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Home My WebLink AboutCT 2017-0004; SIX ON MADISON; HYDROLOGY AND STORM WATER MANAGEMENT REPORT; 2017-07-28• f CITY OF Carlsbad ENGINEERING DIVISION ENGINEER OF WORK VINCENT L. SAMPO - ROE 44173 HYDROLOGY AND STORM WATER MANAGEMENT REPORT FOR SIX ON MADISON CONDOMINIUMS 3095 MADISON ST. PREPARED BY: received AUG 02 2017 CITY OF CARLSBAD PLANNING DIVISION SAMPO ENGfNEERING, !NC. 171 SAXONY ROAD, SUITE 213 ENCINITAS, CA 92024 (760) 436-0880 r 44173 Six on Madison Standard Development Project Sampo Engineering, Inc. 7/28/2017 Introduction: The subject property is Eqiproximately 0.16 gross acres and is located on the westerly side of Madison Street, at the northwest comer intersection of Oak Avenue, in the City of Carlsbad. The property is currently a vacant lot. The subject property's storm water runoff sheet flows across the surface, there is a slight high point onsite where runoff flows predominately westerly, southerly and easterly to the curb and gutter in Madison and Oak. There is no existing public storm drain located onsite however there are two storm drain curb inlets located on both sides of Oak Ave approximately 75' westerly of the site. Flows generated onsite are tributary to the curb inlet box located on the northerly side of Oak. This project proposes to maintain the historical drainage pattem where runoff generated onsite flows offsite to the curb, gutter and alley of Oak Avenue, where it is ultimately collected by public storm drain westerly of the site. The owner proposes to constmct a 6 unit condominium complex with an at grade 1"^ story parking garage (with 6 car lifts) commercial mixed use area, two flow through planters, concrete hardsc^e, landscaping and other associated improvements. The project anticipates an increase in runoff due to an increase in impervious surface area. Hydrology Summary: A hydrology study utilizing the Rational Method for the 100-year 6 hour storm event was performed for the existing and proposed conditions and the results are as follows. The existing condition is con^osed of 1 hydrologic basin that includes the entirety of the property. The drainage basin in the effected area has a tributary area of 0.19 AC with a runoff coefficient of C=0.25 and an anticipated flow for the 100-year storm of 0.25 CPS. The proposed drainage basin, over a smaller area due to the City requirement of dedication of 0.16 AC, produces a runoff coefficient of C=0.89 and an anticipated flow for the 100-year storm of 1.11 CPS. The total site impervious surface area is increased by 7,218 SF from the existing condition, thus an increase in flow is anticipated by 0.86 CPS. To mitigate the increased flow during the 100 year 6 hour storm event die detention of 1129 cubic feet is the anticipated, A 15.5'x 15.5' x 3.4' deep lessen concrete detention Basin will be constructed under the parking garage to detain the increased runoff volume of 817 CP. The flow-through-planters will have a sized outlet and a cross section of 1.4' fiee board with 0.5' gravel storage to provide 320 CY volume detention. The detained volume will have sized outlets to release storm water in a controlled manner and not contribute to an increase in peak flow for the downstream condition. Storm Water Quality Summary: The project has been determined to be a "Standard Development Project" using the City of Carlsbad Storm Water Standards Questionnaire (E-34) and is therefore exempt from priority project and hydromodification requirements. The development proposes to reduce the discharge of pollutants offsite by utilizing Source Control and Lx)w Impact Development (LID) BMP's to the maximum extent practical. Trench drains and catch basins in the parking garage as well as downspouts Sum the roof will flow to a Jensen concrete detention structure that