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HomeMy WebLinkAboutCUP 2017-0009; ECO-FRIENDLY AUTO SPA; DRAINAGE STUDY FOR AVENIDA ENCINAS CAR WASH ECO-FRIENDLY AUTO SPA; 2020-02-11------------ -- -------------------- CTE~ CTE Job No. 10-13214 Construction Testing & Engineering, Inc. Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying DRAINAGE STUDY RECORD COPY \)~(l.. Initial AVENIDA ENCINAS CARWASH -----------.J ECO-FRIENDLY AUTO SPA 6010 Avenida Encinas Carlsbad, California 92011 CUP2017-0009 GR2019-0011 DWG. 517-2A Prepared For: PEGGY KELCHER 6030 A VENIDA ENCINAS, STE220 CARLSBAD, CA 92011 760-496-2931 Prepared By: Construction Testing & Engineering, Inc. 1441 Montiel Road, Suite 115 Escondido, California 92026 ~~ ... I-;::,~ r,~ 1,lE]) M ~ ;_:,1 'i....., J\..:J JI OCT 2t1 2G;.~ LA\'-lD [' , cNT E1\1 <,, ;\j 1:.-:::.l::.1111~G February 11, 2020 1441 Montiel Road, Suite 115 I Escondido, CA92026 I Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-lnc.net ------------------------------- --- -- A venida Encinas Carwash Carlsbad, California Section TABLE OF CONTENTS Page2 CTE Job No. 10-13214 INTRODUCTION ................................................................................................................................... 3 REFERENCES ........................................................................................................................................ 3 DESIGN CRITERIA ............................................................................................................................... 3 DISCUSSION .......................................................................................................................................... 4 CONCLUSION ........................................................................................................................................ 5 DECLARATION OF RESPONSIBLE CHARGE .................................................................................. 6 ENGINEER OF WORK: ......................................................................................................................... 6 SUMMARY ............................................................................................................................................. 5 ATTACHMENTS ATTACHMENT 1-LOCATION MAP ATTACHMENT 2 -PRECIPITATION MAPS AND SOIL MAP ATTACHMENT 3 -EXISTING HYDROLOGY CALCULATIONS ATTACHMENT 4-PROPOSED HYDROLOGY CALCULATIONS ATTACHMENT 5 -HYDROLOGY MAP-EXISTING CONDITIONS ATTACHMENT 6-HYDROLOGY MAP-PROPOSED CONDITIONS ---------- - -- .. -- --------------- A venida Encinas Carwash Carlsbad, California Page3 CTE Job No. 10-13214 OBJECTIVE Determine storm water runoff and site drainage collection, storage, and conveyance system components, sizing, and storm water runoff treatment required for development for a new car wash in Carlsbad, California. INTRODUCTION The site is located A venida Encinas in Carlsbad, California. The project site is approximately 1.211 acres in size. The site is currently developed with an existing building and large quantities of impervious pavement. The proposed development is to precise grade for a proposed carwash facility. This new facility proposes less impervious area than the existing condition. 1. 2. 3. 