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Home My WebLink AboutCT 01-16; CASA LAGUNA; DRAINAGE REPORT; 2002-09-22E taca. civu. EMGHOEERING BY: ^.l-.^. 1014 West Washington st SanOiego, CA. 92103 (619) 2g&3183 Fax: (61^ 29&6180 PROJECT NAME: C/iSA y^A^CWA SUBJECT 1P/^y)//y/ly•,<5 i^ePOJZT /^/? cr o/-/(a APPROVED BY: E.LR. 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CIVU- EMGINEERIMG 1014WestM^sMr^St SanOiego, CA. 92103 (819) 29&3183 Fax: (61^ 2986180 SUBJECT ZPy^/^/Ajgy-D/B ^PBT^Wr BY: APPROVED BY: JOB NO.: o2'yoy3 E.LR. SHEET ^ OF _ DATE: '51/22/02 PROJECT NAME: Qy^^yi ^^<^CJ/(Z4 /=07Z Cr O/^ /rjo A ^ AC. C ^ 0.^6 H ' -^6,^ - 40.Z « (a.io fr. ^ OAy- •5>/r^ EWCCLCMLEMGIMEERIMG BY: 7^ SHEET ^ OF ^ 1014West Washington St SanOiego. CA. 92103 APPROVED BY: E.LR. DATE: '^/22/OZ (81^2g&3183Fax: (81^ 2988180 JOB NO.: O^- /0/3 PROJECT NAME: <^A5>A A.AGU/^A SUBJECT ZPyPA//^A^<^ J?rSPO/?r rOJ2 cr 0/-/Ci:, Fypojear ccAJt5>/37^> or ry^^ CoAj^T/PuQT/o/y or (a - vupy.£)<' yZ^S/Vr^yjai^"^ (/? ao/jZPOM/AJJU/yi^ ) y)fuv /^u/LP//ub pui -v^. -^y^c r^^y^/L/yPT^ 72oA)v. y/y^^r or a/)^/^ Py2o/po^ep COA/iPOAyi/Ay/uA^ 3o/y,7?y^yG oo/u Py?A)yyy TV^^/ZPS 77yy= f^/2/uy)re iZoAV^ryy^ oryy^/z y/y)L/= yo/u vy2A)yyy ro &^CH V^/2P^ v^N£f^s 7?y£ yv^T^TZ. ^:o/^^. p/y>/<:^c> uy^' y^/r/^ Oy)rc/y ^y^^/^y^ y)K>v £>7vyzAyi vym/yJ p/P^s -r^y^r ^/iL 7d>a aoAJyjSdrrsv rv TT/B poj3y/e ^ro/Fy^ TPy^ypy^u €py5>rByy}, py)Cjr/c G€/)ST <]/iy/L,//^a. QfiLOutyiT&D ^To/zy)6}e yoy.uyy)a5 1^072 /O-vy?, (a-y/oufz ^royzA/i yi/uv yi/ze i^eyyjb /AJOo/^fibpyrr&p p^/zr or 77y/^ /2ePO/2r. 2?/7/^/xy/?6<^ tfyy2cjc7u/2a^ i^/u id^s ey)LQuL/)rBD os^/oO ry/^ /o-vrz -^ropAA A)/</o /) 'puAjoFF Qo^rF/Q/£Ajr- or o.~?o . "S/A/CE /T /6 -p^^Z/ZATiLB TO 570rZ^ OJfiT-&/2 ^ (Si - 3.70 QrS /$ P'yiciL/r/^^, EWCCtCIWLEMGIMEERIMe BY: SHEET 4 OF j£_ 1014 West Washingbxi St San Oiego, CA. 92103 APPROVEO BY: E.LR. DATE: ^/TIB/O'Z. (81^ 29&3183 Fax: (81^ 2988180 JOB NO.: 02- /'0/3 PROJECT NAME: CA5A I. A(^7UAJA SUBJECT 7Py?A)/A/A)(b^ 72^5Po^r y^/2 cr o/-/<£, /-/voy^^u^./CS Or- 2y?3 Qyz2 O.OS /^^ ' O.04 /?C. ^ ^'^^ ^ yii^ (3.7d) ^ O /Z drs A,-2,' o o^ Aic ^ 'oQ^c^.-po) oJ(o on . o.cb ^^^^ ''^cS'-yo) - 0.2'^er<^ - 0^' 7-2,70)-' y:>,34cr^ I^/JS- ' 0-03 ^ ^ - O.03 /3.70) ^ o.O'^or'^ ERiCCL CIVIL EMGiNEERIMG BY: y.. "TF SHEET _^ OF 1014WestWashingtonSL SanOiego, CA. 92103 APPROVEO BY: E.L.R. DATE: '^/2^0^ (61^ 2963183 Fax: (61^ 2968180 JOB NO.: 02-y0/3 ^^y- /O/^o/O-Z. PROJECT NAME: 07)5^) lyk^UAJ/^ ^O/^O/oZ SUBJECT i^/pA/Ajnip^ TZBPo/zr rorz dr o/^//„ Oi-i-ciz^ ^3 -f-O^ -^^^-^^(a^ 2.3^-ta/z7/jz+o,/2-fo.i2iaze '3e>'' >y O.3. T^^^fT (a ^ )(^ )/3>o) - e>.o rr - (C.^)(0.5)(^.oX'i6)- '2,2^rT'^ ^ ^ 4M 0. 7S f^^^ (a-O Cu/23 (h) APr^./£S O ^ 4^ -^zos \ ^.37//'^z hh \p.^_^'\\o.6?2' yQ^FP ^,2S ^ ^ ^072^X^37)} -3^" X 3Co (O/) ry^y/ S7)S/AJ /i-p^ (3/0'?