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HomeMy WebLinkAboutTract 6760 - Drainage StudyTract No. 6760 DRAINAGE STUDY 2 Table of Contents 1.0 PURPOSE ...................................................................................................................3 2.0 GUIDELINES ...............................................................................................................3 3.0 DESIGN APPROACH .................................................................................................3 4.0 CONCLUSION AND RECOMMENDATIONS .............................................................5 ..................................................................................................................back of report Soil Map ....................................................................................................back of report Hydrology Calculations..............................................................................back of report Inlet Sizing Calculations ............................................................................back of report Hydraulics Calculations and Profiles .........................................................back of report Basin Exhibit ..............................................................................sleeve in back of report Drainage Exhibit .........................................................................sleeve in back of report Reference ..................................................................................................back of report Reference ..................................................................................................back of report 4. Tract No. 6760 DRAINAGE STUDY 3 1.0 PURPOSE The purpose for this drainage study is as follows: 1. To provide a storm drainage system in accordance with the City of Bakersfield requirements and guidelines. 2. To provide an economical and reasonable design for storm drain conveyance and disposal facilities. 2.0 GUIDELINES The following design standards were used in the development of this study: 1. Initial times of concentration (roof to gutter) are 15 minutes for R-1 Development. 2. Soil Group A is primarily located throughout the site: 127— Granoso sandy loam, 0 to 2 percent slopes, overwash 174— Kimberlina fine sandy loam, 0 to 2 percent slopes MLRA 17 3. The runoff coefficients used are: 0.27 - R-1, 15,000 S.F. 0.38 - R-1, 7,500 S.F. 4. Rainfall intensity curves used are those shown on Plate D-1 of the City of Bakersfield, Subdivision & Engineering Manual. 3.0 DESIGN APPROACH The contributing areas to the existing storm drain system are all zoned residential and therefore were modeled as such. The project area for these improvements is dictated by the flat terrain that is present. More specifically the improvements are bounded to the east by Parcel A of Parcel Map 3790, to the north by Tract 6290, to the south by Taft Highway, and to the west by Tract 6491. The property was previously vacant and had a natural courses of drainage towards the middle of the site. The proposed project will construct 33 residential lots ranging in size from 8,100 sq. ft. to 16,713 sq. ft. and an existing residential lot adjacent to Taft Highway. The proposed drainage differs from the Approved Drainage Study for Tract 6491 by using a lower runoff coefficient and the addition of an existing residence to the watershed. Drainage Areas along Boise River Drive will drain midway between Agassiz Rock Way and the end of each cul-de-sac. Catch basins #1 and #2 will collect the discharge produced by site areas along north of the T-intersection of Boise River Road and Agassiz Rock Way. The existing residential lot, off of Taft Highway, will be incorporated into Drainage Area 3 which will have a composite runoff coefficient. Although this lot drains into CB8, the analysis is more conservative to include this area at the upstream end of the pipe network than further downstream at the existing inlet. Drainage Areas 3 and 4 will discharge into two catch basins (CB #3 and #4) south of the Boise River Road and Agassiz Rock Way T-intersection. Analysis for the proposed improvements along Taft Highway was included as part of Area 8A in the Approved Drainage Study for Tract 6491. (See Reference Section for Drainage Study Map) The flows for the