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Home My WebLink AboutCT 93-04; CARRILLO RANCH VILLAGES L, M, N, Q, R, T; DRAINAGE STUDY; 1993-05-24I I I RANCHO CARRILLO PARK SITE I DRAINAGE STUDY I May 24, 1993 I (Rick Engineering Job Number 12004-G) I I I I I I I Prepared by: I RICK ENGINEERING COMPANY 5620 Friars Road San Diego, California 92110 I I I I I I I I I I I I I I I I I I I I I I I I RANCHO CARRILLO PARK SITE DRAINAGE STUDY Purpose The purpose of this study is to compare natural (May 1993) flows with ultimate-development flows for the channel at the southwest corner of the Rancho Carrillo park site. Exhibits for both cases are included with the report. From the ultimate development exhibit, it can be seen that portions of Villages 11N, 11 11 0, 11 11R," and 11 Q11 will be tributary to the park site. Results The natural (May 1993) area tributary to the park site is 117 acres, with a Q100 of 207 CFS. The ultimate-development tributary area is 92 acres with a Q100 of 205 CFS. Eighteen acres of tributary area for Village 11M11 has been routed northerly to the main channel on Melrose A venue. This provides opportunity for detention behind Melrose (if desired) and reduces impacts on the park's southerly drainage. An additional five acres is diverted around the park from Village 11Q11 and discharged downstream of the park. The result is no net increase in runoff on the channel at the southwest corner of the park. Methodology San Diego County Flood Control Hydrology Manual methods, data, and charts are used for this study. The study entitled Preliminary Drainage Study for Major Roads Within The Rancho Carrillo Master Plan, dated January 18, 1993, is the source for offsite flow data for the area south of Village 11 R. 11 Two additional exhibits that are part of this earlier study are enclosed with this report for reference, along with supporting charts and data for the Rancho Carrillo area. 1 I I I I I I I I I I I I I I I I I I I Natural Basin Methodology A nodal system and rational method computer program is used. At node 100, the offsite tributary area, Q100, and time-of-concentration is "user specified" into the computer model. (See January 18, 1993 study and offsite drainage exhibit.) Working downstream from node to node, the time-of-concentration is modeled by approximating the natural channel cross section between nodes and using increasing flows as each tributary area is inserted at the appropriate time-of- concentration. The channel cross section can be approximated by varying the bottom width and side slopes. The basin boundaries and node locations were chosen at approximate grade breaks in the natural channels. A runoff coefficient of C = .45 is used for the natural areas. Ultimate Development Methodology The rational method computer model nodal system is again used here. At node 100, the Q100, acreage and time-of-concentration is inserted from the January 18, 1993 study data. (See node 330.) As the flows are routed downstream through the riparian mitigation channel, (nodes 101 through 104) tributary basins are added using the appropriate time-of-concentration and a single- family runoff coefficient of C = .55. The riparian mitigation channel profile is illustrated below: 1% I I Iv I The actual elevation difference between nodes 1s inserted into the model along with the approximate riparian channel cross section. The ultimate-development drainage basin layout reflects latest village tentative map layouts. 