^ r /5./3 Or% /6''/)V'S. (S /.o% /<> /)^^u/^rE ERICCLCIVILEWGIMEERIMG BY: ^,7^.17. SHEET_^ OF 1014West Washington St SanOiego, CA. 92103 APPROVEO BY: E.LR. DATE: '^/Ziy/O^ (61^ 2963183 Fax: (81^ 2968180 JOB NO.: 02' /O/^ /^£iy: 'O //9 /OZ PROJECT NAME: <^/^iS/^ yAJSCJAjA SUBJECT TPyP/Q/tuA)/^^ 72(sPO/?r rop. dr o/^p^ dia- •'h Q.n ' 0.06 A - /'"^^ Qrs 70 p7Z/uy)r6 <,r. Ou/7^/;,o7/e72 y^/ov 'b^" s^ALik y^/u /'/y)/opi^ 7=^7.0• /^oj^eT:? B-yyjcar yyj 6/Qd>u/jyo TPTZ. ^/CC ^/d/^y u7^ z-'^'? dr^. ^/2^^l3,^,^L,^/^A /6 Q/z ^ •t^/4 ^^/-^ ^^/c> = o./iis' -f-o.z^-/OM mo'd •/o.7<h - /.OO crs ;^//.d- 7,0 ^r ^^<? (o.2o)(o.^5)(o./o) . o.^y Cr^ .•. soM^ Pb/<jt?/Aj(=> ^" ^'^^^ , y^/^c odcu/7 ^or /T /5 p&s//?A/^ce 5TINC I IS WITH ERATE CROUP C SOILS HAVING SLOW INFILTKAnON RATES WHEN THOROUGHLY WETTED, CONSISTING CHIEFLy OF (1) SOILS WITH A lAVER THAT IMPEDES THE DOWNWARD HOVEMENT OF WATER, OR (2) SOILS WITH MflOERATELY FINE TO FINE TEXTURE ANO A SLOW INFILTRATION RATE. THESE SOILS HAVE A SLOW RATE OF WATER TRANSfaSSION. GROUP D SOILS HAVING VERY SLOW INFILTRATION RATES WHEN THOROUGHLY WETTEO, CONSISTING CHIEFLY OF (I) CIAY SOILS WITH A HIGH SWELLING POTENriAL: (2) SOILS WITH A HIGH PERMANENT WATER TABLE; (3) SOILS WITH CLAY BAN OR CLAY LAYER AT OR HEAR THE SURFACE: AND (<4) SHALLOW SOILS OVER NEARLY IMPERVIOUS MATERIALS THESE SOILS HAVE A VERV SLOW RATE Of WATER TRANSMISSION. LAND USE RUNOFF COEFFICIENTS (RATIONAL METHOD) Coefficient, C Soil Group (1) A B C Undeveloped .30 .35 .40 Residential: .Rural .30 .35 .40 Single Family .40 .45 .50 Multi-Units .45 .50 .60 Mobile Homes (2) .45' .50 .55 Commercial (2) 80% Impervious .70 .75 .80 Industrial (2) 90% Impervious .80 .85 .90 .45 .45 s .65 .85 .95 NOTES: (1) Obtain soil group from maps on file with the Department of Sanitation and Flood Control. (2) Where actual conditions deviate Significantly from the tabulated imperviousness values of 80% or 90%, the values given for coefficient C, may be revised by multiplying 80% or 90% by the ratio of actual imperviousness to the tabulated imperviousness. However, in no case shall the final coefficient be less than 0.50. For example: Consider commercial property on D soil group. Acttial imperviousness = 50% Tabulated imperviousness = 80% Revised C = |^ x 0.85 = 0.53 APPENDIX IX // V £Quy?r/OA/ 7e » TTme o7 co/7ce/7/rgt//orT I » Le/tg/A o/ Moyer^Aed // ' />//7S!re/7ce //? a7eva//an a/onff e/fffcy/re s/oo4s///re (See Aflpem/tXX-B) .r- I ^ M/7as Fise/ y/ouAsX /ia//fa/ea 4—I—e40 SAN DIEGO COUNTY DEPARTMENT OF SPECIAL DISTRICT SERVICES DESIGN MANUAL APPROVED 7/ 7ylry^A^^ jyr^ NOMOGRAPH FOR DETERMINATTON OF TIME OF CONCEhffRATION (Tc) FOR NATURAL WATERSHEDS DATE AM? I APPENDIX X-A lV-A-10 Rev. 5/81 ?0 n < M n (3. 