FLOOD07328

• County: Summit
• Community: Summit County and Unincorporated Areas
• Basin: Colorado Mainstem
• Title: FIS - Summit County and Unincorporated Areas
• Date: 8/9/2001
• Prepared For: Summit County
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

The hydraulic analyses for these studies were based only on the
effects of unobstructed flow. The flood elevations, as shown on the
profiles, are, thus, considered valid only if hydraulic structures
remain unobstructed, operate properly, and do not fail.

All elevations are referenced to the National Geodetic Vertical Datum
of 1929 (NGVD). Elevation Reference Marks (ERMs) and their
descriptions are shown on the maps. ERMs shown on the FIRM represent
those used during the preparation of this and previous Flood Insurance
Studies. The elevations associated with each ERM were obtained and/or
developed during FIS production to establish vertical control for
determination of flood elevations and flood plain boundaries shown on
the FIRM, Users should be aware that these ERM elevations may have
changed since the publication of this FIS, To obtain up-to-date
elevation information on National Geodetic Survey (NGS) ERMs shown on
this map, please contact the Information Services Branch of the NGS at
[phone], or visit their website at www.nqs.noaa.qov, Map users
should seek verification of non-NGS ERN monument elevations when using
these elevations for construction or flood plain management purposes.

4.0 FLOOD PLAIN MANAGEMENT

The NFIP encourages State and local governments to adopt sound flood plain
management programs. To assist in this endeavor, each FIS provides lOa-year
flood plain data, which may include a combination of the following: 10-,
50-,100-, and SOO-year flood elevations; delineations of the 100-year and
SOO-year flood plains; and 100-year floodway. This information is presented
on the FIRM and in many components of the FIS, including Flood Profiles,
Floodway Data tables and Summary of Stillwater Elevation tables. Users
should reference the data presented in the FIS as well as additional
information that may be available at the local community map repository
before making flood elevation and/or flood plain boundary determinations.

4.1 Flood Boundaries

In order to provide a national standard without regional
discrimination, the 100-year flood has been adopted by the Federal
Insurance Administration as the base flood for purposes of flood plain
management measures. The SOa-year flood is employed to indicate
additional areas of flood risk in the county. For each stream studied
in detail or limited detail, the boundaries of the 100- and SOO-year
floods, as applicable, have been delineated using the flood elevations
determined at each cross section; between cross sections, the
boundaries ere interpolated using topographic map scales of 1:600,
with a contour interval of 2 feet (References 17 and 18); 1:1,200,
with a contour interval of 2 feet (References 12 and 14); 1:2,400,
with a contour interval of 2 feet (References 19 and 20); and
1:24,000, with a contour interval of 40 feet (References 21, 24, and
27) ,

The approximate 100-year flood boundaries for Blue River and Soda
Creek were delineated by use of information from topographic maps
(References 12, 20 through 22, and 24) and the computed flood
elevations.

The approximate 100-year flood boundaries for Snake River were
delineated using information from topographic maps (References 19 and
23), the Flood Hazard Boundary Map for Summit County (Reference 28),
and computed flood elevations. The approximate 100-year flood
boundary for South Barton Gulch was taken from the Flood Hazard
Boundary Map for Summit County (Reference 28).

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