ST8402-CS 890615 (2)GINN, INC.
June 15, 1989
M~. Russ~¢Doyle,
City of ~oppell
P.O. Bo~ 478
Coppe~, TX 75019
Re:
Denton Tap Road Improvements
from Sandy Lake Road to Denton Creek
Street Flooding at Station 176+50
Dear Mr. Doyle:
Despite the temporary measures enacted as per my letters dated
May 17, 1989 and June 5, 1989, copies attached, flooding of the
outside lane of the new southbound pavement between Stations
176+50 and 177+80 has continued during the recent persistent
thunderstorms. We have found it to be necessary for the
protection of the lives, safety and property of the traveling
public on Denton Tap Road to order the Contractor to expose
lateral D-13a and install an "X" inlet and connecting piping
along with a relief berm and swale diverting some of the
excessive runoff from the modified inlet and temporary berm at
Station 176+50.
In addition to the previous modifications to the inlet at Station
176+50 this should greatly reduce the amount of runoff getting
onto the road and reduce the hazard to the traveling public. The
pipe and inlet work will be paid for at the applicable Contract
unit Prices, and the required earthwork will have to be paid for
in accordance with extra work provisions of the Contract.
On Friday, June 9, 1989, I met with the Contractor and one of the
owners of the adjacent property, Mr. Glen Hinckley, to discuss
the immediate construction of this proposed storm drainage relief
system. Mr. Hinckley, has been extremely helpful and cooperative
in allowing this work to proceed as soon as possible. Mr.
Hinckley did request that we stipulate that the improvements
mentioned herein are temporary and that he may cause them to be
either removed or modified when his property is developed.
We have assured Mr. Hinckley that when his property develops, he
may remove or modify the storm sewer "X" inlet and the swale and
berm in order to extend the storm sewer system as necessary for
the development of his property and any adjacent roadways. It
should be noted that Mr. Hinckley's property, in its current
condition, drains to Denton Tap Road and as such, its developed
runoff can be accommodated in the Denton Tap Road storm sewer
system.
17103 Preston Road · Suite 100 · LB II8 · Dallas, Texas 75248 · Phone 214/248-4900
We suspect that the excessive runoff which is flowing across the
Hinckley property may be partially a result of the increased
runoff from Skaggs shopping center, the inadequate drainage
system for Shady Dale Estates, and some filling of old gravel
pits on the adjacent property. The box culvert which is to be
extended south from the high school site may provide the solution
to this flooding problem. We recommend that this situation be
addressed in the on-going efforts to have the abovementioned box
culvert constructed.
We will continue to monitor the effectiveness of the
abovementioned modifications to the drainage system and attempt
to ascertain the principal sources of the excessive stormwater
runoff. Please call me if you have any questions.
Sincerely,
John C. Karlsruher, P.E.
Project Engineer
JCK/dsp
cc:
Glen Hinckley
Scott Balch
H. Wayne Ginn, P.E.
Randy Fleming
File 379/280
enclosures