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HomeMy WebLinkAboutCUP 2017-0008; OAKMONT OF CARLSBAD; HYDROLOGY; 2020-01-01Table of Contents INTRODUCTION .2 Purpose of Study Scope - Existing and Proposed Drainage STUDYAREA............................................................................................................................2 Soils Groups Land Uses HYDROLOGY............................................................................................................................. 3 Modified Rational Method Description Program Process RESULTS...................................................................................................................................4 SUMP PUMPS AND DIVERTER BOXES.......................................................................................4 CONCLUSION...........................................................................................................................5 List of Appendices APPENDIX A - Vicinity Map APPENDIX B - Site Development Plan APPENDIX C - Rational Method Reference Charts APPENDIX D - Isopluvial Map (100-Year, 6-Hour & 100-Year, 24-Hour) APPENDIX E - Hydrologic Soils Group Map APPENDIX F - Hydrologic Modeling Output (CivilDesign) - Developed Condition 100-Year APPENDIX G - Existing Condition Reference Plans APPENDIX H - Developed Condition Hydrology Map APPENDIX I - Pipe Sizing Exhibit INTRODUCTION Purpose of Study The Oakmont assisted living facility project is located on the north side of Faraday Avenue, west of the intersection at El Fuerte Street in the City of Carlsbad, San Diego County (see Appendix A for Vicinity Map). In the current state, the project is a mass graded lot (Lot 1) per Grading plans 415-9A, Appendix G. Lot 1 is approximately 6.38 acres. This study will consider the proposed disturbed site area consisting of 5.64 acres. The purpose of this hydrology study is to assess peak flowrates for the proposed Oakmont facility (see Appendix B). The developed site will consist of a three-story luxury assisted living facility, a two-story memory care building, and a one-story models building. A pool, parking areas, pickle ball court, bocci ball court, outdoor picnic area, various landscaped areas, and associated infrastructure are also proposed. Scope - Existing and Proposed Drainage The existing mass graded pad for Oakmont of Carlsbad drains to an existing desilting basin located inside the southeastern corner of the property near the street intersection of Faraday Avenue and El Fuerte. A spillway outlets the onsite desilting basin and runs south to an existing diverter box that splits drainage from higher magnitude stormwater flows. An existing water quality basin is located just offsite to the east of the property for low flows (see Sheet 20 of Dwg No 415-9C Appendix G). High flows run to an existing 24" stormdrain (sized to convey 28.1 cfs) that runs beneath Faraday Ave to the southeast corner of the El Fuerte and Faraday intersection where they are discharged to the natural channel and canyon below. Prior to discharge into the offsite canyon, stormwater flows from the Oakmont project site are comingled within the 24" drain with Street flows from Faraday Ave and El Fuerte. All existing onsite and offsite stormdrain infrastructure, including the 24" RCP, was originally designed for an industrial land use site previously proposed on this property. The industrial Site was only rough graded with drainage items installed and was never constructed. The developed condition site will not utilize the offsite water quality basin for low flows. Proposed structural BMPs will be used to treat onsite flows, and include two biofiltration basins and one media filter. All treated flows will be routed to a new manhole installed just downstream of the existing diverter box at southeast corner of the site. The diverter box will remain, however it will be plugged with brick and mortar at the existing 12" low flow outlet, and the outlet line will be abandoned. The treated flows will drain south across Faraday Avenue through the existing 24" RCP public storm drain system (see Appendix G, Sheet 20 of As-Built Stormdrain Plans for Dwg No 415-9C). It should be noted that the 100-year discharge for the proposed Oakmont project is shown not 2 to exceed the design capacity of the existing 24" RCP shown on Sheet 20 of Dwg No 415-9C. For this reason, no existing hydrology for this project has been provided. STUDY AREA Soils Groups The site is characterized by soil group D. Refer to Hydrologic Soils Group Map, Appendix E. Hydrologic group 0 soils have very slow percolation rates when thoroughly wet. The rate of water transmission is very slow. Land Use The