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Home My WebLink About6.7-314HYDROLOGY STUDY FOR The Open Door Network Bakersfield: Homeless Center Campus Project # 22047.00 June 2024 Prepared for: The Open Door Network 1921 19th Street Bakersfield, CA 93301 Contact: Lauren Skidmore (661) 322-9199 Prepared By: David Fidelino Checked By: Sean E. Reed R.C.E. 64620 10800 Stockdale Hwy, Suite 103 Bakersfield, CA 93311 (661) 834-4814 2 Table of Contents 1.0 PURPOSE ................................................................................................................. 3 2.0 GUIDELINES ............................................................................................................ 3 3.0 DESIGN APPROACH ............................................................................................... 3 4.0 CONCLUSION AND RECOMMENDATIONS ............................................................ 4 Soil Map .................................................................................................. back of report Hydrology Calculations ........................................................................... back of report Inlet Sizing Calculations .......................................................................... back of report Drainage Exhibit ...................................................................... sleeve in back of report Reference ............................................................................................... back of report 3 1.0 PURPOSE The purpose for this hydrology study is as follows: 1. To provide adequate sizing for inlets that capture storm runoff 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. The time to concentration is 10 mins since there are no roof to gutter since the roof drains from the buildings will discharge directly into the proposed storm drain system. 2. The entire site is Soil Group A – Kimberlina-Urban land Cajon complex, 0 to 2 percent slopes. The soil group was obtained from the US Department of Agriculture Soils Survey. A Soil Map is enclosed with this report. 3. The runoff coefficient used is: · 1.00 - Pavement without landscaping 3. Rainfall intensity curves used are those shown on Plate D-1 of the City of Bakersfield, Subdivision & Engineering Manual. 4. The run-off coefficient will be 1.00 since the analyzed area is impervious and will have an insignificant amount of landscaping. 3.0 DESIGN APPROACH The contributing areas to the two StormTech Drainage Chambers are commercial therefore were modeled as such so that the improvements were accurate. This report studies the required capacity for these StormTech drainage chambers and the proposed inlet sizes. The project is bounded to the east by Kern Street, to the north by Dolores Street, to the south by Chico Street, and to the west by Tulare Street. Christy Box Inlet #1 is the most upstream end of the northerly proposed storm drain system which collects a portion south of Building B (Drainage Area 1). Drainage Area 2 (GI-2) will discharge into grate inlet located on at the center proposed complex. Area 3 consists of the northerly parking lot off of Dolores Street which drains into GI-3 and adjacent to the underground storage. These areas will be tributary to the northern StormTech Drainage Chamber. GI #7 will collect the discharge produced by Area 7 which is a patio area located within Building A. Drainage Area 4 will consist of a portion of the westerly parking lot off of Tulare Street. The discharge from this area is captured in GI-4 in the middle of a ribbon gutter north of Building A. Drainage Area 5 consists of the northerly parking lot off of Chico Street which drains into GI-5 and adjacent to the underground