HomeMy WebLinkAboutStorm DesignNEW BUILDING FOR
SEIDEL SCHROEDER AND COMP ANY
CITY OF COLLEGE STATION
JC JOB #C0007-005-00
STORMWATER DESIGN CALCULATIONS
APRIL, 2008
The storm drain design calculations for Seidel Schroeder and Company, located at 1410
Copperfield Drive, College Station, TX, Cresent Pointe Phase II, Block 1, Lot 2R, are in
accordance with the drainage report prepared by Kling Engineering & Surveying dated
January 26, 2007. Lot 2R is located within drainage basin DA-3A (pre and pst) in
accordance with the drainage report.
Page 6 of the drainage report states that the maximum impervious lot coverage could not
exceed 80%. The remaining 20% of the lot area is assumed to be landscaped or grassed.
The development of Lot IR is as follows:
Total Area:
Pervious Area:
Impervious Area:
35,431.00 SF
8,246.20 SF
27,184.80 SF
Impervious lot coverage percentage:
8,246.20 I 35 ,431.00 SF = 0.232 = 23.2% > 20%
Stormwater will be collected at a curb inlet located near the northwest property comer.
Stormwater will be directed to a private drainage facility as described in the Kling
drainage report.
The proposed total flowrate to the curb inlet is 7.67 cfs. The attached document shows
the design calculations for the 100 year storm event. The Kling drainage report shows
the peak discharge rate at ultimate development for drainage basin, DA-3A-PST, to be
145 cfs (Table 9, page 9)
7.67 cfs < 145 cfs maximum allowable = OK
. ~ ..
Crescent Point, Phase II, Lot 2R 4/4/08 12:03 PM
CITY OF COLLEGE STATION, BRAZOS COUNTY, TX
REFERENCE: UNIFIED STORMWATER DESIGN GUIDELINES, CITIES OF B/CS (February 2008)
STORM EVENT:
100YR STORM
B D
96
E
8.0 0.73
100 YEAR STORM
Drainage Area 1 (Flow into the Pond)
PROPOSED:
TRAVEL V,FPS
CONCENTRATED FLOW D, FT s Table C-4
TC VOID 378 2.0% 5.7
I TYPE C (Table C-3}1
C, -GOOD GRASS (AVERAGE SLOPE) 0.35
PARKING LOT I ROOF 0.95
I, IN/HR B/(TC+D)"E
TIME
SEC
67
%
23.3%
76.7%
100.0%
MIN
1
10
c
0.08
0.73
0.81
11.64
I
I TYPE SF I ACRES I
A, ACRES GOOD GRASS (AVERAGE SLOPE) 8,246 0.19
PARKING LOT I ROOF 27,185 0.62
35,431 0.81
Q,CFS CIA 7.67