proposed land use is a mix of High Density Residential use (24DU/AC or less) and open space for the landscaped portion. The composite land use and soil group have been used to determine a runoff coefficient of 0.71 for the proposed hydrology calculations. HYDROLOGY The hydrologic analyses are performed according to the 2003 San Diego County Hydrology Manual. The overall drainage area is less than one square mile and includes junctions of independent drainage systems; therefore, the Modified Rational Method is being used for the analysis. The Modified Rational Method is applicable to a 6-hour storm duration because the procedure uses Intensity-Duration Design Charts that are based on a 6-hour storm duration. In some cases, the 6-hour precipitation must be adjusted based on the ratio of the 6- to 24-hour precipitation. This will be performed where necessary. Modified Rational Method Description The modified rational method, as described in the 2003 San Diego Flood Control/Hydrology Manual, is used to estimate surface runoff flows. The basic equation: 0 = CIA C = runoff coefficient (varies with surface) = intensity (varies with time of concentration) A = area in acres For the 100-year design storm, the 6-hour rainfall amount is 2.8 inches and the 24-hour rainfall amount is 5.1 inches (see Appendix D). San Diego County Rational-Hydrology Program Package Version 7.9, developed by CIVILCADD/CIVILDESIGN Engineering Software © (1991-2012), was used to determine the rainfall amount, times of concentration, corresponding intensities and flows for the various hydrologic basins within this model. The program was then used to route flows through drainage conveyance structures and confluence basins per the modified rational method. 3 Program Process The Rational-Hydrology program is a computer-aided design program where the user develops a node link model of the watershed. Developing independent node link models of each interior watershed and linking these subareas together at confluence points create the node link model. The program has the capability of performing calculations for 11 different hydrologic and hydraulic processes. These processes are assigned and printed in the output. They are as follows: Initial sub-area input, top of stream. Street flow through sub-area, includes sub-area runoff. Addition of runoff from sub-area to stream. Street inlet and parallel street and pipeflow and area. Pipeflow travel time (program estimated pipe size). Pipeflow travel time (user-specified pipe size). Improved channel travel - Area add option. Irregular channel travel time - Area add option. User-specified entry of data at a point. Confluence at downstream point in current stream. Confluence of main streams. RESULTS The results of the analysis of the runoff from Oakmont of-Carlsbad are presented below: 100-YEAR STORM EVENT Acreage Q (cfs) Existing Condition (Allowable) N/A 28.1 * Developed Condition 5.64 23.5 A 0.12 -4.6 * per 'As-Built' storm drain plans Dwg No 415-9c, Sht 20 SUMP PUMPS AND DIVERTER BOXES There are two sump pumps proposed for this project. The sump pumps are located at bottom of entry ramps to the each of both underground parking garages. The primary purpose of these pumps is to remove surface runoff that is captured by a trench drain at the bottom of each ramp so the parking garage does not get flooded. These pumps will also remove residual flow from within the parking garage itself like hose wash. The sump Pumps are not independent from storm drain system since they accept runoff from 4 parking garage entry ramps. Sump pumps have been sized to convey at least this contribution from the outside surface. There are also several diverter boxes that will separate low flow from high flow from within the main storm drain line proposed for this project. The diverter boxes are located upstream of all water quality BMP. Within each box a low flow outlet pipe is set with an invert at bottom of the box and a high flow outlet pipe with invert at soffit of the low flow outlet pipe. Once capacity of the low flow outlet is exceeded, water will pond within the diverter box and be carried away by the high flow pipe. The low flow outlet pipe is sized to convey the required water quality flow for the particular BMP that it is feeding. Diverter boxes that route flow to the two above ground water quality basins, which act as detention basins, will only reduce peak flowrates to the project outlet since the low flow component will take a longer path and be routed through the actual basin. However, no loss is being accounted for and flows reported on the hydrology map are therefore considered conservative. Similarly, the diverter boxes that route flow to the three