2 I ************************************************************************** RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT 1985,1981 HYDROLOGY MANUAL I I I (c) Copyright 1982-92 Advanced Engineering Software (aes) Ver. 1.3A Release Date: 3/06/92 License ID 1261 Analysis prepared by: RICK ENGINEERING COMPANY IL************************* DESCRIPTION OF STUDY************************** ,..RANCHO CARRILLO RATIONAL METHOD CALCULATIONS * * PARK SITE ULTIMATE DEVELOPMENT TRIBUTARY 100-YR. FLOW * I J .N. 12004G MAY 24, 1993 * ************************************************************************* FILE NAME: A:PARKU2.DAT (::~~~~~=~-~:~~=~~::_:~:~:---~~~~~:::: ____________________________________ _ USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION: [ig;;-;i;-~rE~~-~i~-cRrTERri ___________________________________________ _ USER SPECIFIED STORM EVENT(YEAR) = 100.00 16-HOUR DURATION PRECIPITATION (INCHES) = 2.800 SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00 SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE= .90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED INOTE: ONLY PEAK CONFLUENCE VALUES CONSIDERED ( ************************************************************************** FLOW PROCESS FROM NODE 100.00 TO NODE 100.00 IS CODE= 7 --------------------------------------------------------------------------->>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<< (usi;=sPE~IFIED-VALUEs ARE-As F~LLows~----- TC(MIN) = 13.00 RAIN INTENSITY(INCH/HOUR) = 3.98 I TOTAL AREA(ACRES) = 49.00 TOTAL RUNOFF(CFS) = rt.OflJ1 IJl'Ell1 .; 7i-,C,,ftl//r/ ~fHP, ~/7£,fmO SitJIJ {I /JllJf(; 118. 00 l-16·1/ 3 / Sff NtJl)c **************************************************************************** l~~~;~~;~~;~-~i~~;~~;~;~~~~;i;;=;~~~~~~;~~~~~~~~-=~~~-: ___ : ___________ _ >>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< I DEPTH OF FLOW IN 48.0 INCH PIPE IS 34.5 INCHES PIPEFLOW VELOCITY(FEET/SEC.) = 12.2 UPSTREAM NODE ELEVATION= 343.00 I DOWNSTREAM NODE ELEVATION= 341.00 FLOWLENGTH(FEET) = 200.00 MANNING'S N = .013 ESTIMATED PIPE DIAMETER(INCH) = 48.00 NUMBER OF PIPES= PIPEFLOW THRU SUBAREA(CFS) = 118.00 I TRAVEL TIME(MIN.) = .27 TC(MIN.) = 13.27 1 i*************************************************************************** I F~W PROCESS FROM NODE 101. 00 TO NODE 101. 00 IS CODE = 8 l=>>>>>ADDITION OF SUBAREA TO MAINLIN~-~~AK-~LOW~~~~~----------------------- 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.930 SOIL CLASSIFICATION IS "D" I SINGLE FAMILY DEVELOPMENT RUNOFF COEFFICIENT= .5500 SUBAREA AREA(ACRES) = 5.10 SUBAREA RUNOFF(CFS) = 11.02 TOTAL AREA(ACRES) = 54.10 TOTAL RUNOFF(CFS) = 129.02 I TC(MIN) = 13.27 **************************************************************************** 1-:~~-:~~=~~~-:~~~-~~~~---=~=:~~-=~-~~~~---=~=:~~-~~-=~~~-=---~------------ >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< I 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.930 SOIL CLASSIFICATION IS "D" SINGLE FAMILY DEVELOPMENT RUNOFF COEFFICIENT= .5500 SUBAREA AREA(ACRES) = 5.30 SUBAREA RUNOFF(CFS) = 11.46 I TOTAL AREA(ACRES) = 59.40 TOTAL RUNOFF(CFS) = 140.48 TC(MIN) = 13.27 t ************************************************************************** FLOW PROCESS FROM NODE 101.00 TO NODE 102.00 IS CODE= 51 l >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< >>>>>TRAVELTIME THRU SUBAREA<<<<< UPSTREAM NODE ELEVATION= 341.00 I DOWNSTREAM NODE ELEVATION= 325.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 300.00 CHANNEL SLOPE= .0533 CHANNEL BASE(FEET) = 40.00 "Z" FACTOR= 2.000 I MANNING'S FACTOR= .030 MAXIMUM DEPTH(FEET) = 5.00 CHANNEL FLOW THRU SUBAREA(CFS) = 140.48 FLOW VELOCITY(FEET/SEC) = 6.98 FLOW DEPTH(FEET) = .49 I TRAVEL TIME(MIN.) = .72 TC(MIN.) = 13.99 **************************************************************************** 1-:~~-:~~=~~~-:~~~-~~~~---=~~:~~-=~-~~~~---=~~:~~-=~-=~~~-=---~------------>>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< I 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.799 SOIL CLASSIFICATION IS "D" SINGLE FAMILY DEVELOPMENT RUNOFF COEFFICIENT= .5500 I SUBAREA AREA(ACRES) = 14.40 SUBAREA RUNOFF(CFS) = 30.09 TOTAL AREA(ACRES) = 73.80 TOTAL RUNOFF(CFS) = 170.57 TC(MIN) = 13.99 I************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 103.00 IS CODE= 51 l >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< >>>>>TRAVELTIME THRU SUBAREA<<<<< UPSTREAM NODE ELEVATION= 325.00 I DOWNSTREAM NODE ELEVATION= 300.