00 tn COUNTY OF SAN DIEGO DEPARTMENT OF SANITATION FLOOD CONTROL lO-YEAR 6-HOUft PRECIPITATION -16- ISOPLUVIALS PRECIPITATIOfI IN OF iq-YEAR EfJTIIS OF AM INCH a X X P«pJr»d by > U.S. DEPARTMElir OP COMMFRPP ^5' 30' Rftvised 1/85 APPENDTX YT-r < (A : a. COUNTY OF SAM OIEGO . ?. n^J"^?!^^ SANITATIOM ^ FLOOD CONTROL ^5' 10-YEAR 24-HOU'R PRECIPITATION "20^ ISOPLUVIALS PRECIPITATIOn IN )F 10-YEAR 24-HOUR ENTHS OF AN INCH Pr«pi|r*d by U.S. DEPARTMErfT OF COMMERCE .»»,.... "^TrONAL OCEANIC AND AT .lOSPIIERIC ADMINISTPATIOM SPECAt STUDIES BRANC... OKP.CE OP . VDROLOCV.^A^NirJilATHH SERVICE 30" Revised 1/8."? 15' 116' ADDCMnrv VT INTENSITY^-DUWION DESIGN CHART ITrlTIIUiilil i J-J-i "'• niiiimiiiiiiihiN. r . T ni.u.mj.-Hmirhn -.645 10 15 20 Minutes 40 50 1 Duration Directions for Application: 1) From precipitation naps determine 6 lir. and 24 hr. amounts for tiie selected frequency. Tiiese maps are printed In tiie County Hydrology Manual (10, 50 and 100 yr. maps Included In the Design and Procedure Manual). 2) Adjust 6 hr. precipitation (If necessary) so that It Is within the range of 45% to 65% of the 24 hr. precipitation. (Not npplicable to Desert) y 3) Plot 6 hr. precipitation on the right side of the chart. 4) Draw a line tiirough the point parallel to the plotted lines. 5) This line Is the intensity-duration curve for the location being analyzed. Application Form: 0) Selected Frequency /O yr. 1) Pe " / ^ in.. P24» 3.7 . *Pg « ^S%* 2) Adjusted *Pg« / 7 3) t^ » _ -^-^^ min. 4) 24 in. I ^•S^ in/hr. *Not Applicable to Desert Region Revised 1/R'i Annnxinrv vr A 1073.02 Ol .2 .9 .4 .9 .•.7.9.9L0 C > 4 > 0 7 0 0 10 C3 8UREAU OF PUBLIC ROADS CAPACITY OF GRATE INLET IN SUM? DIVISION TWO WASH, O.C WATER PONDED ON GRATE Casa Laguna Preliminary Hydrology and Detention Calculations Carlsbad, Califomia 3/08/02 PREPARED FOR: PREPARED BY: LAGUNA CARLSBAD LLC 31225 La Baya Drive, Ste 103 Westlake Village, CA 91362 (818) 991-1040 PACIFIC COAST CIVIL, INC. 30141 Agoura Court, Suite 200 Agoura Hills, CA 91301 -4311 (818) 865-4168 Page 1 of 2 Randall A. Greenwood From: "Randall A. Greenwood" <rag@pacificcoastcivil.com> To: "John Maashoff' <jmaas@ci.carisbad.ca.us> Sent: Friday, March 08, 2002 5:05 PM Subject: Re: Storm Drain at Casa Laguna Project John, We've prepared some prelinninary liydrology calculations for this project and have concluded the following: The 10-year, 6-hour stonn is the control in designing the detention. Using the side yard area bounded by the walkway to Unit 1, the driveway, Laguna Drive and the wall at the easterly boundary, and the 18" HDPE storm drain pipe, there is sufficient storage to limit the outflow from the development to predevelopment conditions. The catch basin (C.B.#2) adjacent to Unit 1 will have a top of grate elevation of 40.0', which will allow ponding in this turf area up to 0.5'. Water ponding higher than 40.5' will flow back out into the driveway and/or over the street right of way and into the proposed catch basin (C.B.