HomeMy WebLinkAboutPM12201 Stockdale River Village - Drainage Study
Drainage Study
Heath Road, Stockdale River Village
PM 12201
Prepared for: Rosedale Land and Development Inc.
August 2020 REVISED JULY 2021
Prepared by:
1800 30TH STREET, SUITE 260
BAKERSFIELD, CA 93301
__________________________________________
Ian J. Parks, RCE 58155
Commercial Development - Drainage Study 265-05
2
Purpose: Calculate the runoff volume for the Heath Road, Stockdale River Village
commercial development site located on the northwest corner of Stockdale
Highway and Heath Road in the City of Bakersfield, to determine the on-site
sump volume required. Runoff volume will be calculated from centerline of Heath
Road and centerline of Stockdale Highway to said commercial development site.
Approach: The following assumptions will be used to determine the required volumes of the
retention basins.
a. Volume of runoff for on-site areas shown in Figure 1.
b. Retention required for the runoff
c. Design of retention basin
Assumptions: The following information was assumed to apply to this study:
a. Areas for retention basin calculations are shown in Figure 1 and based on
the site grading plan.
b. The runoff coefficient used was as follows:
0.95 for pavement and roof areas
0.05 for landscape/backyards
(Based on City of Bakersfield Design Manual)
Calculations: V=0.15*SUM(C*A)
(From the City of Bakersfield Department of Public Works Subdivision and
Engineering Design Policy Manual)
See Table 1 for calculations.
Conclusion: Total volume required for the commercial development is 58,800 cubic feet (1.35
acre-feet). The designed retention basin will provide approximately 73,616 cubic
feet 1.60 acre-feet) as shown in Figure 2. Therefore, the capacities of the designed
retention basin is adequate to retain the required runoff. Hydraulic grade line
calculations shown in Table 2 meet City of Bakersfield Standards. See Figure 3
for the drainage areas that were included in the hydraulic grade line calculations.
The largest anticipated flow rate into a U23 2’ x 2’ catch basin will be 4.1 cubic
feet per second. The proposed catch basin will have a maximum flow rate of 9.02
cubic feet per second shown in Table 3. As a result, the proposed catch basins are
sufficient to drain surface water from the proposed site.
Commercial Development - Drainage Study 265-05
3
Table 1
Commercial Development - Drainage Study 265-05
4
Table 2 Hydraulic Grade Line Calculations
\
Commercial Development - Drainage Study 265-05
5
Table 3
Open Flow Available
Square Feet
Clear Open Area:77%3.08
50% Clogged 50%1.54
Table 3
U23 Catch Basin 2' x 2' Capacity
Commercial Development - Drainage Study 265-05
6
Figure 1
Commercial Development - Drainage Study 265-05
7
Figure 2
VOLUME REQ: 1.35 AC-FT
VOLUME PROVIDED: 1.60 AC-FT
Commercial Development - Drainage Study 265-05
8
Figure 3