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HomeMy WebLinkAboutCDP 07-28; Leucadia Wastewater; Hydrology/Hydraulic Study; 2005-11-01LEUCADIA WASTEWATER DISTRICT SITE IMPROVEMENTS CARLSBAD, CA HYDROLOGY & HYDRAULIC CALCULATIONS November 28, 2005 Updated: April 17, 2006 III No. 34867 xiSl EXP.f ^1 RECEIVED JUN 0 6 2006 ARCHITECTSINC. ^iKO.W. fllCE. 34867 BDS ENGIHEERIMG, INC. CTVIL ENGINEERS 6859 Federal Boulevard Lemon Grove, CA 91945 (619) 582-4992 Project 04-38 Qf::7-^7 STORM DRAIN STUDY FOR LEUCADIA WASTEWATER DISTRICT SITE IMPROVEMENTS LEUCADIA WASTEWATER DISTRICT CARLSBAD, CA L SCOPE OF WORK 3 II. HYDROLOGIC ANALYSIS 3 m. CALCULATIONS 4 IV. CONCLUSIONS 4 V. VICINITY MAP 6 VI. 2003 COUNTY OF SAN DIEGO HYDROLOGY REFERENCE MATERL\L 7 VII. FLOW CALCULATIONS SPREAD SHEET 8 VIII. DRAINAGE MAP 9 L:\PROJECTS\0438\Admin\H)rdro\HYDRO STUDY AND COVER.doc I. SCOPE OF WORK The scope of this study is to provide the hydrology and hydraulic calculations for the Leucadia Wastewater District Site Improvements. The improvements involve the demoMon of existing buildings and paved areas and the construction of several new buildings, landscaped areas, parking facilities and associated walkways, wliich include regrading. II. HYDROLOGIC ANALYSIS A hydrologic analysis was made to estimate peak flood flows with retum periods of 100 years. This hydrologic analysis was made by die use of an aerial survey by TO WIL, October 5,2004 and the proposed grading plan. Calculations were supplemented by a report tided "Hydraulic Study for FEMA Conditional Letter of Map Revisions (CLOMR) for San Marcos Creek Near La Costa Plaza in the City of Carlsbad San Diego County, Califomia" dated September 1997 and "HEC-2 Study for La Costa Lucky Sav-On Shopping Center #121-283" dated Febmary 1997 by Howard H. Chang, Ph.D., P.E. and also "Addendum #1 to Hydrologic and Hydraulic Study, Albertsons #6720" by O'Day Consultants dated December 21, 2001. The rational mediod of mnoff" computation was used to determine die quantity of storm water mnoff. The basic rational formula is Q=CIA where: "Q" is die peak rate of flow in cubic feet per second (CFS). "C" is a mnoff coefficient expressed as diat percentage of rainfall, which becomes surface mnoff. We are using soil group 'D'. "F is the average rainfall intensity in inches per hour for a storm duration equal to die time of concentration (t) of die contributing drainage area. "A" is die drainage area in acres tributary to design point. V is the time of concentration required for mnoff" to ff ow from die most remote part of the watershed to die oudet point under consideration. L:\PROJECTS\0438\Adniln\Hydro\HYDRO STUDY AND COVER.doc III. CALCULATIONS Please refer to die attached calculations. IV. CONCLUSIONS The improvements involve die demolition of existing buildings and paved areas and die constmction of several new buildings, landscaped areas, parking facilities and associated walkways. (Please note diat die proposed grade