will be constructed in the parking garage area. Downspouts tied into the concrete detention basin will be constructed with Kristar Six on Madison Sampo Engineering, Inc. Standard Development Project 7/28/2017 Downspout Filters for storm water treatment and drains located within the parking garage will flow through an oil/grease/sand separator prior to detention. A Sump Pump will pump detained runoff from the flow through planter located in the Oak Right of way. The raised flow through planters will be utilized in the yard area to detain flow and treat roof runoff. The flow through planter will be constructed with an engineered soil for storm water treatment prior to discharge through two curb underdrains into Oak Ave. Six on Madison Sampo Engineering, Inc. Standard Development Project 7/28/2017 BAMPO KMaiMCCHlNO. INCX IMPERVIOUS AREA CALCULATIONS SITE EXISTING Note: Areas from AutoCAD ' Impervious Areas per Layer. v-calc-lrnpervlous "Pervhus Areas per Layer JN: 17-120 INITIALS: DB DATE: July 28, 2017 DESCRIPTION IMPERVIOUS (SF)DESCRIPTION PERVIOUS (SR TOTAL (SR 8397.00 X:0.00 0% PROPOSED ' Imparvhua Areas per Layer c^tinpervca^ DESCRIPTION IMPERVIOUS (SR BulkMrtg 6581.00 concrete sidewalk 657.00 2 •• 8397.00 "^Pervious Areas per Layer. , DESCRIPTION PERVIOUS (SR landscape 8397.00 T(S5?r 1179.00 TOTAL (SF) X.-7218.00 86% X:1179.00 8387.00 14%100% PROPOSED A A IMPERVIOUS (SF):7218.00 A PERVIOUS (SF):-7218.00 171 Saxony Rood, Buffo 213 • Endntao, CA 02024 • P; 760-436-0660 • F: 760-436-0659 • Ifrfo08ampoonotneering.eom SAMFD CNOINKSniNO* INB DRAINAGE STUDY CALCULATOR EXISTING SITE DESCRIPTION: JN: 17-120 INITIALS: DB DATE: July 28, 2017 8,397 SF i-1 per County Hydrology Manual} SoD Typo B, % Impervloua <0% therafbrs Cp = C* = (0,90X% ImpervlouB) + (CP)(1 - % Impervious) 0,25 (0.9K0) + (0.26X1) 0.19 AC 0.25 D S Id 67 3 ( Watercourse Distance, FT) (Slope, %) 1.8(1.1 -C)(D)" (S)" 1.8(1.1-0.35)(57)M/2 (3)*r/3 7.07 MIN fl Elo Eioo It ho I too 1.2 n ( 2-Year, 6-Hour Isopluvlal) i.7 > n ' ; (10-Year, 6-HourIsophjvlal) Z6 \ (100-Year, 6-Hour Isopluvlal) 7.44 P, 7.44 P,o Drd'^ 7.44 P,x 7.44(1.^(7.07)'i-0.646) 7.44(1.7)(7.07)'(-0.64B) 7.44(2.5)(7.0T)'(-0.645) Z53 IN7HR 3.58 IN/HR 5.27 IN/HR Q.13. Q.m CIA CIA 01 A (D.2£i)(Z53 IN/HR)(0.19 AC) (0.25)(3.S8 IN/HR)(0.19 AC) (0.25)(5.27 IN/HR)(0.19 AC) 0.12 CFS 0.17 CFS 0.25 CFS PerSan Dhgo County Hydrology Manuel 2003 171 Saxony Road, Sulta 213 • Encfnitas, OA 92024 • P; 760-436-0660 • F; 760-436-0669 • lnfoe«ampoenolnoering.com ^SAMPO DRAINAGE STUDY CALCULATOR PROPOSED SITE DESCRIPTION: JN: 17-120 INITIALS: DB DATE: July 28, 2017 8,397 8F C-Factor (Values per Table 3-1 per County Hvdroloav Manual) SoBType B, % Impervtous < 90K tharafore Cp > 0,84 n g Impervious) (^X"!" Impervious)(O,0XO.86)+(O.84)(O.14) 0.19 AC 0.89 S Id Tc2 El Eio Eioo ll I IB hot 59 0.5 ( Watercourse DisfarKe, FT) ( Slope, %) 1.8(1.1 -CXD)" (S)" 2fl/sec 1.2 (2-Year, 6-Hoib-laopluvlal) 1.7...' - i (lO-Year, 6-Hour Isophivlal) 2.6 f 100-Year, 6-Hour Isopluvlal) 7.44 P, 7.44 P,o 7-44 Pros Dto,-^ ' 1.8(1.1.C.9)(69)M/2 (O.S)''1/3 To Total 5 min under Inspection 7.44(1.2)(5)'i-0.645) 7.44(1.7)(6)'i-0.646) 7.44{ZB)(B)'i-C.846) 3.48 MIN Ml MIN 3,89 5.00 MIN 3.16 IN/HR 4.48 IN/HR 669 IN/HR Qi Qio Sm CIA CIA Cl A (0.89J(3.16 IN/HR)(0.19AC) (0.89)(4.48 IN/HR)(0.19 AC) (0.89)(6B9 IN/HR)(0.19 AC) 653 CFS 0.76 CFS 1.11 CFS Per Sen Diego County Hytirology Manual 2003 171 Saxony Road, Suits 213 • Endnltaa, CA 92024 • P: 760-436-0860 • F: 780-436-0659 • Info@sampoonglnoor1ng.com DRAINAGE VOLUME CALCULATOR EXISTING BASIN # 1 VOLUME DESCRIPTION: El Eiao Yi Yioo #REFI 8,397 SF (0.90)(% Impefvtoua) * (CPHI - % impervlixig) " 1.2 ( 2-Year, 6-Hoiir Isoptuvlal) = Z5, ; (100-Year, 6-Hour Isopluvtal) Per San Dtego Coiftty Hydrology Uartual 2003 = C P, A C P,„ A PROPOSED BASIN # 1 VOLUME DESCRIPTION: Aroa - £1 #REF1 8,397 SF (0.90)<% ImpCTVtous) + (CPK1 - % ImpefvtotiB) (0.9)(0)+(0,25)(1) (0.25)(0.1 FV(B397 SF) (0.25)(0.21 FT)(8397FT) (0.9)(0.86><-(0.84K0.14) JN: 17-120 INITIALS; DB DATE: July 28, 2017 8397 SF 0.2B 0.10 FT 0.21 FT 209.9 CF 440.8 CF 8397 SF 0.89 El Eioo Yi Yix AV Ym X.omL 1.2 (2-Year, 6-HouriMopluvlal) : ZB (100-Yeer, 6-Hoir Isopluvial) PerSan DIago County Hydrology Manual 2003 CPj A C P10^ A ^ ^100 PROPOSED-Y100 EXISnVO Total EITecttvo Area of Basins Per Qrsdino Plan =■ (AeXHrRMBOfRD dcpth) ■ (AE) (MORAvn DST><)-Asauming wtw votos" = (0.89)(ai FT)(8397SF) (0.89)(0.21 FT)(8397 SF) (1S69.4F7)-(440.8 FT) (200 SF)(1.4 FT) (2O0SF)(0.S')(a4) Y TOTAL 0.10 FT 0.21 FT 747.3 CF 1S69.4 CF 1129 CF 200 SF 280 CF 40 CF 320 CF Flow Through Pfantan shall be constructed to have a minlmulm effective area of 2{X) sq. ft, constructed with 18 In. min. depth of freeboard, 12" of engineered soil and 6" gravel storage as shown on tfie Preliminary Grading Plan, A 15.5'X15.5'X3.4' Jensen Concrete Detention Basin proposedwith the capadty volume of 817 CF. Detention volumes as stated above are designed to detain the Increase stormwater runoff In the lOO-year peak storm event from ttio new proposed development 171 Saxony Road, Suite 213 • Endnltas, OA 92024 • P; 760-436-0880 • F: 760-436-0659 • lnfo®sampoenj^no<ir1ng.com STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov INSTRUCTIONS: . To address post-development pollutants that may be generated from development projects, the city requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual, refer to the Engineering Standards (Volume 5). This questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to 'STANDARD PROJECT' requirements or be subject to 'PRIORITY DEVELOPMENT PROJECT' (PDP) requirements. Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. If staff determines that the questionnaire was incorrectly filled out and Is subject to more stringent storm water standards than initially assessed by you, this will result in the return of the development application as incomplete. In this case, please make the changes to the questionnaire and resubmit to the city. If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, please seek assistance from Land Development Engineering staff. A completed and signed questionnaire must be submitted with each development project application. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. PROJECT INFORMATION PROJECT NAME: Six on Madison Condominiums ADDRESS: 3095 Madison Street, Carlsbad, CA 92008 The project is (check one): 0 New Development PROJECT ID: PRE 2017-0015 APN: 203-305-10 □ Redevelopment The total proposed disturbed area Is: ft^ ( 0 '^92 ^ acres T 91R 0 16The total proposed newly created and/or replaced impervious area is: ' ft^ ("•'" ) acres If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the SWQMP # of the larger development project: Project ID PRE 2017-005 SWQMP #: Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. STEP 1 ^ TO BE COMPLETED FOR ALL PROJECTS ^ To determine if your project is a "development project", please answer the following question: n YES NO is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building i—i or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)? If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant information. Justification/discussion: (e.g. the project includes only interior remodels within an existing building): If you answered "no" to the above question, the project is a 'development project', go to Step 2. STEP 2'■■'•'vi-ft:.'"?'': ■■ TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer the following questions: Is your project LIMITED to one or more of the following: YES NO 1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria: a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non- erodible permeable areas; b) Designed and constructed to be hydrauiically disconnected from paved streets or roads; c) Designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets guidance? 