HomeMy WebLinkAbout53 Development Permit 405 Prairie View Heights BLK 4GALINDO ENGINEERS AND PLANNERS
3833 South Texas Ave., Suite 280 Bryan, Texas 77802
Mr. Kent Laza, P.E.
City Engineer
City of College Station
1101 Texas Avenue South
College Station , TX 77840
Subject: Drainage Report
0 .39-acre tract
August 26, 1996
(409) 846-8868
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Part of Block 4, Prairie View Heights Addition
College Station , TX
Dear Mr. Laza :
Please find enclosed , for your review, an estimate of the stormwater runoff for the
referenced project. These calculations have been performed using our as -built
survey dated May 31, 1996 , a copy of which is enclosed , and the site plan proposed
by C. Barbu Co ., Architects , dated August 7 , 1996 .
The current site conditions reflect its prior use as a commerc ial location w ith
considerable impervious coverage (concrete, gravel , and compacted dirt). The
proposed conditions will not considerably alter the existing conditions but will rather
minimize the impact created by a potential increase in runoff rate .
The attached calculations show that the Q values for a 100-year return , p re and post
developments , show very little change.
Sincerely ,
GALINDO ENGINEERS AND PLANNERS
~t~
.._ ,._ .... -
Christian A. Galindo, P.E., R.P.L.S.
Pres ident
Job:
Name :
Date :
Section
Tot al
Total
1
2
2
17-96
Part of Block 4, Prairie View Heights
OOf.23196
RUNOFFCALCUU\TIONS
RATIONAL METHOD
(County: Brazos)
TABLE 1
Tc= 10.0 (min .)
=====a::== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ======
Soll
Type
A
Acres
c Veloc.
fps
Length
ft
Tconc., min .
Cale. Used 10yrs 25yrs
I
50yrs 100yrs
a
10yrs
a
25yrs
a
50yrs
a
1 OOyrs
=====-=== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ====== ======
EXISTING CONDmONS
Grass/grarel
Concrete
0 .234
0.156
0.300
PROPOSED CONDmONS
Commercial
Commercial
0 .234
0 .156
0.300
0.650
O.!XXJ
O.!XXJ
O.!XXJ
4.000
6.000
6.000
6.000
120
140
140
140
0.5
0.4
0.4
0.4
10.0
10.0
10.0
10.0
8635
8635
8635
8635
9 .861
9 .861
9.861
9 .861
11 .148
11 .148
11 .148
11 .148
11 .639
11 .639
11 .639
11 .639
1 .31
1.21
1 .50
1.38
1.70
1.57
1.77
1 .63
-----------------
2.526
1 .82
1 .21
2.884
200
1.38
3 .261
235
1.57
3.404
2.45
1 .63
------------------------
3.03 3.46 3.91 4 .09
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