet 279 ,606 3 .856 254 ,085 23 .814 0 .000 -0 .768 Depth i nches 675 ,110 9 .311 613 ,484 57 ,498 0 .000 Volume ************************** Flow Routing Continuity ************************** Ory Weather [nf low Volume acre -feet 10'6 gal Wet Weather [nf low , , , , , , , Groundwater [nf low ,,,,,,, RDII Inf low . , , , , , , , , , , , , , External Inf low , , , , , , , , , , External Outflow ,,,,,,,,, Flooding loss , , , , , , , , , , , , Evaporation loss , , , , , , , , , Exf iltration loss , , , , , , , , Initial Stored Volume , , , , Final Stored Volume , , , , , , Continuity Err or(%) , , , , , 0 .000 23 .814 0 .000 0 .000 0 .000 23 .814 0 .000 0 .000 0 .000 0 .000 0 .000 0 .000 0 .000 7 .760 0 .000 0 .000 0 .000 7 .760 0 .000 0 .000 0 .000 0 .000 0 .000 38 Subcat chment Runoff Summary ------------------------------------------------------------------------------------------------------------------------------ Subcat chment Basi n-1 Slopes Anal ysi s begun on: Anal ysi s ended on: Tot al e l apsed t i me: Tot al Precip in 675 .11 675 .11 Tot al Runon in 0.00 0.00 Tue Oct 8 11:29:16 2024 Tue Oct 8 11:29:29 2024 00:00:13 Tot al Evap in 9.53 8.72 Tot al Infil in 616.85 604.45 Imperv Runoff in 0.00 0.00 Perv Runoff i n 53.29 68.79 Tot al Runoff i n 53.29 68.79 Tot al Runoff 10"6 gal 5.24 2.52 Peak Runoff Runoff Coeff CFS 3.92 0 .079 1.52 0 .102 39 POST-DEV OUTPUT (POC-1) EPA STORM WATER MANAGEMENT f\ODEL -VERSION 5,1 (Build 5 ,1 ,015) ************* Element Count ************* Number of rain gages '''''' 1 Number of subcat chments ''' 9 Number of nodes ''''''''''' 1 Number of links ''''''''''' 0 Number of pollutants Number of land uses **************** Raingage Summary **************** Name Oceanside ******************** Subcatchment Summary ******************** Name DMA-1 BF-1 DMA-2 DMA-3 DMA-8-Slopes DMA-4 DMA-5 DMA-6 DMA-7 ******************* LID Cont rol Summary ******************* Subcatchment LID '''''' 0 ''''''' 0 Data Sour ce Oceanside Area 0.15 0.13 0.09 0.49 1 .35 0.22 0.58 0.25 1 . 71 Cont r,ol BF-1 BF-1 ************ Node Summary ************ Name POC-1 Type OUTFALL Widt h 33.00 10.00 37.00 91.00 549.00 35.00 84 .00 106.00 211.00 No . of Units 1 %Imperv 100.00 0 .00 100.00 94 .00 0 .00 100.00 100.00 100.00 84 .00 Unit Area 5583 .00 Invert Elev. 0.00 Data Type INTENSITY Recordi ng Interval 60 mi n, %Slope Rain Gage 0.5000 Oceanside 0.0000 Oceanside 0.5000 Oceanside 1.5000 Oceanside 50.0000 Oceanside 1.5000 Oceanside 1.5000 Oceanside 0.5000 Oceanside 1.5000 Oceanside Outlet BF-1 POC-1 BF-1 BF-1 POC-1 BF-1 BF-1 BF-1 BF-1 Unit % Area % Imperv Max ~ Dept h 0 .00 Wi dt h 0 .00 Ponded Area 0 .0 Covered 100.00 External Inf low Treated 100.00 % Perv Treated 100.00 40 NOTE: The sunmary statistics displayed i n t hi s r epor t ar e based on r esults found at every computational time step, not j ust on results f r om each r epor ting time step, ************x************************************•******* Analvsi s Oot:ons ************x*** Flow Units ''''''''''''''' CFS Pr ocess Mode:s: Rainf all/Runoff , , , , , , , , YES RDII , , , , , , , , , , , , , , , , , , , NO Snowmelt ... , , , , , , , , , , , , NO Gr oundwater , , , , , , , , , , , , NO Flow Routing , , , , , , , , , , , NO Water Qual:t y , , , , , , , , , , NO Inf iltr ation Method , , , , , , GREEN_AMPT Star ting Date , , , , , , , , , , , , 08/28/1951 05:00:00 Ending Date ,, , , , , , , , , , , , , 05/23/2008 23:00:00 Antecedent Ory Days , , , , , , 0.0 Repor t Time Step , , , , , , , , , 01 :00:00 Wet Time Step , , , , , , , , , , , , 00:15:00 Dry Time Step , , , , , , , , , , , , 04:00:00 Runoff Quant :t y Continu ity ************x************* Initial LID Storage , , , , , , Total Pr ecip:tation , , , , , , Evapor ation loss , , , , , , , , , Inf iltr ation loss , , , , , , , , Sur f ace Runoff , , , , , , , , , , , LID Dr ainage , , , , , , , , , , , , , Fi nal Stor age , , , , , , , , , , , , Continu ity Error(%) , , , , , Volume acr e -f eet 0.026 279.786 41 ,016 83.389 13.501 144,425 0.046 -0.917 Depth irches 0.062 67~.110 96.970 201. 