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 400.00 CHANNEL SLOPE = . 0625 I CHANNEL BASE(FEET) = 30.00 "Z" FACTOR= 2.000 I MANNING'S FACTOR= .030 MAXIMUM DEPTH(FEET) = 5.00 CHANNEL FLOW THRU SUBAREA(CFS) = 170.57 I FLOW VELOCITY(FEET/SEC) = 8.77 FLOW DEPTH(FEET) = TRAVEL TIME(MIN.) = .76 TC(MIN.) = 14.75 .62 ' *************************************************************************** FLOW PROCESS FROM NODE 103.00 TO NODE 103.00 IS CODE= 8 ---------------------------------------------------------------------------->>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< I 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.672 SOIL CLASSIFICATION IS 11 D11 I SINGLE FAMILY DEVELOPMENT RUNOFF COEFFICIENT= .5500 SUBAREA AREA(ACRES) = 3.00 SUBAREA RUNOFF(CFS) = 6.06 TOTAL AREA(ACRES) = 76.80 TOTAL RUNOFF(CFS) = 176.63 TC(MIN) = 14.75 l*************************************************************************** FLOW PROCESS FROM NODE 103.00 TO NODE 103.00 IS CODE= 8 1-;;;;;i~~i;io;-o;-~~B~ii-;~-~i;ii;i-~iii-;i;;~~~~~----------------------- 100 .YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.672 I SOIL CLASSIFICATION IS 11D11 SINGLE FAMILY DEVELOPMENT RUNOFF COEFFICIENT= .5500 SUBAREA AREA(ACRES) = 8.50 SUBAREA RUNOFF(CFS) = 17.16 I TOTAL AREA(ACRES) = 85.30 TOTAL RUNOFF(CFS) = 193.79 TC(MIN) = 14.75 I *************************************************************************** FLOW PROCESS FROM NODE 103.00 TO NODE 104.00 IS CODE= 51 ---------------------------------------------------------------------------->>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< I >>>>>TRAVELTIME THRU SUBAREA<<<<< UPSTREAM NODE ELEVATION= 300.00 I DOWNSTREAM NODE ELEVATION = 263. 00 CHANNEL LENGTH THRU SUBAREA(FEET) = CHANNEL SLOPE= .0822 450.00 I I CHANNEL BASE(FEET) = 30.00 "Z" FACTOR= 2.000 MANNING'S FACTOR= .030 MAXIMUM DEPTH(FEET) = 5.00 CHANNEL FLOW THRU SUBAREA(CFS) = 193.79 FLOW VELOCITY(FEET/SEC) = 9.99 FLOW DEPTH(FEET) = TRAVEL TIME(MIN.) = .75 TC(MIN.) = 15.50 .62 **************************************************************************** 1-:~~:~~;~~;-;~;;~~~~ii-~~;~i=;i;~~~~:=~~:~~-=~-~~~~-=--~=------------ >>>>>TRAVELTIME THRU SUBAREA<<<<< I UPSTREAM NODE ELEVATION= 263.00 DOWNSTREAM NODE ELEVATION= 256.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 300.00 I CHANNEL SLOPE = . 0233 CHANNEL BASE(FEET) = .00 "Z" FACTOR= 5.000 MANNING'S FACTOR= .030 MAXIMUM DEPTH(FEET) = 5.00 CHANNEL FLOW THRU SUBAREA(CFS) = 193.79 I FLOW VELOCITY(FEET/SEC) = 7.95 FLOW DEPTH(FEET) = TRAVEL TIME(MIN.) = .63 TC(MIN.) = 16.13 2.21 I l~*:*********************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE= 8 [;;;;;~~~i~i;N-;;-~~;~;~-;;-~i;ii;;-;;~;-;~;~~~~~----------------------- 100 YEAR RAINFALL INTENSITY{INCH/HOUR) = 3.466 I *USER SPECIFIED(SUBAREA): RURAL DEVELOPMENT RUNOFF COEFFICIENT= .5000 SUBAREA AREA(ACRES) = 6.20 SUBAREA RUNOFF(CFS) = 10.74 l TOTAL AREA(ACRES) = 91.50 TOTAL RUNOFF{CFS) = 204.54 TC(MIN) = 16.13 END OF STUDY SUMMARY: l PEAK FLOW RATE(CFS) = TOTAL AREA(ACRES) = 204.54 91.50 END OF RATIONAL METHOD ANALYSIS I I I I I I I I I I I I I I Tc(MIN.) = 16.13 '~*:************************************************************************ FLOW PROCESS FROM NODE 100.00 TO NODE 101.00 IS CODE= 8 1--------------------------------------------------------------------------->>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.045 I SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT= .4500 SUBAREA AREA(ACRES) = 13.20 SUBAREA RUNOFF(CFS) = 24.03 I TOTAL AREA(ACRES) = 28.50 TOTAL RUNOFF(CFS) = 64.03 TC(MIN) = 12.69 ' ************************************************************************** FLOW PROCESS FROM NODE 101.00 TO NODE 102.00 IS CODE= 51 >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< L>>>>>TRAVELTIME THRO SUBAREA<<<<< UPSTREAM NODE ELEVATION= 330.00 DOWNSTREAM NODE ELEVATION= 300.00 I CHANNEL LENGTH THRO SUBAREA(FEET) = CHANNEL SLOPE= .0600 500.00 CHANNEL BASE(FEET) = 50.00 11 Z11 FACTOR= 2.000 /J,P.!21<.'0X! /)h'rE /1//11//;tlfr_ f#-1i/111ct .f cf!T/tJl!J ,, <;trJ;:Jc I MANNING'S FACTOR= .030 MAXIMUM DEPTH(FEET) = 3.00 CHANNEL FLOW THRO SUBAREA(CFS) = 64.03 FLOW VELOCITY(FEET/SEC) = 4.94 FLOW DEPTH(FEET) = .26 TRAVEL TIME(MIN.) = 1.69 TC(MIN.) = 14.38 I **************************************************************************** t;~;;~~~i;~~;:~;~;~~~ii-~~~~~;~i;i~~~ii-;~~;~~:~~-~~~~-=---~------------ I 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.732 SOIL CLASSIFICATION IS "D" RURAL DEVELOPMENT RUNOFF COEFFICIENT= .4500 SUBAREA AREA(ACRES) = 8.40 SUBAREA RUNOFF(CFS) = 14.11 I TOTAL AREA(ACRES) = 36.90 TOTAL RUNOFF(CFS) = 78.14 TC(MIN) = 14.38 ' ************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 102.00 IS CODE= 1 t >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< TOTAL NUMBER OF STREAMS= 2 CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE: I TIME OF CONCENTRATION(MIN.) = 14.38 RAINFALL INTENSITY(INCH/HR) = 3.73 TOTAL STREAM AREA(ACRES) = 36.90 PEAK FLOW RATE(CFS) AT CONFLUENCE= 78.14 '*************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 201.00 IS CODE= 21 f;;;;;AA;i;;;i-;E;~;~-i;iiiii-;u~~;;-~iii;i;::~~~------------------------ SOIL CLASSIFICATION IS "D" I RURAL DEVELOPMENT RUNOFF COEFFICIENT= .4500 NATURAL WATERSHED NOMOGRAPH TIME OF CONCENTRATION WITH 10-MINUTES ADDED= 12.17(MINUTES) I INITIAL SUBAREA FLOW-LENGTH= 650.00 I UPSTREAM ELEVATION= 544.00 DOWNSTREAM ELEVATION= 420.00 I ELEVATION DIFFERENCE= 124.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = SUBAREA RUNOFF(CFS) = 13.28 4.157 I TOTAL AREA(ACRES) = 7.10 TOTAL RUNOFF(CFS) = 13.28 **************************************************************************** ' -:~~-:~~=~~~-:~~~-!~~~---~~::~~-=~-!~~~---=~~:~~-=~-=~~~-=--~: ___________ _ >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<< >>>>>TRAVELTIME THRU SUBAREA<<<<< I UPSTREAM NODE ELEVATION= 420.00 DOWNSTREAM NODE ELEVATION= 300.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 1000.00 IJ/J;J1!J't//t11i'f"(; ;:J/;-:-t,121:J(,, tJ/ll/11///Cl $ce'~1//J' \:; t!.tJ/c I CHANNEL SLOPE = .1200 CHANNEL BASE(FEET) = .00 "Z" FACTOR= 3.000 MANNING'S FACTOR= .030 MAXIMUM DEPTH(FEET) = 3.00 CHANNEL FLOW THRU SUBAREA(CFS) = 13.28 I FLOW VELOCITY (FEET/SEC) = 8. 36 FLOW DEPTH(FEET) = TRAVEL TIME(MIN.) = 1.99 TC(MIN.) = 14.16 .73 I*************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 102.00 IS CODE= 1 I >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<< >>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< I TOTAL NUMBER OF STREAMS= 2 CONFLUENCE VALUES USED FOR INDEPENDENT TIME OF CONCENTRATION(MIN.) = 14.16 RAINFALL INTENSITY(INCH/HR) = 3.77 STREAM TOTAL STREAM AREA(ACRES) = 7.10 I PEAK FLOW RATE(CFS) AT CONFLUENCE= 13.28 ** CONFLUENCE DATA** I STREAM RUNOFF NUMBER (CFS) 1 78.14 2 13.28 Tc (MIN.) 14.38 14.16 INTENSITY ( INCH/HOUR) 3.732 3.770 2 ARE: AREA (ACRE) 36.90 7.10 I RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO CONFLUENCE FORMULA USED FOR 2 STREAMS. I ** PEAK STREAM NUMBER I ~ FLOW RATE RUNOFF (CFS) 90.64 91.29 TABLE** Tc (MIN.) 14.16 14.38 INTENSITY (INCH/HOUR) 3.770 3.732 COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS: I PEAK FLOW RATE(CFS) = 91.29 Tc(MIN.) = TOTAL AREA(ACRES) = 44.00 14.38 I*************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 102.00 IS CODE= 8 I >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<< 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.732 SOIL CLASSIFICATION IS "D" I RURAL DEVELOPMENT RUNOFF COEFFICIENT= .4500 I t I·· ~· I ~ ~ ~· ~ ~ ~ I I I I ~ I ' ~ .. ~.; APPENDIX A: RATIONAL METHOD BACKUP CHARTS