ST0003-CS040305HUITT ZOLLARS, INC ~ 3131 McKinne¥ Ave ~ Suite 600 ~ Dc~llos, TX 7S204-2~.89 ~ 2148713311 phone ~ 2145710757 fax ~ huitt zollors corn
March 5, 2004
Ms. Suzan C. Taylor
City of Coppell
Engineering Department
255 Parkway Boulevard
Coppell, TX 75019
RE: Coppell Road Reconstruction
Dear Ms. Taylor:
Attached for your review are three sets of preliminary paving plans, cross-sections and drainage
area maps for the Coppell Road reconstruction project.
As you are well aware the section of Coppell Road that we are designing is very flat. As we have
looked at the existing topography in setting preliminary grades we have discovered that almost all
of the connecting streets and driveways are high and the adjacent properties are low with respect to
the existing Coppell Road pavement. This has driven the proposed grades down in an effort to
allow the adjacent properties to continue to drain into the Coppell Road right-of-way. On the north
end of the project we have also set grades that will save many of the existing trees on the west side
of the road. Due to the relatively flat grades, the drainage design also presents some challenges.
The natural high point for this section of Coppell Road is at its intersection with Hawken Drive.
Surface runoff drains north and south from this location. The drainage to the south results in a few
challenges that we would like to get your input on.
Due to the flat grades and normal depth of the proposed storm sewer system draining to the
south, the only way to daylight the pipe is to extend it approximately 1,000 feet to the south
and grade to drain approximately 150 feet to the creek. This would be in the area of the
roadway that Freese & Nichols is designing. Freese & Nichols would need to design the
extension of the storm sewer to the south so that it could be included with our plans for
construction.
Another option would be to take this water (approximately 20 cfs) to the north and connect it to
the storm sewer that is draining to the north. This solution would add about 100 feet of pipe to
the job and increase the pipe sizes by about six inches.
A third option would be to build our project in two phases. The first phase would be the north
half of the job from Hawken Drive north. The second phase would be to include the section
from Hawken Drive south with the construction of the remainder of the south end of Coppell
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Road (the Freese & Nichols section) so that all of the south storm sewer could be built under
one contract.
We are open to any of these options or any that you might have.
We look forward to meeting with you on April 6, 2004 to discus this challenging project. If you
have any questions or need additional information, please feel free to call.
Sincerely,
HUITT-ZOLLARS, INC.
Kenneth A. Roberts, P.E.
Vice President
Attachments