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Home My WebLink AboutDEV 2017-0074; ROYAL JET HANGER EXPANSION; PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER MANAGEMENT PLAN (SWQMP); 2017-09-28I I CITY OF CARLSBAD PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) for: ROYAL JET REMODEL PROJECT ID -- DEV2017-0074 DRAWING No. -- DWG 503-6A ENGINEER OF WORK: AESSIo* 2P 6/30/1877j Bruce A. Robertson, PE CALIFORNIA PROFESSIONAL ENGINEER LICENSE #: 48529 PREPARED FOR: Li P1 I Department of Public Works, Airports County of San Diego 1560 Joe Crosson Dr. El Cajon, CA 92020 (619) 956-4819 PREPARED BY: REC CONSULTANTS, INC. 2442 2 ND AVENUE SAN DIEGO, CA 92101 (619) 232-9200 DATE: September 28, 2017 I I Ii I I I I 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 la: DMA Exhibit Attachment 1 b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment ic: Harvest and Use Feasibility Screening Attachment id: Categorization of Infiltration Feasibility Condition (when applicable) Attachment le: Pollutant Control BMP Design Worksheets / Calculations Attachment 2: Backup for PDP Hydromodification Control Measures Attachment 2a: Hydromodification Management Exhibit Attachment 2b: Management of Critical Coarse Sediment Yield Areas Attachment 2c: Geomorphic Assessment of Receiving Channels Attachment 2d: Flow Control Facility Design Attachment 2e: This Project's Hydromodification Management Plan Attachment 3: Structural BMP Maintenance Thresholds and Actions Attachment 4: Single Sheet BMP (SSBMP) Exhibit Attachment 5: NRCS Websoil Survey Hydrologic Soil Group CERTIFICATION PAGE Project Name: Royal Jet Remodel Project ID: DEV2017-0074 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. Engineer of Work's Signature Bruce A. Robertson, RCE 48529, Exij. 06-30-2018 Print Name REC Consultants, Inc. Company September 29, 2017 Date PROJECT VICINITY MAP \ (Photo credit: OpenStreetMap.org) 'ROJECT p '<\SITE 17i it '\ \ STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov I INSTRUCTIONS: To address post-development pollutants that may be generated from development projects, the City requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMP's) into the project design per the City's Standard Urban Stormwater Management Plan (SUSMP). To view the SUSMP, refer to the Engineering Standards (Volume 4, Chapter 2). Initially 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 Stormwater Requirements' or be subject to additional criteria called 'Priority Development Project Requirements'. Many aspects of project site design are dependent upon the storm water standards applied to a project. 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 separate completed and signed questionnaire must be submitted for each new development application submission. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. In addition to this questionnaire, you must also complete, sign and submit a Project Threat Assessment Form with construction permits for the project. Please start by completing Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. 11 - STEP TO BE COMPLETED FOR ALL PROJECTS To determine if your project is a priority development project, please answer the following questions: YES NO Is your project LIMITED TO constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria: (1) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-erodible permeable areas; OR (2) designed and constructed to be hydraulically disconnected from X paved streets or roads; OR (3) designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets guidance? Is your project LIMITED TO retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in accordance with the USEPA Green Streets guidance? If you answered "yes" to one or more of the above questions, then your project is NOT a priority development project and therefore is NOT subject to the storm water criteria required for priority development projects. Go to step 4, mark the last box stating "my project does not meet PDP requirements" and complete applicant information. If you answered "no" to both questions, then go to Step 2. E-34 Page 1 of 3 Effective 6/27/13 I I STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov STEP TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS To determine if your project is a priority development project, please answer the following questions: YES NO 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 X development projects on public or private land. Is your project creating 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, x industrial, public development projects public private land. _residential, _mixed-use,_and _on _or Is your project a new or redevelopmeit project that creates 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, incLiding stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption. 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 ratural slope that is twenty-five percent or greater. 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 parking lot. A parking lot is a land area or facility for the x temporary parking or storage of motor vehicles personally for business commerce. _used _orfor 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 street, road, highway freeway or driveway? A street, road, highway, freeway or driveway is any paved impervious surface used for the transportation of X automobiles, trucks, motorcycles, and other vehicles. Is your project a new or redevelopment project that creates 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 tc" includes flow that is conveyed overland a distance of 200 feet or less x from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project the commingles lands).* _to_ _ESA _(i.e._not _with _flows _from _adjacent Is your project a new development 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, x 5014, 5541, 7532-7534, or 7536-7539. Is your project a new development 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 X 100 or more vehicles per day. 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? x ills 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%? If you answered "yes" to one or more of :he above questions, you ARE a priority development project and are therefore subject to implementing structural Best Management Practices (BMP's) in addition to implementing Standard Storm Water Requirements such as source control and low impact develqpment BMP's. A Storm Water Management Plan (SWMP) must be submitted with your application(s) for development. Go to step 3 for redevelopment projects. For new projects, go to step 4 at the end of this questionnaire, check the "my project meets PDP requirements" box and complete applicant information. If you answered "no" to all of the above questions, you ARE NOT a priority development project and are therefore subject to implementing only Standard Storm Water Requirements such as source control and low impact development BMP's required for all development projects. A Storm Water Management Plan (SWMP) is not required with your application(s) for development. Go to step 4 at the end of this questionnaire, check the "my project does not meet POP requirements" box and complete applicant information. E-34 Page 2 of 3 Effective 6/27/13 I STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov STEP TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPEMENT PROJECTS ONLY Complete the questions below regarding your redevelopment project: 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? If you answered yes," the structural BMP's required for Priority Development Projects apply only to the creation or replacement of impervious surface and not the entire development. Go to step 4, check the "my project meets POP requirements" box and complete applicant information. If you answered 'no," the structural BMP's required for Priority Development Projects apply to the entire development. Go to step 4, check the "my project meets PDP requirements" box and complete applicant information. CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with additional stormwater criteria per the SUSMP and I understand I must prepare a Storm Water Management Plan for submittal at time of application. I understand flow control (hydromodification) requirements may apply to my project. Refer to SUSMP for details. U My project does not meet PDP requirements and must only comply with STANDARD STORMWATER REQUIREMENTS per the SUSMP. As part of these requirements, I will incorporate low impact development strategies throughout my project. Applicant Information and Signature Box Address: 2200 Palomar Airport Rd., Carlsbad, CA, 92011 Accessor's Parcel Number(s): 760-221-96-02 Applicant Name: Michael Whitney Applicant Title: Applicant Signature: - Date: .... •..Qusi'€4i4.. This Box for City Use Only City Concurrence: YES NO By: Date: Project ID: * 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 bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their quivalent under the Multi Species Conservation Program within the Cities and County of San Diego; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. E-34 Page 3 of 3 Effective 6/27/13 11 I I SITE INFORMATION CHECKLIST Project Summary Information Project Name Royal Jet Remodel Project ID DEV201 7-0074 Project Address 2220 Palomar Airport Rd Carlsbad, CA 92011 Assessor's Parcel Number(s) ':APN(s)) 760-221-96-02 Project Watershed (Hydrologic Unit) Carlsbad 904.4 Parcel Area 1.37 Acres (59,877 Square Feet) Existing Impervious Area (subset of Parcel Area) 1.08 Acres (47,186 Square Feet) Area to be disturbed by the project (Project Area) 1.21 Acres (52,785 Square Feet) Project Proposed Impervious Area (subset of Project Area) 1.10 Acres (47,922 Square Feet) Project Proposed Pervious Area (subset of Project Area) 0.11 Acres (4,863 Square Feet) Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project. This may be less than the Parcel Area Description of Existing Site Condition and Drainage Patterns Current Status of the Site (select all that apply) Existing development Lii Previously graded but not built out Agricultural or other non-impervious use LI Vacant, undeveloped/natural Description / Additional Information The existing conditions of the project site consist on an existing 9,923 sf building, which is an airplane hangar. The site also consists of asphalt and concrete pavement. The project site resides along the southern border of McClellan-Palomar Airport, bound by Palomar Airport Road to the south and the airfield on the remaining sides. The project site is approximately 2,500 ft west of the intersection of Palomar Airport Rd and El Camino Real. The project site receives runoff from 2.95 acres of upstream, completely impervious area from the north and west. The site and additional runoff outlet to concrete drainage channels to the south and east, which eventually meet a confluence within another concrete swale. All flows terminate at a downstream depressed curb inlet, which conveys flows to the public storm drain system. Existing Land Cover Includes (select all that apply) Vegetative Cover LI Non-Vegetated Pervious Areas Impervious Areas Description / Additional Information In total, the landcover is 45,633 sf of impervious area and 540 sf of landscaped areas. As previously mentioned, the impervious area consists of an existing hangar, asphalt pavement and concrete pavement. The existing landscaped area is along the eastern border of the site and receives runoff from the building. Underlying Soil belongs to Hydrologic Soil Group (select all that apply): LI N RCS Type A LIII N RCS Type B LI N RCS Type C N RCS Type. D Approximate Depth to Groundwater: LI Groundwater Depth <5 feet LI 5 feet < Groundwater Depth < 10 feet LIII 10 feet < Groundwater Depth <20 feet Groundwater Depth > 20 feet Existing Natural Hydrologic Features (select all that apply) LI Watercourses LI Seeps LI Springs LI Wetlands None Description / Additional Information: Per the NRCS Websoil Survey, there are no natural hydrologic features within the project site boundary. I a 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]: Please see the Pre-Development Drainage Area Map in Attachments Point of Compliance For drainage analysis, one (1) point of compliance, denoted as POC-1, has been designated within an existing concrete swale approximately 30 feet north of the southeast corner project site boundary. From POC-1, flows continue east along an existing concrete swale that terminates at an existing catch basin, which conveys flows to the public storm drain system. Summary of Pre-Development Conditions In the pre-development condition, there is a single contributing drainage management area (DMA), denoted as El, that ultimately discharges to POC-l. El has an area of 46,173 sf (1.06 ac), length of 160 ft, slope of 4%, and impervious area fraction of 97%. El generally drains north to south discharging to a concrete swale that terminates at POC-1. El consists of the existing hangar to be remodeled, asphalt and concrete pavement, and landscaping. There are two (2) DMAs, Al & R2, that produce storm water runoff that comingles with runoff from El in the existing condition. The confluenced runoff discharges to the City MS4 downstream of POC-1. Ri & R2 are relatively undisturbed by