will be approximately 1.0' higher tiian die existing grade) The existing site is approximately 4.06 acres; die improvements will raise die C-value from 0.65 to 0.77. This results in an increase in total flow of 3.41 cfs. (Pre- development of 14.4 cfs to Post-development of 17.8 cfs) See Section VII for Calculations. EXISTING CONDITIONS The existing drainage design separates die site into two systems. Approximately 4.7 cfs discharges dirough die gravity storm drain line located generally at die soudiem and westem boundaries while die odier 9.68 cfs will be collected and discharged at die nordiwestern comer of die site. At die nortiiwestem comer is an existing 250 gal/min (0.56 cfs) sump pump to collect and discharge die 9.68 cfs. The district can discharge excess storm water runoff" into dieir wastewater distribution system. During a major storm event, die district shall divert runoff into tiieir 227,000 gallon (30,345 cubic foot) overffow tank. The overflow tank is part of dieir main sewage pump station. The distiict also maintains 2 potable pumps and 2 emergency generators for additional pumping capacity during a major rain event. PROPOSED CONDITIONS The proposed drainage design will keep die stormwater draining to two systems but die majority (16.9 cfs) shall flow to die sump pump in die nortiiwestem comer and only approximately 0.9 cfs to die gravity flow system. This will result in an increase of 7.18 cfs to die sump pump and a decrease of 3.77 cfs to die gravity flow system. Area H and Bl will be conveyed by a bio-swale located at the nordi west comer of the site. The bio-swale will be used as a BMP for nuisance water and small storms. The max capacity is approx. 0.37 cfs and will have a velocity of 0.26 cfs. See Flow Master calculations and cross section located behind die Flow Calculations Spreadsheet in Section VII. Water quality objectives will be met for die gravity flow system by die use of Kristar EoGard Plus filter inserts or approved equal. The filters will be used in (3) proposed catch basins and (1) existing catch basin, all on die soudieast corner ofthe site. Water quality objectives for die rest of die site will be discharging to die sump pump which currentiy includes a diverter valve to discharge to die sewer daily and is switched over to die 10" force main storm drain system during a storm event. In case of a storm event, Leucadia Wastewater District must test die storm water discharge widiin a time acceptable to die Regional Water Quality Board on diis system because it is not filtered. It should be noted diat BDS Engineering, Inc. recommends increasing die sump pump size and also having an additional pump to help discharge storm water or serve as a back-up. As noted previously under Existing Conditions, die district can discharge excess storm water mnoff" into dieir wastewater distribution system. During a major storm event, die district can divert mnoff into 4 L:\PROJECTS\0438\Admin\Hydro\HYDRO STUDY AND COVER.doc dieir 227,000 gallon (30,345 cubic foot) overflow tank. The overflow tank is part of dieir main sewage pump station. The district also maintains 2 potable pumps and 2 emergency generators for additional pumping capacity during a major rain event If pump failure should occur, die expected volume of stormwater to flood die site is approx. 