#3) in Laguna Drive. Unit 1's finished floor elevation is 42.9', so it will not be impacted by this detention. Detention will occur by the installation of 2-4" diameter HDPE pipes between C.B.#2 and C.B.#3, which limit the outflow to pre-development conditions. Note that C.B.#1 (serving the adjacent lot) has a top of grate elevation of 41.1', so no ponding will occur in this property as a result of the detention on this lot. Some of the data supporting this design Is as follows: P6 =1.7 in. 1=4.48 in./hr. A=1.18ac. c(undeveloped)=0.33 c(developed)=0.70 Q(undeveloped)=1.74 cfs Q(developed)=4.48 cfs Detention volume required: 749.5 cf Detention volume provided: 942.4 cf Maximum outflow from 2-4" pipes is 1.73 cfs. Developed Q was calculated using the County's single hydrograph form and detention storage computation worksheet. P24=2.9 in CN(undeveloped)=78 CN(developed)=90 Q(undeveloped)=0.4 cfs Q(developed)=0.5 cfe Developed Q was calculated using the County's peak flow computation 3/8/02 Page 2 of 2 worksheet and by using the hydrograph method and both yield the same result. My calculations are preliminary In the sense that they are not accompanied by final design plans. I will forward them to you for review on March 11. Based upon these calculations and proposed storm drain design, runoff from this development will not exceed predevelopment conditions. Randy Greenwood Pacific Coast Civil 818-865-4168 3/8/02 3 Current Map -117*21'OS-. 33' Map Image Created Using Precision Mapping Streets * .0 Copyright 1999. Chicago Map Cofporabon COUNTY OF SAN DIEGO DEPARTMENT OF SANITATION & FLOOD CONTROL 10-YEAR 6-KOUll PRECIPlTATSOfi 33" I^- ISOPLUViALS OF lO-YEAR G-!i3Un PRECIPITATIOij IFJ TEfJTHS OF AN INCH NATIONAL OCEANIC AND AT SPECIAL STUDIES DRANCH, OFFICE OF U.S. DEPARTMEN^T OF COMMERCE I 30' 'lOSIMIERIC ADMINISTRATION I VDROLOOY. NATIONAL WEATHER SERVICE 16' COUNTY OF SAN DIEGO . DEPARTMENT OF SANITATIOfi & FLOOD CO.NTROL 10-YEAR 24-HOuk PRECIPITATION^ -20.x ISOPLUVIALS pF 10-YEAR 24-HOUR PRECIFiTATIOn KJ i-e EfJTHS OF AN luCH 33' • Prep. U.S. DEPARTMEr NATIO.VAL OCEANIC AND AT SPECIAL STUDIES DRANCII. OKPICE OK 1 (YDKOLOGY, NATIONAL WEATHER SERVICF 30 I > I o INTENSITY-DUKAmiN DESIGN CHART > 10 15 20 Minutes 30 40 50 1 Ouv*Atfon Directions for Application: 1) From precipitation naps determine 6 hr. and 24 hr. amounts for the selected frequency. Tiiese maps are printed in the County Hydrolog; Manual (10, 50 and 100 yr. maps included in ti Design and Procedure Manual). 2) Adjust 6 hr. precipitation (if necessary) so that it is within the range of 45% to 65% of the 24 hr. precipitation. (Not npplicable to Desert) 3) Plot 6 hr. precipitation on the right side of the chart. 