underground storage chambers, are designed to detain and reduce peak flowrates. Again though, in order to remain conservative, no reduction in flowrate (except in hydromod analysis for the project SWOMP) is being accounted for on this hydrology. CONCLUSION Site drainage patterns in the developed condition will drain southeast to an existing underground 24" storm drain line along Faraday Ave that has been sized to convey 28.1 cfs. The developed condition peak flowrate for the 100-yr event of 23.5 cfs will be less than the capacity of the existing storm drain outlet. Prior to discharge from the site, drainage will be routed to underground storage units, water quality basins, and a biofiltration unit not shown in this report and these items are addressed in a separate SWOMP for this project. Since the facilities are not accounted for in this report, the developed Os are considered conservative and appropriate for design. Lastly, the existing 24" storm drain this project outlets drains to will not directly discharge into the ultimate receiving water body, Agua Hedionda Lagoon. Therefore, this project is not exempt from hydromodification, but is addressed in the SWOMP report mentioned above. For these reasons, this project is considered to have no significant hydrologic impacts to the surrounding environment and is acceptable for development. 5 \\ SITE LOCATION FARADAY C) 'S • \) Vicinity Map NO SCALE PRELIMINARY TITLE REPORT ZONING OAKMONT OF CARLSBAD FIRST AMERICAN TITLE INSURANCE COMPANY EXISTING: P-M PLANNED INDUSTRIAL SITE 4380 LA JOLLA VILLAGE DRIVE, SUITE 200 PROPOSED: (0) OFFICE SITE PLAN SAN DIEGO, CA 92122 LOCATIO (858) 410-1303 LOT 1 OF TRACT No. 14926 ATTN.: DIANNE LIVINGSTON LAND USE CUSTOMER REFERENCE MV-4046827 (06) EXISTING USE: ,,-DEMONSTRATION 5 FARADAY LEGAL DISCRIPTION PROPOSED USE: COMMERCIAL SENIOR LIVING — // -GARDEN REAL PROPERTY IN THE CITY OF CARLSBAD, COUNTY PROVIDERS // OF SAN DIEGO, STATE OF CA;IFORNIA, DESCRIBED AS — / 26420, 3u' PLANN IJG FOLLOWS: WATER: CARLSBAD MUNICIPAL WATER DISTRICT / 7/15) ETBAC 10 LOT 1 OF CARLSBAD TRACT NO. 97-13-1 SEWER: CARLSBAD MUNICIPAL WATER DISTRICT .- CARLSBAD NORTH PHASE 1, IN THE CITY OF CARLSBAD, SCHOOL: CARLSBAD UNIFIED SCHOOL DISTRICT COUNTY OF SAN DIEGO, STATE OF CALIFORNIA, 10' MAX HEIGHT 4, ACCORDING TO MAP THEREOF NO.14926, FILED IN RETAINING WALL OFF COUNTY, DECEMBER 15, 2004. ICE OF THE CRECORDER OF SAN DIEGO THE PHONE AT&T OUNTY A T ITCW 1 CABLE: AT&T GAS: SEMPRA 111 NJAPOH D 2/ 00 APN: 209-120-00 ELECTRIC: SEMPRA GROSS LAND AREAANALYSIS - — / rJ%i%n1i 1 Vicinity Map 6.38 ACRES PARKING ANALYSIS CALCULATIONS 50' PLAHIMIG / I SETBACK I NO SCALE SURFACE 64 SPACES CITY OF CARLBAD MAIN BUILDING 67 SPACES CARE CENTER - 32 SPACES (EMPLOYEE PARKING) N872O57 D TPUCTUF[ I GENERAL PLAN AMENDMENT, ZONE CHANGE, SPECIFIC MARKETING COMPLEX = 4 SPACES 9.O2) - 12' MAX HEIGHT / R H \EL / PLAN AMENDMENT, CONDITIONAL U.SE PERMIT TOTAL = 167 SPACES - Q / RETAINING WALL 1. (6) ACCESSIBLE SPACES PROVIDED —28.1 CIFS SCHEDULE "B" EASEMENTS (167) TOTAL PARKING SPACES PROVIDED LEGEND EXISTING POLLUTION PROJECT BOUNDARY —EXISTING SPILLWAY. PARKING REQUIREMENT CALCULATIONS t TO'OE'R~EMOVF[) Ag AN EASEMENT SHOWN OR DEDICATED ON THE MAP CONTROL BASIN No.3 PROPOSED DRAIN LINE 'FIRE FF=255.60 AS REFERRED TO IN THE LEGAL DESCRIPTION. / ONE PARKING SPACE PER 3 BEDS (175 BEDS TOTAL) 39 SPACES ABUTTER'S RIGHT OF INGRESS AND EGRESS TO OR PIT A, PAD=254.93, /_1xIsTINC_, FLOW SPUTTER PROPOSED WATER LINE FROM LOT IIIN AND TO FARADAY ADJACENT TOTAL REQUIRED = 61 SPACES LANAI' 4' MAX HEIUH I OS PER D',VG. 0p415-98 TO RIEMAN DEDICATED OR RELINQUISHED ON THE FILED MAP, X v Z THERETO, EXCEPT ACCESS OPENING HAVE BEEN (RETAINING WALL H i X11 11 PROJECT DATA !1 1 1 30' PLANNING j) FIRE HY[~RA —S— PROPOSED SEWER LINE AS EASEMENT SHOWN OR DEDICATED ON THE MAP SETBACK I I // \ \ EXISTING PROPOSED RETAINING WALL AS REFERRED TO IN LEGAL DESCRIPTION I Qj 4 11/ i \ \ /i'/ \ \ 2 W MA TRAFFI PROPOSED PERIMETER WAL FOR SIGHT DISTANCE CORRIDOR AND INCIDENTAL CONTRACTOR TYPE =VA-BUILDING IA- PARKING GARAGE L II \ / " '- / - -"-" - EXISTING PERIMETER WALL PURPOSES. NUMBER OF STORIES = 3 STORIES OVER UNDERGROUND OCCUPANCY WATER L PARKING GARAGE I /// STET EXISTING SEWER LINE 17. AS EASEMENT FOR PUBLIC UTILITIES AND BUILDING GROSS LIVING AREA = 128,745 SO FT 7' LANDSCAPE-'I/ N - 'LIGHT - - EXISTING CURB & GUTTER INCIDENTAL PURPOSE, RECORDED NOVEMBER 9, PARKING GARAGE = 32,078 SO FT SETBACK o '- \ I / "-v — /) /ç \ EXISTING 1 2006 AS INSTRUMENT NO. 2006-0800401 OF I I It \ / / \ — SEWER UN _____________ SIDEWALK OFFICIAL RECORDS. MEMORY CARE BUILDING / \ \ ' \ BUILDING I 77 SETBACK ~~-EXISTING 24" STORM CROSSWALK IN FAVOR OF: SAN DIEGO GAS AND ELECTRIC CONTRACTOR TYPE =VA-BUILDING IA - PARKING GARAGE FF-26000 ) /EASEMENT '\/\ --- AIRSPACE LINE COMPANY, A CORPORATION OCCUPANCY GROUP =R2.1, A-2, A-3, BANDS-2 PARKING GARAGE / I / GARAGE FF249 00 7Z DEDICATIONNUMBER OF STORIES = 2 STORIES OVER' UNDERGROUND — DAYLIGHT LINE AFFECTS: THE LAND - NOT PLOTTABLE BUILDING G LIVING AREA = 432749 SO FT 7' FIRE FET8C PARKING GARAGE 15,921 SO FT EXIST. STRE \ t / — — TOP/TOE OF SLOPE £ A PERPETUAL EASEMENT FOR SEWER L;INES. I i - 7 > 7/7' 77MbNEV 7'— RECLAIMED \ \ \\ / H CUT/FILL LINE EXISTING 12" PIPELINES AND INCIDENTAL PURPOSE, RECORDED MARKETING COMPLEX / / ,/z SIGNAGE' WATER '[JE FEBRUARY 26, 2009 AS INSTRUMENT NO.