213 32 .576 346,491 0.112 ************x************* Flow Routing Continu ity ************x************* Ory Weather :nf low ,,,,,,, Wet Weather :nf low , , , , , , , Gr oundwater :nf low ,,,,,,, Volume acr e -f eet Vol ume 10'6 ga l RDII Inf low , , , , , , , , , , , , , , Exter nal Inf :ow , , , , , , , , , , Exter nal Out flow ,,,,,,,,, Flooding l oss , , , , , , , , , , , , Evapor ation loss , , , , , , , , , Exf iltr ation loss , , , , , , , , Initial Stor ed Volume , , , , Fi nal Stor ed Volume , , , , , , Continu ity Error(%) , , , , , 0.000 157.926 0.000 0.000 0.000 157.926 0.000 0.000 0.000 0.000 0.000 0.000 0.000 51. 462 0.000 0.000 0.000 51. 462 0.000 0.000 0.000 0.000 0.000 41 Subcat chment Runoff Summary ------------------------------------------------------------------------------------------------------------------------------ Tot al Precip Subcat chment i n DMA-1 675.11 BF-1 675.11 DMA-2 675.11 DMA-3 675.11 DMA-8-Sl opes 675.11 DMA-4 675.11 DMA-5 675.11 DMA-6 675.11 DMA-7 675.11 *********************** LID Performance Summary *********************** Subcat chment LID Cont rol Tot al Runon in 0.00 14509.59 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Tot al Inflow in Tot al Evap i n 107 .46 1116.73 104.43 99 .25 6.12 106 .19 106 .66 104.31 90 .55 Evap Loss i n BF-1 BF-1 15184.70 1116.77 Anal ysi s begun on: Tue Oct 8 11:25:20 2024 Anal ysi s ended on: Tue Oct 8 11 :25:34 2024 Tot al el apsed t ime: 00:00:14 Tot a l Imperv Perv Tot al Tot al Peak Runoff Inf il Runoff Runoff Runoff Rurnoff Runoff Coeff i n i n in i n 10"6 ga l CFS 0.00 574.49 0.00 574.49 2 .39 0.18 0.851 0.00 0.00 0.00 14066 .97 48 .96 4.34 0.926 0.00 579 .54 0.00 579 .54 1.42 0.11 0.858 36.25 543 .52 4.16 547 .68 7 .29 0.59 0.811 604. 75 0.00 68 .28 68 .28 2 .50 1.52 0.101 0.00 576 .53 0.00 576 .53 3.44 0.26 0.854 0.00 575 .78 0.00 575 .78 9 .07 0.70 0.853 0.00 579 .74 0.00 579 .74 3.94 0.30 0.859 97 .25 483 .74 10.15 493 .89 22 .96 2.04 0.732 Inf il Surface Drain Ini t i al Final Cont inuit y Loss Out fl ow Out flow St orage St orage Error i n i n in i n in % 0.00 544 .86 13522 .62 2.40 3.15 -0.00 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: Typical maintenance indicators and actions for proposed structural BMP(s) based on Section 7.7 of the BMP Design Manual Final Design level submittal: Attachment 3 must identify: 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 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) Manufacturer and part number for proprietary parts of structural BMP(s) when applicable 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.) Recommended equipment to perform maintenance When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management □ □ □ □ □ □ □ □ PREVENTATIVE MAINTENANCE AND ROUTINE INSPECTION LANDSCAPING & IRRIGATION PROPER IRRIGATION & FERTILIZER. LESS THAN 80% COVERAGE 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR AND MONTHLY RE-SEED OR RE- PLANT. REPAIR IRRIGATION SYSTEM WITH-IN 5-DAYS. ALL SLOPES AND LANDSCAPED AREAS ARE TO HAVE A MINIMUM COVERAGE OF 80% TRASH STORAGE AREAS TRASH FREE AND REMOVAL OF SILT VISUAL INSPECTION DAILY INSPECTION REMOVE TRASH AND SILT DAILY. ALL TRASH STORAGE AREAS TO BE FREE FROM TRASH AND SILT AT ALL TIMES BIOFILTRATION TRASH FREE AND