10,060 cubic feet. This will flood up to die approximate elevation of 7.5 Mean Sea Level. (See Section VII) DISCHARGE TO PUMP Q2 Q10 Q100 PRE DEVELOP 4.30 6.46 9.68 POST DEVELOP 7.49 11.24 16.86 INCREASE 3.19 4.78 7.18 TOTAL DISCHARGE SUMMARY 02 QIO QIOO PRE DEVELOP 6.40 9.60 14.40 POST DEVELOP 7.91 11.87 17.81 INCREASE 1.51 2.27 3.41 ESTIMATED FLOOD CONDITIONS ONSITE 0100=16.9 CFS with No Discharge ELEVATION VOLUIVIE (CF) TIME (MIN) 5.5 . 6.0 162 0.2 6.5 1,474 1.5 7.0 4,175 4.1 ^"••^77s7\ 10,415 10.3 8.0 18,724 18.5 8.5 29,186 28.8 9.0 41,893 41.4 9.5 57,308 56.6 10.0 76,194 75.3 L:\PROJECTS\0438Vkdmin\Hydro\HYDRO STUDY AND COVER.doc V. VICINrrY MAP Fraamya Mghway* Ramfw Maior Roads Cautetan Roads AH Roads • Paroals 40 loot topo 303 d Ualad Rlvara and Baaoha* • 303 d Bays • Eatiiarias and Lakss Mvars Lakss CI^INatar OuaM^ Sansitivo Araas Coun^ Env SanaMva Araas • WMirshsd Managamant AMZA^OMUaO • • ED I SAY PEft AMU rros SANoaaoaAv lAHOHaDRMBR UNoaGwromv iD • EH SAN LUIS REY WMTA MAI«l*mrA TUMHARIWn viruirsw.T<iM wwreMATCR I I ZipCodss Municipal Coun<y Boundary VIoMty County • AllgHO CwtMMy Orn9«Ctmly • P • E3 • fbMraktoCevmty I I VI. 2003 COUNTY OF SAN DIEGO HYDROLOGY REFERENCE MATERL\L I I L:\PROJECTS\043e\Adnnin\Hydro\HYDRO STUDY AND COVER.doc 5 6 7 8 9 10 15 20 30 40 50 1 Minutes Duration 3 4 5 6 Hours Directions fbr Application: (1) From precipitation maps determine 6 hr and 24 hr amounts for the selected frequency. These maps are included in the 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 precipitetion (not applicaple to Desert). (3) Plot 6 hr precipitation on the right side of the chart. (4) Draw a line through tfie point parallel to the plotted lines. (5) This line is the intensity-duration curve for the location being analyzed. Application Fonti: SEE ATTACHED CHART (a) Selected frequency. year ^, (b)P6 = in. P24 = •p. %(2) 24 in. (c) Adjusted Pg<2) = _ (d) tj( = min. (e) I = in./hr. Note: This chart replaces the Intensity-Duration-Frequency curves used since 1965. P6 DuratTdn 10 15 SO M 90 120 180 240 300 360 3.5 I I I 2.63 13.95[5.271 6.59 i 2.12 3.18i4i4i 5.30 ; 1.68 1,30 7.90 9J22 6.3617.42 2.53 3.3714.21 15.05'5.90 t.95i2.59i3.24i3.89!4.S4 1.08 1.62i 0.93 i1.40i 0.83 11.24 ^9 1 ca 0.60 !0.90 0.tK> 0.53 0.41 0.34 ISO 0.29 0.26 0.22 0.19 0.17 0.61 0.51 0.44 0.39 0.33 0.28 0.25 2 15 1.87 1.66 1.38 1.19 1.06 0.82 0.68 0.59 0.62 0.43 0.38 0.33 2.69 2 33 2.07 1 72 1.49 1.33 1.02 43 1 I 5.5 6 I I 10.54i11.86: 8.48 ! 