-2009-0095509 OF OFFICIAL RECORDS. CONTRACTOR TYPE =VA . PORTE 7 — / 77 \ / EXISNG \ // EXISTING TREE COCHERE OCCUPANCY GROUP = R2.1, AND B OR U EXISTING (322.22) EXISTING ELEVATION IN FAVOR OF: THE BUENA SANITATION DISTRICT NUMBER OF STORIES 1 STORY ,,SIDEWAL '4 BUILDING GROSS LIVING AREA 4,208 SO FT AFFECTS: THE LAND POH%IE 4., Z 16" PARKING GARAGE 1,130 SO FT —EXIST. ELEC. ~E --SEWER _Q~E COCHER EXISTING 10 20' VAULT _n SE1_ ORCE EXISTING 12 RECLAIMED PROJECT FAR: NOT APPLICABLE SPECIFIC PLAN D.F. DEEPEND FOOTING WATER LINE 1 3.5% EX OIL 51 F. S. FINISHED SURFACE EXISTING 24"— THE SUBJECT PROPERTY IS LOCATED WITHIN THE TOTAL LOT AREA: 277,953 SO FT SEWER FORCE "CARLSBAD OAKS NORTH" BUSINESS PARK SPECIFIC G. B. GRADE BREAK PROPOSED BUILDING COVERAGE: 24.5% (68,035 SO FT) MAIN PLAN — SP 211 < PROPOSED LANDSCAPE AREA: 41,9% (113,289 SO FT) FLOOD ZONE DESIGNATION EMPLOYEE EATING AREAS BLDG 1 428 SO FT I / I / I / -c /777' 12" DW 8LOWOFF' Ln SEWER LINE (INTERIOR/EXTERIOR BLDG 2 335 SO FT I i I BUILD 2 L_\\ \ STING / \\ % ELEqTRICAL 60.72 TOTAL COMMON AREA: 44,174 SO FT I MAP NUMBER: 06073CO79G PRIVATE OPEN SPACE: 5,280 SO FT (66 DECK/PATIOS) FF=2 ~J EFFECTIVE DATE: MAY 16, 2012 TOTAL AREA OF RESIDENT STORAGE: 11,500 SQ FT (LOCATED IN GARAGE) !/, GARAG - EXISTING / 7' (II E FF IRRIGATION 7' V NOTE: THE PROPERTY IS DEFINED AS "AREAS OF 0.2% TOTAL UNDEVELOPABLE AREA: NOT APPLICABLE . / 6' MAX / . / yALVE//'/ ANNUAL CHANCES OF FLOOD; AREAS OF 1% ANNUAL H1 ' . DEEPENED UNIT SUMMARY CHANCE FLOOD WITH AVERAGE DEPTHS OF LESS THAN 1 /,, FOOT OR DRAINAGE AREAS LESS THAN 1 SQUARE MILE; ANTICIPATED DAILY TRAFFIC . - AND AREAS PROTECTED BY LEVEES FROM 1% ANNUAL , \ ' I i I i '/1-k' / \7' / \ 11 ' HIGH O -' SID ISTING EWALK MAIN BUILDING CHANCE FLOOD". X TOTAL DAILY TRIPS: 466 RET WAL COD PEAK AM HOURS: 25 A — STUDIO 15 UNITS BASIS (U 1U' A Diii PEAK PM HOURS: ' / . .- ',7'-Ile LANDSCAPE 7' 7 7" B - STUDIO = 14 UNITS 1 UNIT ', 60 2 1 6O /CURB C - STUDIO = 45 UNITS PROPOSED WATER DEMAND THE BEARINGS SHOWN HEREON ARE BASED ON THE _T D — STUDIO = 11 UNITS BEARING N52*10'48"E FOR THE CENTERLINE OF FARADAY TC11 DAILY AVERAGE. AVENUE, AS SHOWN ON CARLSBAD TRACT NO. 153 ' 297 GPD ' / &/ . -- . -2 7' 7' SUB-TOTAL UNITS 98 UNITS 97-13-1, CARLSBAD NORTH P[HASE 1, IN THE CITY OF DAILY PEAK: / 'I --' SUB-TOTAL BEDS = 98 BEDS CARLSBAD, COUNTY OF SAN DIEGO, STATE OF CARE CENTER BUILDING CALIFORNIA, ACCORDING TO THE MAP THEREOF NO. MASTER DRAINAGE BASIN: CARLSBAD OAKS NORTH 14926, FILED IN THE OFFICE OF THE PUBLIC RECORDER J ACESS//_-, X IN AZ — STUDIO = 18 UNITS SEWER OAKMONT SENIOR LIVING EXISTING EASEMENT y / _.— DESCRIPTION: 2" ALUMINIUM DISC STAMPED GPS 9240 OLD REDWOOD HWY JOIN EXIST MAINTENANCE ., .. ---'. ' - \ \/_- \ SUB-TOTAL UNITS = 52 UNITS CATE CONTROL PT. 2002. WINDSOR, CA 95492 ACCESS ROAD . / 7' SUB-TOTAL BEDS = 54 UNITS LOCATION: IN SIDEWALK NORTH SIDE OF PALOMAR ATTN: HANNAH DAUGHERTY (707) 535-3211 EASEMENT - IRRIGATION - MARKETING COMPLEX AIRPORT ROAD, 300-FEET WEST OF .. -2 MARKETING — — ." ''-EXISTING VALVES MELROSE DRIVE SITE DATA / /1/ WATER LINE__-7/" 10 FIRE HYDRANT A STUDIO = U UNIT NIT RECORD FROM:R.O.S. NO. 17271 (PT. NO, 71 SEWER LINE C — 1 BEDROOM 1. THERE ARE NO EXISTING STRUCTURES ON, SITE. '~EEXI~~TING 12" APPLICANT CIVIL ENGINEER ENVIRONMENTAL; ELEVATION: 444.00 M.S.L. 2. THERE ARE NO EXISTING RAILROADS ADJACENT TO SITE. RECLAIMED OAKMONT SENIOR LIVING ALLIANCE LAND PLANNING AND ENGINEERING OAKMONT SENIOR LIVING WATER LINE' 9240 OLD REDWOOD HWY 2248 FARADAY AVE 9240 OLD REDWOOD HWY 7 WINDSOR CA 95492 CARLSBAD, CA 920064 WINDSOR, CA 95492 GRAPHIC SCALE SUB-TOTAL UNITS 4 UNITS SUB TOTAL BEDS 6 UNITS EXIS11NG24" (707) 535-3200 FAX (707) 535-3299 (760) 431-9896 (707) 535-3200 FAX (707) 535-3299 40 0 20 40 80 t7 EXISTING 7'7/ SEWER FORCE 'L L -h ] GRAND TOTALS I SDGE VAULT - MAIN DESIGNER LANDSCAPE ARCHITECT _________________________ ALl IQBAL LANDESIGN GROUP = 9240 OLD REDWOOD HWY 3344 GAVENSTEIN HWY NORTH 1 inch - 40 ' it 23.7 UNITS/AC IN FEET UNITS 151 UNITS WINDSOR, CA 95492 SEBASTOPO, CA 95472 BEDS 175 BEDS (707) 535-3200 FAX (707) 535-3299 (707) 829-2380 FAX (707) 892-3417 2248 FARADAY AVE. 