REMOVAL OF SILT. CLEAR CLOGGED OUTLETS AND STANDING WATER. SILT BUILD UP OF MORE THAN 2” NO TRASH, EXPOSED SOILS, DEAD VEGETATION, PONDED WATER, AND EXCESSIVE VEGETATION (SEE TC-32) 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR, MONTHLY DURING RAINY SEASON, AND AFTER STORM EVENT REMOVE TRASH AND SILT – REPAIR AND RESEED EXPOSED AREAS, MAINTAIN GRASS HEIGHT SO AS NOT BE SHORTER THAN 2” OR HIGHER THAN 5” REMOVE ALL PONDED WATER WEEKLY INSPECTIONS, (SEE TC- 32) ALL BIO-FILTERS TO BE FREE FROM TRASH AND SILT AT ALL TIMES, GRASS AREA TO BE FREE FROM EXPOSED SOIL AND MAINTAINED TO PROPER HEIGHT, PONDING OF WATER FOR MORE THAN 72 HOURS MAINTENANCE WILL BE REQUIRED STORMWATER CONVEYANE SYSTEM STENCILING & SIGNING MUST BE LEGIBLE AT ALL TIMES AND HAVE A CLEAR VIEW. FADING OF PAINT OR ILLEGIBLE LETTERS OR SEMI- ANNUALLY, 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR & MONTHLY DURING RAINY SEASON REPAINT STENCILING AND/OR REPLACE SIGNS 30 DAYS PRIOR TO OCTOBER 1ST. APPLICABLE TO ALL STENCILING AND SIGNS OUTLET STRUCTURS MUST BE KEPT FUNCTIONAL AT ALL TIMES. CLEAR CLOGGED OUTLETS AND STANDING WATER. SILT, DEBRIS, TRASH ACCUMULATION, PONDING WATER 30 DAYS PRIOR TO OCTOBER 1ST EACH YEAR AND WEEKLY DURING RAINY SEASON OR WITHIN 24 HOURS PRIOR TO RAIN FORECASTS. SILT, DEBRIS, TRASH ACCUMULATION AND REPAIR ANY STRUCTURAL DAMAGE TO THE OUTLET STRUCTURES. ALL OUTLET STRUCTURES SHALL BE KEPT FUNCTIONAL AT ALL TIMES. ROUTINE ACTION MAINTENANCE INDICATOR FIELD MEASUREMENT MEASUREMENT FREQUENCY MAINTENANCE ACTIVITY FREQUENCY (# OF TIMES PER YEAR) VEGETATION MANAGEMENT FOR AESTHETICS (OPTIONAL) AVERAGE VEGETATION HEIGHT GREATER THAN 12-INCHES, EMERGENCE OF TREES OR WOODY VEGETATION, VISUAL OBSERVATION AND RANDOM MEASUREMENT S THROUGH OUT THE SIDE SLOPE AREA ANNUALLY, PRIOR TO START OF WET SEASON CUT VEGETATION TO AN AVERAGE HEIGHT OF 6- INCHES AND REMOVE TRIMMINGS. REMOVE ANY TREES, OR WOODY VEGETATION. 1.0 SOIL REPAIR EVIDENCE OF EROSION VISUAL OBSERVATION ANNUALLY, PRIOR TO START OF WET SEASON RESEED/REVEGETATE BARREN SPOTS PRIOR TO WET SEASON. 1.0 STANDING WATER STANDING WATER FOR MORE THAN 96 HRS VISUAL OBSERVATION ANNUALLY, 96 HOURS AFTER A TARGET STORM (0.60 IN) EVENT DRAIN FACILITY. CORRECTIVE ACTION PRIOR TO WET SEASON. CONSULT ENGINEERS IF IMMEDIATE SOLUTION IS NOT EVIDENT. 1.0 TRASH AND DEBRIS TRASH AND DEBRIS PRESENT VISUAL OBSERVATION ANNUALLY, PRIOR TO START OF WET SEASON REMOVE AND DISPOSE OF TRASH AND DEBRIS 1.0 SEDIMENT MANAGEMENT SEDIMENT DEPTH EXCEEDS 10% OF THE FACILITY DESIGN MEASURE DEPTH AT APPARENT MAXIMUM AND MINIMUM ACCUMULATION OF SEDIMENT. CALCULATE AVERAGE DEPTH ANNUALLY, PRIOR TO START OF WET SEASON REMOVE AND PROPERLY DISPOSE OF SEDIMENT. REGRADE IF NECESSARY. (EXPECTED EVERY 2 YEARS) 1.0 UNDERDRAINS EVIDENCE OF CLOGGING VISUAL OBSERVATION ANNUALLY, PRIOR TO START CORRECTIVE ACTION PRIOR TO WET SEASON. 1.0 OF WET SEASON CONSULT ENGINEERS IF IMMEDIATE SOLUTION IS NOT EVIDENT. GENERAL MAINTENANCE INSPECTION INLET STRUCTURES, OUTLET STRUCTURES, SIDE SLOPES OR OTHER FEATURES DAMAGED, SIGNIFICANT EROSION, BURROWS, EMERGENCE OF TREES OR WOODY VEGETATION, GRAFFITI OR VANDALISM, FENCE DAMAGE, ETC. VISUAL OBSERVATION ANNUALLY, PRIOR TO START OF WET SEASON CORRECTIVE ACTION PRIOR TO WET SEASON. CONSULT ENGINEERS IF IMMEDIATE SOLUTION IS NOT EVIDENT. 1.0 TRASH AND DEBRIS FROM WIER TRASH AND DEBRIS PRESENT VISUAL OBSERVATION MONTHLY DURING WET SEASON REMOVE AND DISPOSE OF TRASH AND DEBRIS 6.0 WATER SEAL ON WIER WATER SEEPAGE THROUGH SIDE OF WIER PLATE VISUAL OBSERVATION MONTHLY DURING WET SEASON REMOVE CAULKING AROUND WIER PLATE, RECAULK, REPLACE WIER PLATE IF NECESSARY 6.0 SEDIMENT MANAGEMENT AROUND ORIFICE OF WIER PLATE ANY AND ALL SEDIMENT AROUND WIER PLATE VISUAL OBSERVATION MONTHLY DURING WET SEASON REMOVE AND PROPERLY DISPOSE OF SEDIMENT. 