Waters Edge P2-CS 930122'T~uary 22, 1993
Box 478
~oppei!, Texas 75019
4-~62-0022
Mr. Mike Daniel
Nathan Maier Consulting Engineers
Three North Park
8800 N. Central Expy., Suite 300
Dallas, TX 75231
Re: Waters Edge Revisions
Dear Mike:
The City of Coppell has received and reviewed the revised plans for Waters Edge that eliminates
the enclosed drainage system along the southern property line and replaces it with a temporary
open ditch. The City of Coppell understands that this ditch is a temporary solution until the
property south of Waters Edge develops. The reasoning behind not installing the closed system
at this time is that the property to the south conceivably could develop as residential property
instead of commercial property. This would reduce the amount of runoff, thereby reducing the
size of the drainage system needed to handle the storm drainage. Letters have been received
from the property owners to the south that they are in agreement with the temporary ditch
design. While we are in agreement with the temporary ditch design, we do offer several areas
of concern.
What means of erosion control will be utilized to protect the dirt from entering into the
proposed wye inlet?
It appears as though the hydraulic grade line is above the throat opening of the wye inlet
and therefore the system may not function as designed.
As you and I discussed on January 21, 1993, I would like a written response of your
opinion on how this system will function during a hundred year storm, i.e., how far will
the water be backed up into the open ditch, how long will it take the water to drain into
the system, and are there other points of positive overflow (you mentioned that nearby
there is an area where the water flows over the top of the wall).
An additional requirement for this temporary ditch was that it be included as part of the
Homeowners Maintenance Agreement for Waters Edge. The City will be looking for
that caveat in the Homeowners Maintenance Agreement when it comes through the City.
Two additional copies of the plan should be submitted to the City of Coppell for inclusion in our
plans. Also any copies to be forwarded to the contractor should be submitted to the City for
signing by the City Engineer.
If you should have any questions concerning this letter, please feel free to contact me at your
convenience. If not, I would anticipate a response in the very near future concerning the
aforementioned issues.
Sincerely,
Kenneth M. Griffin, P.E.
City Engineer
cc:~'~'Iqfike Martin, Graduate Engineer
Tim House, Matthews Southwest