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HomeMy WebLinkAboutCT 03-01-01; LA COSTA RESORT & SPA MSTR PLAN; HYDROLOGY AND HYDRAULIC REPORT; 2008-03-24HYDROLOGY AND HYDRAULIC REPORT (DATED 8/15/07) (Revised 3/24/08) FOR ARENAL ROAD CT 03-01 OWNER: KSL LA COSTA RESORT CO., LLC 210 COSTA DE MAR ROAD CARLSBAD, CA 92009 (760)929-6337 APNs: 216-592-02 & 216-590-07 KECEIVED MAY 09 2008 ENGINEERiNG DEPARTMENT LOCATION: Arenal Road in the City of Carlsbad, west of The La Costa Country Club, approx. 2400' northeast of Batiquitos Lagoon and 2.3 miles east of the Pacific Ocean PREPARED BY: SPEAR & ASSOCIATES, INC. CIVIL ENGINEERS AND LAND SURVEYORS 457 Production Street San Marcos, CA 92078 PHONE: (760) 736-2040 FAX: (760) 736-4866 Date: 3/24/08 Abada, PE S&A, INC J.N. 05-140 A I 1: % -J. TABLE OF CONTENTS I. INTRODUCTION 1 II. DISCUSSION/CONCLUSION 1 SUMMARY OF FLOW RATES 1 ATTACHMENTS A. LOCATIONMAP. 2 B. 100-YR STORM WATER CALCULATIONS 4 GUTTER CAPACITY CALCULATION @ ARENAL RD. 15 C. 10-YR STORM WATER CALCULATIONS 16 D. 2-YR STORM WATER CALCULATIONS 21 E. SUSMP FLOW CALCULATIONS 26 F. HYDRAULIC CALCULATIONS 28 G. DRAINAGE AREA MAP 33 I. INTRODUCTION This hydrology report is prepared for improvement plans for Arenal Road, prepared by Spear & Associates, Inc. The project consists of improvements to a portion of Arenal Road, in the city of Carlsbad, located approximately 800 feet east of El Camino Real. The plans involve relocating and paving a portion of Arenal Road and removing pavement from the old alignment. There will be no significant change in grades or imperviousness. The existing impervious paved portion to be removed and relocated is approximately 0.088 acres and the new impervious paved area is approximately 0.13. The total net gain in imperviousness is 0.046 acres. A new storm drain system will collect runoff at stations 2+98 and 3+80, direct the flow through an 18" HDPE pipe, and discharge through a headwall into the existing swale adjacent to Arenal Road. We have used the County of San Diego Hydrology Manual (June 2003) to determine the run-off from the site for the 2, 10 and 1 OO-year storm events and the storm event that would produce an intensity of 1=0.2 in/hr (WQV). Based on the soil hydrologic map in appendix A of the County Hydrology Manual, the project soil uniformly consists of type B across all sub areas. II. DISCUSSION/CONCLUSION This project will not alter existing drainage pattems along the site and will not divert runoff from existing conditions. There will be no significant change in grades or imperviousness from the existing alignment of Arenal Road. Total post development runoff discharging from the site will not significantly exceed the pre-development amounts. The proposed post development source control and treatment control BMPs, as shown in the stormwater management plan, will protect water quality and mitigate water quality objectives to the maximum extent practicable, prior to discharging the runoffinto San Marcos Creek, Batiquitos Lagoon and ultimately the