6.0 BF-1 Biofiltration BMP MAINTENANCE FACT SHEET FOR STRUCTURAL BMP BF-1 BIOFILTRATION Biofiltration facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Biofiltration facilities have limited or no infiltration. They are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Typical biofiltration components include: • Inflow distribution mechanisms (e.g., perimeter flow spreader or filter strips) • Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap) • Shallow surface ponding for captured flows • Side slope and basin bottom vegetation selected based on climate and ponding depth • Non-floating mulch layer • Media layer (planting mix or engineered media) capable of supporting vegetation growth • Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer • Aggregate storage layer with underdrain(s) • Impermeable liner or uncompacted native soils at the bottom of the facility • Overflow structure Normal Expected Maintenance Biofiltration requires routine maintenance to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health; maintain infiltration capacity of the media layer; replenish mulch; and maintain integrity of side slopes, inlets, energy dissipators, and outlets. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet. Non-Standard Maintenance or BMP Failure If any of the following scenarios are observed, the BMP is not performing as intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance, increased inspection and maintenance, BMP replacement, or a different BMP type will be required. • The BMP is not drained between storm events. Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected. • Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume within one month. This means the load from the tributary drainage area is too high, reducing BMP function or clogging the BMP. This would require pretreatment measures within the tributary area draining to the BMP to intercept the materials. Pretreatment components, especially for sediment, will extend the life of components that are more expensive to replace such as media, filter course, and aggregate layers. • Erosion due to concentrated storm water runoff flow that is not readily corrected by 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. BF-1 Page 1 of 11 January 12, 2017 BF-1 Biofiltration Other Special Considerations Biofiltration is a vegetated structural BMP. Vegetated structural BMPs that are constructed in the vicinity of, or connected to, an existing jurisdictional water or wetland could inadvertently result in creation of expanded waters or wetlands. As such, vegetated structural BMPs have the potential to come under the jurisdiction of the United States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the United States Fish and Wildlife Service. This could result in the need for specific resource agency permits and costly mitigation to perform maintenance of the structural BMP. Along with proper placement of a structural BMP, routine maintenance is key to preventing this scenario. BF-1 Page 2 of 11 January 12, 2017 BF-1 Biofiltration SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to an agency, community facilities district, homeowners association, property owners association, or other special district. Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently. Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the minimum inspection and maintenance frequency can be determined based on the results of the first year inspections. Threshold/Indicator Maintenance Action Typical Maintenance Frequency Accumulation of sediment, litter, or debris Remove and properly dispose of accumulated materials, without damage to the vegetation or compaction of the media layer. • Inspect monthly. If the BMP is 25% full* or more in one month, increase inspection frequency to monthly plus after every 0.1-inch or larger storm event. • Remove any accumulated materials found at each inspection. Obstructed inlet or outlet structure Clear blockage. • Inspect monthly and after every 0.5-inch or larger storm event. • Remove any accumulated materials found at each inspection. Damage to structural components such as weirs, inlet or outlet structures Repair or replace as applicable • Inspect annually. • Maintenance when needed. Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans. • Inspect monthly. • Maintenance when needed. Dead or diseased vegetation Remove dead or diseased vegetation, re-seed, re-plant, or re-establish vegetation per original plans. • Inspect monthly. • Maintenance when needed. Overgrown vegetation Mow or trim as appropriate. • Inspect monthly. • Maintenance when needed. 2/3 of mulch has decomposed, or mulch has been removed Remove decomposed fraction and top off with fresh mulch to a total depth of 3 inches. • Inspect monthly. • Replenish mulch annually, or more frequently when needed based on inspection. *“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure). BF-1 Page 3 of 11 January 12, 2017 BF-1 Biofiltration SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR BF-1 BIOFILTRATION (Continued from previous page) Threshold/Indicator Maintenance Action Typical Maintenance Frequency Erosion due to concentrated irrigation flow Repair/re-seed/re-plant eroded areas and adjust the irrigation system. • Inspect monthly. • Maintenance when needed. Erosion due to concentrated storm water runoff flow Repair/re-seed/re-plant eroded areas, and make appropriate 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. • Inspect after every 0.5-inch or larger storm event. If erosion due to storm water flow has been observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. 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 BMP for longer than 24 hours following a storm event Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health Make appropriate corrective measures such as adjusting irrigation system, removing obstructions of debris or invasive vegetation, clearing underdrains, or repairing/replacing clogged or compacted soils. • Inspect monthly and after every 0.5-inch or larger storm event. If standing water is observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology If mosquitos/larvae are observed: first, immediately remove any standing water by dispersing to nearby landscaping; second, make corrective measures as applicable to restore BMP drainage to prevent standing water. If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates controlled by an orifice installed on the underdrain, the [City Engineer] shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared with concurrence from the County of San Diego Department of Environmental Health, may be required. • Inspect monthly and after every 0.5-inch or larger storm event. If mosquitos are observed, increase inspection frequency to after every 0.1-inch or larger storm event. • Maintenance when needed. Underdrain clogged Clear blockage. • Inspect if standing water is observed for longer than 24-96 hours following a storm event. • Maintenance when needed. BF-1 Page 4 of 11 January 12, 2017 BF-1 Biofiltration References American Mosquito Control Association. http://www.mosquito.org/ California Storm Water Quality Association (CASQA). 