SC-CFBISD Riverchase-CS 990712 Federal Emergencv Managern nt
Washingt°n' D'CI' 20~t72
CERTIFIED MAIL IN REPLY REFER ~I".~:
The Honorable Candy Sheehan Community: City of Coppell, TexaX~-I I ~'
255May°r' City of Coppellparkway Boulevard Community No.: 480170
Coppell, TX 75019 104
Dear Mayor Sheehan:
This responds to a request that the Federal Emergency Management Agency (FEMA) comment on the
effects that a proposed project would have on the effective Flood Insurance Rate Map (FIRM) for your
community in accordance with Part 65 of the National Flood Insurance Program (NFIP) regulations. In
a letter dated June 23, 1999, Mr. Ronald W. Morrison, P.E., C.F.M., Morrison Hydrology
Engineering, Inc., requested that FEMA evaluate the effects that proposed placement of fill along Ell Fork
of Trinity River (Ell Fork) and proposed excavation associated with proposed construction of the River
Chase Elementary School would have on the flood hazard information shown on the effective FIRM and
Flood Insurance Study (FIS) report.. ~The proposed fill will be placed approximately 2,300 feet south of
Sandy Lake Road.and approximately 800 feet east of Macarthur Bou, levard, and the proPosed eXcavation
will occur approximately 1,800 feet south of Sandy Lake Road'and from approximately 300 feet east to
approximately 700 feet east of Macarthur Boulevard. " '
All data required to complete our review of this request for a Conditional Letter of Map Revision
(CLOMR) were submitted with letters from Mr. Morrison.
We have completed our review of the submitted data, the flood data used to prepare the effective FIRM,
and data submitted to reflect existing conditions in support of a CLOMR dated June 7, 1999, for your
community. The submitted existing conditions HEC-2 hydraulic computer model, dated April 24, 1999,
based on updated topographic information, was used as the base conditions model in our review of the
proposed conditions model for this CLOMR request. We believe that, if the proposed project is
constructed as shown on the topographic work map entitled "River Chase Elementary School, Proposed
100 year Hoodplain," contained in the report entitled "Flood Study in support of a Conditional Letter of
Map Revision for River Chase Elementary School, City of Coppell, Texas," prepared by Morrison
Hydrology Engineering, Inc., dated June 15, 1999, and the data listed below are received, a revision to
the FIRM would be warranted.
As a result of the more detailed topographic information, the elevations of the flood having a 1-percent
chance of being equaled and exceeded in any given year (base flood) and the width of the Special Flood
Hazard Area (SFHA), the area that would be inundated by the bas~ flood', along Ell Fork decreased in
the. vicinity of the proposed project compared to the effective base flood elevatiOns (BFEs) and' SFHA
width.' . . ..... ' " ' ' ' · "'
2
Because the proposed placement of fill and excavation along Elm Fork will occur largely within the
floodplain of the flood having a 0.2-percent chance of being equaled or exceeded in any given year, the
proposed project will not affect the existing conditions BFEs. The widths of the SFHA and the regulatory
floodway along Elm Fork will not change as a result of the proposed project.
Upon completion of the project, your community may submit the data listed below and request that we
make a final determination on revising the effective FIS report and FIRM.
Effective March 1, 1999, FEMA revised the fee schedule for reviewing and processing
requests for conditional and final modifications to published flood information and maps.
In accordance with this schedule, the fee for your map revision request will be $3,400 and
must be received before we can begin processing your request. Payment of this fee shall
be made in the form of a check or money order, made payable in U.S. funds to the
National Flood Insurance Program, or by credit card. The payment must be forwarded
to the following address:
Federal Emergency Management Agency
Fee-Collection System Administrator
P.O. Box 3173
Merrifield, VA 22116-3173
As-built plans, certified by a registered professional engineer, of all proposed project
elements
· Community acknowledgment of the map revision request
Certification that all fill placed in the currently effective base floodplain and below the
proposed BFE is compacted to 9:5 percent of the maximum density obtainable with the
Standard Proctor Test method issued by the American Society for Testing and Materials
(ASTM Standard D-698) or an acceptable equivalent method for all areas to be removed
from the base floodplain
This CLOMR is based on minimum floodplain management criteria established under the NFIP. Your
community is responsible for approving all floodplain development, and for ensuring all necessary permits
required by Federal or State law have been received. State, county, and community officials, based on
knowledge of local conditions and in the interest of safety, may set higher standards for construction in the
SFHA. If the State, county, or community has adopted more restrictive or comprehensive floodplain
management criteria, these criteria take precedence over the minimum NFIP criteria.
If you have any questions regarding floodplain management regulations for your community or the NFIP
in general, please contact the Consultation Coordination Officer (CCO) for your community. Information
on the CCO for your community may be obtained by contacting the Director, Mitigation Division of
FEMA in Denton, Texas, at (940) 898-5127. If you have any technical questions regarding this CLOMR,
please contact Mr. Alan Johnson of our staff in Washington, DC, either by telephone at (202) 646-3403
or by facsimile at (202) 646-4596.
Sincerely,
Alan A. Johnson, P.E., Project Engineer
Hazards Study Branch ~
Mitigation Directorate
For:
Matthew B. Miller, P.E., Chief
Hazards Study Branch
Mitigation Directorate
Enclosure(s)
CC:
Mr. Kenneth M. Griff'm, P.E.
Director of Engineering and Public Works
City of Coppell