storage. GI #6 will collect the discharge produced by the patio area on the westerly portion of Building D (Area 6). The southerly drainage chamber will handle the discharge from Areas 4-7. Christy Box Inlets #1, #2, & #4 were sized to be 2’x2’ with a 50% clogging factor while accounting for the area of the bars. Christy Box Inlets #3, & #5 were sized to be 2’x3’ with a 50% clogging. Christy Box Inlets #6 & #7 will be a 1’x1’ opening since it only takes a small area within a building courtyard. The proposed storm drain lines were not analyzed since the system will be privately maintained and located onsite, as verified with the City. The required chamber volumes were calculated using the City of Bakersfield volume equation (V=0.15 x Ʃ (CxA)). The chambers will be designed to accommodate the runoff from the parking lots, patios, and portions of the building based on the location of the roof drains. The total contributing areas equal 2.35 acres; this acreage is divided into the areas as noted on the following page. 4 Area Acres Coefficient C x A "STORMTECH" SOUTH DRAIN CHAMBER 1.26 1.00 1.26 VOLUME REQUIRED (AF) = 0.189 "STORMTECH" NORTH DRAIN CHAMBER 1.09 1.00 1.09 VOLUME REQUIRED (AF) = 0.1635 4.0 CONCLUSION AND RECOMMENDATIONS The main objectives of this study were to design an economical storm drain system and meet the design standards set by the City of Bakersfield. The proposed StormTech drainage chamber will be located between Buildings B & C on the northerly part of the site. This chamber will be able to store 0.172 acre-feet (AF) = 7526 cf, of storm water with a required volume of 0.1635 AF = 7122 cf. The other drainage chamber will be located on the southerly end between Buildings A & D. This chamber will be able to store 0.196 acre-feet (AF) = 8528 cf, of storm water with a required volume of 0.189 AF = 8233 cf. SOIL MAP Hydrologic Soil Group—Kern County, California, Northwestern PartNatural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/6/2023Page 1 of 43916020 3916040 3916060 3916080 3916100 3916120 3916140 39161603916020 3916040 3916060 3916080 3916100 3916120 3916140 3916160318440 318460 318480 318500 318520 318540 318560 318580 318600 318620 318640 318660 318680318440 318460 318480 318500 318520 318540 318560 318580 318600 318620 318640 318660 31868035 ° 22' 20'' N 118° 59' 55'' W35 ° 22' 20'' N118° 59' 45'' W35 ° 22' 15'' N 118° 59' 55'' W 35 ° 22' 15'' N118° 59' 45'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS840 50 100 200 300Feet0 15 30 60 90MetersMap Scale: 1:1,140 if printed on A landscape (11" x 8.5") sheet.Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATIONArea of Interest (AOI) Area of Interest (AOI) SoilsSoil Rating PolygonsA A/D B B/DCC/DDNot rated or not availableSoil Rating Lines A A/D B B/DCC/DD Not rated or not available Soil Rating Points A A/D BB/DC C/DD Not rated or not availableWater Features Streams and Canals TransportationRails Interstate Highways US Routes Major Roads Local Roads BackgroundAerial PhotographyThe soil surveys that comprise your AOI were mapped at1:24,000.Warning: Soil Map may not be valid at this scale.Enlargement of maps beyond the scale of mapping can causemisunderstanding of the detail of mapping and accuracy of soilline placement. The maps do not show the small areas ofcontrasting soils that could have been shown at a more detailedscale.Please rely on the bar scale on each map sheet for mapmeasurements.Source of Map: Natural Resources Conservation ServiceWeb Soil Survey URL:Coordinate System: Web Mercator (EPSG:3857)Maps from the Web Soil Survey are based on the Web Mercatorprojection, which preserves direction and shape but distortsdistance and area. A projection that preserves area, such