2003. Municipal BMP Handbook. https://www.casqa.org/resources/bmp-handbooks/municipal-bmp-handbook County of San Diego. 2014. Low Impact Development Handbook. http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet BF-1. http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=250&Itemid=220 BF-1 Page 5 of 11 January 12, 2017 BF-1 Biofiltration Page Intentionally Blank for Double-Sided Printing BF-1 Page 6 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): Property / Development Name: Responsible Party Name and Phone Number: Property Address of BMP: Responsible Party Address: INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 1 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Accumulation of sediment, litter, or debris Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove and properly dispose of accumulated materials, without damage to the vegetation ☐ If sediment, litter, or debris accumulation exceeds 25% of the surface ponding volume within one month (25% full*), add a forebay or other pre-treatment measures within the tributary area draining to the BMP to intercept the materials. ☐ Other / Comments: Poor vegetation establishment Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Re-seed, re-plant, or re-establish vegetation per original plans ☐ Other / Comments: *“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure). BF-1 Page 7 of 11 January 12, 2017 I I I BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 2 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Dead or diseased vegetation Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove dead or diseased vegetation, re- seed, re-plant, or re-establish vegetation per original plans ☐ Other / Comments: Overgrown vegetation Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Mow or trim as appropriate ☐ Other / Comments: 2/3 of mulch has decomposed, or mulch has been removed Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Remove decomposed fraction and top off with fresh mulch to a total depth of 3 inches ☐ Other / Comments: BF-1 Page 8 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 3 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Erosion due to concentrated irrigation flow Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Repair/re-seed/re-plant eroded areas and adjust the irrigation system ☐ Other / Comments: Erosion due to concentrated storm water runoff flow Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Repair/re-seed/re-plant eroded areas, and make appropriate 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 ☐ Other / Comments: BF-1 Page 9 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 4 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Obstructed inlet or outlet structure Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Clear blockage ☐ Other / Comments: Underdrain clogged (inspect underdrain if standing water is observed for longer than 24-96 hours following a storm event) Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Clear blockage ☐ Other / Comments: Damage to structural components such as weirs, inlet or outlet structures Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Repair or replace as applicable ☐ Other / Comments: BF-1 Page 10 of 11 January 12, 2017 BF-1 Biofiltration Date: Inspector: BMP ID No.: Permit No.: APN(s): INSPECTION AND MAINTENANCE CHECKLIST FOR BF-1 BIOFILTRATION PAGE 5 of 5 Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted Standing water in BMP for longer than 24-96 hours following a storm event* Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Make appropriate corrective measures such as adjusting irrigation system, removing obstructions of debris or invasive vegetation, clearing underdrains, or repairing/replacing clogged or compacted soils ☐ Other / Comments: Presence of mosquitos/larvae For images of egg rafts, larva, pupa, and adult mosquitos, see http://www.mosquito.org/biology Maintenance Needed? ☐ YES ☐ NO ☐ N/A ☐ Apply corrective measures to remove standing water in BMP when standing water occurs for longer than 24-96 hours following a storm event.