4. REFERENCES San Diego County Hydrology Manual (2003). San Diego County Drainage Design Manual (May 2005). Soil Survey, San Diego Area, California. United States Department of Agriculture (December 1973). Sheet 24. CIVILCADD/CIVILDESIGN Engineering Software,© 1991-2006 Version 7.6. San Diego County Control Division 2003 Manual Rational Hydrology Study . DESIGN CRITERIA The majority of the subject property, the soil group is classified as a HrC-Huerhuero loam, 2 to 9 percent slopes and hydro logic soil Group "D". (NCRS, USDA Custom Soil Resource Report, 2016 survey) See Attachment 2. Per the San Diego County Hydrology Manual (2003) Table 3.1: • The existing condition is classified as Undisturbed Natural (0% impervious area) and Low Density Residential (1 DU/A -10% impervious area). • The proposed conditions on the grading pads are classified as Low Density Residential ( 1 DU/A-10% impervious area). Per the San Diego County Hydrology Manual (2003) Rainfall Isopluvial Map: • 100 Year Rainfall Event -6 hours P6 = 2.5 inches/hour • 100 Year Rainfall Event -24 hours P24 = 4 .2 inches/hour Hydro logic calculations were performed using either of the following: Autocad Civil 3d SSA (storm and storm analysis) a SWMM EPA engine. CIVILCADD/CIVILDESIGN Engineering software version 7 .6 per methods as outlined within the San Diego Hydrology Manual (2003). ------------- ----- - -- ------- ---- A venida Encinas Carwash Carlsbad, California EXJSJJNG CONDITIONS DISCUSSION Page4 CTE Job No. 10-13214 Existing lot is a developed commercial industrial site of 1.15 acres. The site is paved with a building and perimeter landscaping. Slopes are mild to moderate. There is no underground storm drain system. Surrounding lots are similar use. There is no run-on, no natural drainage features, and no public drainage facilities. The site is on the east side of A venida Encinas. Runoff exits the driveway, conveys south towards a public storm drain curb inlet, and continues down a hardened drainage ditch and RCB culvert to a point of safe discharge in tidal lands next to the ocean. The flow path does not enter a natural channel or water body subject to sizing capacity restrictions. Below is a summary of pre-development criteria for the subject property: TABLE 1: 100 YEAR PRE-DEVELOPMENT CRITERIA Tc Area Node C (Min.) (acre) 0100 (cfs) 102 0.81 8.00 1.211 4.79 TOTAL 1.211 4.79 PROPOSED CONDITIONS The project objective is to maintain the existing drainage patterns, determine the 100 year storm event flows, size the proposed facilities, and discharge the flow without negatively impacting adjacent properties. The proposed commercial industrial site of 1.15 acres will consist of buildings, paving, and landscaping. Slopes are mild to moderate, impervious area will be reduced. Runoff will initiate as overland flow from buildings and pavement to surface open channel flow. Runoff will enter 2 BMP basins. From there runoff will be storage routed into a proposed storm drain system to exit the site. Proposed Storm Drain -A storm drain system will capture BMP basin runoff with catch basins and pipe and connect to the adjacent south private property storm drain. The properties have the same owner. The connection is so chosen because there are utility conflicts and other issues with