2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in accordance with the USEPA Green Streets guidance? 3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark the second box stating "my project is EXEMPT from PDP ..." and complete applicant information. Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with the USEPA Green Street guidance): If you answered "no" to the above questions, your project is not exempt from PDP, go to Step 3. TEi-O .. ... .V ' 0 BECOMPilETED ^OR ALL NEW OR REDEVELOPMENT^RCQECfS^ To determine If your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)): YES NO 1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces collectively over the entire project site? This Includes commercial, Industrial, residential, mixed-use, and public development projects on public or private land. □0 2. Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of impervious surface collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surface? This Includes commercial, industrial, residential, mixed-use, and public development projects on public or private land. □0 3. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). □0 4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a hillside development project? A hillside development project includes development on any natural slope that is twenty-five percent or greater.□0 5. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is a land area or facility for the temporary parking or storage of motor vehicles used personally for business or for commerce. □0 6. Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface collectively over the entire project site and supports a street, road, highway freeway or driveway? A street, road, highway, freeway or driveway Is any paved Impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles. □0 7. Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? "Discharging Directly to" Includes flow that Is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed In a pipe or open channel any distance as an Isolated flow from the project to the ESA (I.e. not commingled with flows from adjacent lands).* □0 8. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious surface that supports an automotive repair shop? An automotive repair shop Is a facility that Is categorized In any one of the following Standard Industrial Classification (SIC) codes: 5013, 5014, 5541, 7532-7534, or 7536-7539. □0 9. Is your project a new development or redevelopment project that creates and/or replaces 5,000 square feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category Includes RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Dally Traffic (ADT) of 100 or more vehicles per day. □0 10. Is your project a new or redevelopment project that results in the disturbance of one or more acres of land and are expected to generate pollutants post construction?□0 11. Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of impervious surface or (2) increases impervious surface on the property by more than 10%? (CMC 21.203.040) □0 If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ..." and complete applicant information. If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the second box stating "My project is a 'STANDARD PROJECT'..." and complete applicant information. i STEP 4 r-]I TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP) i — ONLY /Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b (2)); ' ~ —YES NO STs^than replacement of impervious surface in an amountCompete me potent Existing impervious area (A) = « __sq.n. g gTotal proposed newly created or replaced impervious area (B) = gq Percent impervious area created or replaced (B/A)*100 = % t-^-,-^.,jei-iaiBiKlHE APRROPR|ATE BOX AMD COMPLETE APPLICANT °pr4e™rLormW^,?Se7i^'MS,eglTnfpta''(l!