sizing of the pipes were estimated utilizing the City of Bakersfield Rational Method in accordance with the Subdivision Standards. Flows were computed for the 10-year event using the formula Q = CIA, where Q is the flow in cubic feet per second, C is the runoff Tract No. 6760 DRAINAGE STUDY 4 coefficient, I is the intensity in inches per hour, and A is the catchment’s area in acres. The storm drain system and the curb capacities were calculated based the 10-year storm event. The existing retention basin is located at the southwest corner of Tract 6491 and handles all of the discharge from Tract 6760 and the existing residential lot. The existing basin volume was calculated in the Approved Drainage Study for Tract 6757 and 6758 which does included the drainage areas for Tract 6757, 6758, and 6491. The rational method for the 10-year event was performed using Autodesk Hydraflow Storm Sewers Extension 2015. This program routes the flows and calculates the HGL for the system. The program has the ability to calculate the time of concentrations, but it also allows you to enter your own time. A spreadsheet similar to the curb capacity spreadsheet was used to determine the initial time of concentrations in a 10-year event. The flows from the 10-year event were calculated and routed. Starting HGL at the existing stub was at an elevation of 341.82 which was established by the Approved Drainage Study for Tract 6491 per CB5. 4.0 CONCLUSION AND RECOMMENDATIONS The flows from the 10-year event were calculated and routed. All the pipes in this system were sized to be 18” RCP and is not less than 0.5’ below the proposed grade at any manhole or inlet. The required sump capacity for Tract 6760 and an existing residential lot is 0.54 ac-ft. Based on the Approved Drainage Study for Tract 6491, the required sump capacity for Area 5 was calculated at 0.55 ac-ft which is 0.01 ac-ft greater than the current analysis. Thus the previously analyzed required sump capacity is about the same volume for the proposed required sump. The coefficient values are provided for each area and the calculations for the required volumes are shown below. (See Reference Section for Existing Basin Capacity) Area Acres Coefficient C x A Approved TRACT 6491 See Approved Drainage Study for Tract 6491 AREA 5 8.71 0.42 0.35 AREA 5 Ʃ(CXA) =3.66 TOTAL (AC)8.71 VOLUME REQUIRED (AF) =0.55 Proposed TRACT 6760 R-1, 7500 SF 8.92 0.38 3.39 R-1, 15000 SF 0.71 0.27 0.19 TRACT 6536 Ʃ(CXA) =3.58 TOTAL (AC)9.63 VOLUME REQUIRED (AF) =0.54 The Basin Exhibit, part of this study, shows the existing basin based with the proposed improvements based on Approved Drainage Study for Tract 6757 and 6758. This basin will be deepened by 0.55 feet to account for the proposed improvements. The basin will have a new water depth of 9.0’ by holding the existing design water surface elevation at 343.0. The updated basin will be able to store 11.99 AF of runoff with required volume for all tracts is 11.97 AF which has an excess volume of 0.02 AF. Tract No. 6760 DRAINAGE STUDY 5 Vicinity Map NOT TO SCALE SOIL MAP Hydrologic Soil Group—Kern County, California, Northwestern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 1 of 4 39 0 4 5 9 0 39 0 4 6 4 0 39 0 4 6 9 0 39 0 4 7 4 0 39 0 4 7 9 0 39 0 4 8 4 0 39 0 4 8 9 0 39 0 4 9 4 0 39 0 4 9 9 0 39 0 5 0 4 0 39 0 4 5 9 0 39 0 4 6 4 0 39 0 4 6 9 0 39 0 4 7 4 0 39 0 4 7 9 0 39 0 4 8 4 0 39 0 4 8 9 0 39 0 4 9 4 0 39 0 4 9 9 0 39 0 5 0 4 0 312140 312190 312240 312290 312340 312390 312440 312090 312140 312190 312240 312290 312340 312390 312440 35° 16' 15'' N 11 9 ° 3 ' 5 7 ' ' W 35° 16' 15'' N 11 9 ° 3 ' 4 2 ' ' W 35° 16' 0'' N 11 9 ° 3 ' 5 7 ' ' W 35° 16' 0'' N 11 9 ° 3 ' 4 2 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 100 200 400 600 Feet 0 30 60 120 180 Meters Map Scale: 1:2,310 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Kern County, California, Northwestern Part Survey Area Data: Version 8, Sep 9, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 13, 2013—Oct 23, 2013 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—Kern County, California, Northwestern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 2 of 4 Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Kern County, California, Northwestern Part (CA666) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 127 Granoso