creating a new connection to the public storm drain in Avenida Encinas. The existing south connection is 24" pipe with significant head to provide capacity. In the event of capacity exceedance, blockage, or similar offline event the runoff would fill the structures and pipes to the WSE of inlets and catch basins which are below building FF and convey as surface flow to the street with no property damage. ----------------- --- ----------- - - A venida Encinas Carwash Carlsbad, California The proposed hydrologic conditions are summarized below: Page 5 CTE Job No. 10-13214 TABLE 2: 100 YEAR POST-DEVELOPMENT WITHOUT DETENTION CRITERIA Tc Area Node C (Min.) (acre) QlOO (cfs) 105 0.73 7.74 1.211 4.521 TOTAL 1.211 4.521 Hydromodification HMP analysis is performed in the SWQMP where applicable. This project is exempt on the grounds that the downstream flow path is hardened concrete drainage facilities all the way to the ocean. There are no natural channels along the route. SUMMARY Summary calculations indicate no increase in peak flows resulting from the proposed development. The Ql00 is decreased by 0.27 cfs in the proposed condition. The reduction of impervious area is main factor which achieved this result. Additional modelling with SWMM in SSA provides stage storage routing results for mitigation. In this case mitigation is not need. Additional flow reduction will occur in the BMP basins, those calculation are not performed. CONCLUSION A hydrology and hydraulic analysis has been conducted for the subject property and surrounding properties for a 100 year storm event. All facilities have adequate capacity to convey Q 100 flows. The proposed development does not increase peak flow. Downstream facilities are not negatively impacted. The site is not in a FEMA floodway. --------------- ---- --------------- - A venida Encinas Carwash Carlsbad, California DECLARATION OF RESPONSIBI,E CHARGE Page6 CTE Job No. 10-13214 I, hereby declare that I am the Engineer of Work for this project, 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 current standards. I understand that the check of project drawings and specifications by the County of San Diego is confined to a review only and does not relieve me, as Engineer of Work of my responsibility for project design. ENGINEER OF WORK; Construction Testing and Engineering, Inc. 1441 Montiel Road, Suite 115 Escondido, CA 92026 Dan Math R.C.E. 61013 03/04/2020 Date --.. ----------ATTACHMENT 1 --LOCATION MAP ------------------ --- ~ CIT OF PACIFIC OCEA I VICI ITY SIDE MAP NOT TO SCALE CITY OF E Cl t1JTapMeecsO Oco.tco"'!"'"- ,. 60 .. \ • ·~ q,,' l \ \.\\ 1-0 .;•"' '\ 61Et1<onow1.,. \: I ,I:. Ii' w_..,_, Pf!i~DdtJo,la .,, \ i l \ \ \ \ 'i ' \ Go gle l 0 \ ~\ !, ··~ ii ~ -.. Map data ~2017 Google SOON C, OF MARCOS \ , Col< 1.. !z ; .. 1111 -.. -.. -------------------------------- ATTACHMENT 2 PRECIPITATION MAPS AND SOIL MAP I t t 6 I <") ! 0 1 1 l't--I . l I . I ~ ..... T ' ir, ..... 0 l't--.... .... . ' t j I . I ' . • 1 i I ! . t r , I • j b i 1 1 I J 0 I I 1 0 I , ,-.. f ' •• +--f ' I • t 1 I I I I 1 I 1 I j I f I C j 1 j I t I I 1 ' t 1 1 . • I I ' . l . ; • l I ' 1 ' I . ' I rl, ' I v •-<b l .... 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IL. 1 " ~-, • ~,.l , 1. , <-l t t i t ,,.,'.'