9.54 • 6.74 T 7.58' 13.171 lo.ed: 14.491 11.6is1 9.27 ' 15.81 12.72 10.11 0.88 0.73 0.65 0.54 0.47 0.42 323 3 77 2.8013.27] 2 49 2 90^ 2 07*2 41' 1.79:2.09| 1.59i 1.861 1.23^1.431 5.19 fsJB4T6.49 ' 7.13 j 7.78 1.02 0.88 0.78 0.65 0.56 0.50 M8, 1.Mj 0.76 0.66 0.58 4^31J 4J5 3.73 I 4.20" 3.32 ,' 3.73 2 76 1 3.10 2 39j 2.59 2.12 [ 2.39 1.63]'i:84 1.36 ! 1.53 J.18 I 1.32 1.041 1.18 0.87 i 0^98 0 75 • 0 85 0.67 1 0.75 5.39 4 67 4 15 345 2.98 2.65 2.04 1.70 1.47 1_,31 1.08 0.94 0.84 593 5.13 456 379 3 28 2.92 2 25 1 87 1 62 1.44 1 19 1 03 0.92 6.46 5.60 4.98 4.13 3.58 3.18 2.45 2.04 1J6 1.57 1.30' 1.13 1.00 FIGURE Intensity-Duration Design Chart - Template San Diego County Hydrology Manual Date: June 2003 Section: Page: 3 6 of 26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS Land Use Runoff Coefficient "C" Soil Type NRCS Elements Coimty Elements % IMPER. A B C D Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30 0.35 Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41 Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 Medium Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52 Mediuni Density Residential (MDR) Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57 Medium Density Residential (MDR) Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 Medium Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63 High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71 High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79 Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 0.79 Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80 0.81 0.82 Commercial/Industrial (O.P. Com) Ofiice Professional/Commercial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (General I.) General Industrial 95 0.87 0.87 0.87 0.87 *The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff coefficient, Cp, for the soil type), or for areas that will remain xmdisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area is located in Cleveland National Forest). DU/A = dwelling units per acre NRCS = National Resources Conservation Service 3-6 100 I-UJ UU UL lu O z CO a LU o o UJ I EXAMPLE: Given: Watercourse Distance (D) = 70 Feet Slope (s) =1.3% Runoff Coefficient (C) = 0.41 Overland Flovi^ Time (T) = 9.5 Minutes SOURCE: Airport Drainage, Federal Aviation Administration, 1965 T = 1.8 (1.1-C) VD" FIGURE Rational Formula - Overland Time of Flow Nomograph I I San Diego County Hydrology Manual Date: June 2003 Section: Page: 3 12 of 26 Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres. Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in hydrology studies. Initial Ti values based on average C values for the Land Use Element are also included. These values can be used in planning and design applications as described below. Exceptions may be approved by the "Regulating Agency" when submitted with a detailed study. Table 3-2 MAXIMUM OVERLAND FLOW LENGTH (LM) Element* DU/ Acre .5% 1% 2% 3% 5% 10% Element* DU/ Acre LM Ti LM Ti LM Ti LM Ti LM Ti LM Ti Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4 LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8 LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6 MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3 MDR 7.3 50 9.2 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 6.9 90 6.4 100 5.7 100 4.5 MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3 HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5 HDR 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7 N. Com 50 5.3 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.