4) Draw a line through the point parallel to the plotted lines. 5) This line is the intensity-duration curve for the location being analyzed. Application Form: 0) Selected Frequency 1) Pfi° 1-7 in.. Po,= _L2 .5^ %* 2) Adjusted *Pg 3) t^ = _^ 4) 1 24 in. min. I = iM6 in/hr. *Not Applicable to Desert Region Revised 1/85 APPENDIX XI-A 03/01/2002 11:18 FAI ©052/054 DETENTION STORAGE COMPtrTATION PROCEDURE SINGLE HYDROGRAPH FORM I Input Variables (Urban Conditions) \oirSix hour precipitation amoxmt (inches) |.7 Time of concentration (min.) b coefficient of runoff C .70 Basin area (acres) A (. |fi Computgition Time to peak Tp = 2.0T^o/(l + Kp) = 1.1072T, -fUolLYr:) T 5.33 Time of hydrograph to begin ' TB = 20 - T, . T, mi Txme of hydrograph to end TE = 20 -h 1.5 T,--^ot0.5>5-53) TB ^h30 5. = 7.44 VT,°- = H.Hfe in./hr. ^ -^JOct3 Surrounding flow (Qj) Depth of precipitation for 2 hours Dia, = 7.44 Ff/120'^^(2 hr.) D120 = 0.6785 P( = \-\5 in. M Depth of precipitation for hydrograph DH = (P,Tfi^)/5.S3 = 0.52. in, Surrotinding Intensity Is = 60(0,20 - .DH)7(120^- 2.5TJ to(|.15-.5I>f j-2,5(5)) Is = ^'•7:> m./hr. ^ Qs « CIjA r C-7oX.3>s)(;iiife) Plot Hydrograph and Surrounding Flow Outflow / Basin Size (Natural Conditions) Outflow c = '33> T. = 5 jain. I = 7.44 P«/T.«f« ="Z3351 in./hr. (TM^Xn/s^''^^ Q„ = CIA C33Xq.Mg)a I&) /.7^ 1. Plot on Hydrograph a. Draw line from surrounding flow intercept with beginning hydrograph limb to <^ 2. Estimate volume needed for reservoir a. Determine preliminary reservoir dimensions b. Surrounding flow discharges directly through reservoir without detaining any storage 3. size outlet works a. Outlet flow, Q, less than or equal to b. Stay within the limits of the reservoir 4. Rout a. Refine reservoir dimensions and/or outflow facility PACIFIC COAST CIVIL, INC. II 30141 AGOURA COURT, SUITE 200 AGOURA HILLS, CA 91301-4334 PH: (818) 865-4168 FAX: (818) 865-4198 DATE PROJECT ENGINEER 6 SHEET NO. O. OF WORK ORDER CHECK BY i 1 1 : ! — ; 1 — 1 1 — — — — 1 1 — — I i 1 ' 1 i j 1 ; ! ! ! 1 ' 1 9 ! 1 1 i 1 ! 1 1 1 ! i i 1 _* ((. \ I O ! r 5 • 7o - M »^ 1 :^ h fx \ \ Oir •V . 1. 5.- > Do )(l F —— 7 ( 1 Q 1 i 17 ^ \ N \ \ ^ ^^ \ 1 K V \ \ \/ \ •4 1. / \ \ \ \ ( : \ > ^ '— ( K •> z > 0 T F( Mb ) Tp ^— ^ -w n 1 1 j ! ! 1 1 / 1" . 1 lOi » In = ( i 1 i A Y i 1 ! 1 i A '/ i 1 1 i 1 y i 1 i 1 i ; i ; ! ' i 1 1 1 1 : j ' 3 ^4T3 , Q- ew o o ^ o - o 37.3 0.% +Q36 ^•0 LOb storage ^blcs? -f©^ D&lcnti'on /\rta i>e"t>een U^it L uJolk^vl ^ potto r/y./: log6 B(b3F T(l^ ^ C(3ii3 be <=^t ^o.^ ^ uoKick 13 o.s' Iccoer tk*^ du:>a^j Stof^in C&^Z ' (3'y3'X^o:o-3S.6>37.8cF To^l %3rog(i: ^q.2& + 3M7.W+37.8+ 9H^.a?5 6F ^ W3cf ORAVJ . Ccunuted by: |2ai^^ GmrixllA^'-'' II DEPARTMENT OF SANITATION AND F{/>00 CONTROL S.^N PI EGO COUNTY 1. 2. 