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Home My WebLink AboutCT 99-03; VILLAGES OF LA COSTA GREENS; MASS-GRADED HYDROLOGY STUDY; 3005-08-23..... - • Pl.ANNING ENGINEERING SURVEYING IRVlNE tOSANGEl.ES RIVERSIDE • SANDIEGO HUNSAKER &ASSOCIATES S A N D I E G 0, I N C . MASS-GRADED HYDROLOGY STUDY ·for LA COSTA GREENS NEIGHBORHOODS 1.1-1.3 & EL cAIVifNO REAL WIDENfN.G City of Carlsbad, California Prepan~d for: Real E:state Coif ateraf Management Company c!o M·orrow Development 1903 Wright Place Suite 180 C_arlsbad, CA 92008 W.O. 2352-138 August23,2005 Q.J • 0 -~?; - ---• --- Hunsaker & Associates San Diego, Inc. • DAVE HAMMAR • ::::;:~y~ RAY MARTIN . b aondl.Martin, R.C.E. 10179 HuennekensSt SanDiego,CA 92121 (858) 5S8--4S00 PH (858) S58-1414 FX Vice President • www.Huns~__6p.com lnfo@Hu;-isakerSD.com .. IF,; -: ~-4.J i.,.";:r~ .... i. ... ·_. t1 ~ z CT Cf°CJ-o8<'C f;-leJrq ~ AH:.\:::: H:\=Oil.TS~\13! Gi=ns 1.1 :h;u 1.3ti";d SU3MITTAU..03..doc n. 1 JJ w.o.:a.,..1:i.s ~2nqs 1:z:zo?M - -r! --7 -IT_ -J -r-~ --' ;,:!llj -r?• l I .J -' •J -~ C' i 1 -,i -~ ·['1 -., -• i • [~ ., " • ;t -~& -~ [/ -,.:l -17 -~ •. , i •·· ------ FLOW PROCESS FROM NODE 107 _ 00 TO NODE 107_. 0,0 IS CODE.,;;_ >>>>>DESIGNATE·INDEPENDENT STREAM FOR CONFLUENCE<<<<< -------------------------------------.- 'I'OTAL NUMBER. OF STREF.MS = 2 CONFLUENCE VALUES USED FOR INDEPENDIDiT STRR..2\M 1 .ARE: ~IME OF CONCENT.RATION(MIN.) 9.08 RAINFALL INTENSITY(INCH/BR) = 5.02 TOTAL .STRR.~ AREA {ACRES) ,,;. 1. 8 6 PEAK FLOW RATE (CFS) AT CONFLUENCE = 6.84 1 ***************************************************************~************ FLOW PROCESS FROM NODE 108. 00 TO NODE 109.00 IS CODE= 21 ---------------------·----------------------------------------·------------- >>>>>RATIONAL METHOD INITIAL SUB.AREA ANALYSIS<<<<< =======.========================================-===--=---=--=-=------------ *USER SPECIFIED (SUJ3A,REA): INDUS'J;lUAL I?EVELOPMENT RUNOFF COEFFICIENT= .9000 IN~TIAL SUB.AREA. FLOW-LENGTH= 314.00 UJ?S~ ELEVATION = 314. B 0 DOWNSTREAM ELEVATION = 310.00 ELEVA.TIO-µ DIFFERENCE = 4, 80 URBAN SUI3.AREA. oVEIUJu:ID· TIME OF FLOW (MINUTES) ;= 5. 53 8 TIME. OF CONCENTRATION ,?\SSUMED AS 6-MINUTES 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.559 SOB~ RUNOFF(CFS) = 2.30 TOTAL AREA(ACR.ES) = Q.39 TOTAL RUNOFF(CFS} = 2.30 **************************************************************************** FLOW PROCESS FROM NODE 109.00 TO NODE li0.00 ~S CODE·= 51 ----.-----------.----------------------------------------------------------- >>>>>COMPU'L'E TRAPEZOIDAL CHAJ:W-EL FLOW<<<<< >>>>>TRAVELTIME TERU SUBAREA<<<<< -------------------------------------------------------------.------------- UPSTREAM NODE ELEVATION= 310.00 DOWNSTREAM NODE ELEVATION= 301.70 CHAI:mEL LENGTH THRU SUBAREA{FJIBT} ~ 633.50 CHANNEL SLOPE= 0.0131 CBANNBL BASB(FEET} = 0.00 nzn FACTOR= 99.990 MANNrnG'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = Q.50 CE:ANNEL FLOW THRU SOBAREA(CFS} = 2-30 FLOW VELOCITY (FEET/SEC} = 1. 03 FLOW DEPTH (FEET) = o .15 TRAVEL TIME{MIN.) = 10.28 ·TC(MIN.) = 16.28 **************************************************************************** FLOW PROCESS FROM N0DR 109.00 TO NODE 110.00 IS CODE= 8 ---· ---------_---. ------------------------------------.