FS8901-CS 890809NDI
NATHAN D. MAIER
CONSULTING ENGINEERS, INC.
August 9, 1989
Mr. Russell Doyle
City Engineer
P.Oo Box 478
Coppell, Texas 75019
Re:
HRWS Tract
4.5 Acres in Coppell, Texas
NDM No.: 88-02-017
Dear Mr. Doyle:
In response to your letter of May 18, 1989, regarding the subject tract, the following information is pro-
vided:
1. Two copies of a technical report documenting the hydraulic evaluation performed for
the subject tract. Upon your review and approval, this report may be forwarded to FEMA
for processing the requested Conditional Letter of Map Revision (LOMR).
2. Two copies of the recorded deed.
3. Two copies of a topographic survey showing existing grades on the tract as certified to
by a registered surveyor.
4. Two copies of a proposed grading plan for the tract. Minimum fill is at elevation 445 or
1.0 foot above the existing Q100' First floor of any structures will be at 2.0 feet above
existing Q10o and 1.2 feet above future Q100'
5. No waters of the U.S. are on the tract; therefore, no permits other than those required by
the City of Coppell are needed. See technical report for letter from C.O.E.
6. No change in the existing land use is contemplated.
7. Since the portion of the tract to be filled is in an ineffective flow area, no additional loss
of conveyance is involved. The conveyance was taken out in the FIS.
8. Two copies of the Private Roadway Agreement and the easement for ingress, egress on
the property.
9. The full cross section width across the river is provided in the technical report.
t0. Two copies of the cross section cut across the site, These sections were used to
determine the floodplain storage lost as follows:
Ex sting Q10o = 1.1 AC-FT = 0.09% of Storage in Reach 88150-90000
Existing Qsr~' = 18.8 AC-FT = 0.9% of Storage in Reach 88150-90000
Future Q10o = 4.5 AC-FT = 0.3% of Storage in Reach 88150-90000
Future QSPF = 21.6 AC-FT = 0.9% of Storage in Reach 88150-90000
In reality, no additional storage is lost, since the aera was blocked out ss ineffective in
the revised FIS.
Please note that no credit was taken for storage of the SPF above the fill elevation.
Three NorthPark/8800 N. Central Expwy./$uite 300/Dallas, Texas 75231/(214) 739-4741
Mr. Russell Doyle
August 9, 1989
Page 2
We believe that the above Information, attached report, and documents address the items in your letter
of May 18, 1989. If there are any further questions, please call.
Our client has agreed to have the review made by Mr. Morrison on your behalf. He would, however, like
to have some idea as to the magnitude of the fee.
Ve~j truly yours,
NATHAN D. MAIER
CONSULTING ENGINEERS, INC.
Emin A. Meyer; P.E. .~ .
EAM/rdp
Attachments (6)