HomeMy WebLinkAboutTract 6758 and 6757 Drainage Study DRAINAGE STUDY
FOR
TENTATIVE TRACTS
6757 AND 6758
Project # 04-102
June 2006,
Rev. July 2007
Prepared for:
CENTEX HOMES
Almed Sejati
Design Engineer
Gregg Buckle
Project Manager
Prepared By:
2001 Wheelan Court
Bakersfield, CA 93309
DRAINAGE STUDY
FOR
CENTEX HOMES
TRACTS 6757 AND 6758
TABLE OF CONTENTS
1.0 PURPOSE ...............................................................................................................................2
2.0 GUIDELINES .........................................................................................................................2
3.0 DESIGN APPROACH ...........................................................................................................2
4.0 ASSUMPTIONS .....................................................................................................................2
5.0 OFFISITES .............................................................................................................................2
6.0 CONCLUSIONS AND RECOMMENDATIONS ...............................................................3
7.0 REFERENCES .......................................................................................................................4
8.0 APPENDICES
8.1 Curb Capacity Calculations
8.2 Peak flows, Time of Concentration and Catch Basin Length
8.3 HGL Calculations
FIGURES
FIGURE 1 – Display Map ........................................................................... sleeve in back of report
FIGURE 2 – Pipe Profiles............................................................................ sleeve in back of report
FIGURE 3 – Sump Detail ..................................................................................... in back of report
PURPOSE
The purpose for this Drainage Study is to revise the original drainage study using the City of
Bakersfield requirements and guidelines.
The original drainage study for Tract 6757 and 6758 for Centex Homes was submitted and
approved by the City of Bakersfield on October 11, 2006. The revised study adds runoff to our
storm drain system from the west half width of Ashe Road, and modifies Drain Areas 29 and 30
due to the relocation of access street Okemo Way further north of Ashe Road.
GUIDELINES
The following design standards were used in the development of this study:
1. Initial times to concentration (roof to gutter) are 15 minutes for R-1 Development.
2. The runoff coefficients used are:
A. 0.10 - Lawns & Landscaped Areas, Flat Slope, 2%
B. 0.27 - R-1, 15,000 S.F.
C. 0.34 - R-1, 10,000 S.F.
D. 0.38 - R-1, 7,500 S.F.
E. 0.42 - R-1, 6,000 S.F.
F. 0.95 - Pavement, drives and roofs
3. Rainfall intensity curves used are those shown on Plate D-1 of the City of Bakersfield,
Subdivision & Engineering Manual.
4. Sub-areas using multiple run-off coefficients were given a weighted average based
on the area relative to each coefficient.
DESIGN APPROACH
The project site and surrounding areas containing flowlines sloping towards the project site were
divided into sub-areas to roughly estimate anticipated flow contributions into the proposed
drainage inlets. The flows were estimated utilizing the City of Bakersfield Rational Method in
accordance with the Subdivision Standards. Flows were computed for both the 5-year and 10-
year event using the formula Q = CIA, where Q is the flow in cubic feet per second, C is the
runoff coefficient, I is the intensity in inches per hour, and A is the catchment’s area in acres. The
5-year event was used to determine the curb capacities and the 10-year event was used to
determine the catch basin sizes and pipe sizes.
ASSUMPTIONS
The rational method for the 10-year event was performed using Haestad Methods StormCAD 5.5.
This program routes the flows and calculates the HGL for the system. However, the program
does not calculate the time of concentrations for the sub-areas. Therefore, a spreadsheet similar
to the curb capacity spreadsheet was used to determine the initial time of concentrations in a 10-
year event. The 10-year flows may differ slightly between the spreadsheet and StormCAD due to
different methods in approximating the IDF curve.
OFFSITES
The original study includes the half-width street flow of McKee Road from the north, Mountain
Ridge Drive from the east, Taft Highway from the south, and Ashe Road from the west. The
revised study adds the west half-width of Ashe Road runoff, from the intersection of Ashe and
McKee Road running approximately 1484 feet south near the intersection of Ashe and
Provincetown Avenue (See Area 48 of the Display Map). A catch basin will be placed in sag (CB
#48) to collect the flows into our storm drain system.