proposed site improvements, except that their respective runoff flows are routed around the disturbed area via storm drain facilities. These facilities neglibly impact the hydrology of Ri & R2 and are thus excluded from analyses for Pollutant Control and Hydromodification, since the impact due to Ri & R2 at POC-i would be the same pre- and post-development. As a side note, Ri & R2 are included in the flood control analyses to size the proposed storm drain facilities; please see the Drainage Study prepared by REC Consultants dated September 28, 2017 for more information. I I 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): The proposed site alters drainage patterns by introducing ridges, depressions, and storm drain infrastructure to divide the contributing drainage area to POC-i into two (2) DMAs, denoted as Ni & N2. Ni drains north to south. Ni's land cover consists of concrete pavement, the western hangar extension and the existing hangar. Ni outlets to a proposed Biofiltration BMP, denoted BMP-1. Ni has a total area of 38,960 sf (0.894 ac); length of 192 if, slope of 3.5% and impervious fraction of 99.6%. BMP-1 at the outlet of Ni has an area of 1153 sf; runoff from Ni is managed by a low flow orifice within the gravel layer of BMP-1 and a grated catch basin that acts as a weir for larger flows. Flows from the catch basin outlet via a proposed 12" PVC storm drain pipe that terminates at a proposed 24" RCP storm drain pipe to the south, confluencing with runoff from R2. N2 drains west to east. N2's land cover consists of concrete pavement as well as the eastern extension of the existing hangar; all impervious areas drain to landscaping and ultimately to a proposed Biofiltration BMP, denoted BMP-2. N2 has a total area of 5,586 sf (0.128 ac); length of 156 ft, slope of 1% and impervious fraction of 98.8%. BMP-2 at the outlet of N2 has an area of 474 sf; runoff from N2 is managed by a low flow orifice within the gravel layer of BMP-2 and a grated catch basin that acts as a weir for larger flows. Flows from the catch basin outlet via a 6" PVC storm drain pipe that terminates at pOC-11, confluencing with flows from Ni & R2. As mentioned above, since R2 is undisturbed by the proposed site improvements, its hydrologic impact should be the same pre- and post-development and thus are excluded from the analyses in this report. List/describe proposed pervious features of the project (e.g., landscape areas): Pervious/Landscaped area was increased in the post-development condition. A majority of the proposed pervious area resides in the Biofiltration BMP areas. There are two (2) proposed BMPs, denoted "BMP-1" and "BMP-2", with top basin areas of 1,313 sf and 540 sf, respectively. Does the project include grading and changes to site topography? Yes ENo Description / Additional Information: Proposed grading entailed an increase in elevation along the southern edge of pavement, resulting in shallower slopes across the concrete pavement along the front of the proposed hanger. A retaining wall along different portions of the edge of pavement is proposed to tie into the existing hill slope. Near the northwestern corner of the proposed building extension, a ridge was introduced to divert runoff away from the building. I I Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)? Yes El No I Description /Additional Information: As mentioned previously, ridges and depressions were proposed to divert runoff to the two (2) proposed BMPs. In total, there are eight (8) proposed private storm drain pipes, six (6) of which convey flow to and from the BMP areas and two (2) diverting run-on flow around the disturbed area. There are two (2) proposed concrete drainage swales. One swale is proposed directly south of the remodeled hangar to convey flow to BMP-1. Another swale conveys runoff from the proposed concrete pavement to the no-th of the hangar to BMP-2. Trench drains were employed along the northern and western edges of the project site to divert run-on from undisturbed upsiream areas (Ri & R2). The trench drain diverting flow from R2 discharges to a proposed stcrm drain pipe that runs west to east and terminates at a headwall at P00-i. Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply) Onsite storm drain inlets Interior floor drains and elevator shaft sump pumps E Interior parking garages Need for future indoor & structural pest control Landscape/outdoor pesticide use LI Pools, spas, ponds, decorative fountains, and other water features LI Food service LI Refuse areas LI Industrial processes Outdoor storage of equipment or materials Vehicle and equipment cleaning Vehicle/equipment repair and maintenance Fuel dispensing areas LI Loading docks Fire sprinkler test water Miscellaneous drain or wash water Plazas, sidewalks, and parking lots I $ I 1/ 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): Runoff leaving the project site flows south via public storm drain facilities to Canyon de las Encinas. Flowing west, Canyon de las Encinas terminates at the Pacific Ocean List any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water bodies: 303(d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs N/A Identification of Project Site Pollutants Identify pollutants expected from the project site based on all proposed use(s) of the site (see manual Appendix B.6): Pollutant Not Applicable to the Project Site Expected from the Project Site Also a Receiving Water Pollutant of Concern Sediment X X Nutrients X X Heavy Metals X Organic Compounds Trash & Debris X Oxygen Demanding Substances Oil& Grease X Bacteria & Viruses X Pesticides X I, I I I 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. E 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) A continuous simulation analysis was performed using EPA-SWMM to design the Biofiltration BMPs for hydromodification compliance. See the "Hydromodification Management Plan" prepared by REC Consultants on April 17, 2017 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? LII Yes No, No critical coarse sediment yield areas to be protected based on WMAA maps If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual been performed? LI 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite LI 6.2.2 Downstream Systems Sensitivity to Coarse Sediment LI 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite 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 LI Critical coarse sediment yield areas exist but additional analysis has determined that protection is not required. Documentation attached in Attachment 8 of the SWQMP. LI Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit. Discussion /Additional Information: Refer to Attachment 2b to see the proximity of the project site to nearby critical coarse sediment yield areas. I I I I 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. As mentioned previously, one (1) point of compliance, denoted as POC-1, has been designated at the confluence of two existing concrete swales approximately 90 feet east of the project site. The two existing concrete swales convey runoff flows from 4.08 acres of upstream area, which consists of the 1.06 ac. project site and existing 2.95 acres of run-on areas. From POC-1, flows continue east along an existing concrete swale that terminates at an existing catch basin, which conveys flows to the public storm drain system. Has a geomorphic assessment been performed for the receiving channel(s)? No, the low flow threshold is 0.102 (default low flow threshold) Yes, the result is the low flow threshold is 0.102 Yes, the result is the low flow threshold is 0.3Q2 LI Yes, the result is the low flow threshold is 0.502 If a geomorphic assessment has been performed, provide title, date, and preparer: No Geomorphic assessment was performed; therefore, the low flow threshold is 0.102 was used. Discussion / Additional Information: (optional) Low flows were managed by orifices managing discharges within the French Drain within the gravel storage layer of the Biofiltration BMPs. I I I I, 1 I 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. Existing graded slopes to the south and east of the site affect the size and shape of the BMPs as the proposed design aims to mitigate impact to existing vegetated areas while providing an economical design (i.e. value engineering). 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. I I 1 1 a i I .1 I I Caty of Carlsbad STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov Project Information Project Name: Royal Jet Remodel Project ID: DEV2017-0074 DWG No. or Building Permit No.: 503-6A Source Control BMPs All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix EA of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement source control BMPs shown in this checklist. Answer each category below pursuant to the following. "Yes means the project will implement the source control BMP as described in Chapter 4 and/or Appendix EA of the Model BMP Design Manual. Discussion/justification is not required. No means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. N/A means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be provided. Source Control Requirement Applied? SC-1 Prevention of Illicit Discharges into the MS4 Li Yes D No D N/A Discussion/justification if SC-1 not implemented: Biofiltration BMPs will ensure that Illicit Discharges to the downstream MS4 will be mitigated up to the 85th percentile storm event for DMAs Ni & N2. SC-2 Storm Drain Stenciling or Signage Li Yes LI No LI N/A Discussion/justification if SC-2 not implemented: See Single Sheet BMP Exhibit. Storm Drain Stenciling or Signage will be displayed at all proposed trench drains and catch basins. SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind El Yes EL No ii N/A Dispersal Discussion/justification if SC-3 not implemented: N/A - There are no proposed Outdoor Material Storage Areas associated with the subject redevelopment E-36 Page 1 of 4 Revised 09/16 Source Control Requirement (continued) Applied? SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal U Yes 0 No 9 N/A Discussion/justification if SC-4 not implemented: N/A - There are no proposed Outdoor Work Areas associated with the subject redevelopment SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal 0 Yes I 0 No Iii N/A Discussion/justification if SC-5 not implemented: N/A - Trash storage will be managed indoors and protected from storm water and wind. SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for guidance). I!1 On-site storm drain inlets lJ Yes 0 No 0 N/A lI Interior floor drains and elevator shaft sump pumps ll Yes 0 No 0 N/A Interior parking garages 0 Yes 0 No K N/A Need for future indoor & structural pest control !1 Yes 0 No 0 N/A ll Landscape/Outdoor Pesticide Use El Yes 0 No U N/A Pools, spas, ponds, decorative fountains, and other water features El Yes 0 No ll N/A Food service 0 Yes 0 No lI N/A El Refuse areas II Yes 0 No 0 N/A El Industrial processes 0 Yes 0 No II N/A Outdoor storage of equipment or materials 0 Yes 0 No Lii N/A LII Vehicle and Equipment Cleaning lii Yes 0 No 0 N/A LII Vehicle/Equipment Repair and Maintenance Al Yes El No 0 N/A L Fuel Dispensing Areas LII Yes 0 No 0 N/A Loading Docks 0 Yes 0 No Ill N/A III Fire Sprinkler Test Water LII Yes 0 No 0 N/A IlL Miscellaneous Drain or Wash Water LII Yes 0 No 0 N/A Iii Plazas, sidewalks, and parking lots Lii Yes 0 No 0 N/A For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers. The subject redevelopment does not include any interior parking garages, water features, commercial food service, industrial processes, outdoor storage areas, or loading docks. Additionally the proposed site does not include large trash generating facilities, animal facilities plant nurseries/garden centers or automotive related uses (other than driving and parking). Inlets shall be stenciled with prohibitive language. Floor drains shall be plumbed to the sanitary sewer. Indoor and outdoor pest control will be applied minimally in accordance with the manufactures recommendations. Trash, recyclables and green waste will be stored and disposed in accordance with all applicable Local, State and Federal regulations. Fire sprinkler test water will be collected and plumbed to the sanitary sewer. Miscellaneous drain and/or wash water will either drain to landscaping or will be plumbed to the sanitary sewer. Stormwater runoff from plazas, sidewalks and parking lots will drain to the proposed Biofiltration BMPs. All areas pertaining to vehicle storage, cleaning, or maintenance will be plumbed to the sanitary sewer. E-36 Page 2 of 4 Revised 09/16 Adk Site Design BMPs All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement site design BMPs shown in this checklist. Answer each category below pursuant to the following. Yes means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of the Model BMP Design Manual. Discussion/ justification is not required. No means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be provided. Please add attachments if more space is needed. N/A means the BMPs is not applicable at the project site because the project does not include the feature that is addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be provided. Site Design Requirement Applied? SD-1 Maintain Natural Drainage Pathways and