--------------------- >>>>>P..DDITION OF SUBliREA. TO MAINLL"/IB PEAK FLOW<<<<< --=============~===========~====================================-=------- 100 YEAR R..:zuNFALL INTRNSIT.f(INCH/HOUR) = 3 .4/4,5 *USER SPECIFIED (S1J131UIBA): INDtrSTRLZU. DEVELOPMENT RUNOFF COEFFICIRriiT = . 8700 SIT.BA.~ ARK.~ (ACRES) = 9. 8 8 SUB..Zl..."1IB.<i RUNOFF (CFS) = 29.61 -------- ~-i__ -·' ~ t·_: --~-... --· -- -- TOTAL JI.REA {ACRES) = T-C(MIN} = 16.28 FLOW PROCESS FROM NODE 10.27 TOT/1..L RUNOFF {CFS) = 31.91 110.00 TO NODE 111.00 IS CODE= 4 ------------------------------------------------------------·---. ------· -• __ -- >>>>>COMPUTE PIPEFLOW TRAVBLTIMR T.ERU ?UBARR.Z\.<<<<< >>>>>USING USER-SPECIFIED PIPESIZE<<<<<. ========-======================================. -==-=-=. ===-==-=--. ---• -• --- DEPTH OF FLOW' IN 3 0. 0 INCH PIPE .IS 11. 5 INCHE,$ PIP.EFLOW VELOCITY (FEET/SEC. ) = 18. 4 DPSTRE.:1\M NOJ;)E ~TION = .DOWNSTREAM NODE ELEVATION .. FLOWLENGTH (FEET) = 65. 00 GIVEN J;>IPE DIAMETER (.INCH} = PIPEFLOW TBRU SUBAREA{CFS} = TRAVEL TIME (MIN.) = o. o 6 290.68 286-:22 MANNING'S·N = .0.013 30. 00 NUMBER oF··PIPES 31.91 TC(MIN.) = ·16.34 FLOW PROCESS FROM NODE ,.111.00 TO NODE 113. 00 IS CODE = 4 --:·. :-----. --------------------------------.-------------· ____ • _________ ._. >>>>>COMPUTE PIPEFLOW TRAVELTIME TRRU SOB.AREA<<<<< >>>>>USING USER-SPECIFIED PIPESIZE<<<<< DEPTH OF·FLOW IN 30.0 INCH PIPE IS 8.8 INCHES_ , ·. . PIPEFLOW VELOCITY(FEE'.!-'/S~C.) = 26.8 UPS'I'R.EAM NODE ELEVATION = 285. 89 DOWNSTREAM NODE ELEVA'l'ION = F.Ii0WLENGTH(FEET) = 48.78 ~IVEN PIJ?E·DIAMETER(INCH) = PIPRFLOW T.!'IRU SUBAREA(CFS) ~VEL TIMR(Mill.} = 0.03 • 276.38 MANNING'S N = 0.013 30. 00 NUMBER. OF PIPES = 31.91 TC(~IN.) = 16.37 1 . FLOW PROCESS FROM NODE 113.00 TO NODE 107". 00 IS CODE = 53" ------------· ------·-----------------------------------·---------~--·----- >>>>>COMPUTE NATURAL MOUNTAIN CHANNEL FLOW<<<<< ~->>~>>'l'RAVELTIME THRU SUB.AREA<<<<< . ==. -7 _: ·-= -: ========. == ·====-===== -==. ================· ===== -• • ====· ··======= • -'UPSTREAM NODE ELEVATION? 275.00 DOJl?NS'r.REAM NODE ELEVATION= 224.00 6Hru5INEL LENGTH THRU SUBAREA (FEET) 302. O·O ~ ·GEANNEL SLOPE= 0.1689 .CHANNEL FLOW TBR.U SDBAREA.(CFS) = 31.91 FLOW VELOCITY(FEBT/SEC) = 7 .29 (PER PL..Z\.TE D-6 ."3) 'J;RAVEL TIMR(MIN.} = ·0.69 TC(MIN.) = 17.06 FLOW PR0CESS FROM NODE 113.00 TO NODE 107.00 IS CODE=· 8 --------------· ----------------·-------------------.• --.----· --------------- ?>>>>.ADDITION OF SUB.ARRA TO MAINLINE PR:.UC FLOW<<<<< 1.00 YE1L~ R..~1v?ALL :prr'ENSITY(INCH/HODR) = 3 .343 = -r1 -=i. -r1 ... -n -J>f.. -[7 -. -9 [ 't ,) :i -__ (J )J(_ -[~ • I ! -.! -l~--·l • J -l ~; -j -[~ ! t 1111 11 • r..;.~ '· .--., -□'-!1 -:: --- .... - •. ----- . *USER SJ?ECIF~ED (~ll~) : • RDR..2\L DEv"ELOPMEN'"'T RUNOFF COEFFICIENT = .4700 SDR~Z\. AP..R.<l (ACRES) = l. 54 SDB...:2\..>IB..Z\. RUNOFF [CFS) = 2. 42 TOT.Ur A..~{ACRES) = ll.81 TOT-2IT: RDNOFF{CFS) 34.33 TC (.MIN) l 7 . 0 6 . . FLOW PROCESS FROM NODE 107.00 TO NODE 107.00 IS CODE= . . --.---.-:--------. : • .. -.