'PLANS PREPARED BY:- SHEET SHEET CARLSBAD, CA 92008 E PROPERTYOWNER: TY OF CARLSBAD TEL: (760) PLANS PREPARED FOR: BENCHMARK 431-9896 F SAN DIEGO COUNTY PUBLIC WORKS BENCHMARK NO,: FAX:(760) 431-8802 ALLIANCE LAND PLANNING & ENGINEERING INC. 2248 FARADAY AVE., CARLSBAD, CA 92008 Z_ - OAKMONT OF CARLSBAD SUITE 140 c 27451 TOURNEY ROAD OWNER NAME: OAKMONT SENIOR LIVING DESCRIPTION: 2" ALUMINUM DISC STAMPED CPS CONTROL PT. 2002 NO. 61297 z OWNER NAME: OAKMONT SENIOR LIVING, < ALLIANCE VALLNA, CA 91355 ( 6 ) * EXP 6-30-19 SITE DEVELOPEMENT PLAN CrVIL STREET 9240 OLD REDWOOD HWY, SUITE 200 LOCATION: IN SIDEWALK NORTH SIDE OF PALOMAR AIRPORT ROAD, STREET 220 CONCOURSE BLVD. LAND PLANNING & ENGINEERING INC. TEL: (661) 799-2760 PLANS P D U E~R DIRECTION OF: 's, 300—FEET WEST OF MELROSE DRIVE. SAN DIEGO COUNTY, CALIFORNIA ADDRESS WINDSOR, CA 95492 FAX: (661) 254-1929 ADDRESS SANTA ROSA, CA 950403 01 2740 FARADAY AVENUE ____________________________ 12/18/19 0'CAL\ ATTN: HANNAH DAUGHERTY (707) 535-3211RECORD FROM: 17271 71) ATTN. ATTN. HANNAH DAUGHERTY (707) 535-3211 CARLSBAD, C'A 92008 CIVIL ENGINEERING • LAND PLANNING • HILLSIDE DESIGN • SURVEYING I' ELEVATION: 444.00 MSL JASO F,,/'ROOM NO. 61297 DATE I:\CAD\1672\STE DEVELOPMENT PLAN\1672SE-DEV-PLAN.dwg . . .. . PLAN PREPARATION DATE: 06/30/17 OAKMONT OF CARLSBAD APPENDIX C RATIONAL METHOD REFERENCE CHARTS San Diego County Hydrology Manual Date: June 2003 Section: 3 Page: of 26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use Soil Type NRCS Elements County Elements I % 1MPER. A B C D Undisturbed Natural Terrain (Natural) Low Density Residential (LDR) Low Density Residential (LDR) Low Density Residential (LDR) Medium Density Residential (MDR) Medium Density Residential (MDR) Medium Density Residential (MDR) Medium Density Residential (MDR) High Density Residential (HDR) High Density Residential (HDR) Commercial/Industrial (N. Corn) Commercial/Industrial (G. Corn) Commercial/Industrial (O.P. Corn) Commercial/Industrial (Limited I.) Permanent Open Space 0 0.20 0.25 Residential, 1.0 DU/A or less 10 0.27 0.32 Residential, 2.0 DU/A or less 20 0.34 0.38 Residential, 2.9 DU/A or less 25 0.38 0.41 Residential, 4.3 DU/A or less 30 0.41 0.45 Residential, 7.3 DUIA or less 40 0.48 0.51 Residential, 16.9 DU/A or less 45 0.52 0.54 Residential, 14.5 DU/A or less 50 0.55 0.58 Residential, 24.0 DUIA or less 65 0.66 0.67 Residential, 43.0 DU/A or less 80 0.76 0.77 Neighborhood Commercial 80 0.76 0.77 General Commercial 85 0.80 0.80 0111cc Professional/Commercial 90 0.83 0.84 Limited Industrial 90 0.83 0.84 General Industrial 95 0.87 0.87 0.30 0.35 0.36 0.41 0.42 0.46 0.45 0.49 0.48 0.52 0.54 0.57 0.57 0.60 0.60 0.63 0.69 0.71 0.78 0.79 0.78 0.79 0.81 0.82 0.84 0.85 0.84 0.85 The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3. 11 (representing the pervious runoff coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area is located in Cleveland National Forest). DU/A dwelling units per acre NRCS National Resources Conservation Service - 34 IJJIIIIlllJllIDIJ[flhII1JIIIliIillllhIIIIllhII IIIItIIIllh1Illlhl EQUATION 1111111 huE 1 *11 141 fliHIl'II P Durafion i1I!IIi!u;1IIi; !!Il!!it fllq jthlluullhuuIIIIIIuhIIIllI 441 1111 119111. Nis, 11b"1111111111H Mill 1111111111 0111111111 N1 oil 141,1111 N, it m sn kk IH!tb UlI•NUIIUUuIIIIIIIIIIIh!IDuhIIIlHh1 tilillilhlill 1IUDUh IIuIIhii: iiiuu••uuniuiiuiuiiiiiiiiirniimii IIHhi1llIllllhIIk1PO IIIIItii HI1IIIIIIIIUIIHIIIIIIIllhIIDllhIJIib11 UIIIIDfflflIll!!1IDIl!iIIi H!!IIi HIIIIIIIIIIIIIHhIIUhI11I01III11IuhI I!IIllhIllIlluhJiUloin !ii!ll!! HIIIIIIIHUIIIIIIIllhIftIIflIllhIIlllhIllHIlI1lliillhIiflHhi1!!I Wil k.- 1k, oil 1111 INI 11111 MINft 1110 ME 111111 fl 1~ 1 H Irk 11 In 111111 1,1111 i'l fla a NSSauUflUuIlIIISpIS.S.,UJSI,uI*aSI.,,flhI,fl_,__ aflhlNI•tflufllfll IuSIIIIis,iziurn .. s.... nms ass. .gIn,,.ssI URN .0 Ian uI.nunhsu,IIc.j:u a... hjasu.uusrnu,M. Se • S.O.SUUJ.I, ISIUV!IflN.Ut..,uIfllJISSIIIIIflfl •S,R.S•PIS.Sfl..%. _._.. ••U•s.11blllluulgUlsflhssuulfltl$1111a11111a .. •CS..U.IuluIIIh,t3, ..a..u..,,I,n,s,na.s........ pn,c.,,u,l,s.ur.1 ..n....,n....n, . •NU....usugOguIsIul....a,..uu IMhIIlI so, fl11111 ... ...S'..u..,I.p, • •• ••UU• UIUuUIIIII .luIuuiiii,t.j u..........ui,ii iuiuiu, j".lIuupilutsi uluilsuiw I I MMM il I I UI im.R..lIkIIuu.1IrnIuu1j ••• MEMO monsonso oil" In •UUUiUuiiUuIEIJiIIuIII IIIiuIUtIu1IIuqIIitIuIIJiIIIIt•uulIuiiuuuiuij(jpflft IIIIUuuItIIHIIflh11IIIIIIiIiiII•utuuuuuIIuij5 IIIIIIIIIuIIIIIuIIlIIIIIItIIII1IIIIII...UlluuI u•u I1IluIulIIIpL1I aU••UUIN•uuuliiullluuiil 11111111 IIflhIIIIIIIIIIItIPUhIIIIIIUU MEMO uuIHhIuuIIIIIIHIIjI ...i.iii.iuflhu IIIIllhuIJItIihIU lull IIHlIllffllluIllhIIuhulI1flHujlllnrnlnllll EJAIn Chart • TmnJt 100 30 Ui U. 0 20 Ui C.) z Ui Ui U, U- 0 10z C) w - EXAMPLE: Given: Watercourse DiStance (0) = 70 Feet Slope (s) =1.3% Runoff Coefficient (C) = 0.41 T= 1.8 (1.1-C) Y Overland Flow Time (1) = 9.5 Minutes SOURCE: Airport Drainage, Federal Aviation AdmInistration, 1965 Rational Formula Overland Time of Flow Nomograph FIG U RE r 3-3 San Diego County Hydrology Manual Section: 3 Dale: June 2003 Page: 12 of 26 Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres. Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in hydrology studies. Initial Ti values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the "Regulating Agency" when submitted with a detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (L 1) & INITIAL TIME OF CONCENTRATION (T) Element DU/ Acre .5% 1% 2% 3% 5% 10% LM T. Li T. LM T1 LM T1 LM I T1 LM I 1 Natural 50 13.2 70 12.5 85 10.9 100 1031 100 8.7 1001 6.9 LDR 1 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR 2 501 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8 LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3 MDR 7.3 50 9.2 65 8.41 80 7.4 95 7.0 100 6.0 100 4.8 MDR 10.9 501 8.7 65 7.91 80 6.9 90 6.4 100 5.7 1004.5 MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5 I-IDR 43 50 5.3 65 4.7 75 4.01 85 3.81 95 3.4 1001 2.7 N. Corn 501 5.31 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G. Corn 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.P./Cont 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 Limited 1. 50 4.2 60 3.7 70 3.1 1 80 2.9 90 2.6 100 2.2 General I. 501 3.71 601 3.21 701 2.71 80 2.6 90 2.31 1001 1.9 See Table 3-I for more detailed description 3-12 EQUATION AE Tc (LI.BL3 O.3BS — 1Feet AE 5000 Tc Time of concentration (hews) I Watercourse Distance (miles) J4000 AE Change In elevation along effective slope line (See Figure 3-5) (feat) I_3000 Tc I-. Hours Minutes 1-.- 2000 4_L 240 180 —1000 900 __ 00 2 120 8 700 100 6o\ 90 _500'%% •0 —4 70 00 1 60 —300 so 'S —200 'S 40 L Miles Fast 30 'S 'S —100 1, 4000 20 'S 18 3000 16 as 'S 50 'S 14 40 2000 12 1100 1600 10 30 1400 1200 a 20 1000 900 100 6 700 600 10 500 4 400 300 .5 I )-200 AE L Tc California Division of Highways (1941) and Klrpich (1940) Nomograph for Determination of Time of Concentration (Ic) or Travel Time (It) for Natural Ytersheds FIGURE 3.I4 I 117°30 I 117°15 117°15 I 117°OO 116°45 116°30 11615 11 117°OO II 116°45' II 116°30 I 116°15' 02 Aiunon itijdw' ri CD CD IJc rnnnn[ LL HHHHLLJ W CD 00W cn CD u DU I g - cop Cn San Diego County Rational Hydrology Program CIVILCADO/CIVILDESIGN Engineering Software,(c)199172012 Version 7.9 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual. Rational Hydrology Study Date: e8/3e/19 ------------------------------------------------------------------------ 051 Carlsbad - Q100 Developed Condition ------------------------------------------------------------------------ Hydrology Study Control Information S$******** Program License Serial Number 6301 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.80e 24 hour precipitation(inches) = 5.100 P6/P24 54.9% San Diego hydrology manual 'C' values used Process from Point/Station 1.000 to Point/Station 2.000 INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance .= 330.000(Ft.) Highest elevation = 60.000(Ft.) Lowest elevation = 54.500(Ft.) Elevation difference = 5.500(Ft.) Slope = 1.667 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 75.00 (Ft) for the top area slope value of 1.67 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration 5.13 minutes TC . [1.8*(1.1_C)*distance(Ft.).5)/(% slope '(1/3)] TC = [1.8*(1.1_0.7100)*( 75.000".5)/( 1.667"(1/3)J= 5.13 Rainfall intensity (I) = 7.259(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.71e Subarea runoff = 6.648(CFS) Total initial stream area • 1.290(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 2.000 to Point/Station 5.000 ' PIPEFL4 TRAVEL TIME (Program estimated size) Upstream point/station elevation = 54.500(Ft.) Downstream point/station elevation = 50.100(Ft.) Pipe length = 348.00(Ft.) Slope = 0.0129 Manning's N = 0.013 No. of pipes 1 Required pipe flow = 6.648(CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 6.648(CFS) Normal flow depth in pipe = 11.18(In.) Flow top width inside pipe • 13.07(m.) Critical Depth = 12.45(In.) Pipe flow velocity = 6.78(Ft/s) Travel time through pipe • 8.84 mm. Time of concentration (TC) = 5.96 mm. Process from Point/Station 2.008 to Point/Station 5.000 SUBAREA FLOW ADDITION Rainfall intensity (I) = 6.585(In/Hr) for a 180.0 year storm Decimal fraction soil group A = e.000 Decimal fraction soil