Mansions Phase 1-CS 990705CHANGES ARE MADE IN DETERMINATIONS OF BASE FLOOD ELEVATIONS FOR THE CITY
OF LEWISVILLE, DENTON COUNTY, TEXAS, UNDER THE NATIONAL FLOOD INSURANCE
PROGRAM
On April 2, 1997, the Federal Emergency Management Agency identified Special Flood Hazard Areas
(SFHAs) in the City of Lewisville, Denton County, Texas, through issuance of a Flood Insurance Rate
Map (FIRM). The Mitigation Directorate has determined that modification of the elevations of the flood
having a 1-percent chance of being equaled or exceeded in any given year (base flood) for certain locations
in this community is appropriate. The modified base flood elevations (BFEs) revise the FIRM for the
community.
The changes are being made pursuant to Section 206 of the Flood Disaster Protection Act of 1973 (Public
Law 93-234) and are in accordance with the National Flood Insurance Act of 1968, as amended {Title XIII
of the Housing and Urban Development Act of 1968, Public Law 90-448), 42 U.S.C. 4001-4128, and
44 CFR Part 65.
A hydraulic analysis was performed to incorporate placement of fill, grading, and excavation of two ponds
associated with the Mansions on the Lake development; addition of the State Highway 121 bridge to the
hydraulic model for Denton Creek; and more detailed topographic information from approximately
3,840 feet downstream to just upstream of State Highway 121. This has resulted in a revised delineation
of the regulatory floodway, a decrease in SFHA width, and decreased BFEs for Denton Creek from State
Highway 121 to approximately 1,100 feet upstream. The table below indicates existing and modified BFEs
for selected locations along the affected lengths of the flooding source(s) cited above.
Existing BFE Modified BFE
Location (feet)* (fee0*
Just upstream of State Highway 121 468 467
*National Geodetic Vertical Datum, rounded to nearest whole foot
Under the above-mentioned Acts of 1968 and 1973, the Mitigation Directorate must develop criteria for
floodplain management. To participate in the National Flood Insurance Program (NFIP), the community
must use the modified BFEs to administer the floodplain management measures of the NFIP. These
modified BFEs will also be used to calculate the appropriate flood insurance premium rates for new
buildings and their contents and for the second layer of insurance on existing buildings and contents.
Upon the second publication of notice of these changes in this newspaper, any person has 90 days in which
he or she can request, through the Chief Executive Officer of the community, that the Mitigation
Directorate reconsider the determination. Any request for reconsideration must be based on knowledge
of changed conditions or new scientific or technical data. All interested parties are on notice that until the
90-day period elapses, the Mitigation Directorate's determination to modify the BFEs may itself be
changed.
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Any person having knowledge or wishing to comment on these changes should immediately notify:
The Honorable Bobbie J. Mitchell
Mayor, City of Lewisville
P.O. Box 299002
Lewisville, Texas 75029-9002