REFERENCES
“The City of Bakersfield Design Manual”, prepared by the Department of Public Works
for the City of Bakersfield, 1501 Truxtun Avenue, Bakersfield, CA 93301.
8.0 Appendices
8.1 Appendix
Curb Capacity Calculations (5 year Storm)
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: 5 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: 2.02 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25
b: -0.051 Grasslands, Type C Soil 0.35
P60: 0.460 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45
K1: 31.00 (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 Curb
NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Cap
Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time In
AC. MIN. Feet Ft/Ft MIN.
CURB CAPACITY CALCULATIONS
FLOW TO CATCH BASIN #1
AREA 1 0.49 0.95 4.33 21.62 853 3.34 0.392%2.01 60 2.15 21.62 15 6.62 3.82
FLOW TO CATCH BASIN #2
AREA 2 0.36 0.83 7.45 26.07 1272 3.71 0.292%2.23 60 1.92 26.07 15 11.07 4.11
FLOW TO CATCH BASIN #3
AREA 3 0.43 1.00 7.11 20.02 543 1.42 0.262%3.10 60 1.80 20.02 15 5.02 4.52
FLOW TO CATCH BASIN #4
AREA 4 0.42 0.97 3.42 20.89 575 1.49 0.259%1.41 60 1.63 20.89 15 5.89 3.64
FLOW TO CATCH BASIN #5
AREA 5 0.35 0.88 3.39 23.97 840 2.24 0.267%1.05 60 1.56 23.97 15 8.97 3.30
FLOW TO CATCH BASIN #6
AREA 6 0.90 1.51 1.16 10.00 535 1.07 0.200%1.58 90 1.32 10.00 0 6.74 4.82 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #7
AREA 7 0.33 1.01 1.99 19.83 418 1.12 0.268%0.66 60 1.44 19.83 15 4.83 2.93
FLOW TO CATCH BASIN #8
AREA 8 0.36 0.88 5.30 23.89 977 2.89 0.296%1.69 60 1.83 23.89 15 8.89 3.77
FLOW TO CATCH BASIN #9
AREA 9 0.35 0.93 4.20 22.27 763 2.31 0.303%1.37 60 1.75 22.27 15 7.27 3.50
FLOW TO CATCH BASIN #10
AREA 10 0.34 0.90 4.47 23.31 872 2.66 0.305%1.37 60 1.75 23.31 15 8.31 3.50
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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: 5 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: 2.02 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25
b: -0.051 Grasslands, Type C Soil 0.35
P60: 0.460 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45
K1: 31.00 (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 Curb
NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Cap
Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time In
AC. MIN. Feet Ft/Ft MIN.
CURB CAPACITY CALCULATIONS
FLOW TO CATCH BASIN #11
AREA 11 0.37 0.93 2.92 22.28 678 1.86 0.274%1.00 60 1.55 22.28 15 7.28 3.26
FLOW TO CATCH BASIN #12
AREA 12 0.35 0.82 7.16 26.59 1198 3.05 0.255%2.08 60 1.72 26.59 15 11.59 4.11
FLOW TO CATCH BASIN #13
AREA 13 0.46 1.06 0.89 18.90 329 1.1 0.334%0.43 60 1.41 18.90 15 3.90 2.43
FLOW TO CATCH BASIN #14
AREA 14 0.32 0.99 2.69 20.53 506 1.38 0.273%0.85 60 1.52 20.53 15 5.53 3.12
FLOW TO CATCH BASIN #15
AREA 15 0.37 0.92 3.71 22.56 725 1.81 0.250%1.25 60 1.60 22.56 15 7.56 3.49
FLOW TO CATCH BASIN #16
AREA 16 0.36 0.99 2.92 20.42 507 1.27 0.250%1.04 60 1.56 20.42 15 5.42 3.30
FLOW TO CATCH BASIN #17
AREA 17 0.35 0.98 2.56 20.63 516 1.42 0.275%0.88 60 1.53 20.63 15 5.63 3.14
FLOW TO CATCH BASIN #18
AREA 18 0.37 1.04 1.56 19.39 407 1.33 0.327%0.60 60 1.54 19.39 15 4.39 2.66
FLOW TO CATCH BASIN #19
AREA 19 0.40 0.99 1.98 20.48 497 1.32 0.266%0.78 60 1.51 20.48 15 5.48 3.06
FLOW TO CATCH BASIN #20
AREA 20 0.40 0.98 1.64 20.58 504 1.49 0.296%0.65 60 1.50 20.58 15 5.58 2.84
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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: 5 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: 2.02 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25
b: -0.051 Grasslands, Type C Soil 0.35
P60: 0.460 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45
K1: 31.00 (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 Curb
NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Cap
Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time In
AC. MIN. Feet Ft/Ft MIN.