group B = 0.600 Decimal fraction soil group C = e.eee Decimal fraction soil group D = 1.008 (HIGH DENSITY RESIDENTIAL (24.8 DU/A or Less Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 5.96 mm. Rainfall intensity = 6.585(In/Hr) for a 108.8 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 2.130 Subarea runoff = 7.378(CFS) for 1.710(Ac.) Total runoff = 14.026(CFS) Total area = 3.000(Ac.) +++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 3.000 to Point/Station 5.000 CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 1 Stream flow area = 3.000(Ac.) Runoff from this stream = 14.026(CFS) Time of concentration = 5.96 mm. Rainfall intensity = 6.585(In/Hr) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 3.000 to Point/Station 4.000 '' INITIAL AREA EVALUATION Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = i.oee (HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 490.000(Ft.) Highest elevation = 60.000(Ft.) Lowest elevation = 58.000(Ft.) Elevation difference 2.000(Ft.) Slope = 0.408 X INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.41 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 6.69 minutes TC = [1.8*(1.1_C)*distance(Ft.)A.5)/(% slope'(1/3)] TC = [1.8*(1.1_e.7100)*( 50.000.5)/( 0.408(l/3)]= 6.69 Rainfall intensity (I) = 6.112(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 11.457(CFS) Total initial stream area = 2.640(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 4.000 to Point/Station 5.000 PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 58.00e(Ft.) Downstream point/station elevation 50.100(Ft.) Pipe length = 405.00(Ft.) Slope 0.0195 Mannings N = 0.013 No. of pipes = 1 Required pipe flow = 11.457(CF5) Nearest computed pipe diameter = 18.00(In.) Calculated individual pipe flow = 11.457(CFS) Normal flow depth in pipe = 11.96(In.) Flow top width inside pipe = 17.00(In.) Critical Depth = 15.48(m.) Pipe flow velocity = 9.18(Ft/s) Travel time through pipe = 0.74 mm. Time of concentration (IC) 7.43 mm. Process from Point/Station 4.000 to Point/Station 5.000 CONFLUENCE OF MINOR STREAMS Along Main Stream number: 1 in normal stream number 2 Stream flow area = 2.640(Ac.) Runoff from this stream = 11.457(CFS) Time of concentration 7.43 mm. Rainfall intensity = 5.715(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (mm) (In/Hr) 1 14.026 5.96 6.585 2 11.457 7.43 5.715 Qmax(1) = 1.006 1.000 a 14.026) + 1.000 0.803 a 11.457) + = 23.224 Qmax(2) - 0.868 a 1.000 a 14.026) + 1.000 * 1.000 11.457) + = 23.63e Total of 2 streams to confluence: Flow rates before confluence point: 14.026 11.457 Maximum flow rates at confluence using above data: 23.224 23.630 Area of streams before confluence: 3.000 2.640 Results of confluence: / Total flow rate - 23.63e(CFS) Time of concentration 7.428 mm. Effective stream area after confluence = 5.640(Ac.) End of computations, total study area = 5.640 (Ac.) I U --- DETAIL 'A' NOT 10 SC41E SEE SHEET No. 4 SElf!?? NOTES 8 1. EXIST 12" EXCESS EFFLUENT LINE PB? BUENA SAil/TA 11CM 0/ST W. Na 5-80-14 IN PARADA Y A W. AND LOT 1 72 BE RELOCA lED O4/5-9a ST CO. V. DK& No. 3821 ' 2 EXIST 12" EXCESS EFFLUENT LINE IN LOT 2 TO BE PRO TEC1ED IN PLACE EXIST 12" EXCESS EFFLUENT LINE IN EL Fl/ERiE STREET 7 0 BE RELOCA lED PER a a v DKt'. 3821 EXIST 14" SEIE7? FORCE MA/N PER BUENA SAN/TA 110/1 0/ST we No. 5024 7 BE PROTECTED IN PLACE R/Cl/T—CF—WA Y PERMIT fl?CM CITY 6F kISTA REQUIRED PRIOR To ANY V#VRK WIN/N BUENA SAN/TA 110/I &4S&$ILNT - NO TEll ELECTRON/C DATA FiLES ARE FOR REFERENCE ONL Y AND ARE NOT TO BE USED FOR HORIZONTAL OR WR11CAL SUR kEY CCW1ROL i'( \ IW, I21 ICD mUj of NO. 55381 EXP. 12/31/04 *1 Vik. OF DESIGNED BY H.R.DATE APRIL 2003 "AS BUILT" 0 DRAWN ey: T.G., C.Q. SCALE: -.11 = 50' CONSULT NTS ___________________ P. E. EXP._____ DATE 2710 Laker Avenue West Civil Engineering ENGINEER or WORK Suite 100 Planning REVIEWED BY Carlsbad, California 92008 Processing 760-931-7700 Surveying Fax: 760-931-8680 DATE www.odayconsultants.com TIMOTHY 0. CARROLL JR. RCE: 55381 INSPECTOR DATE BENCHMARK: DESCRIPTION: 2# ALUMINUM DISC STAMPED 01'S CONTROL PT 2002 LOCATION: IN SIDEWALK NORTh' SIDE 6 PALOMAR AIRPORT ROAD, 300 FEET PEST OF MELROSE DRIfrE RECORD FROM: RO.5 NO. 17271 (PT NO. 71) ELEVATION: 444.00 M.S.L. DATUM: NCI'Z) 1929 SHEET CITY OF CARLSBAD SHEETS 5 ENGINEERING DEPARTMENT 15 €40/AV PLANS FOR CARLSBAD OAKS NORTH PHASE! CI 97-13 APPROVED LLOYD B. HUBBS PE 23889 EXP: 12-31-05 CITY ENGINEER DATE L1ADDED F LE, k1STA FM, REV-90 EELINE NOTES DWN BY: _____ PROJECT NO. DRAWING NO. CHKD BY: RVWD BY: _______ C. T. 97-13 415'9A DATE INITIAL REVISION DESCRIPTION DATE INITIAL DATE INITIAL ENGINEER OF WORK OTHER APPROVAL CITY APPROVAL 1:\961005\9605A005.dwg Apr 13, 2006 2:37pm Xrefs: 