Pacific Ocean. Summary of pre and post development flow rates Storm Event 2-year 10-year lOO-year WQV Pre-Development 4.23 cfs 6.34 cfs 12.44 cfs Post-Development 4.25 cfs 6.38 cfs 12.52 cfs 0.31 cfs ATTACHMENT A ltr 2099 Arenal Rd: 1127 F7 ATTACHMENT B Developed Conditions 100-yr Event REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Q cfs 13.9 0.41 2.38 0.98 2.70 3.68 3.59 12.3 0.41 3.67 1.50 2.70 3.98 5.99 Arenal Rd. 0.9 0.046 0.04 12.3 1.55 2.70 3.98 6.15 14.8 0.41 2.49 1.02 2.70 3.53 3.61 14.8 2.57 2.70 3.53 9.07 14.8 3.54 2.70 3.53 12.52 Ol 02 Arenal Rd. Type F @ 2+98 Total Type F @ 2+98 03 Inlet @ 3+80 I new pipe @ Type A juction Total Flow Undeveloped Conditions 100-yr Event REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Qcfs 01 Arenal Rd. 13.9 0.41 2.38 0.98 2.70 3.68 3.59 02 Arenal Rd. 12.3 0.41 3.72 1.53 2.70 3.98 6.07 03 Arenal Rd. 14.8 0.41 2.49 1.02 2.70 3.53 3.61 1 Total Flow 14.8 3.52 2.70 3.53 12.44 Rational Method Reference: San Diego County Hydrology Manual 2003 Soil Type B Note: Total new paved area for Arenal Road = 0.13 acres, Total Existing Portion of Arenal Road to remove pavement = 0.088 acres. Total new extra net impervious area @ Arenal Road = 0.046 acres. County of San Diego Hydrology Manual Rainfall Isopluvials 100 Year Rainfall Event - 6 Hourg Isopluvial (Inches) LAT: 117 15'53" LONG:33 05'47" «0s S^GIS IPWMMMTM 3 0 3 Miles Dlractions fbr Application: (1) From precipitatton maps detemnine 6 hr and 24 hr amounts for the selected firequency. These maps are included in the County Hydroiogy 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 applicaple 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 Fonn: (a) Selected frequency (b) Pg= 100 year in.,Po.= ±2^ 24 2 . 7 •p. 57 24 %(2) in. (c) Adjusted Pg^^' = . (d) = min. (e) I = in./hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. P6 Duration 5 7 iij 20 1.5 I 2.5 I 3.5 I 2.63 2A2 1.68 1.30 1.08 25l 0.93 30 40 0, SO iM 180 300 380 0.83 0.60 0.53 90 0.41 0.34 1501 0.29 0.26 0722 0.19 017 3.95 i 5.27 i3.18'4.24 "2,53? 3.37 ' 1.95'2.59 'l.62i2.15 ' 1.40! 1.87 ; 1.241 1.66 11.03! 1.38 iOSOi 1.19 lOSOi 1.06 i0.61 i 0.82 l0.5110.68 io.44! 0.59 *0.39T0,52 !0,33l0 43 '0.2810.38 io.2Sio.33 6,59 6.30 4.21 "3,24" • 2.69 2.33 2.07 1,72 • 1.49 1.33 1,02 0.85 0.73 0.65 0,54 0.47 ' 0.42 7.90 9.22 6.36 7.42 5.05 5.90 3,8924.54 3.23 3.77 2.803.27 2.49 i 2.90 2.07 2.41 1.79 2.09 1.59 1.86 1.23 1,43 1.02 1.19 0.88'1.03 0.78'0.91 0,65'0,76 0.56 0.66 0.50" 0.58 4.5 i 10,54 8.48 6,74 '5."lT 4.31 3.73 3.32 2,76 2.39 2.12 1.63 1.36 1.18 1,04 0,87 0.75 0,67 11.86 9.54 7.58 5.84 4.85 4.20 3,73 3.10 2.69 2.39 1.84 1.53 1.32 1.18 0.98 0.85 0.75 S.S ... ^ ... 13.17:14.49! 