CURB CAPACITY CALCULATIONS
FLOW TO CATCH BASIN #21
AREA 21 0.40 1.02 2.71 19.61 539 2.29 0.425%1.11 60 1.95 19.61 15 4.61 3.16
FLOW TO CATCH BASIN #22
AREA 22 0.62 0.93 4.15 22.45 874 3.97 0.454%2.38 90 1.95 22.45 15 7.45 3.85
FLOW TO CATCH BASIN #23
AREA 23 0.34 0.97 2.78 21.07 560 1.47 0.263%0.93 60 1.54 21.07 15 6.07 3.19
FLOW TO CATCH BASIN #24
AREA 24 0.37 0.90 3.07 23.50 794 2.14 0.270%1.02 60 1.56 23.50 15 8.50 3.28
FLOW TO CATCH BASIN #25
AREA 25 0.49 1.03 2.54 19.43 427 1.16 0.272%1.30 60 1.61 19.43 15 4.43 3.53
FLOW TO CATCH BASIN #26
AREA 26 0.38 0.90 4.66 23.23 893 2.52 0.282%1.60 60 1.81 23.23 15 8.23 3.70
FLOW TO CATCH BASIN #27
AREA 27 0.43 1.13 1.36 17.55 220 0.55 0.250%0.65 60 1.44 17.55 15 2.55 2.92
FLOW TO CATCH BASIN #28
AREA 28 0.42 0.97 2.03 20.92 571 1.6 0.280%0.82 60 1.61 20.92 15 5.92 3.03
FLOW TO CATCH BASIN #29
AREA 29 0.55 1.01 4.67 19.85 563 1.68 0.298%2.59 60 1.94 19.85 15 4.85 4.24
FLOW TO CATCH BASIN #30
AREA 30 0.48 1.13 1.43 17.43 260 1.1 0.423%0.78 60 1.79 17.43 15 2.43 2.83
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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: 5 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: 2.02 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25
b: -0.051 Grasslands, Type C Soil 0.35
P60: 0.460 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45
K1: 31.00 (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 Curb
NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Cap
Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time In
AC. MIN. Feet Ft/Ft MIN.
CURB CAPACITY CALCULATIONS
FLOW TO CATCH BASIN #31
AREA 31 0.38 1.00 2.70 20.07 542 2.01 0.371%1.03 60 1.78 20.07 15 5.07 3.13
FLOW TO CATCH BASIN #32
AREA 32 0.44 1.06 1.45 19.00 386 1.41 0.365%0.68 60 1.61 19.00 15 4.00 2.76
FLOW TO CATCH BASIN #33
AREA 33 0.40 1.08 1.88 18.57 325 0.89 0.274%0.81 60 1.52 18.57 15 3.57 3.08
FLOW TO CATCH BASIN #34
AREA 34 0.40 1.04 2.22 19.27 488 1.91 0.391%0.93 60 1.91 19.27 15 4.27 3.02
FLOW TO CATCH BASIN #35
AREA 35 0.39 1.04 2.37 19.37 502 2.09 0.416%0.96 60 1.91 19.37 15 4.37 3.04
FLOW TO CATCH BASIN #36
AREA 36 0.36 0.97 4.30 20.87 629 2.01 0.320%1.51 60 1.79 20.87 15 5.87 3.62
FLOW TO CATCH BASIN #37
AREA 37 0.44 1.10 0.99 18.09 236 0.62 0.263%0.48 60 1.27 18.09 15 3.09 2.72
FLOW TO CATCH BASIN #38
AREA 38 0.40 1.11 1.47 17.82 243 0.6 0.247%0.66 60 1.44 17.82 15 2.82 2.92
FLOW TO CATCH BASIN #39
AREA 39 0.45 1.18 0.49 16.63 122 0.39 0.320%0.26 60 1.25 16.63 15 1.63 2.40
FLOW TO CATCH BASIN #40
AREA 40 0.35 1.00 2.55 20.05 493 1.47 0.298%0.90 60 1.63 20.05 15 5.05 3.09
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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: 5 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: 2.02 I=a+bTc (Tc<20min.) Grasslands, Type B Soil 0.25