^^^ ' I «e,p,>emep,C/«P*«P<„p,E^^e„e,„cp^"i;3,errp^S4:3™^^^^ rs^^NMRD p7o7ot ^ cal^-teliona□ My Project re NOT e 'development projecf and Is not subject to the requirements of tlie BMP Manual. Applicant Information and Signature Box ' Applicant Name: Tehran Saberi Applicant SignatureN—^ ^UUMorJ/nt, Applicant Title; P'"6S'"dent. Date: ilsi 117 Fo-r ^ P . y — ^ fKdogical Signffican^y®11^'®' designated as Areas of Specialdesignated wtth the RARE beneficial use by the State Wai^ei^cM con^of If amendments): water bodieslOTondments); areas designated as proseives or their equiv^ent un^meMutt^SnS^jBo f^ ^ B®"" (199^) andManagement Plan; and any other equivalent environm^taliy s^sXe aJ^s t^fb^S Ke®CI? " ^ This Box for City Use On! City Concurrence: Project ID: REV 02/16 ^City of Carlsbad STANDARD PROJECT REQUIREMENT CHECKLIST E-36 Development Services Land Development Engineering 1635 Faraday Avenue (760) 602-2750 www.carlsbadca.gov Project Name: SIX ON MADISON CONDOMINIUMS Project ID: pre 2017-005 DWG No. or Building Permit No.: Source Control BMPs All development projects must implement source control BMPs SC-1 through 80-6 where applicable and feasible. See Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to implement source control BMPs shown in this checklist. Answer each category below pursuant to the following. • "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.I 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. ^^ij,jSource Control |Lequireme,r) SC-1 Prevention of Illicit Discharges into the MS4 D Yes □ No □ N/A Discussion/justification if SC-1 not implemented: SC-2 Storm Drain Stenciling or Signage Discussion/justification if SC-2 not implemented: m Yes □ No □ N/A Discussion/justification if SC-3 not implemented: SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind _ ygg n No □ N/A Dispersal protect SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal n Yes □ No □ N/A Discussion/justification if SC-4 not implemented: SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal m Yes □ No □ N/A Discussion/justification if SC-5 not implemented: 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). □ On-site storm drain inlets IS m Yes □ No □ N/A □ Interior floor drains and elevator shaft sump pumps Yes □ No □ N/A □ Interior parking garages B Yes □ No □ N/A □ Need for future indoor & structural pest control B Yes □ No □ N/A □ Landscape/Outdoor Pesticide Use B Yes □ No □ N/A □ Pools, spas, ponds, decorative fountains, and other water features □ Yes □ No B N/A □ Food service □ Yes □ No B N/A □ Refuse areas m Yes □ No □ N/A □ Industrial processes □ Yes □ No m N/A □ Outdoor storage of equipment or materials □ Yes □ No B N/A □ Vehicle and Equipment Cleaning □ Yes □ No B N/A □ Vehicle/Equipment Repair and Maintenance □ Yes □ No B N/A □ Fuel Dispensing Areas □ Yes □ No B N/A □ Loading Docks □ Yes □ No ■ N/A □ Fire Sprinkier Test Water IE1 Yes □ No □ N/A □ Miscellaneous Drain or Wash Water □ Yes □ No B N/A n Plazas, sidewalks, and oarkino lots □ Yes □ No m N/A For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers. Interior floor drains from the parking garage, including fire sprinkler test water, will flow to a sand-oil separator and concrete detention basin for treatment. Refuse areas will be kept indoors to prevent pollution of stormwater. All other stormwater will flow through planters or landscaping areas for treatment. Page 2 of 4 Revised 09/16 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 n Yes □ No I □ N/A Discussion/justification if SD-1 not implemented: SD-2 Conserve Natural Areas, Soils, and Vegetation □ Yes □ No m N/A Discussion/justification if SD-2 not implemented: u • SD-3 Minimize Impervious Area 1 B Yes □ No □ N/A