10.60!l1.66l 8,42 ' 9.27 ' 15.81 12.72 10.11 6.49 5.39 4,67 4.15 3.45 2.98 2,65 2,04 1,70' 1.47 1.31 1.08 0,94 0.84 7.13 5.93 5.13 4.56 3.79 3.28 2,92 2,25 1.87 1.62 1.44 1.19 1.03 0.92 7.78 6.46 5,60 4,98 4.13 3.58 3.18 2.45 2.04 1.76 1,57 1,30 1.13 1.00 FIGURE Intensity-Duration Design Chart - Template Sin Daeo Contf; Hydmlaey Manil DOE hmXia 3 6 of 26 Tabk 3-1 RUNOFF (XXFFKSESTS FOR VRBAN AREAS Lmd Use RnaofiTCoeebMBt*^ SoilTne NRCS Eh Comty ElcmEiB HIMPBR. A B C D UidBiiiilicdNinnlT BmlfiMtmS) PenmaeatOpen ^lece 0* 0,20 0J5 OJO OJS Low DasHy KesideDliil (LEiQ Hwidmiiel, 1.0 DU/A or lem 10 0.27 0J2 QJ6 0.41 Lonr Dosiqr Rcsdotiil CL£^ Resdadnl, 2.0 DU/A or Isis 20 0J4 0.3S 0.42 0.46 Low Dasiqr Kcnlcnlial ^iXI) ResdHUid, 2.9 DU/A or less 25 03S 0.4S 0.49 Uedinm Dasiqr Kcni ieBiiI9A>R) RsadoBiil, 4J DU'A or les 30 0.41 0.45 0.41 0.52 MHUBD Densiiy Rea fatal (^BX) ResidBitid, 7 J DU/A or lest 40 0.41 OJI aJ4 0.57 MwtinmDenBiyRem iBtfiil^IDR) Residential, ia9 DU/A or less 45 0.52 0.54 0J7 0.60 MediiBn OinsiQr Sesi iBOiilOlDK) Hwidwitiil. 14.5 DU/A or less 50 OJS 0.5S 0.60 0.63 High Dcmily Rcsadm ill (HDS) Residauid, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71 Dnncy Scsidei ielCHDR) Resdonid, 43.0 DU/A or less SO 0.76 0.77 0.78 0.79 fTfitiifiiffiTil/fiiifaiffliri (N.COBO Nei^AortBod COmnenjd SO 0.76 0.77 0.78 0.79 r.mm.i.mmt.imVfmAnmtnt» ^ Com) Gencsii ComoeKid as OJO 0.S0 OJI 0J2 fnfinfffiil/tiilBMi il! (OJ>.CaB4 Office RnlHwind/rnnMiiemd 90 0.13 0.S4 0J4 OJS fMWnMfri»lffwitMBITial ^ nwa<»H T ) Xjniled SodttsKial 90 0J3 0.S4 0J4 OJS (GoHilL) Genndbdnssial 95 0.S7 0.87 OJSJ 0J7 *lbe nines assodsBd wilk OH nqisniiiis raiy be I coeffidBit, C^, fa Ae soQ qpe),« Sir inas ttniiill is locaed B CInclndNitiaul FoRsQ. DU/A = dneliniE nits per aoe 1 fa direct rshiilaliiin of die ••in iiiiMimliiil in ^iM|i^iri>y rii»iiii ima as desdiied in Scctko 3.1.2 (i Aisti&atiaDmstlM sinndiitfte maiiiniew NRCS=Nitioml ResooKcs CansHTHiai Sfsvke SKI Dtrga Comity Hy*oU)gy Mmiial Due . lime 2003 Scctnc R«e: 3 12 of 26 Note diat die butial Time of Cuncenlnliai diould be reflective of the geoend land-nse it die i^Htreamendofadnmi^basiiL A lot with an aiea of two or less acres does not bave a aignificaid effict-ndieie die dtakoige baSB area is 20 to 600 acies. Tabk 3-2 provides hmits of the lei^ (Mawmmn Lengdi Q^t)} of sheet flow to fae used m hydrology studies, hkial Ti vahies based on average C values foe the Land Use Hfimmt ire also included. These values can be used in pbmiii^ and desiga ajiplMatiiniS is described below. Excqitions may be approved by the "Regulating Agency" when sabnntted with a detailed study. Tabk 3-2 MAXmUM OVERLAND FLOW LENCTH (Lu) Ekment* DU/ Acre .5% 1% 2% 3% 5% 10% Ekment* DU/ Acre LM Ti LH Ti Lu Ti LM Ti LM Ti U Ti N^nral 50 132 70 12.5 85 10.9 100 103 100 8.7 100 65 LDR 1 50 12.2 70 11.5 85 10.0 100 9J 100 8.0 100 6.4 LDR 2 50 113 70 10.5 85 92 100 8.8 100 7.4 100 5.8 LDR 25 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6 MDR 4J 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 53 MDR 73 50 92 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8 MDR 10.9 50 8.7 65 7.9 80 65 90 6.4 100 5.7 100 4J MDR 14J 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 43 HDR 24 50 6.7 65 6.1 75 5.1 90 45 95 4.3 100 3J HIHl 43 50 53 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7 N. Com 50 53 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7 