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2 General I. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9 *See Table 3-1 for more detailed description 3-12 I I AE Feet • 5900 .4000 .3000 -2000 — 1000 900 800 TOO 500^ Tc Tc L AE EQUATION 11.9L3\0.385 AE / Time of concentration (hours) Watercourse Distance (miles) Chaise in elevation along effecfive slope line (See Rgure 3-5) (feet) Tc Hours N .400 \ • 300 -200 -100 S S X Miles Feet ^1-\- . 4000 \ — 3000 '50 '40 • 30 — 20 • 10 0.5- IMintites -240 '180 •1» 100 — 70 • GO .»I00 1800 1600 — 1400 — 1200 .1000 — 900 — 800 700 t—600 -500 — 400 — 300 • 200 \ •50 — 40 — 30 -20 18 — 16 — 14 — 12 S •10 9 —8 — 7 —6 — 4 —3 AE SOURCE: California Division of Highways (1941) and Kirpich (1940) Tc Nomograph for Determination of Time of Concentration (Tc) or Travel Time (Tt) for Natural VWatersheds FIGURE 20 . 18- 16- 14 - 12 . 10- 9 . 8 • 7 . 6 • 5 • a. o W w V 03 o 2 • 1.8 • 1.6 • 1.4 • 1.2 • 1.0 . 0.9 • 0.8 • 0.7 . 0.6 • 0.5 . 0.4 • 1.5' -n = .015- Concrete Gutter 5 6 7 8 9 10 Discharge (C.F.S.) EXAMPLE: Given: Q = 10 S = 2.5% Chart gives: Depth = 0.4, Velocity = 4.4 f.p.s. SOURCE: San Diego County Department of Special District Services Design Manual FIGURE Gutter and Roadway Discharge - Velocity Chart County of San Diego Hydrology Manual Rainfall Isopluvials 2 Year Rainfall Event - 6 Hours Isopiuvial (inches) SOs SIRGIS Havi: San Oiego C'.(iv(:rt:d! THTS MV n PROVIDS WITHOin'WMVUHTY OF ANY NW. STHER Cmna OK MRJED, MCUJDMa BUT HOT UMTS TO, THE KTUW WNVWdlGB OF MENC»W«TAMJTY AM) FTTNen FOR A PARTKUUn PUN>OeE. 3 0 3 Miles County of San Diego Hydrology Manual Rainfall Isoplwials 2 Year Rainfall Event - 24 Hours Isopiuvial (inches) DPW ^GIS SaS^GIS Have Sitn Dit^ti Cxncrcd'. THnMVnPWrVlOB) WITHOUT WMVWrrr OF M4V NNO, BTH5tB««ESS OR MFUBl, MCUJDMQ. BUT NOT UHTTED TD. THE MPUED WMWAMTIEB OF M9CWNTABUTV AM) FTTMEta FOR A PMmCUUA MRPOSE. 32?30' 3 0 3 Miles 33*30^ County of San Diego Hydrology Manual Rainfall Isopluvials 10 Year Rainfall Event - 6 Hours Isopiuvial (inches) «GIS Sa&GIS THH MW IS PROVDH) WITHOUT WAARANTY OF ANV MM), BTHER B(PRE3S OR IMPUB). MCUJOMa BUT NOT UMnED TO. THE MPUS WARfwriEa OF MBKHMfTABUTY AM> FITNEBS FOR A PARTICULAR PURPOBE. OwrtKil BenQIB. Al RW«« RuMwd. 3 0 3 Miles 33'30'-33'30' 33'IS' 32*45! 33*00' 32*30' County of San Diego Hydrology Manual Rainfall Isopluvials 10 Year Rainfall Event - 24 Hours Isopiuvial (Inches) DPW ^^^To ^GIS SanGIS Wc Ha,v;: .