as theAlbers equal-area conic projection, should be used if moreaccurate calculations of distance or area are required.This product is generated from the USDA-NRCS certified data asof the version date(s) listed below.Soil Survey Area: Kern County, California, Northwestern PartSurvey Area Data: Version 16, Aug 31, 2023Soil map units are labeled (as space allows) for map scales1:50,000 or larger.Date(s) aerial images were photographed: Data not available.The orthophoto or other base map on which the soil lines werecompiled and digitized probably differs from the backgroundimagery displayed on these maps. As a result, some minorshifting of map unit boundaries may be evident.Hydrologic Soil Group—Kern County, California, Northwestern PartNatural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/6/2023Page 2 of 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 180 Kimberlina-Urban land- Cajon complex, 0 to 2 percent slopes A 3.3 100.0% Totals for Area of Interest 3.3 100.0% 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. Rating Options Aggregation Method: Dominant Condition Hydrologic Soil Group—Kern County, California, Northwestern Part Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/6/2023 Page 3 of 4 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 11/6/2023 Page 4 of 4 HYDROLOGY CALCULATIONS CITY OF BAKERSFIELD RATIONAL METHOD(In accordance with City of Bakersfield Standards)TABLE OF RUNOFF COEFFICIENTSR-1, 6000 SF 0.42JOB TITLE: THE OPEN DOOR NETWORK - 529 DOLORES STREET R-1, 6750 SF 0.4DATE: Nov-23 R-1, 7500 SF 0.38R-1, 10000 SF 0.34Rational Values: R-1, 15000 SF 0.27Event: 10 YEAR Values: 5, 10, 50 R-3, R-4, M-H 0.8M.A.P. 6 in./yr. Values: 6, 10, 15, 20, 25, 30 Commercial 0.9Water Well Site 0.1Curve Values Parks 0.15 a: 2.38 I=a+bTc (Tc<20min.) Grasslands, Type A Soil 0.15b: -0.058 Grasslands, Type B Soil 0.25P60: 0.550 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type C Soil 0.35K1: 40.00 (Tc>=20min.) Grasslands, Type D Soil 0.45Pavement without Landscaping 1.00Pavement with Landscaping 0.9Lawn-landscape 2% slope 0.10 0.17Lawn-landscape 2-7% slope 0.15 0.22Lawn-landscape 7% slope 0.20 0.35SUBAREA C I A rslt Tc L dH Sg Q Street V Trial Tc Roof to Tm D CurbNAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Gutter Travel Pipe CapCoef. IN/HR Area Conc. Feet Diff. Slope CFS FPS Time Time Dia. InAC. MIN. Feet Ft/Ft MIN. MIN. In.AREA 1 1.00 1.80 0.12 10.00 59 1.20 2.04% 0.22 2.27 10.00 0.43 1.30AREA 2 1.00 1.80 0.40 10.00 188 1.16 0.62% 0.72 1.81 10.00 1.73 2.62AREA 3 1.00 1.80 0.25 10.00 124 2.39 1.93% 0.45 2.48 10.00 0.83 1.98AREA 4 1.00 1.80 0.36 10.00 143 2.10 1.47% 0.65 2.14 10.00 1.11 2.20AREA 5 1.00 1.80 0.26 10.00 136 2.26 1.66% 0.47 2.51 10.00 0.90 2.00AREA 6 1.00 1.80 0.09 10.00 64 0.50 0.78% 0.16 1.97 10.00 0.54 1.04AREA 7 1.00 1.80 0.02 10.00 20 0.20 0.98% 0.04 1.97 10.00 0.17 0.23Tc CALCULATIONS THE OPEN DOOR NETWORK - 529 DOLORES STREETHydrology_10_yr.xls McIntosh Associates2001 Wheelan CtBakersfield, CA 93311 10 yr Calc10800 Stockdale Hwy, Suite 103 DINLET SIZINGT CALCULATIONS Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Sunday, Nov 5 2023 Drainage Area 1 - Christy Box #1 Drop Grate Inlet Location = Sag Curb Length (ft)= -0- Throat Height (in) = -0- Grate Area (sqft) = 0.85 Grate Width (ft) = 2.00 Grate Length (ft) = 2.00 Gutter Slope, Sw (ft/ft) = 0.022 Slope, Sx (ft/ft) = 0.022 Local Depr (in) = -0- Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.22 Highlighted Q Total (cfs) = 0.22 Q Capt (cfs) = 0.22 Q Bypass (cfs) = -0- Depth at Inlet (in) = 0.52 Efficiency (%) = 100 Gutter Spread (ft) = 5.98 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Sunday, Nov 5 2023 Drainage Area 2 - Christy Box #2 