3. PEAK FLOW COMPUTATION WORKSHEET (For use with Peak Flow Charts; Westem Drainage, Precipitation Zones 1.0 to 5.5 only.) REFERENCE IN | Basin Nane Ca^jQ- (jQlOjU KL. HYDROLOGY 1 ~ MANUAL Sec. IV-A Fig. I-A-2, p. I-A-23 Sec. II-B 4. Sec. I-A, p. I-A-16 S. Sec. II-A Fig. II-B-2a, p. II-B-4 Sec. I-B , Sec. I-C Storm Frequency square m.iles. Geographic location of center of basin: Long. \\Yt-[' Lat. p^°\o' lo year. Basin Area .OOZ. PZN = 1.0 1.1 2.0 3.0 _ 4j. ' 1.5 Pi'ecipitation Zone Number (PZN) Antecedent Moisture Condition (interpolate basin AiMC A^5C (35-150yr) - 2_^ for basin PZN) AMC ( 5-35 yr) = 1_^ \.S 2.5 — 2.0 3.0 3.0 CN ^ CN3 Runoff QxxTVQ Numbers (3<2 (interpolate basin CN for basin AMC; CN2 and CN3 are for AMC's = 2 and 3) Precipitation for Storm Duration: 6 hr (P^) |-7 inches 24 hr (P24) ZP) inches P5 X = inches P',4 X Pv^ = inches Area Rainfall Reduction Ratio (R^.) (for areas greater than 2.-2.2.ir/Niri Enter Peak Flow Charts with T^, (For Tpa<Tpb) 8a. From Peak Flow Charts: T, For 10 sq. mi. basin : Tp 8b. From Peak Flow Charts: T, Time to Peak (Tp) . 037 hours (T = 0.862 x Lag time) b^-'^'^'^[—f= n = 0.01b L =.0(p55mi. L =.037S mi. S = S>SaA ft/mi. P5 and P24; select two nearest Tp's available: 6 hr storm 24 hr storm Qa6 3050 cfs Qa24 c£s Q'fi . cfs Qb6 cfs pa pb hr hr hr Qb6 Tpb - Tp (Qa6 - Qb6) Tpb - Tp -_Tpb • "^pa Q'24 Qb24 cfs cfs Qb24 + (Qa24 - Qb24) Tpb - Tpl _Tpb - Tpa 10. t 12. 13. Greater of <l\ and Q'24 , for 10 sq. mile basin, (Q* ) = IJ^SO cfs Basin Area Ratio (Ra) = (basin area) / (10 sq. miles) = • QOPlfH^ Peak Flow (Qp) = (Q'(^ ) x (Rg) = 0.^9 cfs SUMMARY : PCAK FLOW OM'^ cfs , F.HHQUCNCY /Q year , DURATION hr XL CASA U\GUNA PROJE^^ - Developed Conditions , . 10-YEAR, 24 HOUR STORM - B DISTRIBUTION AREA — AREA: 1.18 BASE FLOW: 10.12 P24: 2.9 CN: 90 S: 1.111 Ia = 0.2S = 0.222 i ; ' ' ^ i ^ : 1 2 3 4 5 6 7 8 9 TIME P/P24 P PDELTA I Q QDELTA QDELTA/ QA (Hr.) (In.) (In.) (In/Hr.) (In.) (In.) PDELTA cfe 2.0 1 0.034 0.099 : 0.015 1 0.058 0.058 \ 0.011 0.20 0.2 3.0 0.054 0.157 0.004 1 1 i 0.067 0.067 0.004 0.06 0.1 4.0 0.077 0.223 0.000 0.078 0.078 0.005 0.07 0.1 5.0 0.104 0.302 0.005 0.096 0.096 0.019 0.19 0.2 6.0 0.137 0.397 0.024 0.058 0.116 0.017 0.29 0.2 6.5 0.157 0.455 0.040 0.067 0.133 0.023 0.35 0.2 7.0 0.180 0.522 0.064 0.087 0.174 0.036 0.42 0.2 7.5 0.210 0.609 0.100 0.131 0.261 0.064 0.49 0.3 8.0 0.255 0.740 0.164 0.194 0.389 0.113 0.58 0.3 8.5 0.322 0.934 0.278 0.255 0.510 0.172 0.67 0.4 9.0 0.410 1.189 0.450 0.278 0.557 0.208 0.75 0.4 9.5 0.506 1.467 0.658 0.238 0.476 0.190 0.80 0.5 10.0 0.588 1.705 0.848 0.119 0.238 0.098 0.82 0.5 10.5 0.629 1.824 0.946 0.078 0.157 0.066 0.84 0.5 11.0 0.656 1.902 1.011 0.067 0.133 0.056 0.85 0.5 11.5 0.679 1.969 1.068 0.061 0.122 0.052 0.85 0.5 12.0 0.700 2.030 1.120 0.058 0.116 0.050 0.86 0.5 12.5 0.720 2.088 1.169 1 ! i 0.055 O.I 10 1 0.048 0.86 0.5 13.0 0.739 j 2.143 1.217 I 1 j ! 