Hydrologic Features 0 Yes I 0 No !l N/A Discussion/justification if SD-1 not implemented: N/A - the project is a redevelopment of an existing building and appurtenances that does not contain any existing natural drainage pathways or hydrologic features within the disturbed area. Nevertheless the overall flow pattern and point of discharge will remain more or less unchanged by the proposed improvements.. SD-2 Conserve Natural Areas, Soils, and Vegetation Ll Yes 0 No 0 N/A DiscussiOn/justification if SD-2 not implemented: Existing vegetated hill slope to the south and east of the disturbed areas will be preserved and construction activities will be mitigated to avoid recompaction of soil in undisturbed areas. SD-3 Minimize Impervious Area Ill Yes I 0 No El N/A Discussion/justification if SD-3 not implemented: Pervious areas are increased in the post-development condition. SD-4 Minimize Soil Compaction I ii Yes I 0 No I El N/A Discussion/justification if SD-4 not implemented: Although the soils on-site were compacted in the pre-development condition, the design aims to implement amended soils in the BMPs with limited compaction. SD-5 Impervious Area Dispersion El Yes I 0 No I [I] N/A Discussion/justification if SD-5 not implemented: N//A - Although the site has been designed to disperse runoff from impervious surfaces to depressed permeable areas, those areas have not been evaluated as SD-5 but instead have been designed as Biofiltration BMPs (BF-1). E-36 Page 3 of 4 Revised 09/16 Site Design Requirement (continued) Applied? SD-6 Runoff Collection ll Yes 0 No 0 N/A Discussion/justification if SD-6 not implemented: Although the site has been designed to collect runoff from impervious surfaces and disperse it to depressed permeable areas, those areas have not been evaluated as SD-6 but instead have been designed as Biofiltration BMPs (BF-1). SD-7 Landscaping with Native or Drought Tolerant Species !l Yes I 0 No 0 N/A Discussion/justification if SD-7 not implemented: Please refer to the Landscape Plans for further details. SD-8 Harvesting and Using Precipitation I 0 Yes I 1*1 No I 0 N/A Discussion/justification if SD-8 not implemented: Harvest and Use Feasibility Screening has been discussed in Worksheet B.3-1; Harvest and Use was considered to be infeasible. Alternatively, the proposed Biofiltration Basins have been designed in compliance with the City's water quality/hydromodification management requirements. E-36 Page 4 of 4 Revised 09/16 SUMMARY OF PDP STRUCTURAL BMPS I PDP Structural BMPs I All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s). PDP structural BMPs must be verified by the City at the completion of construction. This may include requiring the project owner or project owner's representative to certify construction of the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the BMP Design Manual). Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet for each structural BMP within the project (copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP). Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated together or separate. The site was designed to drain all proposed impervious surfaces to permeable landscaped areas to promote onsite infiltration and address the City's water quality and hydromodification requirements. Initially the project sought to utilize site design BMPs and infiltration based BMPs in order to comply with the City's requirements. Onsite percolation testing was performed by NOVA Services, Inc (1/12/17) indicating that soils onsite infiltrate relatively poor (0.005 for BMP-1 and 0.088 in/hr for BMP-2) so that full infiltration is not feasible (requires a minimum infiltration rate of 0.5 in/hr). Partial Retention BMPs are feasible for infiltration rates greater than 0.01 in/hr; however, since the project ste is near a pre-existing landfill, we felt undesirable to infiltrate. Furthermore, rainwater harvest and re-use was also considered, but is not a viable option given the limited landscape and toilet/urinal needs. Biofiltration was selected as the best fit for these aforementioned factors combined with the constraints presented by the surrounding topography and previous development of the site. Biofiltration basins allow for redevelopment of the site in accordance with the City's water quality and hydromodification requirements. I Structural BMP Summary Information (BMP-1) Structural BMP ID No. "BMP-1" DWG 503-6A (Sheet 4 of 4) Type of structural BMP: M Retention by harvest and use (HU-l) LII Retention by infiltration basin (lNF-1) Retention by bioretention (INF-2) Fj Retention by permeable pavement (lNF-3) Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1) E 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) E Detention pond or vault for hydromodification management Other (describe in discussion section below) Purpose: Pollutant control only Hydromodification control only Combined pollutant control and hydromodification control Pre-treatmentlforebay for another structural BMP Other (describe in discussion section below) Discussion (as needed): BMP-1 is a Biofiltration BMP with a gravel depth of 8", amended soils depth of 18", ponding depth below riser of 14", and ponding depth above riser of 4". The ponding depth below riser is for water quality pollutant control & hydromodification flow control purposes; also, the depth above the riser is for flood control purposes. The properties of the BMP are compliant with Appendix E.2 "BF-1 Biofiltration". Within the gravel storage layer, flows discharge from the BMP via perforated 6" diameter PVC pipes (i.e. French Drain) running almost the entirety of the BMP length. Discharge from the French Drain is managed by a 7/8" diameter low flow orifice. Larger flows are managed by weir flow via a grated catch basin. The catch basin for BMP-1 is a SDRSD D-08 G-2 catch basin with double D-15 grates. The top of grate coincides with the top of riser. Structural BMP Summary Information (BMP-2) Structural BMP ID No. "BMP-2" DWG 503-6A (Sheet 4 of 4) Type of structural BMP: F Retention by harvest and use (HU-l) Retention by infiltration basin (INF-l) Retention by bioretention (INF-2) Retention by permeable pavement (INF-3) Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1) Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below) Detention pond or vault for hydromodification management Other (describe in discussion section below) Purpose: LI Pollutant control only Hydromodification control only Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP LI Other (describe in discussion section below) Discussion (as needed): BMP-2 is a Biofiltration BMP with a gravel depth of 8", amended soils depth of 18", ponding depth below riser of 9", and ponding depth above riser of 3". The ponding depth below riser is for water quality pollutant control purposes & hydromodification flow control; also, the depth above the riser is for flood control purposes. The properties of the BMP are compliant with Appendix E.2 "BF-1 Biofiltration". With the gravel storage layer, flows discharge from the BMP via perforated 6" diameter PVC pipes (i.e. French Drain) running almost the entirety of the BMP length. Discharge from the French Drain is managed by a i 1/4" diameter low flow orifice. Larger flows are managed by weir flow via a grated catch basin. The catch basin for BMP-2 is a SDRSD D-08 G-1 catch basin with a single D-15 grates. The top of grate coincides with the top of riser. ATTACHMENT I BACKUP FOR PDP POLLUTANT CONTROL BMPS This is the cover sheet for Attachment 1. Check which Items are Included behind this cover sheet: Attachment Contents Checklist Sequence Attachment la DMA Exhibit (Required) Included See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24"x36" Exhibit typically required) Attachment lb Tabular Summary of DMAs Showing Included on DMA Exhibit in DMA ID matching DMA Exhibit, DMA Attachment la Area, and DMA Type (Required)* LII Included as Attachment Ib, separate from DMA Exhibit *Provide table in this Attachment OR on DMA Exhibit in Attachment la Attachment lc Form 1-7, Harvest and Use Feasibility Included Screening Checklist (Required unless LI Not included because the entire the entire project will use infiltration project will use infiltration BMPs BMPs) Refer to Appendix B.3-1 of the BMP Design Manual to complete Form 1-7. Attachment ld Form 1-8, Categorization of Infiltration Included Feasibility Condition (Required unless D Not included because the entire the project will use harvest and use project will use harvest and use BMPs) BMPs Refer to Appendices C and D of the BMP Design Manual to complete Form 1-8. Attachment le Pollutant Control BMP Design Included Worksheets I Calculations (Required) Refer to Appendices B and E of the BMP Design Manual for structural pollutant control BMP design guidelines I 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 I 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) I Structural BMPs (identify location and type of BMP) [1 Pj P-~ I I I I I n L Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV... • •. •..•.••••••••••••••.•........ I 85 h percentile 24-hr storm depth from Figure B.1-1 d= 0.60 inches 2 Area tributary to BMP (s) A= 0....... acres Area weighted runoff factor (estimate using Appendix B.1.1 3 and .2.1) C= 0. unitless 4 Street trees volume reduction TCV= 0 cubic-feet 5 1 Rain barrels volume reduction RCV= 0 cubic-feet Calculate DCV = 1,...... 6 (3630 x C x d x A) - TCV - RCV DCV= cubic-feet B-10 February 2016 Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.2-1. DCV (DMA N2; sizing for BMP-2) 1 85 h percentile 24-hr storm depth from Figure B.1-1 d= 0.60 inches 2 Area tributary to BMP (s) A= 0.128 acres Area weighted runoff factor (estimate using Appendix B.1.1 3 and B.2.1) C 89 urn ess 4 Street trees volume reduction TCV= 0 cubic-feet 5 Rain barrels volume reduction RCV= 0 cubic-feet Calculate DCV = 249 6 (3630 x C x d x A) - TCV - RCV DCV= cubic-feet I B-10 February 2016 11 Royal Jet Remodel Attachment 1 c Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods Worksheet B.3-1. Harvest and Use Feasibility Screening tuitfy Is there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season? I] Toilet and urinal flushing [] Landscape irrigation M Other:______________ If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section B.3.2. (2 employees)*(5.5 gal/employee/day)*(36 hr)*(1 day/24 hr) = 16.5 gal = 123.4 ft3 Calculate the DCV using worksheet B-2.1. DMA Ni: DCV = 1,278 ft3 DMA N2: DCV = 249 ft3 Total: DCV = 1,527 ft3 3a. Is the 36-hour demand 3b. Is the 36-hour demand greater 3c. Is the 36-hour greater than or equal to the than 0.25DCV but less than the full demand less than DCV? DCV? 0.25DCV? Yes / No Yes / No Yes Harvest and use appears to be Harvest and use may be feasible. Harvest and use is feasible. Conduct more detailed Conduct more detailed evaluation and considered to be evaluation and sizing sizing calculations to determine infeasible. calculations to confirm that feasibility. Harvest and use may only DCV can be used at an adequate be able to be used for a portion of the rate to meet drawdown criteria, site, or (optionally) the storage may need to be upsized to meet long term capture targets while draining in longer than 36 hours. B-12 February 2016 Appendix I: Forms and Checklists tfty (ft 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 Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response x 1 to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Per the Preliminary Geotechnical Investigation performed by NOVA Services, Inc on 01/12/17, infiltration rates at the BMP locations were 0.005 in/hr and 0.088 in/hr after a factor of safety of 2 was incorporated (FS=2). These results suggest a variability of the subsurface fill soils in permeability, density, cementation, particle size and other geologic/geotechnical factors present in the subsurface soils. The infiltration results indicate that full infiltration is not feasible at the site. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, 2 groundwater mounding, utilities, or other factors) that cannot x 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: Per the Preliminary Geotechnical Investigation, NOVA did not encounter areas with infiltration rates greater than 0.5 in/hr, during our field testing at the site and the geotechnical hazards that can be created would be unknown since the site is underlain by a significant thickness of variable fill soils from approximately 20 feet and deeper. The infiltration results indicate that full infiltration is not feasible at the site. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 1-3 February 2016 Appendix I: Forms and Checklists Criteri Screening Question Yes No a Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow 3 water table, storm water pollutants or other factors) that cannot •••• a 00000 be mitigated to an acceptable level? The response to this Screening Question shill be based on a comprehensive evaluation of the factors presented ir Appendix C.3. Provide basis: us.rstk. Preliminary Geotechnical Investigation, water contamination was not evaluated at this time b NOVA Services. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change 4 of seasonality of ephemeral streams or increased discharge of ... . contaminated groun .water 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: .scstke preliminary Geotechnical Investigation, the potential for water balance was not evaluated by NOVA Services. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. If all answers to rows 1 - 4 are "Yes" a full infiltration design is potentially feasible. Part 1 The feasibility screening category is Full Infiltration Result * If any answer from row 1-4 is "No", infiltration may be possible to some extent but No 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 M54 Permit. Additional testing 2nd/or studies may be required by the City to substantiate findings. 1-4 February 2016 Appendix I: Forms and Checklists 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 Do soil and geologic conditions allow for infiltration in any 5 appreciable rate or volume? The response to this Screening x Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Per the Preliminary Geotechnical Investigation, the design infiltration rate calculated based on the on-site conditions and field testing was 0.09 inches per hour near the proposed location of BMP-2. This location does not present sufficient space between the existing building and the top of the existing slope to be feasible for an partial infiltration BMP system. The infiltration rate obtained in the area of BMP-1 (with a factor of safety of 2) was recorded at 0.005. 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. Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope 6 stability, groundwater mounding, utilities, or other factors) x 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. I 1-5 February 2016 1 I 1 Appendix I: Forms end Checklists Criteria Screening Question Yes No 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: Preliminary Gotechnica1 Investigation, water contamination was not evaluated at this time by NOVA Services. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Prcvide narrative discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates. Can infiltration be allowed without violating downstream 8 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: '.re Preliminary Geotechnical Investigation, the potential for water balance was not evaluated by NOVA Services. 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. If all answers from row 5-8 are yes then partial infiltration design is potentially feasible. Part The feasibility screening category is Partial Infiltration. No Infiltration Result* 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 ard/or studies may be required by the City to substantiate findings. 1 1-6 February 2016 Royal Jet Remodel Attachment 1e.1 Pollutant Control Compliance (BMP-1) Water Quality Compliance DMA A sf I ai I ap __[C,WQ A,BMPt1 Sf (mm) A,BMPt2 Sf (des) A,WQ Check P85 in DCV 113 I V,BMP Check (5) Ni 38960 1 1.00 1 0.00 1 0.90 1 1048 1153 OK 0.60 1147 OK Minimum area per Worksheet 13.5-1 for Biofiltration BMP Compliance BMP area provided. See Grading Plans. Worksheet B.5-1 : Simple Sizing method for Biofiltration BMPs (BMP-1) Simple Sizing Method for Biofiltration BMPs 1 IRemaining DCV after implementing retention BMPs I 1747 I cubic-feet Partial Retention _2 - Infiltration rate from Form 1-9 if partial infiltration is feasible 0 in/hr 3 - Allowable drawdown time for aggregate storag below the underdrain 36 hours 4 Depth of runoff that can infiltrated [Line 2 x Line 31 0 inches 5 Aggregate pore space 0.4 in/in 6 Required depth of gravel below the underdrain [Line 4/ Line 51 0 inches 7 Assumed surface area of the biofiltration BMP 1153 sg-ft 8 Media retained pore storage 0.1 in/in 9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)/121 x Line 7 173 cubic-feet 10 DCV that requires biofiltration [Line 1 - Line 91 12 cubic-feet BMP Parameters ii Surface Ponding [6 inch minimum, 12 inch maximum] 14 inches 12 Media Thickness [18 inch minimum], also add mulch layer thickness to this line for 18 inches 13 Aggregate Storage above underdrain invert (12 inches typical) - use 0 inches for sizing if 12 inches 14 Media available pore space 0.2 in/in 15 Media filtration rate to be used for sizing (5 in/hr with no outlet control; if the filtration is controlled by the outlet, use the outlet controlled rate) 0.61 . in/hr Baseline Calculations 16 Allowable Routing Time for sizing 6 hours 17 Depth filtered during storm [Line 15 x Line 161 3.6 inches 18 Depth of Detention Storage [Line ii + Line 12 x Line 14 + Line 13 x Line 51 22.4 inches 19 Total Depth Treated [Line 17 + Line 181 26.0 inches Option 1 - Biofilter 1.5 times the DCV 20 lRequired biofiltered volume [1.5 x Line 101 18 cubic-feet 21 1 Required Footprint [Line 20/ Line 191 x 12 8 sg-ft Option 2 - Store 0.75 of remaining DCV in pores and ponding 22 1 Required Storage (surface + pores) Volume [0.75 x Line 101 9 cubic-feet 23 lRequired Footprint [Line 22/ Line 181 x 12 5 sg-ft Footprint of the BMP 24 Area draining to the BMP 38960 sg-ft 25 Adjusted Runoff Factor for drainage area 0.90 26 Minimum BMP Footprint [Line 24 x Line 25 x 0.031 1048 sg-ft 27 Footprint of the BMP = Maximum (Minimum (Line 21, Line 23), Line 26) 1048 sg-ft Royal Jet Remodel Attachment ie.2 Pollutant Control Compliance (BMP-2) Water Quality Compliance DMA A sf ai ap C,WQ A,BMPt1 sf (mm) A,BMPt21 sf (des) A,WQ Check P85 in DCV ft3 V,BMP Check (5) N2 5586 0.99 0.01 0.89 149 474 OK 0.60 249 OK Minimum area per Worksheet 13.5-1 for Biofiltration BMP Compliance BMP area provided. See Grading Plans, Worksheet B.5-1 : Simple Sizing method for Biofiltration BMPs (BMP-2) Simple Sizing Method for Biofiltration BMPs 1 IRemaining DCV after implementing retention BMPs I 249 I cubic-feet Partial Retention _2_ Infiltration rate from Form -9 if partial infiltration is feasible 0 in/hr 3 Allowable drawdown time for aggregate storaq below the underdrain 36 hours 4 Depth of runoff that can infiltrated [Line 2 x Line 31 0 inches _5 Aggregate pore space 0.4 in/in _6_ Required depth of gravel below the underdrain [Line 4/ Line 51 0 inches —7 lAssumed surface area of the biofiltration BMP 474 sq-ft 8 Media retained pore storage 0.1 in/in 9 Volume retained by BMP [[Line 4 + (Line 12 x Line 8)/121 x Line 7 71 cubic-feet 10 DCV that requires biofiltration [Line 1 - Line 91 178 cubic-feet BMP Parameters 11 Surface Ponding [6 inch minimum, 12 inch maximum] 9 inches 12 Media Thickness 118 inch minimum, also add mulch layer thickness to this line for 18 inches 13 Aggregate Storage above underdrain invert (12 inches typical) - use 0 inches for sizing if 12 inches 14 Media available pore space 0.2 in/in 15 Media filtration rate to be used for sizing (Sin/hr with no outlet control; if the filtration is controlled by the outlet, use the outlet controlled rate) 2.98 . in /h Baseline Calculations 16 Allowable Routing Time for sizing 6 hours 17 Depth filtered during storm [Line 15 x Line 161 17.9 inches 18 Depth of Detention Storage [Line 1 + Line 12 x Line 14 + Line 13 x Line 51 17.4 inches 19 Total Depth Treated [Line 17 + Line 181 35.3 inches Option 1 - Biofilter 1.5 times the DCV 20 lRequired biofiltered volume [1.5 x Line 101 267 cubic-feet 21 lRequired Footprint [Line 20/ Line 191 x 12 91 sq-ft Option 2 - Store 0.75 of remaining DCV in pores and ponding 22 Required Storage (surface + pores) Volume 10.75 x Line 101 133 cubic-feet 23 Required Footprint [Line 22/ Line 181 x 12 92 sq-ft Footprint of the BMP 24 Area draining to the BMP 5586 sq-ft 25 Adiusted Runoff Factor for drainage area 0.89 26 Minimum BMP Footprint [Line 24 x _ine 25 x 0.031 149 sq-ft 27 Footprint of the BMP = Maximum(Minimum(Line 21, Line 23), Line 26) 149 sq-ft 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 Contents Checklist Sequence Attachment 2a Hydromodification Management Included Exhibit (Required) See Hydromodification Management Exhibit Checklist on the back of this Attachment cover sheet Attachment 2b Management of Critical Coarse Z Exhibit showing project drainage Sediment Yield Areas (WMAA Exhibit boundaries marked on WMAA is required, additional analyses are Critical Coarse Sed ment Yield optional) Area Map (Required) See Section 6.2 of the BMP Design Optional analyses for Critical Coarse Manual. Sediment Yield Area Determination 6.2.1 Verification of Geomorphic Landscape Units Onsite El 6.2.2 Downstream Systems Sensitivity to Coarse Sediment E 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite Attachment 2c Geomorphic Assessment of Receiving Z Not performed Channels (Optional) Included See Section 6.3.4 of the BMP Design Manual. Attachment 2d Flow Control Facility Design and Z Flow Control Facility Design Structural BMP Drawdown shown in Attachment 2a Calculations (Required) Drawdown Calculations Included See Chapter 6 and Appendix C of the BMP Design Manual Attachment 2e Hydromodification Management Plan I 1 I I I I 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 pie-development and post-project conditions) Structural BMPs for hydromodification management (identify location, type of BMP, and size/detail) I I I I I I I I I 1 I I I I I I I I I Attachment 2b: Project Proximity to Critical Coarse Sediment Yield A-eas The ollowing exhibit shows that the project site is not within a critical coE rse sediment yield area (CCSYA). (Photo Credit: Google Earth) DP J Attachment 2d: Structural BMP Drawdown Calculations Drawdown time is considered the amount of time it takes for the ponding depth below the riser to discharge through the low orifice. Since the Biofiltration BMP is lined, the low flow orifice is solely managing outflows below the riser. Flows above the riser will discharge through the overflow grate(s) in a negligible amount of time. The following equation was used to determine the drawdown time. T Vriser 1 hr = * Qi0 3600 S Where: T = Drawdown time in hr; Vriser = Ponding depth below riser in ft3; QIOW Low flow orifice maximum discharge rate in cfs = 0.61*(do/12)2/4*rr*i(2*g*H); d0 = Diameter of the low flow orifice(7/8" for BMP-1 and 1 1/4" for BMP-2) g = Acceleration due to gravity = 32.2 ft/s2; H Available head to orifice = hgr - do/1212; and, hgr = Gravel depth above invert of orifice = 8" for both BMPs The following tables show the results for each BMP. BMP-1 Drawdown Time Vriser 1117 ft3 QIOW 00162 cfs T 19.1 hr BMP-2 Drawdown Time Vriser 304 1t3 QIOW 0,0327 cfs T 2.6 hr Attachment 2e: This Project's Hydromodification Management Plan I HYDROMODIFICATION MANAGEMENT PLAN for I ROYAL JET REMODEL REMOVAL & REPLACEMENT OF EXISTING HANGAR 1 2220 Palomar Airport Rd., Carlsbad, CA, 92011 Proj. ID: DEV20I7-0074 Dwci. No.: DWG 503-6A I Prepared for: El Paso Oil, Inc. 8135 La Jolla Shores Dr. I La Jolla, CA, 92037 858-412-4902 I Prepared by: I I Consultants, Inc. I Bruce A. Robertson REC Consultants, Inc. 2442 Second Avenue I San Diego, CA 92101 619-232-9200 Report Prepared: October 1, 2017 TABLE OF CONTENTS Chapter 1 - Executive Summary ............................................................................................... I 1.1 Introduction ............................................................................................................................................................................1 ReportPurpose .....................................................................................................................................................1 ProjectSite .......................................................... . ................................................................................................. 1 DesignCriteria.......................................................................................................................................................2 Pointof Comparison .............................................................................................................................................. 2 1.2 Summary of Pre-Development Conditions.............................................................................................................................2 1.3 Summary of Post-Development Conditions...........................................................................................................................3 1.4 Summary of Results...............................................................................................................................................................4 Chapter 2— Methodology...........................................................................................................5 2.1 SWMM Set-up ......... ............................................................................................................................................................... 