Villages C P3&4-CS 910423 DON A TIPTON, INC.
CONSULTING ENGINEERS
3344/3345
ENGINEERING · SURVEYING · PLANNING
6330 Belt Line Road Suite C GARLAND, TEXAS 75043 (214) 226-2967
April 23, 1991
Ms. Shohre Daneshmond
Engineering Department
CITY OF ~3PPE[~.
255 Parkway Blvd.
Coppell, Texas 75019
RE: VIT.T.%GES OF COPPRLL III & IV
Coppell, Texas
Dear Ms. Daneshmond:
Our review of the existing Villages of Coppell I & II drainage
criteria reveals that the systems were designed under the 100-year
storm criteria with a runoff factor of 4.6. The Villages of
Coppell Phases III & IV are being designed on a 100-year storm,
using the City of Dallas design requirements with a runoff factor
being 4.8. All inlet systems are designed in sag conditions and
are able to handle the 100-year storm using a time of concentration
of 10 minutes. Calculations also reveal the calculated time of
concentration for all systems meet or exceed 15 minutes due to the
starting point of the drainage basin and the discharge point of the
existing systems.
If there are any questions, or we can be of further service, please
do noJL-hesitate to call.
s~~erely, ~
/ DON A. TInNed, INC._ ......
~iivneSvice President
PA: lc