.!ti ii -~2i3 ·1. 1 I{) t \ j I I ~ . i f l i_i llJ -~ I County of San Diego Hydrology Manual . -~ ~. ~: ,, ,, - ~~) Rainfall lsopluvials 100 Year Rainfall Event-6 Hours ··-··---lsopluvial (inches) DPW etGIS 0.,,,,-.,Nllc_ ----anuIS \Xie Have S:1n Diego CO\'crcd! N THIS MAP IS PROYIOEO Wmi0l1f WNVWrrY Of N('( l<INl, EITHER EXPRESS + OR l!PUEO, INCLUDIHG, IIU'T NOT lMT'EO TO, T1-E IMPLIED WARRANTlES Of MERCW.NTABUTY AND FITNESS FOR A PAR'TICIAAR PURPOSE. ~--,.Ri1'111- s Thllpntdoda-, _____ SANOAGRogio,111 E""-~--... ........--.. _...,,....ctlSAHOAG. Thil........,. ____ ,__...,.__ ~--..,,--.. 3 0 3 Miles ~ I' l ' I t I b I t < in M I .... 0 + • < 0 I .. + ,..._ I r,... ..-• . ; .... .... 1 .... • • I t I I 1 l 1 ' • 1 l • ++ j!' .. ·1 -·111 ''tj•t b I I I I i ' i ' t ♦ I 1 in I . ' I I 0 -q-I . : j M I J .... I t i ~ ;:_ ''}''. ·1 <O + l I ch i1''1 ' i <0 I. 1 1 1 J' ..-•.i -•-•lj .... 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I, I I I 1t1 11 1·11 'il ,t~· I, I I ' ' ' ~2°30! : ; 1 , j I i ~ f j • I t t o 1 ~ ·-t i t I I : ; I 1 I t l j fr j l I I + :: ~it• ~ i I I • I "'i .... ,I. ! . : j + 1 1 f I 1 -t "-I I l l+llii I ' I , + i l I J_ .. i f l 11 t ; ½ .. l + I I I ~ 1 I • i i + 1 • t t-tj f I l 1 t •i+ 1++11 .. ljI .i -+ +-+-t -t i t1j ilj 11 'I mt 32!3o•1 I ' 2? I I 1 I I £ 1L :;l~i+ County of San Diego Hydrology Manual . -~ ~. . ;~: ,, ,, - ~~) Rainfall lsopluvials 100 Year Rainfall Event -24 Hours lsopluvial (Inches) DPW etGIS 0.,.-oll'IM:---- N alll:ilS We Have San Diqco Ccwcrcd! + TlllS MAP IS PRIMOEDWITHOIIT WAAIW(f'( Of' Nl'f KIND, EmtER EXPRESS OR MPUED, INCUJOING, 1111T NOT UMITBl TO, lME IMPllED WARRANTlES Of' MERCHANTABUTY NI/J FITNESS FOR A PARTICUlAR PURPOSE. ~s.lGIS.M~-- Tl,ls,._ __ W __ ._SAHDAG~ w-.gy. ___ .. ,.__._ _,.,.....,,_ Tl,lsproduct ____ ,,.. __ _ ~ ....... br---Moiio s 3 0 3 Miles ~ . . . .. . "" .... , ;: ., ""' .. . ;: . -" ' " .. '" ,. . '· "" , .. '"" ""' -. ' ' ,. . -. \ . . . ··--4. . r. • . ,. ,. -~ . '1 il -.,,.. ""}._"."~.'l!J.~_~-,'.J 7 .. . . 'a~ ., . . . ' \ \ ,. ~ # I I'., • ·-,, ...... .',. ·,~ ~ ~ ,,, -·•-. ' 1> •, -'• ' \ . ' . ' > • •. ' ' ·' •. ·, . . <;.. .~-.IP.~. ~ .'; _,,,,,., ' . ,-. . <c " ' ,.~ ' . • r \ .•.• ,. -.·. ·",-ir -I..,,,..•_ .. _.,;,.. / . . . .. ·'I; . '"ll~ .. · ;x ,· •.' \' V • . >, r)!<;;;,~<l>'c),.<. • / / ·;1111.. . ~ .• ,. ·, ,,, ~.1):.1/ , .. ,., \ ._ ' • : il .. ~ -·: ... ~,,. -:.~ ., i i .. ~-... ft . ".-.-, •. ,. •, > M "' ,', •~, > •• / ,/ . ' °'A'~ ~ .. . / ✓ . ·~, .. ' '. o A '·. . .-. . . _.,. , \· > ~ ·•. -., • 'v \ \ < > ~ / .,. r . .' ~ ,: . $.:;:,!; '. .\ ' ,. . . .,. \ "'.~ -' '. . ., i . ., / ..... '• ·.•. -.• > ••• ', . .;u '.~ .: '.Y ,,c ,; ',.Ji~ .. ''o,r,.' ~ .• .~. ,. . • ,> ~. • C •• <, ~ ,\ / ~ ,. ... ~ ..... , " ~· -~ . h: -.►.. .. . ' • ~· -• ~ " I ., " " ... / '~ .. ,· ---' "I·.,'"". \ .-., ~ ... , . ·, .. .,. . ' . ·t ... >'! ·~ ·.J ... 1.:.•r~ i ' . . ' ·9>.,.,_ .. '· ... ~ ~ . . .. ' ' ".' . ,. .. ·. .,f!\lv. .