*^ari l'>ii.Y.i! vVivcrciil THW MU>n PROWS) WtTHOUTWMVWKTr Of ANV NND, EFTHER EXPRESS OR MUB). MCUJDMa BUT NOT Li«TED TO, THE IMPUB) WMWMTieS OF MSICHHfTMiJTY AM) FrtMEBS FOR A PMCncUAR PURPOaE CepwHN BenOtB- Ai Ri^ Ifcemil 3 0 3 Miles 33*30' 33*30'I 33*15' 32*45' 32*30' 32*30' County of San Diego Hydrology Manual Rainfall Isopluvials so Year Rainfall Event - 24 Hours Isopiuvial (inches) npw «Gis S^GIS Wc H AYC Sun [^icgfi On-cril-dl TO« MAJ>li PRCW)B) Wmwr W>WIAKTY OF W OR MPm, MOUDBMl. BUT HOT LMTH) TO. THe BiPLJa) WARRMTIES OF yENCHANTAMITY MD FHTCSB POR A mRTKULAR PUnpOBE. 3 0 3 Miles County of San Diego Hydrology Manual Rainfall Isopluvials 100 Year Rainfall Event - 6 Hours Isopiuvial (Inches) «0s S^GIS Hav,- San DitiM ClKcre Jl 3 0 3 Miles County of San Diego Hydrology Manual Rainfall Isopluvials 100 Year Rainfall Event - 24 Hours Isopiuvial (inches) DPW o-^^TO ^Gis SMTGIS WcHav,: S;in l>:t;t:o (xivcn THWIiWPnpK>VIDeDWIT>IOUrWAI«UNTYOFAN<rlQU). STHER BtPRESa ORBinJB).MCtJJCHNa,BUTmTUMrrEDTO.THEMPUBD WAMUNTieS Of MERCHAMTMLJTY AM) FrmEBS FOR A nVrriCUUW PUn>08£. 3 0 3 Miles VIL FLOW CALCULATIONS SPREAD SHEET L:\PROJECTS\0438\Adnnin\Hydro\HYDRO STUDY AND COVER.doc BDS Engineering, Inc. CIVIL ENGINEERS PROJECT: LEUCADIA WASTEWATER DISTRICT SITE IIVIPROVEiVIENTS ENGINEER: R. KUNISHIGE PROJECTNO.: 04-38 R.C.E. NO.: Year Storm 2 10 100 DATE: P6 1.2 1.8 2.7 NOVEMBER 28, 2005 P24 1.9 3.0 4.5 P6/P24 63.2% 60.0% 60.0% DRAINAGE AREA NO. AREA (AC.) LENGTH OF FLOW (FT.) SLOPE (%) % IMPER- VIOUS C Tc I (per att. chart) Q (CFS) DRAINAGE AREA NO. AREA (AC.) LENGTH OF FLOW (FT.) SLOPE (%) % IMPER- VIOUS C (per att. chart) 2 10 100 2 10 100 PRE CONSTRUCTION EX-A 3.01 500 9.5% 50.0% 0.63 9 2.16 3.24 4.86 4.1 6.1 9.1 EX-B 0.19 153 21.6% 40.0% 0.57 5 3.16 4.74 7.11 0.3 0.5 0.8 EX-C 0.35 143 24.5% 25.0% 0.49 5 3.16 4.74 7.11 0.5 0.8 1.2 EX-D 0.23 100 1.0% 100.0% 0.90 5 3.16 4.74 7.11 0.7 1.0 1.5 EX-E 0.21 _ -90.0% 0.85 5 3.16 4.74 7.11 0.6 0.8 1.3 EX-F 0.09 90.0% 0.85 5 3.16 4.74 7.11 0.2 0.4 0.5 POST CONSTRUCTION Bl 0.12 _ 100.0% 0.90 5 3.16 4.74 7.11 0.3 0.5 0.8 B2 0.04 _ 100.0% 0.90 5 3.16 4.74 7.11 0.1 0.2 0.3 B3 0.08 100.0% 0.90 5 3.16 4.74 7.11 0.2 0.3 0.5 B4 0.19 100.0% 0.90 5 3.16 4.74 7.11 0.5 0.8 1.2 A 0.11 275 2.0% 10.0% 0.41 16 1.47 2.20 3.30 0.1 0.1 0.1 B 1.66 520 2.8% 90.0% 0.85 7 2.45 3.67 5.51 3.4 5.2 7.7 C 0.51 575 8.2% 5.0% 0.38 15 1.53 2.29 3.43 0.3 0.4 0.7 • D 0.06 iroo 0.90' • ..5 3.1"6 4 74 7 11 • 02 ' 0.3 ^ d:-4 E 0 02 IOOO". 0.90 - 5 3.]6 471 7 11 ::o.i.; ' 0,1 • - 0.1 F 0.03' 100 0% 0.90 5 3.16 •4.74 7 11 • o.^r^ 0.1 0.2 G 0.10 155 21:9% 5.0% 0.38 ' • 6 ' 2.88 4.32 6 47 0.1 " 0:2. 0.2 H 1.20 475 2.4% 90.0% 0.85 7 2.44 3.66 5.49 2.5 3.7 5.6 I DISCHAR GETO PUMP TOTAL DISCHARGE SUMM ARY Q2 QIO QIOO Q2 QIO QIOO PRE DEVELOP 4.30 6.46 9.68 PRE 6.40 9.60 14.40 PRE DEVELOP 4.30 6.46 9.68 DEVELOP 6.40 9.60 14.40 POST DEVELOP 7.49 11.24 16.86 POST 7.91 11.87 17.81 POST DEVELOP 7.49 11.24 16.86 DEVELOP 7.91 11.87 17.81 INCREASE 3.19 4.78 7.18 1.51 2.27 3.41 INCREASE 3.19 4.78 7.18 INCREASE 1.51 2.27 3.41 NOTE: HIGH ILIGHTEi: ) AREAS FLOV