G.Com 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4 O.PXom 50 4.2 60 3.7 70 3.1 80 19 90 2.6 100 22 LuxiiledL 50 42 60 3.7 70 3.1 80 25 90 2.6 100 22 GeneralL 50 3.7 60 3.2 70 2.7 80 Z6 90 2.3 100 15 *SeeTri]tk3-l Cor move detailed descr^itiiHi 3-12 10 Initial Time of Concentration Initial Average Mannings Location slope % Initial L (ft) Initial T (min) Add'l L (ft) slope % area (ac) Q (Cfs) V(ft/s) Inc. T (min) total T (min) * Est. Average Q OFFSITE * Est. Average Q 01 6 100 7 830 6 2.38 3.6 2 6.9 13.9 02 6 100 7 800 8 3.67 5.5 2.5 5.3 12.3 03 2 85 8.8 750 7 2.49 3.7 2.1 6.0 14.8 11 Offsite 01 Overland Flow Velocity Calculation Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 0,06000 ft/ft Left Side Slope 100.00 ft/ft Right Side Slope 100.00 ft/ft Discharge 3,60 ftVs Results Normal Depth 0.13 ft Flow Area 1,80 ft^' Wetted Perimeter 26.85 ft Top Width 26.85 ft Critical Depth 0.15 ft Critical Slope 0.03098 ft/ft Velocity 2,00 ft/s Velocity Head 0,06 ft Specific Energy 0,20 ft Froude Number 1,36 Flow Type Supercritical GVF Input Data Downstream Depth 0,00 ft Length 0,00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0,00 ft Profile Description Profile Headloss 0,00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.13 ft Critical Depth 0.15 ft Channel Slope 0.06000 ft/ft Critical Slope 0.03098 ft/ft 8/9/2007 4:16:10 PM Bentiey Systems, Inc. Haestad Methods Solution Center FlowMaster [08.01.058.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA+1-203-755-1666 Page lof 1 12 Offsite 02 Overland Flow Velocity Calculation Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 0.08000 ft/ft Left Side Slope 100,00 ft/ft Right Side Slope 100,00 ft/ft Discharge 5,50 nvs Results Normal Depth 0,15 ft Flow Area 2,22 ft= Wetted Perimeter 29,82 ft Top Width 29,81 ft Critical Depth 0,18 ft Critical Slope 0,02928 ft/ft Velocity 2,47 ft/s Velocity Head 0,10 ft Specific Energy 0,24 ft Froude Number 1,60 Flow Type Supercritical GVF Input Data Downstream Depth 0,00 ft Length 0,00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0,00 ft Profile Description Profile Headloss 0,00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0,15 ft Critical Depth 0,18 ft Channel Slope 0,08000 ft/ft Critical Slope 0,02928 ft/ft 8/9/2007 4:17:38 PM Bentley Systems, Inc. Haestad Metiiods Solution Center FlowMaster [08.01.058.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page lof 1 13 Offsite 3 Overland Flow Velocity Calculation Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Tr , Roughness Coefficient 0.030 Channel Slope 0,07000 ft/ft Left Side Siope 100,00 ft/ft Right Side Slope 100,00 ft/ft Discharge 3,70 nvs Results Normal Depth 0.13 ft Flow Area 1,73 ft^ Wetted Perimeter 26,34 ft Top Width 26,34 ft Critical Depth 0,15 ft Critical Slope 0,03086 ft/ft Velocity 2.13 ft/s Velocity Head 0,07 ft Specific Energy 0.20 ft Froude Number 1,47 Flow Type Supercritical GVF Input Data Downstream Depth 0,00 ft Length 0,00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0,00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0,13 ft Critical Depth 0,15 ft Channel Slope 0,07000 ft/ft Critical Slope 0,03086 ft/ft 8/13/2007 3:22:04 PM Bentley Systems, Inc. Haestad Metiiods Solution Center FlowMaster [08.01.058.00] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page lof 1 14 GUTTER FLOW CAPACITY FOR ARENAL ROAD QIOO = 3.59 CFS, S = 4.5% CALCULATED DEPTH = 0.27', CALCULATED VELOCITY =4.6 FT/S Figure 2-2 it'O 0 » r 3% tr 1 ir e- 1.5- •^••^'.