sandy loam, 0 to 2 percent slopes, overwash A 2.3 26.4% 174 Kimberlina fine sandy loam, 0 to 2 percent slopes MLRA 17 A 6.3 73.6% Totals for Area of Interest 8.6 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Hydrologic Soil Group—Kern County, California, Northwestern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 3 of 4 Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—Kern County, California, Northwestern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 2/29/2016 Page 4 of 4 HYDROLOGY CALCULATIONS CITY OF BAKERSFIELD RATIONAL METHOD (In accordance with City of Bakersfield Standards) TABLE OF RUNOFF COEFFICIENTS R-1, 6000 SF 0.42 JOB TITLE:Tract 6760 R-1, 6750 SF 0.4 DATE:Nov-16 R-1, 7500 SF 0.38 R-1, 10000 SF 0.34 Rational Values:R-1, 15000 SF 0.27 Event: 10 YEAR Values: 5, 10, 50 R-3, R-4, M-H 0.8 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Commercial 0.9 Industrial 0.8 Curve Values Parks 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type A Soil 0.15 b: -0.058 Grasslands, Type B Soil 0.25 P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type C Soil 0.35 K1: 40.00 (Tc>=20min.) Grasslands, Type D Soil 0.45 Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.10 0.17 Lawn-landscape 2-7% slope 0.15 0.22 Lawn-landscape 7% slope 0.20 0.35 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Roof to Tm Curb D NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Gutter Travel Cap Pipe Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS Time Time In Dia. AC. MIN. Feet Ft/Ft MIN. MIN. In. Input AREA 1 0.38 1.43 2.11 16.44 180 0.82 0.46% 1.14 60 2.08 16.44 15 1.44 3.10 PIPE 4 23.65 1.14 0.65 0.61 18 17.05 AREA 2 0.38 1.42 2.03 16.45 180 0.82 0.46% 1.10 60 2.07 16.45 15 1.45 3.07 PIPE 3 26.00 1.10 0.62 0.70 18 17.15 PIPE 2 0.38 1.38 4.14 261.63 2.18 1.23 17.15 3.54 18 20.69 0.38 2.83 0.27 0.71 AREA 3 0.36 1.37 3.54 17.25 300 1.42 0.47% 1.74 60 2.22 17.31 15 2.25 3.49 PIPE 6 14.00 1.74 0.99 0.24 18 17.55 AREA 4 0.38 1.34 1.95 17.94 360 1.73 0.48% 0.99 60 2.04 17.94 15 2.94 2.99 PIPE 7 26.30 0.99 0.56 0.78 18 18.72 PIPE 5 0.37 1.29 5.49 394.11 2.60 1.47 18.72 4.47 18 23.19 PIPE 1 0.37 1.09 9.63 159.01 3.92 2.22 23.19 1.20 18 24.39 Required Sump Capacity = 0.15 x C x A =0.54 ac-ft 0.55 ac-ft C = 0.37 A= 9.63 acres C = 0.42 A= 8.71 acres Tract 6760 CALCULATIONS & RESULTS AREA 3 BREAKDOWN Existing R-1, 15,000 SF (APN:532-040-03) Proposed Tract 6760 (Lots 25-33) Required Sump Capacity from (Area 5 of Approved Study) = 0.15 x C x A = Hydrology_10_yr - Copy McIntosh Associates 2001 Wheelan Ct Bakersfield, CA 93309 10 yr Calc 2.25 .49 INLET SIZING CALCULATIONS Inlet Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Nov 17 2016 Catch Basin #1 - Drainage Area 1 Curb Inlet Location = Sag Curb Length (ft) = 3.50 Throat Height (in) = 4.50 Grate Area (sqft) = -0- Grate Width (ft) = -0- Grate Length (ft) = -0- Gutter Slope, Sw (ft/ft) = 0.020 Slope, Sx (ft/ft) = 0.083 Local Depr (in) = 2.00 Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by: Known Q Q (cfs) = 1.14 Highlighted Q Total (cfs) = 1.14 Q Capt (cfs) = 1.14 Q Bypass (cfs) = -0- Depth at Inlet (in) = 4.03 Efficiency (%) = 100 Gutter Spread (ft) = 3.56 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Inlet Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Nov 17 2016 Catch Basin #2 - Drainage Area 2 Curb Inlet Location = Sag Curb Length (ft) = 3.50 Throat Height (in) = 4.50 Grate Area (sqft) = -0- Grate Width (ft) = -0- Grate Length (ft) = -0- Gutter Slope, Sw (ft/ft) = 0.020 Slope, Sx (ft/ft) = 0.083 Local Depr (in) = 2.00 Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by: Known Q Q (cfs) = 1.10 Highlighted Q Total (cfs) = 1.10 Q Capt (cfs) = 1.10 Q Bypass (cfs) = -0- Depth at Inlet (in) = 3.98 Efficiency (%) = 100 Gutter Spread (ft) = 3.51 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Inlet Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Nov 17 2016 Catch Basin #3 - Drainage Area 3 Curb Inlet Location = Sag Curb Length (ft) = 3.50 Throat Height (in) = 4.50 Grate Area (sqft) = -0- Grate Width (ft) = -0- Grate Length (ft) = -0- Gutter Slope, Sw (ft/ft) = 0.020 Slope, Sx (ft/ft) = 0.083 Local Depr (in) = 2.00 Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by: Known Q Q (cfs) = 1.74 Highlighted Q Total (cfs) = 1.74 Q Capt (cfs) = 1.74 Q Bypass (cfs) = -0- Depth