V TO THE I JNDERGROUND SD SYSTEM FROM THE SOUTHEAST TO THE SOUTHWEST. (THEY DO NOT DISCHARGE BY THE PUMP) L:\Projects\"\04-38 hydro 11-28-05.xls BIO-SWALE (TYP.) Worksheet for Irregular Channel Project Description Worksheet BIO-SWALE Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Channel Slope 1.6000 % Water Surface Elevation 1.00 ft Options Current Roughness Improved Letter's Method Method Open Channel Weighting Improved Letter's Method Method Closed Channel Weighting Horton's Method Method Results Mannings Coefficient 0.200 Elevation Range 0.70 to 6.00 Discharge 0.32 cfs Flow Area 1.2 ft^ Wetted Perimeter 8.02 ft Top Width 8.00 ft Actual Depth 0.30 ft Critical Elevation 0.83 ft Critical Slope 145.0701 % Velocity 0.26 ft/s Velocity Head 0.00 ft Specific Energy 1.00 ft Froude Number 0.12 Flow Type Subcritical Roughness Segments Start Station End Station Mannings Coefficient 0+00 0+18 0.200 Natural Channel Points Station (ft) Elevation (ft) 0+00 0+04 0.70 0+08 1.00 0+18 6.00 Project Engineer: Thomas A. Jones l:\projects\0438\admin\hydro\bio swale.fm2 BDS Engineering. Inc. 1666"°"'''"'' ^ PaS'l 6/4/2006 12:26 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-16bb f aye i Cross Section Cross Section for Irregular Channel Project Description Worksheet BIO-SWALE Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Section Data Mannings 0.200 Coefficient Channel Slope 1.6000 % Water Surface 1.00 ft Elevation Elevation Range 0.70 to 6.00 Discharge 0.32 cfs 6.00 5.50 4.50 3.50 2.50 1.50 0.50 (j u,, I 0+00 0+02 0+04 0+06 0+08 0+10 0+12 0+14 0+16 0+18 V:l[\ H:1 NTS Project Engineer: Thomas A. Jones I:\projects\0438\admin\hydro\bioswale.fm2 BDS Engineering, Inc. on, 7« IRR/'""^^""^'^PaSel 6/4/2006 12-27 PM © Haestad Methods, Inc. 37 Brookside Road Waterisury, CT 06708 USA +1-203-755-1666 Pagel ft>S Engmeermg, Inc. CIVIL ENGINEERS JIOJECT: ENGINEER: CE. NO.: LEUCADIA WASTEWATER DISTRICT PROJECTNO.: 04-38 R. KUNISHIGE DATE: APRIL 17, 2006 DETENTION BASIN STORAGE COMPUTATION, SINGLE HYDROGRAPH FROM ^UT VARIABLES (URBAN CONDITIONS) Six hour precipitation amount (inches) Time of concentration (min.) Coefficient of runoff Basin area (acres) )MPUTATION Time to peak Tp=2.0TeKD/ (1 + Kp) = 1.1072Te Time of hydrograph to begin TB = 20-TP Time of hydrograph to end TE = 20+ 1.5Tp Peak flow Qp=CIA lTe = 7.44P6/T 0.645 5.25 in/hr Surroimding Flow (Qs) Depth of precipitation for 2 hours D,2o = 7.44 Pfi / 120°-^^^(2hr) Di2o = 0.6785 Pfi = 1.83 m Depth of Precepitation for hydrograph 0.97 DH = (P6Te°"')/5.83 m. Surrounding intensity IS = 60(DI2O-DH)/(120-2.5T,) I3 = 0.52 in/hr Qs = CIsA PLOT HYDROGRAPH AND SURROUNDING FLOW UTFLOW / BASIN SIZE (NATURAL CONDITIONS) Outflow C= 0.645 jE; 1=7.44 Pfi/T, QN=CIA SERVOIR VOLUME ABOVE Q, LEVEL, Cubic feet in/hr m:\exceMomis\hydraulic.xis 1 of 1 mm P6= C= A=" T = TR= QN= Vol= 2.7 8.0 0.78 4.1 8.86 11.14 TE=_ 33.29 Qp=_ 16.8 1.7 0.0 10061 VIII. DRAINAGE MAP L;\PROJECTS\0438\Admin\Hydro\HYDRO STUDY AND COVER.doc