5 Set-up of Pre-Development Model ........................................................................................................................5 Set-up of Post-Development Model.......................................................................................................................5 2.2 BMP Characteristics...............................................................................................................................................................6 OrificeFlow ...........................................................................................................................................................6 WeirFlow ..............................................................................................................................................................6 2.3 Flow-Duration Curves .............................................................................................................................................................7 2.4 Flow-Frequency Curves.........................................................................................................................................................7 Chapter 3 - Conclusions............................................................................................................7 Chapter 4 - Attachments............................................................................................................7 Flow Duration Curve (FDC) Tables & Charts Flow Frequency Curve (FEC) Tables & Charts Storage-Depth Curves and Rating Curves to be used in SWMM Pre & Post Development Maps and Outlet Details SWMM Printouts Soils Map I CHAPTER 1 - EXECUTIVE SUMMARY 1.1 Introduction Report Purpose This document summarizes the approach used to model the proposed project site in the City of Carlsbad using the Environmental Protection Agency (EPA) Storm Water Management Model 5.0 (SWMM). SWMM simulations were prepared for the pre and post-development conditions to compare flows leaving the project site. In accordance with the City of Carlsbad BMP Design Manual (dated February 16, 2016), this report evaluates the flows from 10% of the 2-yr (0.102) to the 10-yr (Qio) storm events. In addition to Hydromodification, the proposed drainage design of the project site must comply with Flood Control and Pollutant Control requirements as mandated by the 2016 San Diego County Model BMP Design Manual. Please refer to the "Drainage Study" and "Storm Water Quality Management Plan" (SWQMP) prepared by REC Consultants. for the discussion of these requirements. Proiect Site The project site is located along the southern edge of Palomar Airport at 2200 Palomar Airport Rd, City of Carlsbad, County of San Diego, California. The project site is bound by Palomar Airport Road to the south and the existing airport to the north, east and west. The project site has an area of 1.06 acres (within the 1.37-acre parcel). The proposed site improvements include proposed building extensions to the western and east sides of the existing airplane hangar and the rerroval, regrading, and replacements of pavement on site. Proposed impervious areas will drain to two (2) proposed Biofiltration Best Management Practices (BMP), which will treat runoff for water quality purposes, detain low flows for hydromodifiction purposes, and manage larger flows for flood control purposes. Li I I -PROJECT SITE / -- / 1/ - 1 r \ Figure 1. Vicinity Map Design Criteria Per section 23.1 "Hydromodification Management Performance Standards" within the 2016 San Diego Storm Water Standards Manual, hereafter referred to as "Design Manual": "Each PDP (Priority Development Project) must implement onsite BMPs (Best Management Practices) to manage hydromodification that may be caused by storm water runoff discharged from a project as follows: Post-project runoff conditions (flow rates and durations) must not exceed pre-development runoff conditions by more than 10 percent (for the range of flows that result in increased potential for erosion, or degraded instream habitat downstream of PDPs). Each PDP must avoid critical sediment yield areas known to the City or identified by the optional WMAA pursuant to Provision B. 3. b. (4) [of the MS4 Permit], or implement measures that allow critical coarse sediment to be discharged to receiving waters, such that there is no net impact to the receiving water," The project site is completely outside of Critical Course Sediment Yield Areas. Please note that no susceptibility analysis was performed for this project; therefore, the lower flow threshold for comparison will be 0.1%; therefore, per the Design Manual, the range of flows to control for hydromodification must be: V. 1Q2 to 010 for streams with high susceptibility to erosion (this is the default range of flows to control when a stream susceptibility study has not been prepared)" Point of Comparison For drainage analysis, one (1) point of comparison, denoted as POC-1, has been designated within an existing concrete swale approximately 30 feet north of the southeast corner project site boundary. From POC-1, flows continue east along an existing concrete swale that terminates at an existing catch basin, which conveys flows to the public storm drain system. 1.2 Summary of Pre-Development Conditions In the pre-development condition, there is a single contributing drainage management area (DMA), denoted as El, that ultimately discharges to POC-l. El has an area of 46,173 sf (1.06 ac), length of 160 ft, slope of 4%, and impervious area fraction of 97%. El generally drains north to south discharging to a concrete swale that terminates at POC-l. El consists of the existing hangar to be remodeled, asphalt and concrete pavement, and landscaping. There are two (2) DMAs, Rl & R2, that produce storm water runoff that comingles with discharge from El in the existing condition. Runoff from Rl, R2 and El ultimately confluences downstream of POC-l. Rl is an existing DMA that drains north to south and terminates at El. Rl has a total area of 90,785 sf (2.08 ac), length of 192 ft, slope of 2%, and impervious fraction of 100%. Rl consists of an existing building to the northwest of the site, asphalt travel lanes and parking fields. Runoff from Rl flows onto El. R2 is an existing DMA that drains west to east and terminates at El. R2 has a total area of 37,613 sf (0.86 ac), length of 156 ft, slope of 2%, and impervious fraction of 100%. R2 consists of two existing buildings to the west of the site, asphalt travel lanes and parking fields. Runoff from R2 flows onto El. 2 I 1.3 Summary of Post-Development Conditions See Appendix for a detailed view of the DMAs and private storm drain improvements described in this section. I The proposec site alters drainage patterns by introducing ridges, depressions, and storm drain infrastructure :0 divide the contributing drainage area to P00-11 into two (2) DMAs, denoted as Ni & N2. Ni drains north to south. Ni's land cover consists of concrete pavement, the western hangar extension and the existing hangar. Ni outlets to a proposed Biofiliration BMP, denoted BMP-1. Ni has a total area of 38,960 sf (0.894 ac); length of 192 ft, slope of 3.5% and impervious frac:ion of 99.6%. BMP-1 at the outlet of Ni has an area of 1153 sf; rLnoff from Ni is managed by a low flow orifice within the gravel layer of BMP-1 and a grated catch basin that acts as a weir for larger flows. I Flows from the catch basin outlet via a proposed 12" PVC storm drain pipe that terminates at a proposed 24" RCP storm drain pipe to the south, confluencing with runoff from R2. I N2 drains west to east. N2's land cover consists of concrete pavement as well as the eastern extension of the existing hangar; all impervious areas drain to landscapiig and ultimately to a proposed Biofiltration BMP, denoted BMP-2. N2 has a total area of 5,586 sf (0.128 ac); length of 156 ft, slope of 1% and impervious fraction of 98.8%. BMP-2 at the outlet of N2 has an area of I 474 sf; runoff frcm N2 is managed by a low flow orifice within the gravel layer of BMP-2 and a grated caich basir that acts as a weir for larger flows. Flows from the catch basin outlet via a 6" PVC storm drain pipe that terminates at P00-1, confluencing with flows from Ni & R2. I Ri remains relatively undisturbed and outlets to a proposed trench drain along Ri's southern edge. The trench drain, flowing west to east, outlets directly to a 24" diameter pipe. The trench drain outlets to an existing 24" RCP apprcximstel 35' south of the northeast corner of the project site. Runoff from Ri eventually confluences with flows from Ni, N2 & R2 dcwnstream of I POCi. R2 remains relatively undisturbed and outlets to a proposed trench drain along R2's eastern edge The trench drain, flowing north to south, outlets directly to an 13" diameter pipe. The trench drain outlets to a proposed 18" RC to the south of the I disturbed area, which ultimately flows east to Poc-i as described previously. H 1 I I I H LI I I 1.4 Summary of Results Table I below summarizes the comparison between pre- and post-development flows vs frequencies. Table 1. Summary of Flow-Frequency I yrs Q, pre cfs Qpost cfs AQ cfs Duff. % 2 0.569 0.431 -0.138 -24.2% 3 0.606 0.555 -0.051 -8.3% 4 0.706 0.576 -0.130 -18.5% 5 0.727 0.653 -0.074 -10.1% 6 0.745 0.684 -0.061 -8.2% 7 0.784 0.725 -0.059 -7,5% 8 0.805 0.732 -0.072 -9.0% 9 0.856 0.746 -0.110 -12.9% 10 0.940 0.773 -0.167 -17.8% Chart 1 below demonstrates that the development of the project site reduces the durations per respective flow. Aft 1.3 Flow Duration Curves (nat-log) 100 010 0.940 090 1 -----------------------------------------------------------------------------------0856 0808I-------------------------------------------------------------------------------- - 0805 ----------------------------------------------------------------------------- - 0784 6 0.745 :::::::::::::::::::::_::::::::::: ::::::::::::::::0727 070 --------------------0706 04 060 03 -------------------0606 2 ------0569 050 r I - -- - Existing 040 -tigated 030 0.5Q2 -----------------------------------------------------------0284 020LQ ------------------ 0.10 1 0102 000 8 E-06 8 E-05 Percent Exceendance (# of hours of exceedance I total # of hours on record) 8E-04 0171 - 0057 FAI CHAPTER 2- METHODOLOGY See Attachment 5 for detailed information on setting up the SWMM models. 2.1 SWMM Set-up SWMM was used since we found it to be more comparable to San Diego area watersheds than the alternative San Diego Hydrology Model (SDHM) and also because it is a non-proprietary model approved by the HMP document. After each simulation, we transferred the results to Microsoft Excel to develop flow duration and flow frequency curves to determine if the proposed HMP facilities are sufficient to meet the current HMP requirements. The inputs required to develop SWMM simulations include rainfall, watershed characteristics, and BMP configuration. The Oceanside Rain Gage from the Project Clean Water website was used for this study, since it is the most representative of the project site precipitation due to elevaticn and proximity to the project site. The site was modeled with hydrologic soil group D soils as determined by the NRCS Soil Survey. Soils were assumed to be loosely compacted in the existing condition, and fully compacted in the post developed conditions. Evaporation and Infiltration parameters found in Appendix G of the Design Manual. Set-up of Pre-Development Model In the existing condition, a Subcatchrrent object was used and assigned the properties of the single DMA, denoted El. An Outfall object was used for POC-1 ("POC-l" for pre-development conditions) and assigned as the outlet of Subcatchment El. Set-up of Post-Development Model In the proposed condition, Subcatchment objects were used for the two post-development DMAs, denoted NI and N2. Each DMA was assigned their respective areas, widths, slopes, and other watershed properties. Ni and N2 flow to BMPs, denoted as "BMP-l" and "BMP-2", represented as Subcatchment objects. BMP-1 and BMP-2 are assigned a "Bretention Cell" LID Control to represent the portion of the BMP for hydromodification and water quality compliance. See the following section for further information on the BMPs. Each BMP element outlets to a Divider object ("divi" and "div2"), which divert the low threshold flows (10% of pre- development Q2) directly to POC-1 via 'dummy" conduits ('lowflowi" and "10wf10w2"). Remaining (greater) flows divert to a Storage object ("stol" and "st02") object via "dummy" conduits ('bypassl" and "bypass2"), which is assigned a 'Tabular" Storage Curve describing its storage-depth characteristics. Each Storage object represents the ponding depth above tha riser, i.e. detention volume for flood control. Each Storage Unit object flows to an Outlet object ("rci" and "rc2"), which is assigned a "Tabular/Depth" Rating Curve describing its flow-depth characteristics. The Outlet Node for both "rd' and "rc2" is "POC-l". 