•'•'.;•••\^'•;.•^^•^^••;-.'v.••\^'•;l a o w ••-> o (0 1 2 3 4 5 6 7 8 910 3 Discharge (ft Is) Figure 2-2 6-inch Gutter and Roadway Discharge-Velocity Chart San Diego County Drainage Design Manual (July 2005) Page 2-12 20 30 40 50 15 ATTACHMENT C 16 Developed Conditions 10-yr Event REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Q Cfs 13.9 0.41 2.38 0.98 2.70 1.80 1.76 12.3 0.41 3.67 1.50 2.70 1.80 2.71 Arenal Rd. 0.9 0.046 0.04 12.3 1.55 2.70 1.80 2.78 14.8 0.41 2.49 1.02 2.70 1.80 1.84 14.8 2.57 2.70 1.80 4.62 14.8 3.54 2.70 1.80 6.38 01 02 Arenal Rd. Type F @ 2+98 Total Type F @ 2+98 03 Inlet @ 3+80 I new pipe @ Type A juction Total Flow Undeveloped Conditions 10-yr Event REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Q cfs 01 Arenal Rd. 13.9 0.41 2.38 0.98 2.70 1.80 1.76 02 Arenal Rd. 12.3 0.41 3.72 1.53 2.70 1.80 2.75 03 Arenal Rd. 14.8 0.41 2.49 1.02 2.70 1.80 1.84 Total Flow 14.8 3.52 2.70 1.80 6.34 Rational Method Reference: San Diego County Hydrology Manual 2003 Soil Type B 17 County of San Diego Hydrology Manual 18 County of San Diego Hydrology Manual 19 3 4 Hours Directions fbr Application: (1) From precipitation maps determine 6 hr and 24 hr amounts for the selected firequency. These maps are included in the County Hydrotogy Manual (10,50, and 100 yr maps induded 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 applicaple 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. 10 year in..P24=2li. Ze.= 58 •p 1. f 24 %(2) in. Appliction Form: (a) Selected frequency (b) P6= JJI (c) Adjusted Pg^^) = _ (d) tj( = min. (e) I = in./hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. P6 Duration S _ To •is 20 25 30 40 SO 90 120 ISO 180 in 300 2.63 2.12 1.68 1.30 Y.08 0.93 0.83 0.69 0.60 0.53 0,41 0.34 0.29 0.26 0.22 0.19 0.17 1.5 I ' 2.5 I 3.95 5.27 3.18'4.24 2 53'3.37' 1.95'2.59' 1.62*2.15' 1 40! 1.87' 1.24'1.66' 1.03^ 1.38 0.90tl.l9' 0,80i1.06 0.61 i 0,82 0.51 i 0.68 0.44'0 59 O.39i0.S2 0.33"0 43 0,28! 0.38' 0.25' 0.33 6.59 5.30 4,21 3J!4 2.69 2.33 2.07 1,72 1.49 1.33 1,02 0.85 0,73 0.65 0.54 0.47 0,42 3.5 I 7.90 9.22 6,36 7.42 S OS 5.90 3.89'4.54 3,23'3.77 2.80^3.27 2,49° 2 90 2,07 2.41 1.79:2.09 1.591,88 1,23 1,43 1.02 1.19 0.88 1.03 0,78 0.91 0,66'0.76 0.S6 0.66 0.50 0,58 4.5 I 5.5 I 1054 8.48 6.74 5.19 • 4.31" 3.73 • 3,32 2.76 • 2.39 ' 212 1.63 1.36 1.18 1,04 • 0,87 0,75 0,67 ' 11.86 9.54 7.58 5.84 4.85 4.20 3.73 3,10 2.69 2,39 1.84 1,53 1,32 1.18 0.98 0.85 0.75 13.17 10.60 8.42 6.49 5.39 4.67 4.15 3 45 2.98 2.65 2.04 1.70 1,47 1,31 1.08 0,94 0,84 14,49 '11.66 ' 9.27 ' 7.13 5.93 ' 5.13 '. 