HomeMy WebLinkAbout250 South Heath Road - Drainage StudyPORTER & ASSOCILTES, INC.
ENGINEERING & SURVEYING
December 5, 2019
Manny Behl
City of Bakersfield
Public Works Dept.
1501 Truxtun Avenue
Bakersfield, CA 93301
Dear Manny:
P no a a mei
We hereby provide the following calculations and information regarding the Park West Apartments
drainage system. The site is labeled as Area 1 and Area 3 in both the attached Drainage Exhibit and
the approved Drainage Study for Stockdale River Ranch Sump #3 dated August 16, 2018. Stub 1
takes approximately 12.0 acres of runoff, and Stub 2 takes approximately 5.8 acres of runoff. The on-
site pipes are designed to be flowing less than full at peak design discharge.
On-site, the lowest inlet grate elevation is 348.30. This is 1 foot above the high water elevation of the
temporary sump. Therefore, the lowest inlet grate elevation is adequate.
Table A summarizes the results of the on-site inlet sizing calculations. The largest expected flow was
calculated by assuming 50% blockage of the largest area supplied by a single inlet of each type.
Table A - Christy Inlet Peak Flow & Capacity Flow with 50% Blockaqe
Inlet Type
Peak Flow (CFS)
Inlet Capacity w/50% Blockage (CFS)
Catch Basin
3.24
5.6
Chris V-12
0.23
1.7
Christy U-21
1.67
4.7
In accordance with the inlet grating discharge curves attached with the hydrology calculations, Table
A shows that the proposed catch basins and Christy V-12 and U-21 type grates are adequate to
handle the 10 -year flow.
The on-site drainage system design conforms to the approved Stockdale River Ranch Sump #3
Drainage Study and the system is adequate.
Please call me with any questions or comments. Thank you for your consideration in this matter.
Sincerely, �9,OFESS/O
PO/?
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Fred W. Porter 11, RCE 74059 RCE 74059
Enc. Drainage Exhibit Map (P clvl�
Inlet Discharge Curves gTEOF CA
Catch Basin and Inlet Sizing Calculations
1200 21st Street, Bakersfield, California 93301 - 661.327.0362 - FAX 661.327.1065
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LEGEND
UPDATED DRAINAGE AREA FROM
APPROVED DRAINAGE STUDY FOR
STOCKDALE RIVER RANCH SUMP#3
— WORST INLET DRAINAGE AREA
J:\3100\Drainage ,Colcs\2709M—Drainage Exhibit.dwg 12/05/19 fredwporterii
SHEET DATE: 12/05/2019 DRAINAGE
p /\NAGE EX H I B I T
JOB Na. 3100 /�( PORTER & ASSOCIATES, INC.
PARK WEST P ENGINEERING &SURVEYING
ENGINEER: FWP2 �} �+ h�^+ r j }� (� 1200 21St St, Bakersfield, CA 93301
OF 1 SHEETS DRAFTSMEN: LKR AT STOCKDALE RIVER RANCH 661.327.0362 FAX 661.327.1065
Porter & Associates, Inc.
Calculations By: LKR
Date: 12/05/2019 Job No. 3100
Checked By:
Date:
Sheet 1 of 1
Stockdale River Ranch Sump #3 Worst Case Catch Basin 5 -year Flow
Porter & Associates, Inc. Checked By:
Calculations By: KKR Date:
Date: 12/05/2019 Job No. 3100 Sheet 1 of 1
tock ale River Ranch Sump #3 Catch Basin Sizing Table
Catch Basin Q - cfs Opening Required Opening Provided
No. 5 -year ft. ft.
CB 3.24 2.02 150
Notes: 1. Catch Basins are sized in accordance with the attached Inlet Capacity
Chart for Type "A" Standard Catch Basin in a sag condition.
2. Catch Basins wider than the minimum width of 3.50 feet are sized to
the nearest half foot wider than the required width.
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