9605A0; 9605TP04; 9605TF07; 9605PLAN; 9605AMAP; 96057UTL; 9605FUTL; 9605F0R0; 9605EUTL; 9605ECRD; 9605ESTR; 9605FSTR; 9605AGRD; 9605DUTL IL !IAYA!Mñi y] yI :%I;b LE IMM VJFA FAIrd 11 Air, ?AI DRAIN DATA RADIUS LENGTH REMARKS 12 4,0' 7390'.U" RCP - 1350-0 * 10.70' ir RCP 1350-0 * 55.53 18" RCP 1350-D * 64.50' 171.52' 6'.r 7' 80% CULVERT TYPE 0* 2&O0' 1 3'x 5.7' BOX CULVERT TYPE 0* 400.00' 52ø5 24'RCP-135O-D 11 'A' 70WA7RP fir FA L!J for, SAW, S S Al 2'6 tE AWING £ A O K MONTO : CARl SBADN )NDITION HYDROLOGY —2*5---- Vicinity Map NO SCALE PROPERTY LINE ....DRAINAGE BASIN BOUNDARY OVERLAND FLOWPATH Qioo ..........................100 YR. FREQUENCY FLOWRATE (CFS) Qioo ..........................CUMULATIVE 100 YR. FREQUENCY FLOWRATE (CFS) AREA (AC) FLOWPATH LENGTH (FT) NODE NUMBER SURFACE ELEVATION PROPOSED STORMDRAIN PROPOSED STORM DRAIN INLET FLOW ARROW DESIGN CRITERIA: STORM EVENT 100 YR - RESIDENTIAL PADS, ROADWAY R/W 100—YR RAINFALL ISOHYET 6—HR = 2.8 IN, 24—HR = 5.1 IN SOIL TYPE GROUP 'D' LAND USE COMMERCIAL IMPERVIOUSNESS 76% TY BOUNDARY EXISTING Inc 7 /7 / V 001 - 'EXISTING, WQT BASIN PER DWG NO 415-9A, SHEET 5 ._- / TO REMAIN EXISTING DIVERTER BOX > PER DWG NO 415-9B ..- TO REMAIN --- 5e EXISTING 12" H DPE 1101 .- :0 1 PLUG EXISTING DRAIN LINE WITH BRICK AND~ MO AIR 00 7.38 CFS IQ 23.6 CFS 0 ALOWABLE 281 CFS - - PROPOSED MH = 5.64 AC 100, - Izvb 7 * 28.1 CFS PER .!ISIfING 24" SD <PER DWG 4/_9C lp / 000, \\ k\ \ 'l 1.4Z CIFS el TRENCH DRAIN WY GRAPHIC SCALE 40 0 20 40 80 ( IN FEET ) 1 inch = 40 ft. 2248 FARADAY AVE. CARLSBAD, CA 92008 - TEL: (760) 431-9896 FAX: (760) 431-8802 27413 TOURNEY ROAD ALLIANCE SUITE 120 VALENCIA, CA 91355 LAND PLANNING & ENGINEERING INC. TEL: (661) 799-2760 FAX: (760) 431-8802 CIVIL ENGINEERING • LAND PLANNING • HILLSIDE DESIGN • SURVEYING I I I PROPERTY OWNER: SHEET I 1 I CITY OF CARLSBAD SHEET PLANS PREPARED BY: ALLIANCE LAND PLANNING & ENGINEERING INC. 2248 FARADAY AVE., CARLSBAD, CA 92008 (760) 431-9896 PLANS PREPARED UNDER 4E DIRECTION OF: 10/25/19 OAKMONT OF CARLSBAD DEVELOPED CONDITION HYDROLOGY SAN DIEGO COUNTY OWNER NAME: OAKMONT SENIOR LIVING STREET 220 CONCOURSE BLVD. ADDRESS SANTA ROSA, CA 950403 ATTN: ATIN: HANNAH DAUGHERTY (707) 535-3211 NO. 6129\ EXP 6-30---21 CIVIL * CF- CA iY(•wIiiI1M NO. 61297 PLANS PREPARED FOR: BENCHMARK SAN DIEGO COUNTY PUBLIC WORKS BENCHMARK NO.: OWNER NAME: OAKMONT SENIOR LIVING DESCRIPTION: 2" ALUMINUM DISC STAMPED GPS CONTROL PT. 2002 STREET 9240 OLD REDWOOD HWY, SUITE 200 LOCATION: IN SIDEWALK NORTH SIDE OF PALOMAR AIRPORT ROAD, ADDRESS WINDSOR, CA 95492 300—FEET WEST OF MELROSE DRIVE. ATTN: HANNAH DAUGHERTY (707) 535-3211 RECORD FROM: R.O.S. NO.17271 (PT. NO. 71) ELEVATION: 444.00 MSL DATE I: \CAU \16 /2\HYDROLOCY\15 72_DEV—HYDROLOGY.dwg I\\ A ( IL CA'a RLSBA D OF )z/\\ kA h DN _.]I.] SI ZING EXHI BI T Vicinity Map NO SCALE -SEGMENT B AREA =1.18 V7V S \ \ \.00 000, Ar AREP SEGMENT D\ 1) PROPERTY '< T- 0-~ 0~ 28.1 CFS 1100, EXISTING 24" SD,00** PER MWG'415--~k 0000, SEGMENT A SDI AREA =2 40 cc z111001 Total Trib Area Peak Flow at Outlet Unit Flowrate ac cfs cfs/ac 5.64 233 4.17 Segment Size Slope Seg. Area Trib Area Trib Segment Design Q Full Flow Q % Full in ft/ft ac cfs cfs % A 18 0.01 2.37 2.37 - 9.88 11.38 87% B 15 0.01 1.21 1.21 - 5.04 7.00 72% C 18 0.005 0.64 1.85 B 7.71 8.05 96% D 12 0.005 0.66 0.66 - 2.75 2.73 101% F 24 0.01 0.76 5.64 A, B, C, D 23.51 24.51 96% GRAPHIC SCALE 40 0 20 40 80 IN FEET ) 1 inch = 40 ft. TTT - - Pipe Material = Smooth HDPE (n = 0.012) 7, 7, 2248 FARADAY AVE. CARLSBAD, CA 92008 TEL: (760) 431-9896 FAX: (760) 431-8802 27413 TOURNEY ROAD ALLIANCE SUITE 120 VALENCIA, CA 91355 LAND PLANNING & ENGINEERING INC TEL: (661) 799-2760 FAX: (760) 431-8802 I I I PROPERTY OWNER: SHEET I 1 CITY OF CARLSBAD SHEET PLANS PREPARED FOR: BENCHMARK SAN DIEGO COUNTY PUBLIC WORKS BENCHMARK NO.: OWNER NAME: OAKMONT SENIOR LIVING DESCRIPTION: 2" ALUMINUM DISC STAMPED GPS CONTROL PT. 2002 PLANS PREPARED BY: ALLIANCE LAND PLANNING & ENGINEERING INC. 2248 FARADAY AVE., CARLSBAD, CA 92008 (760) 431-9896 OWNER NAME: OAKMONT SENIOR LIVING I OAKMONT OF CARLSBAD PLANS PREPARED UNDER E DIRECTION OF: j4SZA F. ROOM NO. 61297 - OFES8 uj " Of NO. 61297 EXP 6-30-21 CIL * ADDRESS WINDSOR, CA 95492 300-FEET WEST OF MELROSE DRIVE. STREET 9240 OLD REDWOOD HWY, SUITE 200 LOCATION: IN SIDEWALK NORTH SIDE OF PALOMAR AIRPORT ROAD, ATTN: HANNAH DAUGHERTY (707) 535-3211 RECORD FROM: R.O.S. NO.17271 (PT. NO, 71) ELEVATION: 444.00 MSL STREET 220 CONCOURSE BLVD. PIPE SIZING EXHIBIT ADDRESS SANTA ROSA, CA 950403 SAN DIEGO COUNTY ATTN: ATTN: HANNAH DAUGHERTY (707) 535-3211 CIVIL ENGINEERING • LAND PLANNING • HILLSIDE DESIGN • SURVEYING 10/25/19 I: \CAD\1672\HYDROLOGY\1672-PIPE SIZING.dwg