at Inlet (in) = 4.70 Efficiency (%) = 100 Gutter Spread (ft) = 4.22 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Inlet Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 3D® by Autodesk, Inc.Thursday, Nov 17 2016 Catch Basin #4 - Drainage Area 4 Curb Inlet Location = Sag Curb Length (ft) = 3.50 Throat Height (in) = 4.50 Grate Area (sqft) = -0- Grate Width (ft) = -0- Grate Length (ft) = -0- Gutter Slope, Sw (ft/ft) = 0.020 Slope, Sx (ft/ft) = 0.083 Local Depr (in) = 2.00 Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by: Known Q Q (cfs) = 0.99 Highlighted Q Total (cfs) = 0.99 Q Capt (cfs) = 0.99 Q Bypass (cfs) = -0- Depth at Inlet (in) = 3.85 Efficiency (%) = 100 Gutter Spread (ft) = 3.38 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- HYDRAULIC CALCULATIONS AND PIPE PROFILES TR A C T 6 7 6 0 HY D R A U L I C C A L C U L A T I O N S ( O U T P U T ) Li n e I D L i n e L e n g t h L i n e S i z e F l o w R a t e V e l A v e C a p a c i t y F u l l I nv e r t D n H G L D n V e l D n V e l H d D n E G L D n S f D n I n v e r t U p (f t ) ( i n ) ( c f s ) ( f t / s ) ( c f s ) ( f t ) ( f t ) ( f t / s ) ( f t ) ( f t ) ( % ) ( f t) PI P E 1 1 5 9 . 0 1 1 8 3 . 9 2 2 . 2 2 3 . 6 3 3 3 9 . 5 0 3 4 1 . 8 2 2 . 2 2 0 . 0 8 3 4 1 . 9 0 0 . 1 3 9 3 3 9 . 6 9 PI P E 2 2 6 1 . 6 3 1 8 2 . 1 8 1 . 2 3 3 . 6 1 3 3 9 . 6 9 3 4 2 . 1 2 1 . 2 3 0 . 0 2 3 4 2 . 1 4 0 . 0 4 3 3 4 0 . 0 0 PI P E 3 2 6 . 0 0 1 8 1 . 1 0 2 . 0 9 7 . 4 3 3 4 1 . 4 7 3 4 2 . 2 5 1 . 1 8 0 . 1 4 3 4 2 . 4 0 0. 0 0 0 3 4 1 . 6 0 PI P E 4 2 3 . 6 5 1 8 1 . 1 4 2 . 0 6 7 . 4 8 3 4 1 . 3 8 3 4 2 . 2 5 1 . 0 7 0 . 1 5 3 4 2 . 4 0 0. 0 0 0 3 4 1 . 5 0 PI P E 5 3 9 4 . 1 1 1 8 2 . 6 0 1 . 4 7 3 . 6 3 3 3 9 . 6 9 3 4 2 . 1 2 1 . 4 7 0 . 0 3 3 4 2 . 1 5 0 . 0 6 1 3 4 0 . 1 6 PI P E 6 1 4 . 0 0 1 8 1 . 7 4 0 . 9 8 1 0 . 5 0 3 4 0 . 1 6 3 4 2 . 3 9 0 . 9 8 0 . 0 2 3 4 2 . 4 1 0 . 0 2 7 3 4 0 . 3 0 PI P E 7 2 6 . 3 0 1 8 1 . 0 0 0 . 5 7 1 0 . 4 4 3 4 0 . 1 6 3 4 2 . 3 9 0 . 5 7 0 . 0 0 3 4 2 . 4 0 0 . 0 0 9 3 4 0 . 4 2 Li n e I D H G L U p R i m E l e v U p C o v e r U p V e l U p V e l H d U p E G L U p S f U p S fA v e E n e r g y L o s s J - L o s s C o e f f M i n o r L o s s (f t ) ( f t ) ( f t ) ( f t / s ) ( f t ) ( f t ) ( % ) ( % ) ( f t ) ( f t ) PI P E 1 3 4 2 . 0 4 3 4 7 . 7 6 6 . 5 7 2 . 2 2 0 . 0 8 3 4 2 . 1 2 0 . 1 3 9 0 . 1 3 9 0 . 2 2 2 1 0 . 0 8 PI P E 2 3 4 2 . 2 3 3 4 6 . 6 1 5 . 1 1 1 . 2 3 0 . 0 2 3 4 2 . 2 5 0 . 0 4 3 0 . 0 4 3 0 . 1 1 3 1 0 . 0 2 PI P E 3 3 4 1 . 9 9 3 4 6 . 1 7 3 . 0 7 3 . 0 1 0 . 1 4 3 4 2 . 1 3 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 1. 0 0 z n / a PI P E 4 3 4 1 . 9 0 3 4 6 . 0 8 3 . 0 8 3 . 0 6 0 . 1 5 3 4 2 . 0 4 0 . 0 0 0 0 . 0 0 0 0 . 0 0 0 1. 0 0 z n / a PI P E 5 3 4 2 . 3 6 3 4 5 . 9 3 4 . 2 7 1 . 4 7 0 . 0 3 3 4 2 . 3 9 0 . 0 6 1 0 . 0 6 1 0 . 2 4 2 1 0 . 0 3 PI P E 6 3 4 2 . 4 0 3 4 5 . 4 6 3 . 6 6 0 . 9 8 0 . 0 2 3 4 2 . 4 1 0 . 0 2 7 0 . 0 2 7 0 . 0 0 4 1 0 . 0 2 PI P E 7 3 4 2 . 4 0 3 4 5 . 4 9 3 . 5 7 0 . 5 7 0 . 0 0 3 4 2 . 4 0 . 0 0 9 0 . 0 0 9 0 . 0 0 2 1 0 34 1 . 1 4 34 1 . 0 5 No t e s : z - Z e r o J u n c t i o n L o s s PI P E # 1 C O N N E C T I O N T O S T U B M H - 1 PI P E # 2 M H - 1 M H - 2 PI P E # 3 M H - 2 C B # 2 PI P E # 4 M H - 2 C B # 1 PI P E # 5 M H - 2 M H - 3 M H - 3 PI P E # 6 C B # 3 M H - 3 PI P E # 7 C B # 4 DRAINAGE EXHIBITBASIN EXHIBIT TRACT 6760 BASIN SIZING CALCULATIONS 1.20 344.20 343.00 334.55 8.45 feet Abtm = 40,882 sq ft = 0.94 acres Amid = 60,783 sq ft = 1.40 acres Atop = 73,213 sq ft = 1.68 acres Existing Sump Capacity =503,097 Cu. FT 11.55 AC-FT 334.55 334.00 0.55 feet Abtm =32,988 sq ft = 0.76 acres Amid =33,815 sq ft = 0.78 acres Atop =40,882 sq ft = 0.94 acres 19,170 Cu. FT 0.44 AC-FT Existing Sump Capacity =+ Proposed Additional Sump Capacity = 522,268 Cu. FT 11.99 AC-FT Existing Sump Capacity TOTAL PROVIDED SUMP CAPACITY = Proposed Additional Sump Capacity = TOTAL PROVIDED SUMP CAPACITY = Bottom Area of Sump Half Depth Area of Sump Area of Design Water Level Prismoidal Formula: Volume = 1/6 x(A btm+4Amid+Atop) x D Volume = 1/6 x (0.76+3.11+0.94) x 0.55 = 1/6 x (4.81) x 0.55 Exist. Bottom Basin Elev = Prop. Bottom Basin Elev = Depth from Design Water Surface = Provided Sump Capacity Volume = 1/6 x (0.94+5.58+1.68) x 8.45 = 1/6 x (8.20) x 8.45 Depth from Design Water Surface = Bottom Area