5 2.2 BMP Characteristics BMP-1 and BMP-2 each have a gravel storage depth of 8", an amended soils depth of 18", ponding layer (i.e. depth below riser) for water quality and hydromodification detention (driser in table below), and an additional ponding layer for flood control (i.e. depth above the riser; dabove). There is a 6" diameter perforated PVC pipe within the gravel layer (French Drain) that runs the length of each BMP per the BF-1 Biofiltration BMP Fact Sheet in Appendix E of the Design Manual. Flows leaving the French Drain are managed by a low-flow orifice. Larger flows are managed by San Diego Regional Standard Drawings (SDRSD) D-15 grates in SDRSD D-08 catch basins. BMP-1 has a SDRSD D-08 Double G-2 catch basin with two D-15 grates. BMP-2 has a D-08 Single G-1 catch basin with one D-15 grate. The following table outlines the area and outlet characteristics for each BMP. Table 2. BMP Characteristics BMP Aiop sf ABMP sf A801 sf dnser in dabove in d0 in P ft Pe ft BMP-1 1313 1153 620 14 4 7/8 18.4 9.2 BMP-2 540 474 285 1 9 3 11/4 9.2 4.6 Where: Aiop = Ponded area coinciding with the top of the basin; ABMP = Ponded area coinciding with BMP ponding depth; ABOT = Area of the bottom of the basin; driser = depth between bottom of BMP and riser (coincides with water quality depth); dabove = depth between the top of BMP and top of basin; d0 = diameter of the low flow orifice for hydromodification; P = Length of overflow weir (SDRSD D-15 grate has a perimeter of 9.2 ft); and, Pe = Effective weir length of overflow weir (assumes 50% reduction in length for contraction and clogging) Orifice Flow The low flow orifice must be sized to mitigate an increase in flow for 10% of the existing Q2 for hydromodification compliance For each BMP, the following equation was used to determine the diameter of the low flow orifice Q0 = CO A0 /7I Where: Q0 = Orifice Flow (cfs); Co = Coefficient of discharge for orifice = 0.61 (typical); A0 = Cross-sectional area of orifice (ft2) = ird02/4; do = diameter of the low flow orifice for hydromodification (ft); g = acceleration due to gravity = 32.2 ft/s2; and, H = available head to orifice (ft) (gravel depth) - dJ2 Weir Flow The overflow weir manages larger flows (10-yr to 100-yr storm events). The following equation was used to determine the rating curve for the Outlet objects. 3 Q = CW LW H Where: Qw = weir flow (cfs); CW = discharge coefficient for weir = 3.0 (typical); effective weir length (ft); and, H = max available head to weir (ft) = 0.25' for both proposed DMAs 2.3 Flow-Duration Curves The Flow-Duration Curves (FDCs) for the site were compared at the P00 by exporting the hourly runoff time series results from SWMM to an Excel spreadsheet. The FDCs were compared between 10% of the existing condition Q2 up to the existing condition Qio; this range will hereafter be referred to as the "range of observance". The range of observance was divided into 100 equal flow 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 oUained (Q with i3 to 9). For the purpose of the plot, the values were presented as percentages of time exceeded for each flow rate. See Attachment 1 for tables and charts pertaining to the Flow Duration Curves. 2.4 Flow-Frequency Curves The Flow-Frequency Curves (FFCs) for the site were compared at the P00 by exporting the peak flovs from SWMM to an Excel spreadsheet. The peak flows were ranked and the exceedance probabilities were determinec using the Cunnane plotting position method (which is the preferred plotting methodology in the 2011 HMP). The exceedarce probabilities were converted to return/reoccurrence periods. Flows for each return period in the range of observance were interpolated from the data. See Attachment 2 for tables and charts pertaining to the Flow Frequency Curves. CHAPTER 3- CONCLUSIONS This study has demonstrated that the proposed hydromodification BMPs meet the current Hydromodific3tion Requirements if the cross-sectional areas, volumes, and the respective orifices and outlet structures recommended within this technical memorandum are incorporated as specified within the proposed project site. CHAPTER 4- ATTACHMENTS Flow Duration Curve (FDC) Tables & Charts Flow Frequency Curve (FF0) Tables & Charts Storage-Depth Curves and Rating Curves to be used in SWMM Pre & Post Development Maps and Outlet Details SWMM Printouts Soils Map Royal Jet Remodel Attachment 1.1 Flow-Duration Curves Flow-Duration Curves Fraction 10% ex Q2 0.57 cfs exQ10 0.94 cfs Intervals 100 0.0088 cfs N 490918 hrs I Rain Gage =anside Count>=110% FDC HM Complaint? Existina I Mitiaated I Interval Q (cfs) # Hours >=Q % Exceed. # Hours >Q % Exceed. Post/Pre Pass/Fail 0 0.0569 1073 2.19E-03 1042 2.12E-03 97.1% Pass 1 0.0657 936 1.91E-03 679 1.38E-03 72.5% Pass 2 0.0746 808 1.65E-03 551 1.12E-03 68.2% Pass 3 0.0834 725 1.48E-03 526 1.07E-03 72.6% Pass 4 0.0922 667 1.36E-03 488 9.94E-04 73.2% Pass 5 0.1011 612 1.25E-03 443 9.02E-04 72.4% Pass 6 0.1099 612 1.25E-03 443 9.02E-04 72.4% Pass 7 0.1187 575 1.17E-03 403 8.21E-04 70.1% Pass 8 0.1275 528 1.08E-03 338 6.89E-04 64.0% Pass 9 0.1364 493 1.00E-03 319 6.50E-04 64.7% Pass 10 0.1452 450 9.17E-04 294 5.99E-04 65.3% Pass 11 0.1540 417 8.49E-04 279 5.68E-04 66.9% Pass 12 0.1629 390 7.94E-04 266 5.42E-04 68.2% Pass 13 0.1717 361 7.35E-04 250 5.09E-04 69.3% Pass 14 0.1805 319 6.50E-04 239 4.87E-04 74.9% Pass 15 0.1894 319 6.50E-04 239 4.87E-04 74.9% Pass 16 0.1982 299 6.09E-04 227 4.62E-04 75.9% Pass 17 0.2070 280 5.70E-04 207 4.22E-04 73.9% Pass 18 0.2159 269 5.48E-04 171 3.48E-04 63.6% Pass 19 0.2247 251 5.11E-04 158 3.22E-04 62.9% Pass 20 0.2335 234 4.77E-04 148 3.01 E-04 63.2% Pass 21 0.2424 217 4.42E-04 135 2.75E-04 62.2% Pass 22 0.2512 206 4.20E-04 123 2.51E-04 59.7% Pass 23 0.2600 191 3.89E-04 118 2.40E-04 61.8% Pass 24 0.2688 191 3.89E-04 118 2.40E-04 61.8% Pass 25 0.2777 167 3.40E-04 112 2.28E-04 67.1% Pass 26 0.2865 152 3.10E-04 101 2.06E-04 66.4% Pass 27 0.2953 136 2.77E-04 95 1.94E-04 69.9% Pass 28 0.3042 126 2.57E-04 82 1.67E-04 65.1% Pass 29 0.3130 119 2.42E-04 75 1.53E-04 63.0% Pass 30 0.3218 115 2.34E-04 68 1.39E-04 59.1% Pass 31 0.3307 114 2.32E-04 64 1.30E-04 56.1% Pass 32 0.3395 114 2.32E-04 64 1.30E-04 56.1% Pass 33 0.3483 111 2.26E-04 60 1.22E-04 54.1% Pass 34 0.3572 102 2.08E-04 56 1.14E-04 54.9% Pass Page 1 of 3 ExistinQ I MitiQated Interval Q (cfs) # Hours >=Q % Exceed. # Hours >=Q % Exceed. Post/Pre Pass/Fail 35 0.3660 95 1.94E-04 54 1.10E-04 56.8% Pass 36 0.3748 88 1.79E-04 54 1.10E-04 61.4% Pass 37 0.3837 80 1.63E-04 53 1.08E-04 66.3% Pass 38 0.3925 73 1.49E-04 44 8.96E-05 60.3% Pass 39 0.4013 67 1.36E-04 36 7.33E-05 53.7% Pass 40 0.4101 66 1.34E-04 35 7.13E-05 53.0% Pass 41 0.4190 66 1.34E-04 35 7.13E-05 53.0% Pass 42 0.4278 62 1.26E-04 33 6.72E-05 53.2% Pass 43 0.4366 61 1.24E-04 33 6.72E-05 54.1% Pass 44 0.4455 58 1.18E-04 32 6.52E-05 55.2% Pass 45 0.4543 53 1.08E-04 32 6.52E-05 60.4% Pass 46 0.4631 49 9.98E-05 30 6.11E-05 61.2% Pass 47 0.4720 47 9.57E-05 28 5.70E-05 59.6% Pass 48 0.4808 45 9.17E-05 28 5.70E-05 62.2% Pass 49 0.4896 45 9.17E-05 28 5.70E-05 62.2% Pass 50 0.4985 43 8.76E-05 25 5.09E-05 58.1% Pass 51 0.5073 42 8.56E-05 24 4.89E-05 57.1% Pass 52 0.5161 41 8.35E-05 22 4.48E-05 53.7% Pass 53 0.5250 40 8.15E-05 22 4.48E-05 55.0% Pass 54 0.5338 39 7.94E-05 22 4.48E-05 56.4% Pass 55 0.5426 38 7.74E-05 21 4.28E-05 55.3% Pass 56 0.5514 37 7.54E-05 21 4.28E-05 56.8% Pass 57 0.5603 34 6.93E-05 19 3.87E-05 55.9% Pass 58 0.5691 34 6.93E-05 19 3.87E-05 55.9% Pass 59 0.5779 32 6.52E-05 16 3.26E-05 50.0% Pass 60 0.5868 30 6.11E-05 15 3.06E-05 50.0% Pass 61 0.5956 29 5.91 E-05 14 2.85E-05 48.3% Pass 62 0.6044 22 4.48E-05 14 2.85E-05 63.6% Pass 63 0.6133 21 4.28E-05 14 2.85E-05 66.7% Pass 64 0.6221 21 4.28E-05 14 2.85E-05 66.7% Pass 65 0.6309 21 4.28E-05 14 2.85E-05 66.7% Pass 66 0.6398 21 4.28E-05 14 2.85E-05 66.7% Pass 67 0.6486 20 4.07E-05 13 2.65E-05 65.0% Pass 68 0.6574 20 4.07E-05 13 2.65E-05 65.0% Pass 69 0.6662 20 4.07E-05 13 2.65E-05 65.0% Pass 70 0.6751 20 4.07E-05 11 2.24E-05 55.0% Pass 71 0.6839 19 3.87E-05 11 2.24E-05 57.9% Pass 72 0.6927 17 3.46E-05 11 2.24E-05 64.7% Pass 73 0.7016 15 3.06E-05 11 2.24E-05 73.3% Pass 74 0.7104 14 2.85E-05 11 2.24E-05 78.6% Pass 75 0.7192 14 2.85E-05 11 2.24E-05 78.6% Pass 76 0.7281 12 2.44E-05 9 1.83E-05 75.0% Pass 77 0.7369 10 2.04E-05 6 1.22E-05 60.0% Pass 78 0.7457 9 1.83E-05 6 1.22E-05 66.7% Pass 79 0.7546 9 1.83E-05 6 1.22E-05 66.7% Pass 80 0.7634 9 1.83E-05 6 1.22E-05 66.7% Pass 81 0.7722 1 9 1.83E-05 5 1.02E-05 55.6% Pass Page 2 of 3 I I 1 I I I I I I Page 3 of 3 Existinq Mitiaated Interval Q (cfs) # Hours >Q % Exceed. # Hours >Q % Exceed. Post/Pre Pass/Fail 82 0.7811 8 1.63E-05 4 8.15E-06 50.0% Pass 83 0.7899 8 1.63E-05 4 8.15E-06 50.0% Pass 84 0.7987 7 1.43E-05 4 8.15E-06 57.1% Pass 85 0.8075 7 1.43E-05 4 8.15E-06 57.1% Pass 86 0.8164 7 1.43E-05 4 8.15E-06 57.1% Pass 87 0.8252 6 1.22E-05 4 8.15E-06 66.7% Pass 88 0.8340 6 1.22E-05 4 8.15E-06 66.7% Pass 89 0.8429 6 1.22E-05 4 8.15E-06 66.7% Pass 90 0.8517 6 1.22E-05 4 8.15E-06 66.7% Pass 91 0.8605 6 1.22E-05 4 8.15E-06 66.7% Pass 92 0.8694 6 1.22E-05 4 8.15E-06 66.7% Pass 93 0.8782 6 1.22E-05 4 8.15E-06 66.7% Pass 94 0.8870 6 1.22E-05 4 8.15E-06 66.7% Pass 95 0.8959 6 1.22E-05 4 8.15E-06 66.7% Pass 96 0.9047 6 1.22E-05 4 8.15E-06 66.7% Pass 97 0.9135 6 1.22E-05 4 8.15E-06 66.7% Pass 98 0.9224 6 1.22E-05 4 8.15E-06 66.7% Pass 99 0.9312 6 1.22E-05 4 8.15E-06 66.7% Pass 100 0.9400 5 1.02E-05 4 8.15E-06 80.0% Pass I I I I 1 I I I — — — — — — — —, — — — — — ,— — — — - Att 1.2 Flow-Duration Curves (nat-nat) 1.00 010 0.940 ---------------------------------------------------------------------------- - — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 0.856 0 .80 ----------------------------------------------------------------------------0.805 0.784 o ' 0.745 06 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::oi2 0.70 -ç;•Q4 0.706 0.6( _l\--------------------------------------------------------------------------0.606 —0,569 n0.50 I I — — — - Existing LI.. 0.40 Mitigated 0.30 05*02 -0284 -------------------------------------------------------------- 0.20 33*Q 0.171 -------------- - - - - 0.10 (1 1 o,- - ----------------- - - ---------------------------------------------------- 0.057 0.00 0.E+00 5.E-04 1.E-03 ?.E-03 2.F-03 Percent Exceendance (# of hours of exceedance I total # of hours on record) - — — — '- - - - - - - - - - - - - Att 1.3 Flow Duration Curves (nat-log) 1.00 0.901 --------------------H— --------------- 0.80 8L ------f----±----0.856 --------------- 0,940 6 I 0.745 0.70 - .- . - - 1' -- -- 1 0.60 3 ----4------ -- -, - 0.606 2 L -4---4 ---- --- 0.569 .2 I I --- U05 I ..----.-f----------. -, - - ----- - - -. Existing --------------'zç-t -' 0.40 Miti E:::EE:;;; ::::i:E:::: 0.20 :.:Q:::r :4 ::: 01Q2 r--4=±-14-++0.057- 8 E-06 8 E-05 8 E-04 Percent Exceendance (# of hours of exceedance / total # of hours on record) Royal Jet Remodel Attachment 2.1 Flow-Frequency Curves SWMM Analysis I yrs Q,ex. cfs Q,mit cfs AQ cfs Duff. % 2 0.569 0.431 -0.138 -24.2% 3 0.606 0.555 -0.051 -8.3% 4 1 0.706 0.576 -0.130 1 -18.5% 5 0.727 0.653 -0.074 -10.1% 6 0.745 0.684 -0.061 -8.2% 7 0.784 0.725 -0.059 -7.5% 8 0.805 0.732 -0.072 -9.0% 9 1 0.856 0.746 1 -0.110 1 -12.9% 10 1 0.940 0.773 1 -0.167 1 -17.8% I Rain Gage Oceanside Low-Flow Q2 factor (x) 10% x*Q2 to Q10 Check OK FFC HM Compliant?• n 56 years Existing Mitigated Rank Exceed. Freg. I yrs Start Date Duration hr Peak cfs Start Date Duration hr Peak cfs AQ cfs Duff % 1 0.0107 93.67 4/13/03 50 1.205 4/14/03 48 1.139 -0.07 -5.5% 2 0.0285 35.13 1/3/78 73 1.12 9/29/83 69 1.047 -0.07 -6.5% 3 0.0463 21.62 9/29/83 51 1.083 1/3/95 65 1.016 -0.07 -6.2% 4 0.0641 15.61 1/14/79 1 33 1.012 1/14/79 114 0.967 -0.05 -4.4% 5 0.0819 12.22 1/3/95 45 0.975 2/25/03 77 0.783 -0.19 -19.7% 6 0.0996 10.04 9/23/86 31 0.943 1/3/78 83 0.774 -0.17 -17.9% 7 0.1174 8.52 2/24/03 79 0.816 2/3/58 59 0.733 -0.08 -10.2% 8 0.1352 7.39 2/3/58 38 0.791 10/27/04 46 0.731 -0.06 -7.6% 9 0.1530 6.53 2/21/69 1 111 0.775 2/22/69 116 0.717 -0.06 -7.5% 10 0.1708 5.85 10/27/04 34 0.737 2/27/78 154 0.675 -0.06 -8.4% 11 0.1886 5.30 10/29/00 28 0.728 2/13/80 211 0.669 -0.06 -8.1% 12 0.2064 4.84 1/12/93 151 0.726 9/23/86 56 0.645 -0.08 -1.2% 13 0.2242 4.46 2/17/05 41 0.72 3/2/80 42 0.587 -0.13 -18.5% 14 0.2420 4.13 2/13/80 189 0.71 3/17/82 55 0.576 -0.13 -18.9% 15 0.2598 3.85 3/17/82 44 0.701 12/29/91 38 0.575 -0.13 -18.0% 16 0.2776 3.60 2/27/78 142 0.694 2/3/98 49 0.574 -0.12 -17.3% 17 0.2954 3.39 3/30/58 108 0.687 2/5/78 227 0.566 -0.12 -17.6% 18 0.3132 3.19 3/2/80 22 0.636 11/21/65 54 0.563 -0.07 -11.5% 19 0.3310 IN 2/5/78 122 0.606 2/18/05 51 0.558 -0.05 -7.9% 20 0.3488 2.87 12/29/91 13 0.604 2/22/98 79 0.538 -0.07 -10.9% 21 0.3665 2.73 11/21/65 50 0.602 8/16/77 53 0.514 -0.09 -14.6% 22 0.3843 2.60 1/28/83 14 0.602 1/27/80 81 0.513 -0.09 -14.8% 23 0.4021 2.49 2/26/83 164 0.602 1/14/78 86 1 0.494 -0.11 -17.9% 24 0.4199 2.38 2/3/98 41 0.601 1/16/72 33 0.49 -0.11 -18.5% 25 0.4377 2.28 12/16/70 74 0.599 2/22/08 35 0.474 -0.13 -20.9% 26 0.4555 2.20 1/26/08 26 0.588 2/27/91 66 0.474 -0.11 -19.4% 27 0.4733 2.11 4/28/05 4 0.582 2/14/98 158 0.456 -0.13 -21.6% 28 0.4911 2.04 2/22/98 70 0.571 2/6/69 40 1 0.438 -0.13 -23.3% 29 0.5089 1.97 111/11/851 29 1 0.567 4/27/60 33 0.425 -0.14 -25.0% 30 0.5267 1 1.90 111/14/521 46 1 0.563 1/5/79 53 0.405 -0.16 -28.1% Page 1 of 2 I I I I 1 Page 2 of 2 Rank Exceed. Freq. I yrs Start Date Duration hr Peak cfs Start Date Duration hr Peak cfs AQ cfs Duff % 31 0.5445 1.84 2/18/93 52 0.561 3/7/68 41 0.403 -0.16 -28.2% 32 0.5623 1.78 10/17/04 88 0.556 2/14/86 36 0.401 -0.16 -27.9% 33 0.5801 1.72 3/16/63 26 0.546 12/28/04 57 0.399 -0.15 -26.9% 34 0.5979 1.67 2/16/98 1 48 0.539 11/17/86 40 0.397 -0.14 -26.3% 35 0.6157 1.62 12/1/61 34 0.534 2/7/93 46 0.397 -0.14 -25.7% 36 0.6335 1.58 2/3/94 32 0.524 1/20/62 70 0.393 -0.13 -25.0% 37 0.6512 1.54 1/16/78 12 0.501 1/12/97 49 0.391 -0.11 -22.0% 38 0.6690 1.49 3/11/95 24 0.493 2/12/92 45 0.39 -0.10 -20.9% 39 0.6868 1.46 1/5/08 54 0.492 1/12/93 172 0.387 -0.11 -21.3% 40 0.7046 1.42 1/27/80 67 0.484 2/21/05 78 0.387 -0.10 -20.0% 41 0.7224 1.38 2/14/86 12 0.483 1/9/80 128 0.386 -0.10 -20.1% 42 0.7402 - 35 2/14/98 24 0.474 12/24/83 84 0.386 -0.09 -18.6% 43 0.7580 - 32 3/15/86 30 0.469 12/24/88 30 0.363 -0.11 -22.6% 44 0.7758 - 29 12/22/821 25 0.461 1/7/05 125 0.361 -0.10 -21.7% 45 0.7936 - 26 2/12/92 21 0.46 11/30/07 42 1 0.354 -0.11 -23.0% 46 0.8114 - 23 2/27/91 42 0.454 2/19/58 34 0.351 -0.10 -22.7% 47 0.8292 - 21 2/20/08 54 0.453 12/1/61 48 0.339 -0.11 -25.2% 48 0.8470 1.18 1/16/72 15 0.452 2/1/60 32 0.339 -0.11 -25.0% 49 0.8648 1.16 3/19/81 9 0.45 12/16/70 135 0.338 -0.11 -24.9% 50 0.8826 1.13 4/27/60 9 0.442 12/24/71 51 0.329 -0.11 -25.6% 51 0.9004 1.11 2/7/93 38 0.436 3/11/95 49 0.32 -0.12 -26.6% 52 0.9181 1.09 8/16/77 34 0.422 2/25/04 38 0.32 -0.10 -24.2% 53 1 0.9359 1.07 2/11/03 88 0.417 11/21/96 39 0.317 -0.10 -24.0% 54 0.9537 1.05 2/5/69 38 0.416 3/5/95 50 0.316 -0.10 -24.0% 55 0.9715 1.03 12/24/83 73 0.403 12/3/66 110 0.315 -0.09 -21.8% 56 0.9893 1 1.01 1/30/07 18 0.401 1 4/1/58 84 0.314 -0.09 1 -21.7% I I I I I I 1 U I ON — ma No —, — — — = — — — — — — — — — Ratino Curve h ft h,rel ft A sf S ft3 Q cfs 000 620 0 0.016 0.08 656 53 0.016 0.17 1 693 111 1 0.016 0.25 730 172 0.016 0.33 767 237 0.016 0.42 805 307 0.016 0.50 843 381 0.016 0.58 880 458 0.016 0.67 919 540 0.016 0.75 957 626 0.016 0.83 996 716 0,016 0.92 1035 810 0.016 1.00 1074 908 0.016 1.08 1113 1011 0.016 1.17 0.00 1153 1117 0.016 1.25 0.08 1192 1227 0.664 1.33 0.17 1232 1342 1.878 1.42 0.25 1273 1 1460 1 3.450 1.50 0.33 1313 1 1583 1 5.312 Royal Jet Remodel Att 3.1 BMP-1 Rating Curve BMP Characteristics Infiltration h,pond 14 in 1am 5 in/hr A 1153 sf ABMP 1074 sf A 0.0265 ac Qint 0.124 cfs Q,low 0.0162 cfs Low-Flow Orifice N 1 Overflow Weir d 7/8 in N 2 Ao 0.0042 ft2 P 9.2 ft I Co 0.61 Cw 3.0 Cd(SWMM) 0.2212 inAO.5/hr CL 0.5 hgr 8 in Pe 4.6 ft H 0.63 ft h,wcrest 14 in Qdiv 0.0162 cfs H,w,max 0.33 ft f,drain 0.61 1 in/hr Qw 5.31 cfs I I I I I 1 I I I I I I h ft h,rel ft A si S 1t3 Q cfs 0.00 285 0 0.033 0.08 305 25 0.033 0.17 1 326 52 1 0.033 0.25 346 81 0.033 0.33 367 112 0.033 0.42 388 146 0.033 0.50 409 182 0.033 0.58 430 220 0.033 0.67 452 261 0.033 0.75 0.00 474 304 0.033 0.83 0.08 496 349 0.332 0.92 1 0.17 518 396 0.939 1.00 1 0.25 540 446 1.725 h,pond 9 in A 474 sf A 0.0109 ac Low-Flow Orifice NI d 11/4 in Ao 0.0085 ft2 Co 0.61 Cd (SWMM) 1.0984 in0.5/hr h,gr 8 in H 0.61 ft Q,div 0.0327 cfs f,drain 2.98 in/hr Lam 5 in/hr A,BMP 474 sf Q,inf 0.055 cfs Q,des 0.033 cfs Overflow Weir N 1 P 9.2 ft I Cw 3.0 0.5 CL Pe 4.6 ft h,w,crest 9 in H,w,max 0.25 ft Qw 1.73 cfs Royal Jet Remodel Att 3.2 BMP-2 Rating Curve Ratina Curve BMP Characteristics Infiltration S LOCATION MAP N TS U c2.08a) / 1t ,J(E)24"RCP 317 I 318 / I (E) CONCRETE / CHANNEL 317 El (E)HANGAR / 1.06 ac (317.4) FF I 16 / 1111 Im ' I -Poo-1 - CONCRETE CHANNEL \(E) CONCRETE v - CHANNEL PALOMAR AIRPORT ROAD 60 30 0 60 120 180 SCALE: 1" = 60' I hl I I I I I I I I I I I I I I I I LEGEND (E): EXISTING; (N ): NEW/PROPOSED DMA LABEL \## ac) - FLOW DIRECTION - - DMA BOUNDARY LEASEHOLD LINE (PFIOPEIlTY) EXHIBIT NOTES DMAs Ri & R2 ARE UNDISTURBED RUN-ON AREAS; ANALYZED FOR SIZING HYDRAULIC STRUCTURES. STRUCTURAL BMPS, BMP-i & BMP-2, WERE INCORPORATED TO MEET WATER QUALITY & HYDROMODIFICATION REQUIREMENTS FOR DMAs Ni &N2 ENTIRE SITE IS UNDERLAIN WITH HYDROLOGIC SOIL GROUP D -_ 4. PER GEOTECH REPORT, NO GROUNDWATER WAS ENCOUNTERED AT 21.5'. THE SITE DOES NOT CONTAIN ANY EXISTING NATURAL HYDROLOGIC FEATURES (WATERCOURSES, SEEPS, 3PRING3, WETLAND3) THE SITE DOES NOT CONTAIN ANY CRITICAL COARSE SEDIMENT YIELD AREAS TO BE PROTECTED AlT 4.1 PRE-DEVELOPMENT DRAINAGE AREA MAP ROYAL JET REMODEL V (9 z 0.86 ac -- (N) TRENCH DRAIN I I (N) TRENCH DRAIN • z:- , --.----- (N) BLDG EXTENSION 317.4 FF (E) HANGAR (317.4) FF -(N) 24" RCP(SD) 1(E)24" RCP (SD) N2 0.13 ac 7(E) CONC. CHANNEL I F-i Li I I I I I I Fj I MID I - -__ - - -__ ••__ __ 40 20 0 40 80 120 PALOMAR AIRPORT ROAD Pi I SCALE: 1" = 40' EXHIBIT NOTES LEGEND DMA TYPE/NOTES DMAs Ri & R2 ARE UNDISTURBED RUN-ON AREAS; SEE PRE-DEVELOPMENT DRAINAGE AREA MAP STRUCTURAL BMPS, BMP-1 & BMP-2, WERE INCORPORATED TO MEET WATER QUALITY & HYDROMODIFICATION REQUIREMENTS FOR DMAs Ni & N2 ENTIRE SITE IS UNDERLAIN WITH HYDROLOGIC SOIL GROUP D PER GEOTECH REPORT, NO GROUNDWATER WAS ENCOUNTERED AT 21.5'. THE SITE DOES NOT CONTAIN ANY EXISTING NATURAL HYDROLOGIC FEATURES (WATERCOURSES, SEEPS, SPRINGS, WETLANDS) THE SITE DOES NOT CONTAIN ANY CRITICAL COARSE SEDIMENT YIELD AREAS TO BE PROTECTED Ni DRAINS TO STRUCTURAL BMP - BIOFILTRATION BMP (BMP-1) N2 DRAINS TO STRUCTURAL BMP - BIOFILTRATION BMP (BMP-2) Ri DRAINS TO PROPOSED TRENCH DRAIN - BYPASSES BMPs R2 DRAINS TO PROPOSED TRENCH DRAIN - BYPASSES BMPs - - DMA BOUNDARY LIMITS OFWORK - - LEASEHOLD LINE (PROPERTY) (E): EXISTING; (N): NEW / PROPOSED DMA LABEL - -. -- FLOW DIRECTION ATT 4.2 POST-DEVELOPMENT DRAINAGE AREA MAP ROYAL JET REMODEL I Ii I 2/ I II I -I I I-I I I Li_I '-i END CAP w/ FLOW CONTROL ORIFICE PER DETAIL BELOW 4k VTh\ ' LINED BASIN I BASIN TOP AREA (SEE BMP TABLE) BMP AREA (SEE BMP TABLE) k BASIN BOTTOM AREA (SEE BMP TABLE) PLANTING PER CITY SDRSD D-08 CATCH BASIN N APPROVED PLANT LIST\ SEE "B" FOR TYPE /-,—PVC SCREW CAP IMPERMEABLE LINER AROUND BMP NON—PERFORATED STANDPIPE USE 45 WYE & FITTING OR EQUIV. DIRECTIONAL CLEANOUT TO CONNECT UNDERDRAIN TO STANDPIPE LA WATER TIGHT CAP ON TERMINAL END OF PIPE SEE GRADING PLAN OUTFALL PIPE SIZE- NOTES: PER GRADING PLAN SOIL MIX PER CITY OF SAN DIEGO LID MANUAL "WELL DRAINED SOIL" SHALL BE "SANDY LOAM" SOIL MIX WITH NO MORE THAN 5% CLAY CONTENT. THE MIX SHALL CONTAIN 50-60% SAND, 20-30% COMPOST OR HARDWOOD MULCH, AND 20-30% TOPSOIL. BEST MANAGEMENT PRACTICE (BMP) TABLE BMP# BMP TYPE BASIN TOP AREA BMP AREA BASIN BOT AREA CATCH BASIN TYPE BMP-1 BIOFILTRATION(BF-1) 1313 SF 1153 SF 620 SF DOUBLE G-2 BMP-2 BIOFILTRATION (BF-1) 540 SF 474 SE 285 SF SINGLE G-1 N? NATIVE SOIL TABULATED DATA BMP1 BMP2 A 14" 9" B DOUBLE G-2 SINGLE G-1 C 18" 18" D 8" 8" E 3" 3" F 4" 4" C 6" 6" H 6" 6" I 14" 9" J 18" 12" ORIFICE BMP DIAMETER 1 7/8" 2 1 1/4" STORAGE LAYER +7//~ A CLASS II PERM PERFORATED 6"t' a a PVC UNDERDRAIN I I I I CLASS II PERM—/ STORAGE LAYER - - I ORIFICE DETAIL N TS SCH 40 MALE / ADAPTER (MiTPxSoC) /- SCH 40 PVC THREADED = END CAP (FPT) DRILL ORIFICE AT = FLOWLINE OF END CAP if (SEE TABLE TO RIGHT) ATT 4.3 POST-DEVELOPMENT BMP & OUTLET DETAILS ROYAL JET REMODEL Royal Jet Remodel Attachment 5 - SWMM Printouts Pre- & Post-Development Model Overview N2 NI • I II 5M--2 I I dI di2 BYPASS 1 BYPSSAZ LCYWFLOVU FLOWI RCI I Royal Jet Remodel Attachment 5 - SWMM Printouts Pre-Development Input Printout Pa I omarA i rport_PRE_ I np. txt [TITLE] ;Project Title/Notes [OPTIONS] ;;Option Value FLOW UNITS CFS I NE I LTRAT ION GREEN AMPT FLOW _ROUTING K I NWAVE LINK _OFFSETS DEPTH MIftLOPE 0 ALLOW_POND ING NO 5K I P_STEADY_STATE NO START DATE 05/23/1952 START TIME 00:00:00 REPORT _START _DATE 05/23/1952 REPORT _START—TIME 00:00:00 END DATE 05/23/2008 END TIME 23:00:00 SWEEP _START 01/01 SWEEP 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 INERTIAL DAMPING PARTIAL NORMAL _FLOW _LIMITED BOTH FORCE _MA I N_EQUATION H-W VAR I ABLE_STEP 0.75 LENGTHENING STEP 0 MIN_SURFAREA 12.557 MAX _TRIALS 8 HEATOLERANCE 0.005 SYS_ FLOW TOL 5 LAT_FLOW__TOL 5 MINIMUM _STEP 0.5 THREADS 1 [EVAPORATION] IN ;Data Source Parameters MONTHLY 0.06 0.08 0.11 0.15 0.17 0.19 0.19 0.18 0.15 0.11 0.08 0.06 DRY—ONLY NO [RA I NGAGES] ;Name Format Interval SCF Source rain VOLUME 1:00 1.0 TIMESERIES oceanside [SUBCATCHMENTS] ;;Näme Rain Gage Outlet Area %Impery Width %Slope CurbLen SnowPack El rain POC-1 1.060 21.9 289 4.0 0 [SUBAREAS] I ;;Subcatchment N-Impery N-Pery S-Impery S-Pery PctZero RouteTo PctRouted Page 1 i I Pa lomarA i rport_PRE_ i np .txt El 0.012 0.15 0.05 0.10 25 OUTLET [INFILTRATION] ;Subcatchment Suction Ksat IMD El 9.0 0.025 0.33 [OUTFALLS] ;Name Elevation Type Stage Data Gated Route To POC-1 0 FREE NO [TIMESERI ES] Name Date Time Value oceanside FILE oceanside.txt" [REPORT] ;;Reporting Options INPUT NO CONTROLS NO SUBCATCHMENTS ALL NODES ALL LINKS ALL [TAGS] [MAP] DIMENSIONS 0.000 0.000 10000.000 10000.000 Units None [COORDINATES] ;;Node X-Coord Y-Coord PoC-1 -2819.857 3961.105 [VERTICES] ;;Link X-Coord Y-Coord [Polygons] ;;Su catchment X-Coord Y-Coord El -2861.142 8779.395 [SYMBOLS] ;Gage X-Coord Y-Coord 11 rain -2318.321 9314.227 Page 2 Royal Jet Remodel Attachment 5 - SWMM Printouts Pie-Development Report Printout I I I Pa I omarA i rport_PRE_report .txt EPA STORM WATER MANAGEMENT MODEL - VERSION 5.1 (Build 5.1.012) -------------------------------------------------------------- NOTE: The summary statistics displayed in this report are based on results found at every computational time step, not just on results from each reporting time step. *** * ** * ** ** * * * ** * ** *** ** * * * ** ** ** * * * *** *** ** * ** ** *** *** * Analysis *Options *************** Flow Units ............... Process Models: Rainfall/Runoff ........ RDll ................... Snowmelt ............... Groundwater ............. Flow Routing ........... Water Quality .......... Infiltration Method ...... Starting Date ............ Ending Date .............. Antecedent Dry Days ...... Report Time Step ......... Wet Time Step ............ Dry Time Step ............ ** *** ** ** * ** ** ** * ** * ** Runoff Quantity Continuity *** ** * ** ** * ** **** * ** * ** * ** Total Precipitation ...... Evaporation Loss ......... Infiltration Loss ........ Surface Runoff ............ Final Storage ............ Continuity Error (%) ..... ** *** * ** *** ** * * ** * ** * ** * ** Flow Routing Continuity * * *** ** * ** ** * *** * ** * ** * ** Dry Weather Inflow ....... Wet Weather Inflow ....... Groundwater Inflow ....... RDII Inflow .............. External Inflow ........... External Outflow ......... Flooding Loss ............ Evaporation Loss ......... Exfi Itration Loss ........ Initial Stored Volume .... Final Stored Volume ...... Continuity Error (%) CFS YES NO NO NO NO NO GRE EN_AMPT 05/23/1952 00:00:00 05/23/2008 23:00:00 0.0 01:00:00 00:15:00 04:00:00 Volume Depth acre-feet inches 58.087 657.590 3.356 37.991 35.068 396.991 20.572 232.890 0.001 0.009 -1.565 Volume Volume acre-feet 10A6 gal 0.000 0.000 20.572 6.704 0.000 0.000 0.000 0.000 0.000 0.000 20.572 6.704 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 **** ** *** ** *** ** * ** * ** * ** ** Subcatchment Runoff Summary * ** * * ** ** *** ** *** ** * ** * ** ** Page 1 ------------------------------------------------------------------------------------ Pa I omarA I rport_PRE_report .txt -------------------- Total Total Total Total Total Total Peak Runoff Precip Runon [yap Infil Runoff Runoff Runoff Coeff Subcatchment in in in in in lOt6 gal US -------------------- El ------------------------------------------------------------------------------------ 657.59 0.00 37.99 396.99 232.89 6.70 1.20 0.354 Analysis begun on: Wed Jun 28 16:38:48 2017 Analysis ended on: Wed Jun 28 16:39:01 2017 Total elapsed time: 00:00:13 Page 2 Royal Jet Remodel Attachment 5 - SWMM Printouts Post-Development Input Printout Pa I omarA i rport_POST_ I np .txt [TITLE] ;Project Title/Notes [OPTIONS] ;;Option Value FLOW UNITS CFS INFILTRATION GREEN_AMPT FLOW _ROUTING K I NWAVE LINK OFFSETS DEPTH MIN SLOPE 0 ALLOW_POND ING NO 5K I P_STEADY_STATE NO START DATE 05/23/1952 START TIME 00:00:00 REPORT _START _DATE 05/23/1952 REPORT _START—TIME 00:00:00 END DATE 05/23/2008 END TIME 23:00:00 SWEEP START 01/01 SWEEP 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 INERTIAL DAMPING PARTIAL NORMAL _FLOW_LIMITED BOTH FORCE _MA I MAIN—EQUATION H-W VARIABLE STEP 0.75 LENGTHEN I NG_STEP 0 MIN_SURFAREA 12.557 MAX_TRIALS 8 HEAD TOLERANCE 0.005 SYS_FLOWTOL 5 LAT_FLOW__TOL 5 MINIMUM STEP 0.5 THREADS 1 [EVAPORATION] ;Data Source Parameters MONTHLY 0.06 0.08 0.11 0.15 0.17 0.19 0.19 0.18 0.15 0.11 0.08 0.06 DRY—ONLY NO ERA I NGAGES] ;;Name Format Interval SCF Source rain VOLUME 1:00 1.0 TIMESERIES oceanside [SUBCATCHMENTS] ;Name Rain Gage Outlet Area %Impery Width %Slope CurbLen SnowPack 11 Ni rain BMP-i 0.894 99.6 203 3.5 0 N2 rain BMP-2 0.128 98.8 36 1.0 0 BMP-1 rain DIV1 0.0265 0 10 0 0 Page 1 Pa I omarA i rport_POST_ I np .txt BMP-2 rain DIV2 0.0109 0 10 0 0 [SUBAREAS] ;;Subcatchment N-Impery N-Pery S-Impery S-Pery PctZero RouteTo PctRouted ---------- ---------- N1 0.012 0.15 0.05 0.10 25 OUTLET N2 0.012 0.15 0.05 0.10 25 OUTLET BMP-1 0,012 0.15 0.05 0.10 25 OUTLET BMP-2 0.012 0.15 0.05 0.10 25 OUTLET [INFILTRATION] ;Subcatchment Suction Ksat IMD Ni 9.0 0.01875 0.33 N2 9.0 0.01875 0.33 BMP-1 3.5 0.5 0.25 BMP-2 3.5 0.5 0.25 [LID-CONTROLS] ;Name Type/Layer Parameters BMP-1 BC BMP-1 SURFACE 14 0.0 0.0 0.0 5 BMP-1 SOIL 18 0.4 0.2 0.1 5.0 5.0 1.5 BMP-1 STORAGE 8 0.67 0.0 0.0 BMP-1 DRAIN 0.2212 0.5 0 6 BMP-2 BC BMP-2 SURFACE 9 0.0 0.0 0.0 5 BMP-2 SOIL 18 0.4 0.2 0.1 5.0 5.0 1.5 BMP-2 STORAGE 8 0.67 0.0 0 BMP-2 DRAIN 1.0984 0.5 0.0 6 [LID_USAGE] ;Subcatchment LID Process Number Area Width InitSat Fromlmp ToPery RptFi le Dra inTo BMP-1 BMP-i 1 1154.34 10 0 100 0 BMP-2 BMP-2 1 474.80 10 0 100 0 [OUTFALLS] ;;Name Elevation Type Stage Data Gated Route To PÔC-1 0 FREE NO [DIVIDERS] ;;Name Elevatioi Diverted Link Type Parameters dlvi 0 bypassi CUTOFF 0.0162 0 0 0 0 div2 0 bypass2 CUTOFF 0.0327 0 0 0 0 [STORAGE] ;;Name Elev. MaxDepth InitDepth Shape Curve Name/Params Page 