b: -0.051 Grasslands, Type C Soil 0.35
P60: 0.460 I=K1*(6.02*Tc)^(0.17*LN(p60/K1) Grasslands, Type D Soil 0.45
K1: 31.00 (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 Curb
NAME Runoff Intensity Total Time Length Elev. Gutter Flow Type Vel. MIN. Time Travel Cap
Coef. IN/HR Area Conc. Feet Diff. Slope CFS FPS MIN. Time In
AC. MIN. Feet Ft/Ft MIN.
CURB CAPACITY CALCULATIONS
FLOW TO CATCH BASIN #41
AREA 41 0.40 1.10 1.91 18.07 297 0.9 0.303%0.84 60 1.61 18.07 15 3.07 3.04
FLOW TO CATCH BASIN #42
AREA 42 0.38 1.09 1.66 18.39 346 1.49 0.431%0.69 60 1.70 18.39 15 3.39 2.71
FLOW TO CATCH BASIN #43
AREA 43 0.40 0.98 2.42 20.78 613 2.16 0.352%0.95 60 1.77 20.78 15 5.78 3.07
FLOW TO CATCH BASIN #44
AREA 44 A 0.90 1.51 1.25 10.00 783 2.17 0.277%1.70 110 1.35 10.00 0 9.67 5.00 ** USE MINIMUM Tc OF 10 MINUTES
AREA 44 B 0.90 1.51 0.84 10.00 420 1.05 0.250%1.14 110 1.23 10.00 0 5.71 4.17 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #45 (FROM TRACT 6491 DRAINAGE STUDY)
AREA 45 0.90 1.51 0.98 10.00 385 0.97 0.252%1.33 110 1.27 10.00 0 5.06 4.45 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #45 (FROM THIS STUDY)
AREA 45 0.90 1.51 0.88 10.00 710 2.66 0.375%1.20 110 1.24 10.00 0 9.56 4.25 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #45 (TOTAL)
AREA 45 0.90 1.51 1.86 10.00 710 2.66 0.375%2.53 110 1.39 10.00 0 8.54 5.72 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #46
AREA 46 A 0.90 1.51 1.39 10.00 795 2.4 0.302%1.89 110 1.36 10.00 0 9.76 5.16 ** USE MINIMUM Tc OF 10 MINUTES
AREA 46 B 0.90 1.51 0.79 10.00 447 1.7 0.380%1.07 110 1.21 10.00 0 6.15 4.07 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #47
AREA 47 A 0.90 1.51 1.32 10.00 796 2.32 0.291%1.79 110 1.35 10.00 0 9.80 5.08 ** USE MINIMUM Tc OF 10 MINUTES
AREA 47 B 0.90 1.51 0.70 10.00 470 1.73 0.368%0.95 110 1.18 10.00 0 6.62 3.89 ** USE MINIMUM Tc OF 10 MINUTES
FLOW TO CATCH BASIN #48
AREA 48 0.90 1.51 2.09 10.00 895 3.73 0.417%2.84 110 2.02 10.00 0 7.40 4.08 ** USE MINIMUM Tc OF 10 MINUTES
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8.2 Appendix
Time of Concentration, Catch Basin Length, and Sump
Calculations
(10 year Storm)
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
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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
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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
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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
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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
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8.3 Appendix
HGL Calculations (10 year Storm)
Sump Detail
Display Map and Pipe Profiles