Drop Grate Inlet Location = Sag Curb Length (ft)= -0- Throat Height (in) = -0- Grate Area (sqft) = 0.85 Grate Width (ft) = 2.00 Grate Length (ft) = 2.00 Gutter Slope, Sw (ft/ft) = 0.012 Slope, Sx (ft/ft) = 0.012 Local Depr (in) = -0- Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.72 Highlighted Q Total (cfs) = 0.72 Q Capt (cfs) = 0.72 Q Bypass (cfs) = -0- Depth at Inlet (in) = 1.16 Efficiency (%) = 100 Gutter Spread (ft) = 18.07 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Friday, Dec 1 2023 <Name> Drop Grate Inlet Location = Sag Curb Length (ft) = -0- Throat Height (in) = -0- Grate Area (sqft) = 1.00 Grate Width (ft) = 2.00 Grate Length (ft) = 3.00 Gutter Slope, Sw (ft/ft) = 0.020 Slope, Sx (ft/ft) = 0.020 Local Depr (in) = -0- Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.45 Highlighted Q Total (cfs) = 0.45 Q Capt (cfs) = 0.45 Q Bypass (cfs) = -0- Depth at Inlet (in) = 0.73 Efficiency (%) = 100 Gutter Spread (ft) = 8.07 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Drainage Area 3 - Christy Box #3 50% clogging factor Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Sunday, Nov 5 2023 Drainage Area 4 - Christy Box #4 Drop Grate Inlet Location = Sag Curb Length (ft)= -0- Throat Height (in) = -0- Grate Area (sqft) = 0.85 Grate Width (ft) = 2.00 Grate Length (ft) = 2.00 Gutter Slope, Sw (ft/ft) = 0.020 Slope, Sx (ft/ft) = 0.020 Local Depr (in) = -0- Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.65 Highlighted Q Total (cfs) = 0.65 Q Capt (cfs) = 0.65 Q Bypass (cfs) = -0- Depth at Inlet (in) = 1.08 Efficiency (%) = 100 Gutter Spread (ft) = 11.01 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Friday, Dec 1 2023 <Name> Drop Grate Inlet Location = Sag Curb Length (ft) = -0- Throat Height (in) = -0- Grate Area (sqft) = 1.00 Grate Width (ft) = 2.00 Grate Length (ft) = 3.00 Gutter Slope, Sw (ft/ft) = 0.015 Slope, Sx (ft/ft) = 0.015 Local Depr (in) = -0- Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.47 Highlighted Q Total (cfs) = 0.47 Q Capt (cfs) = 0.47 Q Bypass (cfs) = -0- Depth at Inlet (in) = 0.75 Efficiency (%) = 100 Gutter Spread (ft) = 10.34 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Drainage Area 5 - Christy Box #5 50% clogging factor Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Friday, Dec 1 2023 <Name> Drop Grate Inlet Location = Sag Curb Length (ft) = -0- Throat Height (in) = -0- Grate Area (sqft) = 0.42 Grate Width (ft) = 1.00 Grate Length (ft) = 1.00 Gutter Slope, Sw (ft/ft) = 0.008 Slope, Sx (ft/ft) = 0.008 Local Depr (in) = -0- Gutter Width (ft) = 2.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.16 Highlighted Q Total (cfs) = 0.16 Q Capt (cfs) = 0.16 Q Bypass (cfs) = -0- Depth at Inlet (in) = 0.67 Efficiency (%) = 100 Gutter Spread (ft) = 16.04 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- Drainage Area 6 - Christy Box #6 50% clogging factor Inlet Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Sunday, Nov 5 2023Drainage A Drainage Area 7 - Christy Box #7 Drop Grate Inlet Location = Sag Curb Length (ft) = -0- Throat Height (in) = -0- Grate Area (sqft) = 0.42 Grate Width (ft) = 1.00 Grate Length (ft) = 1.00 Gutter Slope, Sw (ft/ft) = 0.010 Slope, Sx (ft/ft) = 0.010 Local Depr (in) = -0- Gutter Width (ft) = 1.00 Gutter Slope (%) = -0- Gutter n-value = -0- Calculations Compute by:Known Q Q (cfs)= 0.07 Highlighted Q Total (cfs) = 0.07 Q Capt (cfs) = 0.07 Q Bypass (cfs) = -0- Depth at Inlet (in) = 0.39 Efficiency (%) = 100 Gutter Spread (ft) = 7.47 Gutter Vel (ft/s) = -0- Bypass Spread (ft) = -0- Bypass Depth (in) = -0- DRAINAGE EXHIBIT PARKINGNONEW GEN ENGINEERING GROUP"STORMTECH"SOUTH DRAINCHAMBER"STORMTECH"NORTH DRAINCHAMBERNOT A PART NOT A PART NOT A PART NOT A PART REFERENCE