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October 25, 2013
Erika Bridges, E.I.T.
Graduate Civil Engineer
City of College Station
Planning & Development Services
1101 Texas Avenue South
College Station, Texas 77842
Re: La Quinta Inn & Suites - Drainage Letter Report
Dear Erika:
The site plan for this new project "La Quinta Inn & Suite" being proposed on Lot # 5R-2
with an area of 1.727 acres will be located on Graham Road between State Highway 6 and
Longmire Drive in College Station, Texas. This Hotel development is also designed to comply
with the drainage requirements and report that was prepared for that subdivision. The drainage
report states that no detention pond is necessary for the Graham Comer Plaza, but in this
property, must provide a drainage report letter indicating that the Hotel development does not
create any flooding or exceed the capacity of the existing and proposed underground 18" RC
pipes located at the private roadway along Popeye's and southwest corner of this Hotel property.
The site will discharge the storm water with pipe all the way to the North Fork of Lick Creek by
using the 24' easement of the adjacent property of Lot 6R-2.
The purpose of this letter is to provide a Summary Analysis of the anticipated runoff
from the site based on the drainage area map (sheet C3a) as Exhibit A. Also shown, the lot
portion area of 0.441 acre, will be discharged to the existing underground 18" RC pipes. The
drainage report for this subdivision indicates that the capacity of that pipe is:
Qioo = 10,59 cfs
By using the Rational Method formula in Exhibit B, from the lot portion of the Hotel
site development, the calculated flow rates are as follows:
Existing Popeye's Chicken Restaurant site .................
Q]oo =
5.40
cfs
Prop. La Quinta Inn & Suites site (0.441 ac).... _........
Qtoo =
3.54
cfs
Total Flow Rate............................. ................... ..............
Qioo =
8.94
cfs
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The Allowable... Qioo = 10.59 cfs > Total flow rate... Qioo = 8.94 cfs
The remaining area for the Hotel site development was also calculated based on Exhibit
A (EX. - A2) with an area of 1.286 acres and also indicates that the capacity of that pipe is:
Qioo = 12.72 cfs
The Total Flow Rates with combined catchment area shown as Exhibit C from the
Planned Development of the La Quinta Inn & Suites site is:
Qtoo = 11.49 cfs
The Allowable ... Qloo = 12.72 cfs > Total Flow Rate... Qloo = 11.49 cfs
From this analysis, we conclude that the flow coming from the proposed site and the
adjoining drainage area is less than the capacity of the existing and proposed 18" RC outfall pipe.
Therefore, no on -site detention pond is necessary for the development of the proposed La Quinta
Inn & Suite site.
Sincerely,
Ably- I
Edward M. Faggett, P.E.
Project Engineer
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