DR8902-CS 890223 GINN, INC. CONSULTING EN¢I E, ERS
Mr. Russ~l Doyle, P.E.
city o~Coppell
P.O. ~x 478
Cop~l, TX 75019 ....
Re: Drainage Evaluation
Bethel School Rd./Falcon Lane Intersection
Dear Mr. Doyle:
This is to confirm our understanding of the results of our
meeting of Monday, February 20, 1989, regarding the above
referenced drainage study.
We will prepare an Executive Summary for the report. We will
await hearing from you regarding:
1. Finalizing the report
2. Presentation/meeting with homeowner
3. Presentation/meeting with Council
For the record, the report is complete.
Please let us know about the above at your convenience.
Sincerely,
H. Wayne Ginn, P.E.
cc: Alan D. Ratliff
File 89407
17103 Preston Road · Suite 100 · LB 118 · Dallas, Texas 75248 · Phone 214/248-4900
STORM D~AINAGE EVALUATION OF BETHEL SCHOOL ROAD AND FALCON L~NE
INTERSECTION ]tND AT PELICAN L~/TE IN THE NORTHLAKE WOODLANDS EAST,
P~ASE VI SUBDIVISION.
1. Based upon a request and the approval of the City, an
investigation was made, due to the reports of flooding during
and after the July 12, 1988 storm at two locations in the
Northlake Woodlands East, Phase VI subdivision. Specifically,
those locations are 721, 725 & 726 E. Bethel School Road at
Falcon Lane intersection and 763, 767 & 771 Pelican Lane.
2. Upon reviewing the development plans, it was found that the
storm drainage system was designed in accordance with the
standards and criteria that were in effect in the City of Coppell
at the time of design.
3. It appears that some of the flooding problem may be
attributable to a combination of unforeseeable circumstances,
such as: inlet capacities, designed for 5-year storms, having to
sustain storms of greater duration; provisions for positive
overflow, between individual homes, being reduced; inadequate
site grading and site drainage; and finished floor elevations of
the homes in question not being high enough with respect to the
street.
4. A recommendation to help alleviate some of the flooding
problems involves a joint effort between the City and the
homeowners. The City would be responsible for construction of the
minimum recommendations in the report, while the homeowner would
be responsible for the improvements to the site grading and
implementation of removal of obstructions along the lot lines
where positive overflow is essential.
5. The report outlines preliminary cost estimates for the
construction of the recommended alternatives. For the above
mentioned minimum recommendations, the following costs will
apply:
Bethel School Road / Falcon Lane
Alternate No. 1 ....................... $ 22,263.00
Pelican Lane
Alternate No. 1 ....................... $ 10,422.00
6. Prior to any City Council action on this matter, a
recommendation is made that the City attorney be consulted.
Respectfully submitted,
H. Wayne Ginn, P.E.