--. ------------- ::>:>>>>DESIGNATE INpEPENDRNT STRRAM FOR CO~UENCE<<<<< ,>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< -TOTAL NUMBER OF ST.REAMS = 2 CO~LUENCB VALUE~ . USED FOR INDEPENDENT STREAM 2 ARE: TIME OF CONCENTRATION (MIN. ) = 17. 0 6 RAINFALL INTENSITY(INCH/HR) =: 3 .34 . TQ'I'.AL . s~ ~(ACRES} = 11. s;t PEAK FLOW RA.TE (CFS) AT CONFLUENCE = 34 .33 **· CONFLUENCE DATA.** . STREAM RUNOFF NUMBER (CFS) l 2 6.84 ._34. 33 Tc (MIN.) 9.08 17.06 INTENSITY (INCH/.HOUR). s. q2z-- 3.343 AREA (ACRE) 1.86 11.81 ~A:r.:r, INTENSI'f'.Y AND TIME O~ CONC)lliTRATION. RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. * * PEAK FLOW RATE TABLE ** STREAM RDNO.FF Tc INTENSITY NONBER (CFS) (MIN.) (INCH/HOUR) 1 29.70 9.08 5.022 2 38. 89 17.06 3.343 COMPUTED CONFLUENCE ESTIMATES ARB AS FOLLOWS:. P~ FLOW .RA.TE (CFS). -· 3-8 .89 Tc (MIN.).= 17. 06 TOTAL .AREA (ACRES) = 13. 6,7 1 * ************* **** ***** ** *** ***** ** ********* * *"**** *** ** ************ ******"" ** FLOW PROCESS FROM NODE , 197. 0.0 TO NODE .114.00 IS CODE = 52 ------------·--------------------------------------·-------------• ___ _ >>>>>COMPUTE NATURAL VALLEY CHANNEL FLOW<<<<< >>>>>'I'RAVELTIME TID.<.U.SUBAREA<<<<< -~STREAM NODE ELEVATION= 224.00 DOWNSTREAM NODE ELEVATION = 125. 00 C8ANIDIT, LENGTH TBRU SDBARE..1!.(FEET) = 1.587 ~ 00 CBAIDlRL SLOPE= 0.0624 Cilll-..NNEL FLOW TBRU SUBAREA(CFS) = 38.89 FLOW VELOCITY(FEET/SEC) = · .9 .. 00 (PER PLATE D-6.1) TR..lt v'EL TIME (Milf .. ) = 2 .. 94 TC (MLli .. ) = 2 0 . 0 0 FLOW PROCESS FROM NODE 1.07 :oo TO NODE 114.00 IS CODE= . 8 I I ll I ll I • • I I I I I I I I I I I • I t I Mass-Graded Hydrology Study. La Costa Greens Neighborhood• 1.1-1.3 & El Camino Real Widening I I t I I I I I I Neighborhoods 1.1 through 1.3 and El Camino Road Widening development also uses the 1993 San Diego County methodology. Future developments, which do not tie into systems designed per the older methodology, will be analyzed yilth the current 2003 San Diego County methodology. For the Rational Method Analysis, a runoff coefficient of 0.45 was used for undisturbed, natural terrain; a runoff coefficient of 0.95 was used for paved streets, corresponding to areas that are 90% Impervious; and a runoff coefficient of 0.55 was used for constructed slopes. For the mass-graded areas, a runoff coefficient of 0.87 was used, which corresponds to commercial land use, due to the fact that in Its ultimate condition the project site will most likely be converted to a commercial site. All runoff coefficients are based on the '1993 San Diego CountyHydrologyManuar. Existing and mass-graded condition peakflowrates, listed on Table 1 below, are based on the AES-99 computer program and the City of Cartsbad Drainage Design • . Criteria (see Chapter 2 for methodology and model development and Chapter 3 for AES model outputs). Watershed delineations and node locations are visually depicted on Exhibits 8.1 and 8.2, which are located In the back pocket of this report (see Chapter 8). TABLE 1 Existing and Mass-Graded Condltlons Hydrologlc Results ------Existing Conditions Mass-Graded Conditions Basin Node A Q Tc A Q Tc ID ID (ac) (cfs) (min) (ac) (cfs) (min) Basin 1 100 88.0 127.3 20.6 