of Sump Half Depth Area of Sump Area of Design Water Level Prismoidal Formula: Volume = 1/6 x(A btm+4Amid+Atop) x D Freeboard (ft)= Exist. Water Surface Elev = Exist. Lowest Inlet Elev = Exist. Bottom Basin Elev = Proposed Additional Sump Capacity + TRACT 6760 BASIN SIZING CALCULATIONS TABLE OF RUNOFF COEFFICIENTS C x A = Sq Ft.Acres R-1, 6000 SF 0.42 R-1, 6750 SF 0.4 R-1, 7500 SF 0.38 R-1, 10000 SF 0.34 R-1, 15000 SF 0.27 30,933 0.71 0.19 R-2 0.55 R-3, R-4, M-H 0.8 Commercial 0.9 Industrial 0.8 Parks 0.15 Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.17 Lawn-landscape 2-7% slope 0.22 Lawn-landscape 7% slope 0.35 n C x A =0.19 Total Total 0.71 =Acres 0.71 Required Sump Capacity = 0.15 x C x A = 0.15 X n C x A =0.03 AC-FT =9.04 AC-FT =2.90 AC-FT TOTAL 11.97 AC-FT 0.02 AC-FT AC-FTTotal Difference of Required Sump Capacity Required Sump Capacity for Tracts 6757 & 6758 Required Sump Capacity for Tracts 6760 & 6491 DRAINAGE EXHIBIT Know what's R REFERNCE CITY OF BAKERSFIELD RATIONAL METHOD (In accordance with City of Bakersfield Standards)Street Flow Chart TABLE OF RUNOFF COEFFICIENTS 60 R/W, Slope=0.200% R-1, 6000 SF 0.42 Q, cfs V, f/s JOB TITLE: CURB CAPACITIES TRACT 6491 R-1, 7500 SF 0.38 0.3 1.07 2.6 DATE: Aug-05 R-1, 10000 SF 0.34 0.64 1.35 3 R-1, 15000 SF 0.27 1.6 1.5 4 Rational Values:R-2 0.55 3.75 1.7 5 Event: 10 YEAR Values: 5, 10, 50 R-3, R-4, M-H 0.8 5 1.8 5.5 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Commercial 0.9 6.5 1.9 6 Industrial 0.8 13 1.9 6 Curve Values Parks 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type A Soil 0.15 Street Flow Chart b: -0.058 Grasslands, Type B Soil 0.25 60 R/W, Slope=0.250% P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type C Soil 0.35 Q, cfs V, f/s Curb Cap K1: 40.00 (Tc>=20min.) Grasslands, Type D Soil 0.45 0.3 1.1 2.5 Pavement, drives & roofs 0.95 0.72 1.5 3 Backyards 0.05 1.8 1.7 4 Lawn-landscape 2% slope 0.10 ` 4.3 1.9 5 Lawn-landscape 2-7% slope 0.15 0.22 5.5 2.02 5.5 Lawn-landscape 7% slope 0.20 0.35 7.3 2.1 6 14.6 2.1 6 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Roof to Tm Inlet Curb NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Gutter Travel Size Cap Street Flow Chart Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS Time Time Feet In 60 R/W, Slope=0.300% AC. MIN. Feet Ft/Ft MIN. MIN. Q, cfs V, f/s Curb Cap 0.3 1.25 2.4 RUNOFF & CURB CAPACITY CALCULATIONS 0.79 1.6 3 1.95 1.9 4 AREA 1A 0.90 1.83 0.90 9.47 933 2.333 0.250%1.48 60 1.64 9.47 0 9.47 3.71 4.6 2.05 5 AREA 1B 0.37 1.27 1.91 19.16 383 0.93 0.243%0.90 60 1.53 19.16 15 4.16 3.17 6 2.2 5.5 CP1 0.541 1.27 2.81 19.16 40 0.25 0.625%1.93 60 2.27 19.16 0 0.29 3.62 8 2.35 6 AREA 1C 0.38 1.26 1.56 19.24 383 0.98 0.256%0.74 60 1.50 19.24 15 4.24 3.02 16 2.35 6 CP2 0.483 1.25 4.37 19.45 245 0.65 0.265%2.64 60 1.77 19.45 0 2.31 4.33 AREA 1D 0.41 1.22 1.44 19.90 441 1.14 0.259%0.72 60 1.50 19.90 15 4.90 3.00 Street Flow Chart CB1 0.464 1.22 5.81 19.90 3.30 19.90 3.5 60 R/W, Slope=0.350% AREA 2A 0.41 1.10 1.32 23.01 663 1.74 0.262%0.59 60 1.38 23.01 15 8.01 2.85 Q, cfs V, f/s Curb Cap AREA 2B 0.37 1.26 1.75 19.27 389 1.01 0.260%0.82 60 1.52 19.27 15 4.27 3.09 0.3 1.3 2.25 CB2 0.387 1.10 3.07 23.01 1.31 23.01 3.5 0.85 1.75 3 AREA 3A 0.37 1.15 1.61 21.74 616 1.79 0.291%0.68 60 1.52 21.74 15 6.74 2.96 2.2 2 4 AREA 3B 0.38 1.30 1.25 18.62 321 1.03 0.321%0.62 60 1.48 18.62 15 3.62 2.79 5 2.25 5 CB3 0.374 1.15 2.86 21.74 1.23 21.74 3.5 6.5 2.45 5.5 AREA 4A 0.59 1.00 2.20 26.29 1088 2.72 0.250%1.30 60 1.61 26.29 15 11.29 3.53 8.5 2.5 6 AREA 4B 0.42 1.27 0.90 19.06 369 1.44 0.390%0.48 60 1.52 19.06 15 4.06 2.44 17 2.5 6 CB4 0.541 1.00 3.10 26.29 1.67 26.29 3.5 4.03 AREA 7B/CB7B 0.40 1.34 1.23 17.85 273 0.91 0.333%0.66 60 1.60 17.85 15 2.85 3.5 2.74 Street Flow Chart AREA 5/CB5 0.42 1.29 8.71 18.80 470 1.508 0.321%4.71 60 2.06 18.80 15 3.80 6.5 5.04 60 R/W, Slope=0.400% AREA 6/CB6 0.38 1.34 2.19 17.96 369 2.04 0.553%1.11 60 2.08 17.96 15 2.96 3.5 3.07 Q, cfs V, f/s AREA 7A 0.90 2.03 0.75 6.02 632 1.95 0.309%1.37 60 1.75 6.02 0 6.02 3.50 0.3 1.35 2.2 AREA 7C 0.40 1.28 0.96 18.92 380 1.75 0.461%0.49 60 1.61 18.92 15 3.92 2.73 0.9 1.9 3 CB7 0.619 1.28 1.71 18.92 1.36 18.92 3.5 2.25 2.2 4 AREA 8A 0.90 1.81 1.69 9.79 1044 2.61 0.250%2.76 60 1.78 9.79 0 9.79 4.38 5.3 2.4 5 AREA 8B 0.38 1.26 1.37 19.21 424 1.74 0.410%0.66 60 1.68 19.21 15 4.21 