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HomeMy WebLinkAboutMS 05-07; EMBASSY SUITES HOTEL; PRELIMINARY HYDROLOGY REPORT; 2005-01-12rK PRELIMINARY HYDROLOGY REPORT FOR CPT /SC Title Holdings Corp 533 South Freemont Street Seventh Floor Los Angeles, CA 90071 PROJECT Embassy Suites, Paseo del Norte CUP XX-XX, CDP XX-XX PREPARED BY: Aquaterra Engineering Inc. 1843 Campesino Place Oceanside, CA 92054 tele: 760-439-2802 fax: 760-439-2866 January 12, 2005 the supervision of: Gary Exp. 12/31/05 (2 ES. Sf Lij 1I1 cc No. 23080 CIVIL OF CA M'i O tS-O7 Project Description The 7± acre project site is currently vacant. The site topography generally is mildly sloping to the northwest due to previous grading. The adjacent land on the north has been developed as a automobile sales operation. Southerly of the site has been improved as a restaurant. Interstate 1-5 borders the site along the westerly edge and Paseo del Norte is along the easterly side. The project is proposed to be developed as an hotel and restaurant with parking and driving surfaces. The proposed drainage pattern approximates the existing condition and outlets to and existing concrete drainage channel located along the west property line within the Caltrans right of way. Purpose of Study The purpose of this study is to identify the proposed method to capture the silt and debris from the storm drainage run off after the site has been improved. The attached hydrology map and calculations are provided to support the design on the preliminary site plan. Our selected approach to limit the transportation of silt and debris downstream is to construct underground storage tube systems located at five areas of the project site. Since the site is within the Coastal Zone the storage systems will also act as a detention basin to limit the storm water discharge to that peak value calculated to be the 10 year frequency level in its undeveloped condition. Pollution Control The program to eliminate polluting elements from downstream drainage systems includes the above referenced permanently constructed Detention I Storage systems. Additional Best Management Practices (BMP) shall be used during the construction phase of the site improvements. The BMP devices installed and maintained during the construction period shall include gravel bag berms around each drainage inlet or catch basin and gravel bag chevrons check dams at locations to control drainage flows which may generate silt, erosion and debris. Post construction BMP's shall include fossil fuel filter inserts in the drainage catch basins to accept and trap silt and hydrocarbon pollutants. The filtration design of the fossil fuel filter shall be based on the "Flow based Criteria" using the established flow rate of 0.2" per hour intensity, The propose slopes are less than 4' in height, however shall be covered with irrigated landscaping material to control the erosion. We believe that the above described design elements and programs will provide satisfactory drainage control to meet agency established requirements. N ct / Hydrology & Hydraulics Report City of Carlsbad This Hydraulics and Hydrology Report was prepared using the following Manuals: Hydrology Manual, County of San Diego Drainage of Highway Pavements, U.S. Dept. of Transportation The Rational Method was used to determine the 10 and 50 yr. storm Q values. The Rational Method uses the following formula to establish the flow: Q=CIA where, Q = the peak runoff in cubic feet per second C = Runoff coefficient representing the ratio of runoff to rainfall = time average intensity in inches per hour A = Area of the subbasin in acres HYDROLOGY REPORT I 4 a I-ld I MEMENNOMENT mmomi-Affillmle MEME _____ / - INTENSITY-DUMTi DESIGN CHART w t. Directions for Application: From precipitation naps determine 6 hr. and 24 hr, amounts for the selected frequency. These maps are printed In the County Hydrology Manual (10 50 and 100 yr. maps included ii th Design and Procedure Manual), Adjust 6 hr. precipitation (i-f necessary) so that it is within the range of 45% to 65% of the 24 hr. precipitation. (Not applicable to Desert) • C.. 3) Plot 6 hr. precipitation on the right side • of the chart. 1 Draw a line through the point parallel to the plotted lines. 16,0 This line is the intensity-duration curve for the location being analyzed. 5.s -a. - Application Form: 0) Selected Frequency .5t yr. P6 ?.in., P24=40P6 = p24 Adjusted *P6= ______in. t 9.7 mm. I = In/hr. *Not Applicable to Desert Region • APPENDIX XI IV-A-14 R?vi ed 1/85 ) 15 20 30 40 50 1 2 3 4 5 6 EQL//?T/OAI f/19L 3 Fe/ ).365 SOOD 7: 7nze of concenMzha, 1 Le179/h of ava/ershed 40,64 H ' D//ferece in c/eva/ian a/awç e/feeh,'e g/oPe line (See 4opend,k K-B) r 3000 L Mi/es Fe/ 4'es Mma/es 2010 240 3 /80 /0 /00iJ r87,'O,O ____ 0t7 2 /20 /01) 501) 80 4 71) / 3 300 21)1) 2 APO 3D \ / '5D01) L. 20 L /8 I' ii 11) 201)0 N 12 N /aao Jw NOTE /0D /1) FOR NATURAL WATERSHEDS /201) B i— 20 ADD TEN MINUTES TO /001) 7 COMPUTED TIME OF CON- 900 CENTRATION- 800 71)0 5 Lb . 51)1) 01)1) 300 H 200 re F SAN DIEGO COUNTY J NOMOGRAPH FOR DETERMINATION DEPARTMENT OF SPECIAL DISTRICT SERVICES OF TIME OF CONCENTRATION (Tc) FOR NATURAL WATERSHEDS PROPOSE U CUVLNANT OF LAS Csft-fll PRWL PER FILEEXISTING 20' 320458C 1130 2 UTILITY EASEMENT LANDS CAPE AND REC~ d6 V UJ EMBASSY SUITE HOTEL CUP XY—XX, CDP XXX—XY CP Co Ln !ItU!IfLPT 1 _ _ 011 -- Lfll Lflk Jim k4iijWlII1ffJ MAI Sm 13"I've JAI moil it 65,0 5.98 WA no S 64,12 JQQI 675 HC LV 0 0-01, low U) 111111111 F""' MUNSM--t OR Anil hk own- Ff ... . .. ... .: .. - - T--- -----=--=- oil.._. 11111111 . . 1---1---- - - --ii - - X. STREET LIGHT STANDARD 43' 431 UrU 10' 33' 33' EXISTING AC PAVEMENT BASE MATERIAL D EXISTING EXISTING URB AND GUTTER CURB AND GUfT-E--RN EXISTING SIDEWALK TYPICAL SECTION - PASEO DEL N NOT TO SCALE P.L. :?ELIMINARY HYDROLOGY MAP SCALE: 1"=0' 10' EXISTING SIDEWALK S. TA ( OF I MARCOS ( LIPç tDh23O2 1 30 0 30 60 Scale 1' = 30' CIVIL ENGINEERING * LAND PLANN ijEta Engineerin'g Ii 1843 Campesino Place Oceanside, CA 92054 Tele: (760) 439-2802 Fax: (760) 439-2866 C:\DWG12\d1-SB—iP.DWG VICINITY MAP VICINITY MAP NDSC.4L ENGINEER OF WORK: PREP' tD/ ND TH PERVISIDN OF, AQUATERRA ENGINEERING INC, 1843 OCEANSIDE, CA 92054 --- M.D PLACE ------ DATE .421Q_c TELEI 760 439 2802 GARY L SKA ROE 23080 EXP RES 12/31/05 PLOT DATE 1/12/05 EMBASSY SUITES HOTEL CARLSBAD CALIFORNIA EMBASSY SUITES PRELIMINARY HYDROLOGY MAP SCALE: 1"3O'