~ ~= -.. \.. ', ' .. , I ; -. . . d =:· t •• • I • 1-.. C\:": • •· I . I.,; r. .. ."'fflill'.l~ . . -. ·-~ lJSI),,\ ... Hydrologic Soil Group-San Diego County Area, California (TOYOTA CARWASH) MAP LEGEND MAP INFORMATION Area of Interest (AOI) □ Area of Interest (AOI) Soils Soll Rating Polygons □ A □ AID □ B □ B/0 □ C □ C/D □ D □ Not rated or not available Soll Rating Lines -A -A/0 -B -B/0 -C -CID -D ,. " Not rated or not available Soll Rating Points ■ A ■ A/0 ■ B ■ BID Natural Resources Conservation Service ■ C ■ CID ■ D □ Not rated or not available water Features -Streams and Canals Transportation +-+-+ Rails ~ Interstate Highways _,_ us Routes :::.:=:: Major Roads Local Roads Bae kg round • Aerial Photography Web Soil Survey National Cooperative Soil Survey The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Diego County Area, California Survey Area Data: Version 12, Sep 13, 2017 Soil map units are labeled (as space allows) for map scales 1 :50,000 or larger. Date(s) aerial images were photographed: Nov 3, 2014-Nov 22, 2014 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 2/25/2018 Page 2 of 4 --------------- ---------- -- ----- Hydrologic Soil Group-San Diego County Area, California TOYOTA CARWASH Hydrologic Soil Group Map unit symbol Map unit name Rating Acres lnAOI Percent of AOI ~ HrC Huerhuero loam, 2 to 9 D 2.3 percent slopes Totals for Area of Interest 2.3 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 C/D). 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. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 100.0% 100.0% 2/25/2018 Page 3 of 4 -------------------------- - • -------- Hydrologic Soil Group-San Diego County Area, California Tie-break Rule: Higher Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey TOYOTA CARWASH 2/25/2018 Page 4 of4 --------------ATTACHMENT 3 - • EXISTING HYDROLOGY CALCULATIONS ------- ---------- I I I I I I I I I I I t I I I I I I I I I I I t I t I I I I I I I I I I I I AREA CA LC ULA TIONS EXISTING HYDROLOGIC BASINS Basin Soil Type Pervious Total Total Natural Impervious Landscape Pervious % CValue % Fraction C Value C Value Runoff Area Area Pavers Impervious Weighted of Site Fraction Final Coefficient SF Acres SF SF SF SF EX-1 A 0.20 0 0.000 0 0 0 0 -0.03 0% 0.00 B 0.25 0 0.000 0 0 0 0 -0.04 0% 0.00 C 0.30 0 0.000 0 0 0 0 -0.05 0% 0.00 D 0.35 52,746 1.211 0 44,474 8,272 0 -0.05 100% 0.05 Total -52,746 1.211 0 44,474 8,272 0 84.32% -100% 0.05 0.814 I I I I I I I I I I I I I t I I I I I I I I I t I I I I I I I I I I I I 10.0 , , , ',,, 1.0 I I I ,,. ' "" '4 ¾ '. ¾ '•-""' .".. I 0.1 +-----,--...----,--.,........-.-......-+----,---,----,-....,.....,...........,....,...f------.--,---.,........,.....,...~ 10 100 1000 1292D -basin calcs_2019.xls Intensity-Duration Design Chart EX-1 Existing Conditions Time of Concentration Calculations Overland Flow Method Land Use= C= Dist.= slope= 0.81 390.00 ft. 2.051 % Tc = 1.8(1.1-C}✓D 1/s *Tc= 8.00 min. * Minimum Tc= 5 Minutes Natural Watershed (Kirpich) L = na ft LlE = na ft -re= #VALUE! min. ** Minimum Tc= 10 Minutes Basin Intensity Calculations Tc= (11~:L 3 rm Selected Frequency, 100 year Pe= 2.5 in. Pe must be within P24 = 4.2 in. 45% to 65% of P24- Pe/ P24= 60% Adjust Pe as needed. Adjusted P6= 2.50 in. Tc(D) = 8.00 min. 11 = 7.44P6D--06451 I= 4.86 in/hr Basin Flow Calculations Q = 4.79 cfs C = 0.81 IQ=C*l*AI I = 4.86 in/hr A= 1.211 ac. EX-1 I I --------------ATTACHMENT 4 --PROPOSED HYDROLOGY CALCULATIONS ------------------.. --.. I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I AREA CALCULATIONS PROPOSED HYDROLOGIC BASINS Basin Soil Type