Applicant response-DRC 1/8/87 I IEROE-LUNSFORD ASSOCIATES,
INC.
~ ~ CONSULTING ENGINEERS
January 8, 1987
· Shohre Daneshmand -
Ms
ciCivilty of Engineeringcoppell Department
P.O. Box 478
Coppell, Texas 75019
Subject: Advantage Self-Storage (Final Plat)
Dear Ms. Daneshmand:
In answer to your engineering review of the above subject project
that I discussed with you on January 5, 1987, the foregoing
answers your questions in the order that you presented them:
1. The property line has been shaded to clearly show the
property lines of the site·
2. We have added a 6' curb-inlet to supplement the existing 10'
inlet at the cul-de-sac on Northlake Drive· At Q5 plus the
overflow to the drainage swale to the north of the
cul-de-sac. The storm sewer capacity now meets your drainage
s tanda rds.
3. All calculations for the subject project were made using
Technical Paper 40 to compute rainfall intensities. Your
design criteria allows for a five year Frequency Storm
if provision is made for the overflow.
4. Hydraulic calculations have been corrected using Q5 plus an
overflow; therefore, the drainage inlet is adequate.
5. Contours for the drainage area map were taken from a U.S.G.S.
Map. The site grading plan are correct as they were made by
my survey in the field. Corrections have been made·
6. X-inlet is from City of Coppell standard details· Outside
dimensions of X-inlet is 3 1/2' square.
7. Our plans will be combined with the architectual plans
prepared by Joseph Gordon, Architect, which will be presented
to you under his cover sheet.
8. Inlet calculations have been added to the Plan Sheet as
requested.
9. The 28 CFS By-Pass on Drainage Area 2, passes through the
blockout in the wall and is passed through the project in the
street to a flume that conducts it into the drainage ditch·
3109 CARLISLE, SUITE 206 3901 W. PIONEER PARKWAY, SUITE 100
DALLA& TEXAS 75204 ARLINGTON, TEXAS 76013
(214) 871-2126 (817) 461-5868 Metro
January 8, 1987
Page 2
10. The storm sewer system is designed for a 5 year Frequency
Storm with the overflow being carried on the surface. Under
these conditions the storm sewer system is adequate.
11. The design engineer and the owner consider the site drainage
adequate for the purpose.
12. We have shown the storm drainage system on the Site Grading
Plan (Sbt. C-2) as requested.
13. Radius pipe will be used in place of the 2-45° bends where it
makes a sharp turn through the project.
14. We will furnish you a letter signed by the adjacent property
owner, William G. Thompson granting permission for grading on
his property.
15. Flow arrows have been heavied up to show the sheet flow of
the storm water on the site as requested.
16. Dimensions have been added to the proposed drainage easement
on the final plat for the property in the northwest corner of
the project.
17. There is only one rest room on the site. Standard
construction for a 4" line into the existing 8" line will be
through a sanitary wye.
18. All Times of Concentrations used in the calculations of this
project have been 10 minutes.
Thank you for your time and consideration in review of this
project. If I can be of further assistance in clarifying design
matters, please call me.
Sincerely Yours,
PIERCE-LUNSFORD ASSOCIATES, INC.
Richard C. Pierce, P.E.
President
RCP/sh
cc: Joe Beard