ST8702-CS 921218 Federal Emergency Management Agency
Washington, D.C. 20472 ....
DEC I8 1992
Mr. Steven G. Goram~ ·
Director of Public Works for 2 f
the City of Coppell ....
P.O. Box 478
Dear Mr. Gor~: ~o~ ~ ~ ~. ~¢l.~?s[~
~is is in response to your November 16, 1992, letter to the Federal Emergency
Management Agency (F~) in support of a revision request to your co~unity's
Flood Insurance Study (FIS) and Flood Insurance Rate Map (FI~) to reflect the
completed Denton Tap Road bridge, which crosses over Grapevine Creek. In your
letter, you stated that "the City of Coppell does not ass~e maintenance
responsibility for floodways on private property. Maintenance of channels is
the responsibility of the property o~er and/or the developer. However, the
City does retain the right to enter the property and perform such work as
deemed necessary." We would like to clarify your co~unity's responsibilities
as a participant in the National Flood Insurance Program (NFIP) with respect
to floodways and channel maintenance.
The regulatory floodway is an administrative tool designed to balance the
economic gain resulting from floodplain development while limiting increases
in future flood hazards. For purposes of the NFIP, the floodway is the stream
channel, plus that portion of the adjacent floodplain area, which must be kept
free of encroachment in order that the lO0-year flood be carried without
substantial increases in flood levels. Subparagraph 60.3(d)(3) of the NFIP
regulations states that the community shall "prohibit encroachment, including
fill, new construction, substantial improvements, and other development within
the adopted regulatory floodway that would result in any increase in flood
levels within the community during the occurrence of the base (100-year) flood
discharge." Thus, your community is responsible for prohibiting such
encroachments within the adopted regulatory floodway on private property as
well as on.public right-of-way. A community may request that an adopted
floodway be revised by providing FEMA with documentation that an alternative
floodway configuration meets NFIP requirements; however, this alternative
configuration must not exceed the 1.0 foot surcharge limit, as measured from
the 100-year flood profile established at the time the original FIS was
completed.
Regarding channel maintenance, Subparagraph 60.3(b)(7) of the NFIP regulations
requires communities to "assure that the flood carrying capacity within the
altered or relocated portion of any watercourse is maintained." Outside of
the public right-of-way, the community may have agreements with land
developers and/or property owners to provide the necessary channel
maintenance. However, by permitting channel modifications to be completed,
the community accepts ultimate responsibility for maintaining the modified
channel should the private interests fail to comply with their maintenance
agreement with the community. This provision is incorporated into your
community's existing floodplain management regulations; consequently, ultimate
responsibility for maintenance of the channel modifications associated with
the Denton Tap Road bridge replacement rests with your community. Please be
aware that FEMA may request that your community submit a description and
schedule of channel maintenance activities.
When your community chose to join the NFIP, the minimum floodplain management
regulations required for participation were adopted into your community's
ordinances. The floodplain management requirements within the special flood
hazard area are designed to prevent new development from increasing the flood
threat and to protect new and existing buildings from anticipated flood
events. Thus, in order for the City of Coppell to continue as an exemplary
participant in the NFIP, the floodway and channel maintenance requirements as
outlined in NFIP regulations (copy enclosed) Subparagraphs 60.3(d)(3) and
60.3(b)(7), respectively, must be adhered to.
We trust that this response has clarified your community's responsibilities as
discussed in your November 16, 1992, letter. However, should you have any
questions regarding this matter, please do not hesitate to contact the Chief,
Natural and Technological Hazards Division of FEMA in Denton, Texas, at (817)
898-5127 or Matthew B. Miller of our Headquarters staff in Washington, D.C.,
at (202) 646-3461, or by facsimile at (202) 646-3445.
Sincerely,
William R. Locke
Chief, Risk Studies Division
Federal Insurance Administration
Enclosure
cc: Mr. Kenneth Griffin, P.E., Coppell City Engineer
Ms. Shohre Daneshmand, P.E., Civil Engineer