HomeMy WebLinkAboutDrainage LetterKLING ENGINEERING & SURVEYING
Consulting Engineers • Land Surveyors
4101 Texas Avenue, Suite A Post Office Box 4234
Bryan, Texas 77802 Bryan, Texas 77805
Telephone 979/846-6212
Fax 979/846-8252
B.J. Kling, P.E., R.P.L.S.
S.M. Kling, R.P.L.S.
To: City of College Station February 17, 2012
Development Services
c/o Alan Gibbs, P.E., City Engineer
From: Fred Paine, P.E.
Re: Douglass Used Cars - Lot 1R, Block 1, Greensworld Subdivision Phase 1
Drainage Letter
The purpose of this Letter is to document that the proposed development is not subject to detention
requirements in accordance with Section ILC.3.b(1) - Adjacent to the Primary System
Detention not beneficial to the system:
Watershed: Carter's Creek
Drainage Basin: Carter's Creek
Project Area: 1.46Ac (0.002 sq mi) Tc=10 min
Above Project Area: Approximately 0.4 acres including a portion of SH 6 right of way and a
portion of Lot 2R, Block 1, Greensworld Subdivision Phase 1
Conveyance Pathway Area: Stormwater runoff will discharge directly into the Carter's Creek
Main Channel.
Tinning & Basin Size Analysis: Carter's Creek drainage area to University Drive — 22.1 sq mi
Carter's Creek Tt to University Drive — 2.4 hr
(Source: F.I.S.LOMR)
Project Area: Main Basin:
0.002 sq mi << 22.1 sq mi (-0.01 % of upstream drainage basin)
Tc=l0 min < Tt — 2.4 hr
Certification:
I have conducted a topographic review and field investigation of the existing and proposed
flow patterns for stormwater runoff from the Douglass Used Cars Site (Lot 1R, Block 1,
Greensworld Subdivision Phase 1) to the main stem of Carter's Creek. At build -out
conditions allowable by zoning, restrictive covenant, or plat note, the stormwater flows
from the subject subdivision or site project will not cause any increase in flooding
conditions to the interior of existing building structures, including basement areas, for
storms of magnitude up through the 100-year event.
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ALFRED A,PAINE Licensed Professional Engineer
97221 °Q State of Texas No. 97221
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