0.049 0.099 0.043 0.87 ; 0.5 13.5 0.756 j 2.192 ; 1.260 1 13 I 2 3 4 5 6 7 8 9 TIME (Hr.) " 13.5 P/P24 " 0.756 P (InT) 2.192 PDELTA 1 " (In./Hr) Q (In.) 1.260 QDELTA QDELTA/ PDELTA QA cfs 0.046 "0.093 0.040 0^87"""^ 0.5 14^0 ~" " 0.772" 2.239 1.300 0.041 0.081 0.036 0.88 0.5 14.5 ^ 0.786 2.279 1.336 0.041 0.081 0.036 0.88 0.5 15.0 0.800 , 2.320 1.371 0.046 0.093 . 0.041 0.88 0.5 15.5 0.816 2.366 1.412 \ 1 i 1 : 1 j i j 1 1 Column 1-Time Intervals, in hours i 1 Column 2-Precipitation Ratio per Table II-B-2, San Diego Countv Hvdroloev Manual Column 3-RainfaII Depth, in inches (P24 x Col. 2) i Column 4-Change in Precipitation Depth between time intervals, in inches Column 5-Intensity, in inches per hour (Col. 4 / Col. 1) Column 6-Total Runoff Depth, in inches (Col. 3 - 0.2S)V(Col. 3 -1- 0.8S) Column 7-Change in Runoff Depth during time increment, in inches Column 8-Runoff to Precipitation Ratio, (Col. 4 / Col. 7) Column 9-Runoff, in cfs (60.5 X Col. 7 X Area)/rime increment in minutes) S = 1000/CN - 10 CN is runoff curve number per Table I-A-1, San Dieeo Countv Hvdrolo^ Manual CASA LAGUNA PROJECT - Pre-Development Conditions 10-YEAR, 24 HOUR STORM - B DISTRIBUTION AREA AREA:'1.18 BASE FLOW: i 0.12 P24: 2.9 CN: 82 S:i2.195 ;Ia=0.2S= 0.439 TIME : P/P24 P 1 PDELTA I Q QDELTA ' QDELTV ^ QA (Hr.) ' (In.) 1 (In.) (In./Hr.) i (In.) (In.) ; PDELTA i cfe 2.0 1 0.034 0.099 i 0.062 i i i 0.058 0.058 0.021 1 0.36 1 0.4 3.0 0.054 0.157 i 0.042 i i 0.067 0.067 0.018 I 0.27 0.3 4.0 0.077 0.223 0.024 0.078 i 0.078 0.014 0.18 0.2 5.0 0.104 0.302 0.009 0.096 ; 0.096 0.008 0.09 0.1 6.0 0.137 0.397 I 0.001 0.058 i 0.116 0.001 0.01 0.0 6.5 0.157 0.455 ! 0.000 0.067 : 0.133 0.003 0.04 0.0 7.0 0.180 0.522 1 0.003 0.087 0.174 0.009 0.11 0.1 7.5 0.210 0.609 0.012 0.131 0.261 0.024 0.18 0.1 8.0 0.255 0.740 0.036 0.194 ^ 0.389 0.055 0.28 0.2 8.5 0.322 0.934 0.091 0.255 0.510 0.100 0.39 0.2 9.0 0.410 1.189 0.191 0.278 0.557 0.137 0.49 0.3 9.5 0.506 1.467 0.328 0.238 0.476 0.135 0.57 0.3 10.0 0.588 1.705 0.463 0.119 0.238 0.073 0.61 0.4 10.5 0.629 1.824 i 0.536 0.078 0.157 0.049 0.63 0.4 11.0 0.656 1.902 0.585 0.067 0.133 0.043 1 0.65 0.4 11.5 0.679 1.969 0.628 ! 0.061 0.122 0.040 i 0.66 0.4 12.0 0.700 2.030 0.669 1 i 0.058 0.116 0.039 i 0.67 0.4 12.5 0.720 2.088 1 1 0.707 i 1 0.055 ! 0.110 0.037 1 0.68 0.4 13.0 j 0.739 2.143 i 0.745 i i i 0.049 i 0.099 0.034 I 0.69 0.4 13.5 1 0.756 2.192 1 0.779 1 15 1 2 3 4 5 6 7 8 9 TIME" P PDELTA I Q" QDELTA QDELTA/ QA " (Hr.")" 13.5 "0.756 (In.) 2.192 (In.) (In./Hr.) (In.) 0.779 PDELTA cfs 0.046 0.093 "0^032" 0.69 0.4 14.0 0.772 2.239 ~0"8ll " 0.041 0.081 0.028 0.70 0.4 14.5 0.786 2.279 0.839 i 0.041 0.081 0.029 0.71 0^^"~" 15.0 0.800 2.320 0.868 1 : 0.046 0.093 0.033 0.71 0.4 15.5 0.816 2.366 1 0.901 i i 1 1 1 1 1 1 , 1 1 t 1 i ] Column 