4.56 3.79 3.28 ' 2.92 ' 225 • 1.87 ' 1.62 • 1.44 ' 1.19 ' 1.03 ' 0.92 15.81 12.72" 10,1 7.78 6.46 5.60 4.98 4.13 3.58 3,18 2.45 2.04 1,76 1.57 1,30 1.13 1.00 FIGURE Intensity-Duration Design Chart - Template ATTACHMENT D 21 Developed Conditions 2-yr Event REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Q cfs 01 Arenal Rd. 13.9 0.41 2.38 0.98 2.70 1.20 1.17 02 Type F @ 2+98 12.3 0.41 3.67 1.50 2.70 1.20 1.81 New extra Impervious Area @ Arenal Rd. 0.9 0.046 0.04 Total Type F ^ J2+98 12.3 1.55 2.70 1.20 1.86 03 Inlet @ 3+80 14.8 0.41 2.49 1.02 2.70 1.20 1.23 new pipe @ T) ^pe A juction 14.8 2.57 2.70 1.20 3.08 Total Flow 14.8 3.54 2.70 1.20 4.25 Undeveloped Conditions 2-yr Event REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Q cfs 01 Arenal Rd. 13.9 0.41 2.38 0.98 2.70 1.20 1.17 02 Arenal Rd. 12.3 0.41 3.72 1.53 2.70 1.20 1.83 03 Arenal Rd. 14.8 0.41 2.49 1.02 2.70 1.20 1.23 1 Total Flow 14.8 3.52 2.70 1.20 4.23 Rational Method Reference: San Diego County Hydrology Manual 2003 Soil Type B 22 County of San Diego Hydrology Manual Raiirfall Impluvicds 2 Year Rainfall Event - 6 Houn laopluvial (inchw) DPW o^-OTO ^GIS SanGIS T 3 0 3 MllM 23 County of San Diego Hydrology Manual Raiirfall Isopluvials 2 Year Rainfall Event - 24 Honn IsoplLNlal (Incha*) DPW «GIS SaSGIS ^ IHeMrpiaRa«K]BD«r[HOUTMUMMnTOFMfrNMIlBTt«l • aRHHE4iN0unMa,>uriaruMiEDmnca«jmi 1 OFWIWIMIlWinYiWDWIMeStOWAIIWIIOlKI 3 0 3 MllM 24 3 4 Hours Directions for Application: (1) From predpitation maps detenmine 6 hr and 24 hr amounts fbr the selected frequency. These maps are included in the County Hydtx>togy Manual (10,50. and 100 yr maps indtxied 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 applicaple 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 Fonn: (a) Selected frequency ^ year (b)P6= ^l!iln.,P24= ^'^ 66 •P 1. 2 24 %(2) in. (c) Adjusted PQ<^^ = . (d) t^ = min. (e) I = in./hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. P6 ; Duiation' IJS I i ^ 120 ISO 180 UO 900 3oa 2,12 1,68 1.30 1.08 0.93 0.83 0.69 0.60 0.53 0.41 0.34 0.29 0.26 0.22 0.19 0.17 13.95! 5.27 •318'4 24 2 53 3 37 1.95 ; 2^59 1 62'2 15 1.40 1.87 1 24 1 66 1.0311.38 i0.90il.l9 i 0,80! 1.06 !0,61!0,82 '0.5110.68 i0.44i0.59 0 39'0 52 '0,33! 0,43 "0 28'038 '0 25^0 33 2.S I ^ 4.5 I 6.59 7.90! 5.30 6.36 4.2 r 5.05 3.24-3.89 2.6913,23' 2,33 2,80' 2.07'2.49 1,72 2.07 1.49i 1.79 1.33*1,59 1,02 1,23 0.85:1.02 0.73! 0.88 0.65 0.78 0.54 065 0.47 0,56 0,42 0,50 9.22! 10.54 7.42 8.48 5.90! 6.74 4.54" 5,19 3.77^ 4.31 3.27 3.73 2,90 3.32 2,41' 2.76 ' 2,09! 2.39 1.86T 2.12 1.43 163 1.19! 1.36 11.86:13.17 9.54 10.60 1.03 0.91 • 1.18 1.04 0,76 0,87 0.66' 0.75 0.58' 0.67 7.58 5.84 485 4.20 3 73 3.10 2,69 2,39 1,84 1.53 1.32 1.18 0.98 0.85 0.75 8.42 649 5.39 4,67 4,15 3.45 2,98 2,65 2,04 1,70 1,47 1,31 1,08 0.94 0.84 J3J 0 -JLI__L. I4.49115.81 11.66:12.72 9.27 10.11 7,13__7.7e 5.93 6.46" 5.13 456 3.79 3.28 2.92 2 25 1.87 1.62 1.44 1,19 1.03 0.92 5.60 4.98 4.13 3.58 3.18 2.45 2.04 1,76 1.57 1,30 1.13 1.00 FIGURE IntensHy-Duration Design Chart - Template ATTACHMENT E 26 SUSMP Flow Calculation REACH