Pervious Total Total Natural Impervious Landscape Pervious % CValue % Fraction C Value C Value Runoff Area Area Pavers Impervious Weighted of Site Fraction Final Coefficient SF Acres SF SF SF SF PR-1 A 0.20 0 0.000 0 0 0 0 0.04 0% 0.00 B 0.25 0 0.000 0 0 0 0 0.05 0% 0.00 C 0.30 0 0.000 0 0 0 0 0.06 0% 0.00 D 0.35 42,116 0.967 0 33,219 8,897 0 0.07 100% 0.07 Total 42,116 0.967 0 33,219 8,897 0 78.88% 100% 0.07 0.784 - Basin Soil Type Pervious Total Total Natural Impervious Landscape Pervious % CValue % Fraction C Value c""'vaiiie Runoff Area Area Pavers Impervious Weighted of Site Fraction Final Coefficient SF Acres SF SF SF SF PR-2 A 0.20 0 0.000 0 0 0 0 0.08 0% 0.00 B 0.25 0 0.000 0 0 0 0 0.10 0% 0.00 C 0.30 0 0.000 0 0 0 0 0.13 0% 0.00 D 0.35 10,630 0.244 0 6,200 4,430 0 0.15 100% 0.15 Total 10,630 0.244 0 6,200 4,430 0 58.33% 100% 0.15 Q,§.l1. I I I I 10.0 1.0 0.1 I I ', ',,, I I 1292D -basin calcs_2019.xls I t I I I I I I 10 I • I I I I I I I I I I I I I I I I I I 100 1000 Intensity-Duration Design Chart PR-1 Proposed Conditions Time of Concentration Calculations Overland Flow Method Land Use= C= Dist.= slope= 0.78 284.00 ft. 2.711 % Tc= 1.8(1.I-C}JD 1/s *Tc= 6.96 min. * Minimum Tc = 5 Minutes Natural Watershed (Kirpich) L = na ft b.E = na ft **Tc = #VALUE! min. ** Minimum Tc= 10 Minutes Basin Intensity Calculations Tc= (ll~:£3 rm Selected Frequency, 100 year Ps = 2.5 in. P6 must be within P24 = 4.2 in. 45% to 65% of P24- Ps / P24= 60% Adjust P6 as needed. Adjusted P6= 2.50 in. Tc(D) = 6.96 min. 11 = 7.44P6D--06451 I= 5.32 in/hr Basin Flow Calculations Q = 4.01 cfs C = 0.78 IQ=C•I•AI I = 5.32 in/hr A= 0.967 ac. PR-1 I I I I I I I I I I I I I I I I I t I I I I I I I I I I I I I I I I I I I I 10.0 '•, , '•, 1.0 I J "-"-"' '° .. '° '•·"'•-'° I 0.1 10 100 1000 1292D -basin calcs_2019.xls Intensity-Duration Design Chart PR-2 Proposed Conditions Time of Concentration Calculations Overland Flow Method Land Use= C= Dist.= slope= 0.67 164.00 ft. 1.000 % Tc= 1.8(1.1-C}v'D 1/s *Tc= 9.91 min. * Minimum Tc= 5 Minutes Natural Watershed (Kirpich) L = na ft LlE = na ft **Tc= #VALUE! min. ** Minimum Tc= 10 Minutes Basin Intensity Calculations Tc = ( 11 ~: L 3 r 3 ss Selected Frequency, 100 year Pe= 2.5 in. Pe must be within P24 = 4.2 in. 45% to 65% of P24. Pe/ P24= 60% Adjust Pe as needed. Adjusted P6= 2.50 in. Tc(D} = 9.91 min. I/= 7.44P6D--064sl I= 4.24 in/hr Basin Flow Calculations Q= 0.69 cfs C = 0.67 IQ=C*f*AI I = 4.24 in/hr A= 0.244 ac. PR-2 I I ---------------------------.. --------- PRl.out San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c}1991-2012 Version 7.9 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 08/01/19 ********* Hydrology Study Control Information********** Program License Serial Number 6313 Rational hydrology study storm event year is 100.0 English (in-lb} input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.500 24 hour precipitation(inches) = 4.200 P6/P24 = 59.5% San Diego hydrology manual 'C' values used ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 101.000 to Point/Station 102.000 **** USER DEFINED FLOW INFORMATION AT A POINT**** User specified 'C' value of 0.780 given for subarea Rainfall intensity (I}= 5.321(In/Hr) for a 100.0 year storm User specified values are as follows: TC= 6.96 