1 -Time Intervals, in hours 1 Column 2-Precipitation Ratio per Table II-B -2, San Diego Countv Hvdrologv Manual Column 3-Rainfall Depth, in inches (P24 x Col. 2) Column 4-Change in Precipitation Depth between time intervals, in inches Column 5-Intensity, in inches per hour (Col. 4 / Col. 1) Column 6-Total Runoff Depth, in inches (Col. 3 - 0.2S)^/(Col. 3 + 0.8S) Column 7-Change in ilunoff Depth during time increment, in inches Column 8-Runoff to Precipitation Ratio, (Col. 4 / Col. 7) Column 9-Runoff, in cfs (60.5 x Col. 7 x Area)/Time increment in minutes) S = 1000/CN - 10 CN is runoff curve number per Table I-A-1, San Die^o Countv Hvdrolo^ Manual TABLE II-B-2 RAINFALL TABLE, ONE-DAY WATERSHED EVALUATION STORf-1-TYPE B Time P/P 24 Time P/P 24 0 .000 12.0 . 700 .5 .009 12.5 .720 1.0 .016 13.0 .739 1.5 .025 13.5 . 756 2.0 .034 14.0 .772 2.5 .045 14.5 .790 3.0 .054 15.0 .800 3.5 .065 15.5 .816 4.0 .077 16.0 .831 4.5 .090 16.5 .845 5.0 .104 17.0 .860 5.5 .120 17.5 .872 6.0 .137 18.0 .885 6.5 .157 18.5 .895 7.0 .180 19.0 .905 7.5 .210 19.5 .914 8.0 .255 20.0 .924 8.5 .322 20.5 .935 9.0 .410 21.0 .945 9.5 .506 21.5 .954 10.0 .588 22.0 .963 10.5 .629 22.5 .972 11.0 .656 23.0 .981 11.5 .679 23.5 24.0 .991 1.000 Rev 11/75 ri-B-2 RUNOFF CURVE NUMBERS FOR HYDROLOGIC SOIL-COVER COMPLEXES (CN) TABLE I-A-1 AMC 2 la = 0.2S n Cover Hydro og ic Soil Groups J 1. Treatment ^ Land Use Practice^ Hydrolog i Cond it ion 5 A B C D Water Surfaces (during floods) 97 98 99 99 Urban Commercial-industrial 89 90 91 92 High density residential. 75 82 88 90 Medium density residential 73 80 86 88 Low density residential 70 78 Sk 87 Barren 78 86 91 93 FalloM Straight row 76 85 90 92 Vineyards (see accompanying land-use descript ion) disked 76 85 90 92 annual grass or Poor 65 78 85 89 legume cover Fair 50 69 79 84 Good 38 61 7^ 80 q Roads (hard surface) 7k 8k 90 92 (dirt) 72 82 87 89 Row crops Straight row Poor 72 81 88 91 Good 67 78 85 89 Contoured Poor 70 79 8k 88 Good 65 75 82 86 Narrowleaf chaparral Poor 7i 82 88 91 Fair 55 72 81 86 I-A-5 RUNOFF CURVE NUMBERS (CN) AMC 2 15 Cover Hydrolog ic Soil Groups Treatment -Hydrolog ic Cond i t ion^ Land Use Practice^ Hydrolog ic Cond i t ion^ A B c D Perennial grass Poor 67 79 86 89 Fair 50 69 79 84 Good 38 61 7k 80 Annual grass Poor 67 78 86 89 Fa ir 50 69 79 84 Good 38 61 7k 80' Close-seeded Straight row Poor 66 77 85 89 legumes or rotated pasture Good 58 72 81 85 Contoured Poor ek 75 83 85 Good 55 69 78 83 Small grain Straight row . Poor 65 76 8k 88 Good 63 75 83 87 Contoured I'oor 63 7k 82 85 Good 61 73 81 84 Meadow Poor 63 77 85 88 Fair 51 70 80 84 Good 30 58 72 78 Open brush Poor 62 76 84 88 Fair kS 66 77 83 Good k] 63 75 81 Farmsteads 59 7k 82 86 Irrigated pasture Poor 58 7k 83 87 Fair kk 65 77 82 Good 33 58 72 79 I-A-6 &iAi^s /''^700' drr oy - yd?