Discussion/justification if SD-3 not implemented: SD-4 Minimize Soil Compaction Discussion/justification if SD-4 not implemented: □ Yes I B No ID N/A Base on the architectural site pian the building will occupy the entire lot and will require remedial grading. As a result minimized compaction is not feasible. SD-5 Impervious Area Dispersion Discussion/justification if SD-5 not implemented: B Yes I □ No ID N/A DesS^R^ullrement (continued SD-6 Runoff Collection Discussion/justification if SD-6 not implemented; B Yes □ No □ N/A SD-7 Landscaping with Native or Drought Tolerant Species Discussion/justification if SD-7 not implemented; !□Yes I □ No □ N/A SD-8 Harvesting and Using Precipitation Discussion/justification if SD-8 not implemented: □ Yes B No B N/A Revised 09/16Page 4 of 4 EQUATION 7/44^)6 I 'I l(denslty (bVhr) « 6-Hour Predpltitton (InJ l>irBSQn(min) H -ao X ukMit HOuca Dlra^hxta for.AppKcallcHU {1) FHoni prefdpOatim imps cfstamilne 0 hr and 24 hr arnounlB fbctbe psleo^ 'freguehw. Thsw mapa-ambduda^l In the CoUTly HydtpfogyMsniffl (10, SO. are} IpO^ytnj^lndudpd in the'Oesjga and Prpoeduv Manual). 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Itote: Ttila.ctjartrepJapeatliplntBnstlyJJunBflon-FfBquaoey cunns used sinca 1866. ■'P34,.%» ESciCliJi fiiiKati-::;»i?a3KiiEt;jr.£i3E3fcx:nif-JE'lEjj IKUK7C:1[E£I EHUillll'.U fi:jcsaEyiiintn;ir.y:iMu EESLlEiJE^JtO fraiTQS rntenslty-OuraHon Deslgp Chart - Tamplate SAN DIEGO county HYDROLOGY MANUAL P T fi T R B 1-1 2.50%,slapa m EXAMPLE: GIvsn: Watenx>urasDblance(D)B 70 Feet Slope (s>-1.3;K Runoff Coeffldisnt (C)" 0.41 Ovartend Flew Time (T) • 9.5 Minute* .i.e'(i.i-c>Vp" SOURCE: Airport Dnrfnaoe, Federal Aviation Administration. 19^ FIGURE Rational Foonula - Overland Time of Flow Nomograph SAN DIEGO COUNTY HYDROLOGY MANUAL 3-3 San Dteso CoiBty HyioloBy Mannil Date: June2003 Section: TabkM RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use NRCS Blemerta County Eleiiigot* tJmfislurb ed Natural Ttaraki P^attml) LowDeoaityRBsideotial (LDR) Low Denshy RciitWtfial (LDR) Low Density Reaidential (LDR) Metfium Density Reddeatial (MDR) MeAun Deoaity ReiifWitial (MDB) Me(&im Doosity Residential (MDR) MetBom Density RoaidontSal (MDR) mghi Density BasideDtial (HDR) Hi^ Density Residential (HDR) ConmiBrclaiyinduslrial (N. Com) CoametolaVIndustrial (O. Com) C^wiTwrrtial/TTytri^rinl (^Q Com) (Lijncted L) r!inmviec^°t/iDduririal COeneral L)lain Peniunent Open Space Residential. 1.0 DU/A or less ReaidertiiL 2.0 DU/A cc less Rdsidential. 25 DU/A or less Residential, 4J DU/A or Jess Reeidwttial, 73 DU/A or less Residential, 10.9 DU/A or less Residential. 14^5 DU/A or less Residentiai. 24.0 DU/A or less Residential, 43D DU/A or less •MfjgJihnrtiond Commercial Oeneral Commerolal OfBce Professionsl/Commeroial Limited Rtdnstrial Ooneral IndustrialuenecBi mountau Runoff Coefltcieof^ Son Type 3 6 of 26 %IMPER.A B C D 2* EXIST 10 0.20 0O5 030 035 007 0.32 036 0.41 20 034 038 0.42 0/46. 25 038 0.41 0.45 0A9 30.0.41 0.45 0.48 032 40 0.48 031 034 037 45 0.52 0.54 - 037 030 50 035 0.58 0.60 033 65 0.66 0.67 039 0.71 80 0.76 0.77 0.78 0.79 80 0.76 0.77 0.78 0.79 85 0.80 030 031 032 90 0.83 0.84 034 0.85 J^PROP 0.83 0^0.84 0.85 95 0.87 0.87 0.87 0.87 — *T1b vahies associated wllit . ooefBdent, Cp, for the soil type), is located fa Cleveland Lfetioiial Focost). DIVA - dweUfagnnita per acreNRCS - NatiooalReflOcrces Coniervatioii Service . . 3-6, Riverside County County of San Dieg Hydrology Manua Rainfall Isopluvials 2 Year Rainfall Event - 6 Hours DPW -«GIS SaiiGIS iTVMBffiiWrwkfMPawaMwmIf —wST SSSSrisss"' Riverside County County of San Diego Hydrology Manual Rainfall Isopluvials L V\100 Year RalnfaO Event - 6 Houn ■74 .- rf, «:/ .hM/ l,■/J \ a !\ A\Vv .|io^ i • ^ Q X \ c 0 IS SafiGISWc l-Un. Su) ^u|tp I'Aku^! N 3UU3S3&'G%'aB^UtS»Ba^^Swptwiryu'Twniiwiaitiarwiiwwww^