2.68 7 2.55 5.5 CB8 0.667 1.26 3.06 19.21 2.58 19.21 3.5 9.2 2.75 6 AREA 9A 0.90 2.01 0.83 6.32 710 2.49 0.351%1.50 60 1.87 6.32 0 6.32 3.48 18.4 2.75 6 AREA 9B 0.41 1.10 2.03 23.06 789 2.49 0.316%0.91 60 1.63 23.06 15 8.06 3.11 CB9 0.552 1.10 2.86 23.06 1.73 23.06 3.5 Street Flow Chart AREA 10A 0.90 2.01 0.81 6.36 677 2.02 0.298%1.47 60 1.77 6.36 0 6.36 3.58 60 R/W, Slope=0.500% AREA 10B 0.38 1.40 1.28 16.86 198 1.34 0.677%0.68 60 1.78 16.86 15 1.86 2.57 Q, cfs V, f/s Curb Cap CB10 0.582 1.40 2.09 16.86 1.70 16.86 3.5 0.3 1.45 2.05 AREA 11/CB11 0.35 1.38 1.20 17.27 230 1.65 0.717%0.58 60 1.69 17.27 15 2.27 3.5 2.83 1 2.05 3 AREA 12/CB12 0.37 1.41 1.43 16.77 194 1.03 0.531%0.74 60 1.83 16.77 15 1.77 3.5 3.02 2.5 2.4 4 AREA 13/CB13 0.90 2.16 0.96 3.76 385 0.97 0.252%1.87 60 1.71 3.76 0 3.76 3.5 4.03 6 2.7 5 SUMP 0.05 0.83 0.63 33.69 0.03 33.69 0 8 2.9 5.5 10 3 6 TOTAL AREA: 0.47 40.91 20 3 6 2.90 Ac.Ft.Assumptions: Bottom Elev. = Design Water Surface Elev. = Hydraulic Grade Line @ Sump = Future Required Basin Volume = 0.15 x C x A= 0.15 x 0.47 x 40.91 = 2.90 ac-ft Required Basin Volume = 0.15 x C x A= 0.15 x 0.46 x 30.16 = 2.07 ac-ft A1= sf A2= sf A3= sf Vol = 1/5*(A1+3*A2+A3)*Depth to DWS Vol = cf =2.17 ac-ft Req. Basin Size:333.95 341.95 337.95 94478 11736 16234 RETENTION BASIN DIMENSIONS 7607 05051DS01 McIntosh Associates 2001 Wheelan Ct Bakersfield, CA 93309 10 yr Calc CITY OF BAKERSFIELD RATIONAL METHOD TABLE OF RUNOFF COEFFICIENTS (In accordance with City of Bakersfield Standards)R-1, 6000 SF 0.42 R-1, 7500 SF 0.38 JOB TITLE: DRAINAGE STUDY TRACT 6757 AND 6758 R-1, 10000 SF 0.34 DATE: June 2006 R-1, 15000 SF 0.27 R-2 0.55 Rational Values:R-3, R-4, M-H 0.8 Event: 10 YEAR Values: 5, 10, 50 Commercial 0.9 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Industrial 0.8 Parks 0.15 Curve Values Grasslands, Type A Soil 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25 b: -0.058 Grasslands, Type C Soil 0.35 P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45 K1: 40.00 (Tc>=20min.) Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.10 0.17 Lawn-landscape 2-7% slope 0.15 0.22 Lawn-landscape 7% slope 0.20 0.35 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Initial Tm Inlet NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Size Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time Feet AC. MIN. Feet Ft/Ft MIN. CURB CAPACITY CALCULATIONS FLOW TO CATCH BASIN #1 AREA 1 0.49 1.16 4.33 21.42 853 3.34 0.392%2.45 60 2.21 21.42 15 6.42 3.50 FLOW TO CATCH BASIN #2 AREA 2 0.36 1.01 7.45 25.91 1272 3.71 0.292%2.71 60 1.94 25.91 15 10.91 3.50 FLOW TO CATCH BASIN #3 AREA 3 0.43 1.23 7.11 19.87 543 1.42 0.262%3.78 60 1.86 19.87 15 4.87 3.50 FLOW TO CATCH BASIN #4 AREA 4 0.42 1.19 3.42 20.69 575 1.49 0.259%1.72 60 1.68 20.69 15 5.69 3.50 FLOW TO CATCH BASIN #5 AREA 5 0.35 1.08 3.39 23.73 840 2.24 0.267%1.28 60 1.60 23.73 15 8.73 3.50 FLOW TO CATCH BASIN #6 AREA 6 0.90 1.80 1.16 10.00 535 1.07 0.200%1.88 90 1.36 10.00 0 6.57 3.50 FLOW TO CATCH BASIN #7 AREA 7 0.33 1.24 1.99 19.59 418 1.12 0.268%0.81 60 1.52 19.59 15 4.59 3.50 FLOW TO CATCH BASIN #8 AREA 8 0.36 1.08 5.30 23.54 977 2.89 0.296%2.06 60 1.91 23.54 15 8.54 3.50 FLOW TO CATCH BASIN #9 AREA 9 0.35 1.14 4.20 21.96 763 2.31 0.303%1.67 60 1.83 21.96 15 6.96 3.50 FLOW TO CATCH BASIN #10 AREA 10 0.34 1.10 4.47 22.95 872 2.66 0.305%1.68 60 1.83 22.95 15 7.95 3.50 FLOW TO CATCH BASIN #11 AREA 11 0.37 1.13 2.92 22.09 678 1.86 0.274%1.22 60 1.59 22.09 15 7.09 3.50 P:\PROJECTS\04102\studies\Drainage\Revisions to Ashe Road Add Street Access (for City Review)\04102DSrevised access steet04102DSrevised access steet 11/18/2015 11:49 AM Page 1 CITY OF BAKERSFIELD RATIONAL METHOD TABLE OF RUNOFF COEFFICIENTS (In accordance with City of Bakersfield Standards)R-1, 6000 SF 0.42 R-1, 7500 SF 0.38 JOB TITLE: DRAINAGE STUDY TRACT 6757 AND 6758 R-1, 10000 SF 0.34 DATE: June 2006 R-1, 15000 SF 0.27 R-2 0.55 Rational Values:R-3, R-4, M-H 0.8 Event: 10 YEAR Values: 5, 10, 50 Commercial 0.9 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Industrial 0.8 Parks 0.15 Curve Values Grasslands, Type A Soil 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25 b: -0.058 Grasslands, Type C Soil 0.35 P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45 K1: 40.00 (Tc>=20min.) Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.10 0.17 Lawn-landscape 2-7% slope 0.15 0.22 Lawn-landscape 7% slope 0.20 0.35 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Initial Tm Inlet NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Size Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time Feet AC. MIN. Feet Ft/Ft MIN. CURB CAPACITY CALCULATIONS FLOW TO CATCH BASIN #12 AREA 12 0.35 1.00 7.16 26.36 1198 3.05 0.255%2.53 60 1.76 26.36 15 11.36 3.50 FLOW TO CATCH BASIN #13 AREA 13 0.46 1.29 0.89 18.69 329 1.1 0.334%0.53 60 1.48 18.69 15 3.69 3.50 FLOW TO CATCH BASIN #14 AREA 14 0.32 1.20 2.69 20.41 506 1.38 0.273%1.03 60 1.56 20.41 15 5.41 3.50 FLOW TO CATCH BASIN #15 AREA 15 0.37 1.12 3.71 22.32 725 1.81 0.250%1.53 60 1.65 22.32 15 7.32 3.50 FLOW TO CATCH BASIN #16 AREA 16 0.36 1.21 2.92 20.28 507 1.27 0.250%1.27 60 1.60 20.28 15 5.28 3.50 FLOW TO CATCH BASIN #17 AREA 17 0.35 1.20 2.56 20.50 516 1.42 0.275%1.07 60 1.56 20.50 15 5.50 3.50 FLOW TO CATCH BASIN #18 AREA 18 0.37 1.27 1.56 19.10 407 1.33 0.327%0.73 60 1.65 19.10 15 4.10 3.50 FLOW TO CATCH BASIN #19 AREA 19 0.40 1.20 1.98 20.37 497 1.32 0.266%0.95 60 1.54 20.37 15 5.37 3.50 FLOW TO CATCH BASIN #20 AREA 20 0.40 1.21 1.64 20.25 504 1.49 0.296%0.79 60 1.60 20.25 15 5.25 3.50 FLOW TO CATCH BASIN #21 AREA 21 0.40 1.25 2.71 19.49 539 2.29 0.425%1.35 60 2.00 19.49 15 4.49 3.50 P:\PROJECTS\04102\studies\Drainage\Revisions to Ashe Road Add Street Access (for City Review)\04102DSrevised access steet04102DSrevised access steet 11/18/2015 11:49 AM Page 2 CITY OF BAKERSFIELD RATIONAL METHOD TABLE OF RUNOFF COEFFICIENTS (In accordance with City of Bakersfield Standards)R-1, 6000 SF 0.42 R-1, 7500 SF 0.38 JOB TITLE: DRAINAGE STUDY TRACT 6757 AND 6758 R-1, 10000 SF 0.34 DATE: June 2006 R-1, 15000 SF 0.27 R-2 0.55 Rational Values:R-3, R-4, M-H 0.8 Event: 10 YEAR Values: 5, 10, 50 Commercial 0.9 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Industrial 0.8 Parks 0.15 Curve Values Grasslands, Type A Soil 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25 b: -0.058 Grasslands, Type C Soil 0.35 P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45 K1: 40.00 (Tc>=20min.) Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.10 0.17 Lawn-landscape 2-7% slope 0.15 0.22 Lawn-landscape 7% slope 0.20 0.35 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Initial Tm Inlet NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Size Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time Feet AC. MIN. Feet Ft/Ft MIN. CURB CAPACITY CALCULATIONS FLOW TO CATCH BASIN #22 AREA 22 0.62 1.13 4.15 22.20 874 3.97 0.454%2.90 90 2.02 22.20 15 7.20 3.50 FLOW TO CATCH BASIN #23 AREA 23 0.34 1.18 2.78 20.92 560 1.47 0.263%1.13 60 1.58 20.92 15 5.92 3.50 FLOW TO CATCH BASIN #24 AREA 24 0.37 1.09 3.07 23.28 794 2.14 0.270%1.25 60 1.60 23.28 15 8.28 3.50 FLOW TO CATCH BASIN #25 AREA 25 0.49 1.26 2.54 19.29 427 1.16 0.272%1.58 60 1.66 19.29 15 4.29 3.50 FLOW TO CATCH BASIN #26 AREA 26 0.38 1.11 4.66 22.83 893 2.52 0.282%1.96 60 1.90 22.83 15 7.83 3.50 FLOW TO CATCH BASIN #27 AREA 27 0.43 1.37 1.36 17.42 220 0.55 0.250%0.79 60 1.51 17.42 15 2.42 3.50 FLOW TO CATCH BASIN #28 AREA 28 0.42 1.19 2.03 20.75 571 1.6 0.280%1.00 60 1.66 20.75 15 5.75 3.50 FLOW TO CATCH BASIN #29 AREA 29 0.55 1.23 4.67 19.77 563 1.68 0.298%3.16 60 1.97 19.77 15 4.77 3.50 FLOW TO CATCH BASIN #30 AREA 30 0.48 1.38 1.43 17.27 260 1.1 0.423%0.94 60 1.91 17.27 15 2.27 3.50 FLOW TO CATCH BASIN #31 AREA 31 0.38 1.22 2.70 19.95 542 2.01 0.371%1.25 60 1.82 19.95 15 4.95 3.50 FLOW TO CATCH BASIN #32 AREA 32 0.44 1.29 1.45 18.72 386 1.41 0.365%0.83 60 1.73 18.72 15 3.72 3.50 FLOW TO CATCH BASIN #33 AREA 33 0.40 1.31 1.88 18.50 325 0.89 0.274%0.98 60 1.55 18.50 15 3.50 3.50 P:\PROJECTS\04102\studies\Drainage\Revisions to Ashe Road Add Street Access (for City Review)\04102DSrevised access steet04102DSrevised access steet 11/18/2015 11:49 AM Page 3 CITY OF BAKERSFIELD RATIONAL METHOD TABLE OF RUNOFF COEFFICIENTS (In accordance with City of Bakersfield Standards)R-1, 6000 SF 0.42 R-1, 7500 SF 0.38 JOB TITLE: DRAINAGE STUDY TRACT 6757 AND 6758 R-1, 10000 SF 0.34 DATE: June 2006 R-1, 15000 SF 0.27 R-2 0.55 Rational Values:R-3, R-4, M-H 0.8 Event: 10 YEAR Values: 5, 10, 50 Commercial 0.9 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Industrial 0.8 Parks 0.15 Curve Values Grasslands, Type A Soil 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25 b: -0.058 Grasslands, Type C Soil 0.35 P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45 K1: 40.00 (Tc>=20min.) Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.10 0.17 Lawn-landscape 2-7% slope 0.15 0.22 Lawn-landscape 7% slope 0.20 0.35 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Initial Tm Inlet NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Size Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time Feet AC. MIN. Feet Ft/Ft MIN. CURB CAPACITY CALCULATIONS FLOW TO CATCH BASIN #34 AREA 34 0.40 1.27 2.22 19.17 488 1.91 0.391%1.12 60 1.95 19.17 15 4.17 3.50 FLOW TO CATCH BASIN #35 AREA 35 0.39 1.26 2.37 19.27 502 2.09 0.416%1.17 60 1.96 19.27 15 4.27 3.50 FLOW TO CATCH BASIN #36 AREA 36 0.36 1.19 4.30 20.60 629 2.01 0.320%1.85 60 1.87 20.60 15 5.60 3.50 FLOW TO CATCH BASIN #37 AREA 37 0.44 1.34 0.99 17.86 236 0.62 0.263%0.59 60 1.37 17.86 15 2.86 3.50 FLOW TO CATCH BASIN #38 AREA 38 0.40 1.35 1.47 17.68 243 0.6 0.247%0.80 60 1.51 17.68 15 2.68 3.50 FLOW TO CATCH BASIN #39 AREA 39 0.45 1.42 0.49 16.58 122 0.39 0.320%0.32 60 1.29 16.58 15 1.58 3.50 FLOW TO CATCH BASIN #40 AREA 40 0.35 1.22 2.55 19.90 493 1.47 0.298%1.09 60 1.68 19.90 15 4.90 3.50 FLOW TO CATCH BASIN #41 AREA 41 0.40 1.34 1.91 17.98 297 0.9 0.303%1.02 60 1.66 17.98 15 2.98 3.50 FLOW TO CATCH BASIN #42 AREA 42 0.38 1.33 1.66 18.13 346 1.49 0.431%0.84 60 1.84 18.13 15 3.13 3.50 FLOW TO CATCH BASIN #43 AREA 43 0.40 1.19 2.42 20.66 613 2.16 0.352%1.15 60 1.81 20.66 15 5.66 3.50 FLOW TO CATCH BASIN #44 AREA 44 A 0.90 1.80 1.25 10.00 783 2.17 0.277%2.03 110 1.36 10.00 0 9.57 AREA 44 B 0.90 1.80 0.84 10.00 420 1.05 0.250%1.36 110 1.27 10.00 0 5.49 Catch Basin #44 0.90 1.80 2.09 3.39 10.00 3.50 P:\PROJECTS\04102\studies\Drainage\Revisions to Ashe Road Add Street Access (for City Review)\04102DSrevised access steet04102DSrevised access steet 11/18/2015 11:49 AM Page 4 CITY OF BAKERSFIELD RATIONAL METHOD TABLE OF RUNOFF COEFFICIENTS (In accordance with City of Bakersfield Standards)R-1, 6000 SF 0.42 R-1, 7500 SF 0.38 JOB TITLE: DRAINAGE STUDY TRACT 6757 AND 6758 R-1, 10000 SF 0.34 DATE: June 2006 R-1, 15000 SF 0.27 R-2 0.55 Rational Values:R-3, R-4, M-H 0.8 Event: 10 YEAR Values: 5, 10, 50 Commercial 0.9 M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Industrial 0.8 Parks 0.15 Curve Values Grasslands, Type A Soil 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25 b: -0.058 Grasslands, Type C Soil 0.35 P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45 K1: 40.00 (Tc>=20min.) Pavement, drives & roofs 0.95 Backyards 0.05 Lawn-landscape 2% slope 0.10 0.17 Lawn-landscape 2-7% slope 0.15 0.22 Lawn-landscape 7% slope 0.20 0.35 SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Initial Tm Inlet NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Size Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time Feet AC. MIN. Feet Ft/Ft MIN. CURB CAPACITY CALCULATIONS FLOW TO CATCH BASIN #45 (FROM TRACT 6491 DRAINAGE STUDY) AREA 45 0.90 1.80 0.98 4.84 385 0.97 0.252%1.59 110 1.33 10.00 0 4.84 3.50 FLOW TO CATCH BASIN #45 (FROM THIS STUDY) AREA 45 0.90 1.80 0.88 9.18 710 2.66 0.375%1.43 110 1.29 10.00 0 9.18 3.50 FLOW TO CATCH BASIN #45 (TOTAL) AREA 45 0.90 1.80 1.86 8.36 710 2.66 0.375%3.01 110 1.42 10.00 0 8.36 3.50 FLOW TO CATCH BASIN #46 AREA 46 A 0.90 1.80 1.39 10.00 795 2.4 0.302%2.25 110 1.37 10.00 0 9.64 AREA 46 B 0.90 1.80 0.79 10.00 447 1.7 0.380%1.28 110 1.26 10.00 0 5.93 Catch Basin #46 0.90 1.80 2.18 3.53 10.00 3.50 FLOW TO CATCH BASIN #47 AREA 47 A 0.90 1.80 1.32 10.00 796 2.32 0.291%2.14 110 1.37 10.00 0 9.69 AREA 47 B 0.90 1.80 0.70 10.00 470 1.73 0.368%1.13 110 1.22 10.00 0 6.40 Catch Basin #47 0.90 1.80 2.02 10.00 3.27 10.00 3.50 FLOW TO CATCH BASIN #48 AREA 48 0.90 1.80 2.09 7.18 895 3.73 0.417%3.39 110 2.08 10.00 0 7.18 3.50 TOTAL SITE:0.44 136.90 Req. Sump Size:9.04 Ac.Ft. (0.15*C*A)Assumptions:Sump Bottom Elev. = 334.25 + 2.90 Ac.Ft. (From Tract 6491) Design Water Surface Elev. = 343.00 11.94 Ac.Ft.Hydraulic Grade Line @ Sump =338.63 A1= sf A2= sf A3= sf Vol = 1/5*(A1+3*A2+A3)*Depth to DWS Vol = cf =12.16 ac-ft529664 SUMP DIMENSIONS 48167 60433 73199 P:\PROJECTS\04102\studies\Drainage\Revisions to Ashe Road Add Street Access (for City Review)\04102DSrevised access steet04102DSrevised access steet 11/18/2015 3:40 PM Page 5