min. Rain intensity= 5.32(In/Hr} Total area= 0.967(Ac.) Total runoff= 4.010(CFS} ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 102.000 to Point/Station 103.000 **** PIPEFLOW TRAVEL TIME (Program estimated size)**** Upstream point/station elevation= 49.660(Ft.) Downstream point/station elevation 48.500(Ft.) Pipe length = 133.00(Ft.) Slope 0.0087 Manning's N 0.013 No. of pipes= 1 Required pipe flow 4.010(CFS} Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 4.010(CFS} Normal flow depth in pipe= 8.94(In.) Flow top width inside pipe= 14.72(In.) Critical Depth= 9.71(In.) Pipe flow velocity= 5.26(Ft/s) Travel time through pipe= 0.42 min. Time of concentration (TC}= 7.38 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 102.000 to Point/Station 103.000 **** CONFLUENCE OF MAIN STREAMS**** Page 1 ----PRl.out -The following data inside Main Stream is listed: In Main Stream number: 1 -Stream flow area= 0.967(Ac.) Runoff from this stream 4.010(CFS) -Time of concentration= 7.38 min. Rainfall intensity= 5.123(In/Hr) -Program is now starting with Main Stream No. 2 -++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -Process from Point/Station 201.000 to Point/Station 202.000 **** USER DEFINED FLOW INFORMATION AT A POINT**** -User specified 'C' value of 0.670 given for subarea -Rainfall intensity (I)= 4.237(In/Hr) for a 100.0 year storm User specified values are as follows: -TC= 9.91 min. Rain intensity= 4.24(In/Hr) -Total area= 0.244(Ac.) Total runoff= 0.690(CFS) -++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -Process from Point/Station 202.000 to Point/Station 103.000 **** PIPEFLOW TRAVEL TIME (Program estimated size)**** -Upstream point/station elevation= 52.860(Ft.) -Downstream point/station elevation 52.420(Ft.) Pipe length 17.00(Ft.) Slope 0.0259 Manning's N 0.013 -No. of pipes= 1 Required pipe flow 0.690(CFS) Nearest computed pipe diameter = 6.00(In.) -Calculated individual pipe flow = 0.690(CFS) Normal flow depth in pipe= 3.93(In.) -Flow top width inside pipe= 5.71(In.) Critical Depth= 5.03(In.) -Pipe flow velocity= 5.06(Ft/s) Travel time through pipe= 0.06 min. -Time of concentration (TC)= 9.97 min. -++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -Process from Point/Station 202.000 to Point/Station 103.000 **** CONFLUENCE OF MAIN STREAMS**** -The following data inside Main Stream is listed: -In Main Stream number: 2 -Stream flow area= 0.244(Ac.) Runoff from this stream 0.690(CFS) Time of concentration= 9,97 min. -Rainfall intensity= 4.222(In/Hr) -Summary of stream data: -Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) --1 4.010 7.38 5.123 2 0.690 9.97 4.222 -Qmax(l) 1.000 * 1.000 * 4.010) + -Page 2 --- ------------------------- --- ----- PRl.out 1.000 * 0.741 * 0.690) + 4.521 Qmax{2) 0.824 * 1.000 * 4.010) + 1.000 * 1.000 * 0.690) + 3.994 Total of 2 main streams to confluence: Flow rates before confluence point: 4.010 0.690 Maximum flow rates at confluence using above data: 4.521 3.994 Area of streams before confluence: 0.967 0.244 Results of confluence: Total flow rate= 4.521{CFS) Time of concentration 7.381 min. Effective stream area after confluence 1.211{Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 103.000 to Point/Station 104.000 **** PIPEFLOW TRAVEL TIME {Program estimated