91.1 143.3 22.5 Basin 2 200 38.8 66.5 14.8 43.2 74.5 18.2 As depicted In Table 1 above, development of the project site increases runoff when compared to the existing condition peak flowrates. In Basin 1 the peak runoff increased by 16.6% and In Basin 2 it Increased by 12.0%. However, the increment in runoff does not affect the existing Allcante Detention Basin since it has been approprtately sized to convey all runoff draining into It based on the 'Master Detention Study for La Costa Greens• prepared by Hunsaker & Associates and dated August 2003. Per the 'Drainage Study for Alicante Road-North of Poinsettia" prepared by Hunsaker and Associates and dated December 2003 the peak discharge of 143.3-cfs at Node 100 is lower than the estimated runoff of 154.2- cfs at that same location; thus, the storm drain system has capacity to handle the fl.ow (see Appendix 7.7). At Node.200 the peak discharge of 74.5-cfs is higher than the estimated runoff of 63.6-cfs per Drawing No. 397-2H (see Appendix 7.8). Therefore, the existing storm drain system along Poinsettia Lane was analyzed hydraulically with the new increased flow to ensure that the increment In peak AH:M~-~1.1ftll1.Nlilla,u,m'l,M.V,Dllalll w.o:naz-111 WDl2QIOIU:OII' .. I I I I I I --------.. -- -------· -"" -••a --i-~~ .......... -'+'-.u.u.u.u.µw.WJ4..J..U.Lj.JJ..u.µ.Ll.UW.lll'l 2 . 3 4 5 6 Direction~ for App_licat'lon: • ··,·s,_.·,,,;,,"t~,,~t, l) From prec.ipitation -n1aps dete.nnina 6 hr. and 24 hr, amounts ~or the selected frequency. These maps ~re printed in the County Hydrology Manual (10, 5!) nnd 100 yr. maps included in the Desi g_n and Pro,cedure Manual). 2) Adjust 6 hr. precipitation (if necessary).so that it is withill the ranoe of 45t to 55,; of the 24 hr. precipitation.· (Not applicable to Desert) • 3) · Pl:it 6 hr, pr~c1p1tatfon on the riol:t &ide of the· chart. 4) Draw a line through the point parallel to the plotted lines. • ~Not Applicable to Desert Region APPENDIX XI IV-A-14 •1: _____ _ 0 15 20 --~~ ~---=-===-==-~ ............... ~=====:==::::_ -~---· ==-·· ~~~~~~-~-~-. ·-~-~ 30 40 50 -- -----• - ---- ------ ------------------------ ---- COUNTY Or SAN DIEGO ~EPARTMENT OF SANITATION & FLOOD CONTROL 1Ko:n •. c.T s iTE. : fioo, lo "' Z. '3 i '(\., U.S. DEPARTMEN r OF COMMERCE NATIONAL OCXAN1C A1CD I\T OSPHERIC A.DIUN'ISTKATIOK I 100-YEAR 6_-HOU PRECIPITATlOi~ -20./ ISOPLUVIALS F 100-YEAR 6-HOUR SPECIAL ST\J~IES BRANCH, OFP1C1t OF II DROLOOY"-NATIONA.L WEATHER SERVICE 45 1 301 15' 117° 45 1 30 1 15' I 16° r .... _.....,.,. __ ... ' 1:1 'J ,. " /,I LEGEND PROJECT BOUNDARY EXISTING HCP LINE WATERSHED BNDY DRAINAGE DIRECTION --· LOCATION ID NODE 0 DITCH ID NODE EXISTING STORM DRAIN PROPOSED STORM DRAIN ==[§]==·== EXISTING DITCH PROPOSED DITCH c.::::::> 100 ·~-~-=-= SCALE 1 "= 100' 200 7 300 l /··-, .... tz~,;i ,.,,,; ,· ,.., H&A 8/22/2005 . ,, __ ,. ......... ~,' .. II PLANNING EN Cl NEERING SURVEYING HUNSAKER & ASSOCIATES SAN Dl~CO, INC 101i9 HUC!nnd.l<M Street San Diego, Ca 92.121 PH{8S8)558•.i500· FX(S58)558·1'11-': LA COST A G:'.REEN-S N·E1GHBORHOODS 1. 1-1.3 CITY OF CARLSBAD, CALIFORNIA ! i i IJ SHEET 1 OF 2 R: \0510\&.>iyd\0510$H02-MG100.dwg[ O]Aug-22-2005: 15: 32