** ☐ Other / Comments: *Surface ponding longer than approximately 24 hours following a storm event may be detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected. **If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates controlled by an orifice installed on the underdrain, the [City Engineer] shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared with concurrence from the County of San Diego Department of Environmental Health, may be required. BF-1 Page 11 of 11 January 12, 2017 ATTACHMENT 4 City standard Single Sheet BMP (SSBMP) Exhibit [Use the City’s standard Single Sheet BMP Plan.] 16 BMP SITE PLAN CARRILLO ES PLAYFIELD REPAIR 19 ---·-- --- 80 40 0 --80 SCALE IN FEET GRAPHIC SCALE 160 240 I 0 I I I I I I I I PARTY RESPONSIBLE FOR MAINTENANCE: NAME SAN MARCOS UNIFIED SCHOOL DISTRICT ADDRESS 255 PICO AVE, SUITE 250 SAN MARCOS, CA 92069 CONTACT TOVA K. CORMAN, M.A. 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: EXECUTIVE DIRECTOR, FACILITIES 1. PHOTOGRAPHS OF THE INSTALLATION OF PERMANENT BMPS PRIOR TO CONSTRUCTION, DURING CONSTRUCTION, AND AT FINAL INSTALLATION. PHONE NO. (760) 752-1299 PLAN PREPARED BY: NAME TRACY H. SANTUCCI COMPANY SWS ENGINEERING. INC ADDRESS 1635 LAKE SAN MARCOS DR. SUIT200 SAN MARCOS, CA 92078 PHONE NO. (760) 744-0011 BMP NOTES: SIGNATURE CERTIFICATION PE 49673 1. THESE BMPSARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S RECOMMENDATIONS AND/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 SWQMP FOR ADDITIONAL INFORMATION. 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 INSTALLED. PRIOR TO RELEASE OF SECURITIES, THE DEVELOPER IS RESPONSIBLE FOR ENSURING THE PERMANENT BMPS HAVE NOT BEEN REMOVED OR MODIFIED BY THE NEW HOMEOWNER OR HOA WITHOUT THE APPROVAL OF THE CITY ENGINEER. BMP TABLE BMP ID# BMPTYPE SYMBOL CASQA NO. QUANTITY HYDROMODIFICATION & TREATMENT CONTROL 0 BIOFILTRATION I• • • ·: I TC-32 AREA (IMP-1) . . . . . .. . SOURCE CONTROL 0 0 STENCILS oii.liiRYM~~&N SD-13 0 BMPSIGN PERMANENT WATER QUALITY TREATMENT FACILITY PERMANENT WATER QUALITY TREATMENT FACILITY KEEPING OUR WA7l'RWAYS CLEAN MAINTAIN WITH CARE -NO MOD/FICA T/ONS WITHOUT AGENCY APPROVAL WATER 0UAUJY SIGN -JlPICAL DETAIL ..5.fill3._ SF. 1 EA. 1 EA. DRAWING NO. SHEET NO.(S) INSPECTION * MAINTENANCE * FREQUENCY FREQUENCY 548-4A 13, 15, 19 MONTHLY MONTHLY& AFTER STORM 548-4A 15 ANNUALLY ANNUALLY 548-4A 15 AS NEEDED AS NEEDED "AS BUil T" RCE ___ EXP. ___ _ DATE REVIEWED BY: INSPECTOR DATE fSHml CITY OF CARLSBAD ISHEETSI 1----+----+----------------+-----<>-----+----+----1 L__j ENGINEERING DEPARTMENT t----+----+--------------------+----+----+-----+---1 GRADING PLANS FOR: sws ENGINEERING, INC. t---+-----+-------------+---+---+---+----t GR2024-0014 :::=::,:::::::::::::::::::::::::::::::===============: C!VlL ENG!NEERJNG • LAND PLANNING • SuRVEYlNG 1635 Lake San limns Drive, Suite 200 1----+---+-------------------+---+---+----+---t APPROVED: JASON S. GELDERT San Marcos, CA 92078 P: 760-744-0011 ENGINEERING MANAGER RCE 63912 EXPIRES 9 30 26 DATE SAN DIEGO -KASHVILLE -PHOENIX -ORLANDO DATE INITIAL REVISION DESCRIPTION DATE INITIAL DATE INITIAL OTHER APPROVAL CITY APPROVAL DWN BY: .A=R~H __ CHKD BY: __ _ RVWD BY: PROJECT NO. DRAWING NO. PD2024-0012 548-4A