size)**** Upstream point/station elevation= 48.500{Ft.) Downstream point/station elevation 47.670{Ft.) Pipe length = 35.00{Ft.) Slope 0.0237 Manning's N 0.013 No. of pipes= 1 Required pipe flow 4.521{CFS) Nearest computed pipe diameter = 12.00{In.) Calculated individual pipe flow = 4.521{CFS) Normal flow depth in pipe= 8.30{In.) Flow top width inside pipe= 11.09{In.) Critical Depth= 10.66{In.) Pipe flow velocity= 7.80{Ft/s) Travel time through pipe= 0.07 min. Time of concentration {TC)= 7.46 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 104.000 to Point/Station 105.000 **** PIPEFLOW TRAVEL TIME {Program estimated size)**** Upstream point/station elevation= 47.670{Ft.) Downstream point/station elevation 47.300{Ft.) Pipe length = 73.00(Ft.) Slope 0.0051 Manning's N 0.013 No. of pipes= 1 Required pipe flow 4.521{CFS) Nearest computed pipe diameter = 15.00(In.) Calculated individual pipe flow = 4.521{CFS) Normal flow depth in pipe= 12.07{In.) Flow top width inside pipe= 11.89{In.) Critical Depth= 10.35{In.) Pipe flow velocity= 4.27(Ft/s) Travel time through pipe= 0.28 min. Time of concentration (TC) 7.74 min. End of computations, total study area= 1.211 {Ac.) Page 3 ---- ------ -------------------------- ATTACHMENT 5 HYDROLOGY MAP -EXISTING CONDITIONS 0, - LEGEND _..--50 ----- EXISTING CONTOUR (MAJOR) EXISTING CONTOUR (MINOR} PROPOSED CONTOUR (MAJOR) PROPOSED CON TOUR (MINOR) HYDROLOGfC BASIN BOUNDA RY -----HYDROLOGIC FLOW PATH PR-1 BASIN NUMBER J l.6J i AREA (ACRES) @ NODE NUMBER (50.00) ELEVATION (FffT) \ \ PARCE L NO . 2 I P M 15386 I -~-~ __ 2 1~~~-~~-----J \ r \ \ \ \ \ \ \ C ½~ Con stru c tion Test in g & En gin ee ring, Inc . f I: -~.---, Inspection J Testing J Geotechnlcal J Envlronmentol & Construction Engineering J CM Engineering J Surveying ~~ 1441 ~ontlel Road, Suite 115. Eocondido. CA 92026 Phone: (760) 746 -4955 Fax: (760) 746 -9806 \ 2 10 -100 -16 \ \ \ \ \ PARCEL NO. P M 1538 6 3 f 20 ----------- 0 20 GRAPHI C SCALE SCALE: 1" = 20' 40 ATTACHMENrf 5 EXISTING HYDROLOGIC CONDITIO NS "'------------------------------------------------------------------------------------------------------------------- ... .. ------------ATTACHMENT 6 -• HYDROLOGY MAP -PROPOSED CONDITIONS ----.. .. --.. 111 • - • .. • - - LEGEND ------50 ......___ ----- EXJSnNG CONTOUR (MAJOR) EXJSnNG CONTOUR (MINOR} PROPOSED CONTOUR (MAJOR} PROPOSED CONTOUR (MINOR} HYDROLOG/C BASIN BOUNDARY HYDROLOGIC FLOW PA TH -----HYDRAULIC PIPE FLOW PR-1 BASIN NUMBER 11.6J I AREA (ACRES) @ NOOE NUMBER (50.00} ELEVA noN (FEET} PARCE L NO. 2 I PM 15386 I 210 -100 -15 _JI ------------------ \ \ \ \ \ C <~ Con struction Testin g & Engineering, In c. f I: .,. Inspection I Testing I Geotechnleal I Environmental & Construction Engineering I Civil Engineering I Surveying ~ 14-41 Montiel Road, Suite 11 5, Escondido, CA 92026 Phone: (760) 7"6 -4955 Fox: (760) 7"6 -9806 \ 2 10 -100 -16 \ \ \ \ \ PARCEL NO. 3 PM 15 386 PARCEL NO. 2 9. 755 AC. PM 1310 2 11 -030 -2 7 --------------------. . . . . . -. . . . . . . . . . -. -. . . -\. . . --. . - \. ---. --. " -. -----\-.-_-_-. ' 20 0 20 GRAPHIC SCALE SCALE: 1"= 20' 40 ATTACHMENT 6 PROPOSED HYDROLOGIC CONDITIONS °"'--------------------------------------------------------------------------------------------------------------------' I I 11