2 Pa I omarA I rport_POST_ I np . txt N/A Fevap Psi Ksat IMD stol 0 0.33 0 TABULAR stol 0 0 st02 0 0.25 0 TABULAR st02 0 0 [CONDUITS] ;Name From Node To Node Length Roughness InOffset OutOffset InitFIow MaxFlow LOWFLOW1 dlvi POC-i 400 0.01 0 0 0 0 BYPASS2 div2 st02 400 0.01 0 0 0 0 LOWFLOW2 div2 POC-1 400 0.01 0 0 0 0 BYPASS1 dlvi stol 400 0.01 0 O 0 0 [OUTLETS] ;;Name From Node To Node Offset Type QTable/Qcoeff Qexpon Gated RC1 stol POC-1 0 TABULAR/DEPTH rd NO RC2 5t02 POC-1 0 TABULAR/DEPTH rc2 NO [XSECT IONS] ;;Link Shape Geomi Geoni2 Geom3 Geom4 Barrels Culvert LOWFLOW1 DUMMY 0 0 0 0 1 BYPASS2 DUMMY 0 0 0 0 1 LOWFLOW2 DUMMY 0 0 0 0 1 BYPASS1 DUMMY 0 0 0 0 1 [CURVES] ;;Name Type X-Value Y-Value rdi Rating 0.00 ---------- 0.000 rcl 0.08 0.664 rcl 0.17 1.878 rcl 0.25 3.450 rcl 0.33 5.312 rc2 Rating 0.00 0.000 rc2 0.08 0.332 rc2 0.17 0.939 rc2 0.25 1.725 stol Storage 0.00 1153 stol 0.08 1192 stol 0.17 1232 Page 3 Pa lomarA I rport_POST_ I np .txt stol 0.25 1273 stol 0.33 1313 5t02 Storage 0.00 474 st02 0.08 496 st02 0.17 518 5t02 0.25 540 [TIMESERI ES] ;;Name Date Time Value oceanside FILE occanside.txt [REPORT] ;;Reporting Options INPUT NO CONTROLS NO SUBCATCHMENTS ALL NODES ALL LINKS ALL [TAGS] [MAP] DIMENSIONS 0.000 0.000 10000.000 10000.000 Units None [COORDINATES] ;Node X-Coord Y-Coord PÔC-1 176.094 1088.581 divl -912.487 5389541 div2 869.797 5442.903 stol -2278.549 4108.858 st02 2427.962 4172.892 [VERTICES] ;;Link X-Coord Y-Coord [Polygons] ;;Su catchment X-Coord Y-Coord Ni -1125.934 8655.283 N2 1008.538 8729.989 BMP-1 -1008.538 6819.637 BMP-2 944.504 6872.999 [SYMBOLS] ;Gage X-Coord Y-Coord rain 179.028 9258.312 (I Page 4 I Royal Jet Remodel Attachment 5 - SWMM Printouts Post-Development Report Printout I I Pa I omarA i rport_POST_report .txt EPA STORM WATER MANAGEMENT MODEL - VERSION 5.1 (Build 5.1.012) -------------------------------------------------------------- WARNING 04: minimum elevation drop used for Conduit LOWFLOW1 WARNING 04: minimum elevation drop used for Conduit BYPASS2 WARNING 04: minimum elevation drop used for Conduit LOWFLOW2 WARNING 04: minimum elevation drop used for Conduit BYPASS1 ********************************************************* NOTE: The summary statistics displayed in this report are based on results found at every computational time step, not just on results from each reporting time step. Analysis Options ** *** * *** * * *** ** Flow Units ............... Process Models: Rainfall/Runoff ........ RDll ................... Snowmelt ............... Groundwater ............. Flow Routing ........... Ponding Allowed ........ Water Quality .......... Infiltration Method ...... Flow Routing Method ...... Starting Date ............ Ending Date .............. Antecedent Dry Days ...... Report Time Step ......... Wet Time Step ............. Dry Time Step ............ Routing Time Step ........ Runoff Quantity Continuity * * * * * * * * * * * * * * * * * * * * * * * * * * Initial LID Storage ...... Total Precipitation ....... Evaporation Loss ......... Infiltration Loss ........ Surface Runoff ........... LID Drainage ............. Final Storage ............ Continuity Error (%) ...... ** ** * * * ** * *** *** *** *** ** ** Flow Routinq Continuity ** * * ** * ** * ** *** *** * ** ** * * Dry Weather Inflow ....... Wet Weather Inflow ....... Groundwater Inflow ....... RDll Inflow .............. External Inflow .......... External Outflow ......... Flooding Loss ............ Evaporation Loss ......... Exf I ltrat ion Loss ........ CFS YES NO NO NO YES NO NO GREEN_AMPT KINWAVE 05/23/1952 00:00:00 05/23/2008 23:00:00 0.0 01:00:00 00:15:00 04:00:00 60.00 sec Volume Depth acre-feet inches 0.006 0.064 58.054 657,590 11.233 127.241 0.196 2.216 6.159 69.765 41 .279 467 .574 0.014 0.164 -1.415 Volume Volume acre-feet 1O'6 gal 0.000 0.000 47.438 15.458 0.000 0.000 0.000 0.000 0.000 0.000 47.438 15.458 0.000 0.000 0.000 0.000 0.000 0.000 Page 1 Pa I omarA i rport_POST_report .txt Initial Stored Volume . 0.000 0.000 Final Stored Volume 0.000 0.000 Continuity Error (%) .. -0.000 Highest Flow Instability Indexes * ** * ** *** * * * * * ** ** ** ** * ** ** ** * All links are stable. *** *** * ** * * ** * * * * * * * ** ** * Routin Time Step Summary ****** ****************** Minimum Time Step : 60.00 sec Average Time Step : 60.00 sec Maximum Time Step : 60.00 sec Percent in Steady State : 0.00 Average Iterations per Step 1.00 Percent Not Converging : 0.00 Subcatchment Runoff Summary ** *** ** * ** * ** ** ** ** ** ***** * -------------------- Total ------------------------------------------------------------------------------------ Total Total Total Total Total Peak Runoff Precip Runon Evap Infil Runoff Runoff Runoff Coeff Subcatchment in in in in in 10A6 gal CFS Ni -------------------- 657.59 ------------------------------------------------------------------------------------ 0.00 99.96 1.84 565.55 13.73 1.08 0.860 N2 657.59 0.00 100.76 5.52 560.01 1.95 0.15 0.852 BMP-1 657.59 19079.02 901.46 0.00 18832.83 13.55 1.11 0.954 BMP-2 657.59 6576.19 793.60 0.00 6439.11 1.91 0.13 0.890 *********************** LID Performance Summary **** ** * ** **** * ** ** ** ** * -------------------------------- Total Evap Infi I Surface Drain Initial Final Continuity Inflow Loss Loss Outflow Outflow Storage Storage Error Subcatchment LID Control in in in in in in in % ------------------------------------------------------------------------------------ I Page 2 Pa I omarA i rport_POST_report .txt -------------------------------- BMP-1 BMP-1 19736.61 901.50 0.00 2784.53 16048.99 1.80 3.73 -0.00 BMP-2 BMP-2 7233.78 793.63 0.00 11.16 6428.25 1.80 2.52 0.00 Node Depth Summary * *** * ** ** * ** ** ** ** Average --------------------------------------------------------------------------------- Maximum Maximum Time of Max Reported Depth Depth HGL Occurrence Max Depth Node Type Feet Feet Feet days hr:min Feet POC-1 OUTFALL 0.00 --------------------------------------------------------------------------------- 0.00 0.00 0 00:00 0.00 divi DIVIDER 0.00 0.00 0.00 0 00:00 0.00 div2 DIVIDER 0.00 0.00 0.00 0 00:00 0.00 stol STORAGE 0.00 0.11 0.11 18588 15:34 0.11 5t02 STORAGE 0.00 0.02 0.02 15566 20:04 0.02 *** ** ** * ** * ** * ** * ** Node Inflow Summary * *** * ** * ** * ** *** Maximum Maximum Lateral Total Flow Lateral Total Time of Max Inflow Inflow Balance Inflow Inflow Occurrence Volume Volume Error Node Type CFS CFS days hr:min 1OA6 gal 1OA6 gal Percent POC-1 OUTFALL 0.00 1.16 18588 16:16 0 15.5 0.000 divi DIVIDER 1.11 1.11 18588 15:46 13.6 13.6. 0.000 div2 DIVIDER 0.13 0.13 15566 20:01 1.91 1.91 0.000 stol STORAGE 0.00 1.09 18588 15:46 0 5.9 -0.001 5t02 STORAGE 0.00 0.10 15566 20:01 0 0.0342 -0.092 * *** * *** *** ** * ** * ** * * Node Flooding Summary * *** *** * * * * ** ** * ** * * No nodes were flooded. * ** * ** ** *** *** *** * ** ** Storage Volume Summary ** ** ** ** * ** ** * ** * ** ** Page 3 I Pa I omarA i rportPOST_report . txt Average Avg Evap Exf I I Maximum Max Time of Max Maximum Occurrence Outflow Volume Pcnt Pcnt Pcnt Volume Pcnt Storage Unit 1CCO ft3 Full Loss Loss 1000 ft3 Full days hr:min CFS --------------------------------------------------------------------------- stol 0.000 0 0 0 0.135 33 18588 15:33 1.11 5t02 0.000 0 0 0 0.012 9 15566 20:03 0.10 I Outfall Loading Summary ******* ************* I Flow Avg Max Total Freq Flow Flow Volume Outfall Node Pcnt CFS CFS 10A6 gal I POC-1 4.85 0.02 1.16 15.457 4.85 0.02 1.16 15.457 I System Link Flow Summary I ----------------------------------------------------------------------------- Maximum Time of Max Maximum Max/ Max/ Flow Occurrence IVeloci Full Full I Link Type CFS days hr:min ft/sec Flow Depth LOWFLOW DUMMY 0.02 176 11:56 BYPASS2 DUMMY 0,10 15566 20:01 I LOWFLOW2 DUMMY 0.03 9733 13:12 BYPASS1 DUMMY 1.09 18588 15:46 RC1 DUMMY 1.11 18588 15:34 RC2 DUMMY 0.10 15566 20:04 I ************************* Conduit Surcharge Summary ,I No conduits were surcharged. I Analysis begun on: Mon Jun 19 12:50:23 2017 Analysis ended on: Mon Jun 19 12:50:58 2017 Total elapsed time: 00:00 35 1 i Page 4 I I Hydrologic Soil Group—San Diego County Area, California (Palomar Airport HSG) 474338 474338 474370 474390 474410 474438 47441 33° 738" N 330 738" N Z4.1 A low JIOA _____ ____ ____ - -• 1 "0 L 4 6 A I Soil Map iniy iiqh' ylid dl .li" ________ - __ 33 732N 33 732 N 474330 474350 474~7C, 4T4YAj 474410 474430 4-4450 Map Scale: 1:791 if printed onArxrlrait(8.5"xll°)sheet N 0 10 20 40 38 MeFers A Feet 0 35 70 : 140 - 210 Map projection Web Mercator Corner cxsdinal WGS84 Edge tics UTM Zone uN WGS84 USDA Natural Resources Web Soil Survey 4/4/2017 Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—San Diego County Area, California Palomar Airport HSG Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit - San Diego County Area, California (CA638) Map unit symbol Map unit name Rating Acres in AOl Percent of AOl LvF3 Loamy alluvial land- D 1.3 100.0% Huerhue-o complex, 9 to 50 percent slopes, severely eroded Totals for Area of Interest 1.3 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one o four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (AID, BID, and CID). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmissioi. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (AID, B/D, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condtion are in group D are assigned to dual classes. USDA Natural Resources Web Soil Survey 4/4/2017 Conservation Service National Cooperative Soil Survey Page 3 of 4 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 Attachment 3: Structural BMP Maintenance Information The table below identifies the specific maintenance indicators and actions for the proposed structural BMPs. BMP-1 and BMP-2 for this project are Biofiltration Basins. All proposed BMPs shall be access via proposed access road. No features proposed to facilitate inspections as all inspections/measurements are based on visual observation. For most maintenance actions, a truck is sufficient. A 10-15 cu-yd truck or backhoe may be necessary when removing sediment from BMP. No proprietary parts or training necessary to perform activities for proposed BMPs. BMP: Biofiltration Basin MAINTENANCE ACTIVITIES ROUTINE ACTION MAINTENANCE INDICATOR FIELD MEASUREMENT MEASUREMENT FREQUENCY MAINTENANCE ACTIVITY Frequency (# of times per year) Vegetation Average vegetation height Visual observation and Cut vegetation to an average height of Management for greater than 12-inches, random measurements Annually, prior to start of wet 6-inches and remove trimmings. Remove 1.0 Aesthetics emergence of trees or woody throughout the side slope season any trees, or woody vegetation. (optional) vegetation, area Annually, prior to start of Reseed/revegetate barren spots prior to Soil Repair Evidence of erosion Visual observation 1.0 wet season wet season Standing water for more than Annually, 96 hours after a Drain facility. Corrective action prior to Standing Water 96 hrs Visual observation target storm (0.60 in) event wet season. Consult engineers if 1.0 immediate solution is not evident. - Trash and Debris Trash and Debris present Visual observation Annually, prior to start of Remove and dispose of trash and debris 1.0 wet season Measure depth at apparent Remove and properly dispose of Sediment Sediment depth exceeds 10% maximum and minimum Annually, prior to start of sediment. Regrade if necessary. 0.5 Management of the facility design accumulation of sediment. wet season (expected every 2 years) Calculate average depth Annually, prior to start of Corrective action prior to wet season. Underdrains Evidence of Clogging Visual Observation Consult engineers if immediate solution 1.0 wet season is not evident. Inlet structures, outlet structures, side slopes or other General features damaged, significant Annually, prior to start of Corrective action prior to wet season. Maintenance erosion, burrows, emergence of Visual observation Consult engineers if immediate solution 1.0 Inspection trees or woody vegetation, wet season is not evident. graffiti or vandalism, fence damage, etc. Reporting 1.0 ATTACHMENT 4 City Standard Single Sheet BMP (SSBMP) Exhibit [Use the City's standard Single Sheet BMP Plan.] ATTACHMENT 5 NRCS Websoil Survey Hydrologic Soil Group I I 4 I I .4, I Soil I'lap naV )e ; fr at tl- 33 732'N I1(>lI\.II!(l - Map Scale: 1:791if printed onArfiat(B.5 x11") §)eet — N Meters 0 10 20 60 Feet J\0 35 70 140 210 Map prqjedion: Web Meitatcr Corner conat: WGS84 Edge tics: WM Zone uN WG584 IusDA Natural Resources Web Soil Survey Conservation Service Natioral Cooperative Soil Survey 4/4/2017 Page 1 of 4 Hydrologic Soil Group—San Diego County Area, California Palomar Airport HSG I Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit - San Diego County Area, California (CA638) Map unit symbol Map unit name Rating Acres in AOl Percent of AOl LvF3 Loamy alluvial land- D 1.3 100.0% Huerhuero complex, 9 to 50 percent slopes, severely eroded Totals for Area of Interest 1.3 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (AID, BID, and CID). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (AID, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. USDA Natural Resources Web Soil Survey 4/4/2017 Conservation Service National Cooperative Soil Survey Page 3 of 4