UPPER LOWER TC C A CA Sum CA Precipitation 1 Q cfs 1 New Impervious Area @ Arenal Rd. 0.9 0.046 0.04 02 0.41 3.67 1.50 Filter unit 1.55 0.20 0.31 Flow Through Devices Intensity I = 0.2 in/hr Reference: California Regional Water Quality Control Board Order NO. 2001-01 27 ATTACHMENT F 28 Scenario: Base Inlet Sta. 2+98 Inlet sta. 3+80 Type A Cleanout 1 \ Type A Cleanout 2 P4 0-1 Title: Arenal Road c;\program files\haestad\stmc\05-140.stm 08/14/07 04:20:44 PM © Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer; Danny Abada StormCAD vg.g [05.06.007.00] Page 1 of 1 Scenario: Base Pipe Report Label Upstream Downstream Total Length Constructed Section Mannings Full Upstream Downstream Upstream Downstream Upstream Downstream Hydraulic Hydraulic Node Node System (ft) Slope Size n Capacity Invert Invert Ground Ground Cover Cover Grade Grade Flow (ft/ft) (cfs) Elevation Elevation Elevation Elevation (ft) (ft) Line In Line Out (cfs) (ft/ft) (cfs) (ft) (ft) (ft) (ft) (ft) (ft) P4 Type A Cleanout O-l 9.07 83,50 0,005389 18 inch 0,009 11,14 31.95 31,50 35,00 31.50 1.55 -1,50 33,12 32.54 P2 Inlet sta. 2+98 Type A Cleanout 5.99 40,50 0,113580 18 inch 0.009 51,13 37.20 32,60 41,10 36,00 2.40 1.90 38.15 33.67 P1 Inlet sta. 3+80 Type A Cleanout 3.61 90.40 0,015487 18 inch 0,009 18,88 34.00 32.60 36,55 36,00 1.05 1.90 34,73 33.67 P3 Type A Cleanout Type A Cleanout 9.07 77.50 0,005806 18 inch 0,009 11,56 32,50 32.05 36.00 35.00 2,00 1,45 33,67 33.06 Title: Arenal Road c:\program files\haestad\stmc\05-140,stm 08/14/07 04:26:53 PM © Bentley Systems, Inc, Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Danny Abada StormCAD vgg [05.06,007,00] Page 1 of 1 t rof iie Scenario: Base Profile: Profile -1 Scenario: Base 45.00 Label: Inlet sta. 2+98 Rim: 41.10ft Sump: 37.20 ft Ground 40.00 Label: Type A Cleanout 1 Rim: 36.00 ft Sump: 32.50 ft Label: Type A Cleanout 2 Rim: 35,00 ft Sump: 32.05 ft Elevation (ft) 35.00 0+00 Up. Invert: 37.20 ft Dn. Invert: 32.60 ft L: 40.50 ft Size: 18 inch S: 0.113580 ft/ft Up. Invert: 32.50 ft Dn, Invert: 32,05 ft L 77,50 ft S-MOsSi^ft Label: P4 Up, Invert: 31.95ft Dn, Invert: 31.50 ft L: 83.50 ft Size: 18 inch S: 0,005389 ft/ft Label: 0-1 Rim: 31.50 ft Sump: 31,50ft 30,00 2+00 3+00 Title: Arenal Road c:\program files\haestad\stmc\05-140,stm 08/14/07 04:26:07 PM Station (ft) © Bentley Systems, Inc, Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Danny Abada StonnCAD vg^ [05,06.007,00] Page 1 of 1 ^1 rof ile Scenario: Base Profile: Profile - 2 Scenario: Base Label: Inlet sta. 3+80 Rim: 36.55 ft Sump: 34.00 ft 0+00 40.00 Label: Type A Cleanout 1 Rim: 36.00 ft Sunlip: 32.50 ft 35.00 Elevation (ft) Label: PI Up. Invert: 34.00 ft Dn. Invert: 32.60 ft L: 90.40 ft Size: 18 inch S: 0.015487 ft/ft — 30.00 1+00 Title: Arenal Road c:\program files\haestad\stmc\05-140.stm 08/14/07 04:26:26 PM Station (ft) © Bentley Systems, lnc, Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Project Engineer: Danny Abada StonnCAD vgg [05,06,007,00] Page 1 of 1 ATTACHMENT G 33 BEST COPY BEST COPY BEST COPY 34