FLOOD10348

• County: Statewide
• Stream Name: Colorado River
• Title: Floodplain Information Report, Volume 4, Colorado River from Rifle to Utah Stateline
• Date: 5/1/1995
• Prepared For: Recovery Implementation Program for Endangered Fish Species in the Upper Colo
• Prepared By: CWCB
• Floodplain - Doc Type: Floodplain Report/Masterplan

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That report was the source for the Parachute FIS, so the two reports are consistent. Additionally,
information was obtained from a report titled "Hydrology Report, Flood Insurance Studies in
Mesa County", dated May 1989 (Reference 10). It was prepared by J.F. Sato & Associates, Inc
as part of their work under contract to FEMA in performing engineering for the 7/92 FIS' for
Palisade, Grand Junction, Fruita and Mesa County.

Preliminary floodplain maps have been prepared by the U.S. Army Corps of Engineers for the
Colorado River from Glenwood Springs to the upstream end of DeBeque Canyon as part of an
ongoing Floodplain Information Report (Reference II). The Corps of Engineers maps and the
hydrologic analyses that preceded them are inconsistent with the City of Rifle FIS. Since the
Corps of Engineers work is more current, it was selected as being more valid for the Rifle area.
There is no conflict between the Parachute FIS and the Corps of Engineers maps. The
preliminary maps from the, Corps of Engineers were used to delineate the floodplain from Rifle
to DeBeque Canyon.

The primary source of hydrology used in this study for the upstream portion of the study reach
(between Rifle and the confluence with Plateau Creek, which is approximately 2.5 miles upstream
of Cameo) is a 1985 Hydrology Report by the U.S. Army Corps of Engineers (Reference 7). The
primary source of hydrologic information for the downstream portion of the study reach (between
the confluence with Plateau Creek and the Utah stateline) was the 1989 Sato Hydrology Report
prepared for the 1992 FEMA studies of Mesa County and associated municipalities. The
Hydrology Report and the FIS' provide peak flow values for 50-year and 100-year floods for
Palisade, Grand Junction, and Fruita and the adjoining areas of unincorporated Mesa County.

The reports referenced above are available at the office of the Colorado Water Conservation
Board, at the Federal Emergency Management Agency (Region VIII), at the U.S. Army Corps
of Engineers (Sacramento District), at the Cities of Rifle and Grand Junction, at the Towns of
Parachute, DeBeque, Palisade and Fruita, and at Mesa and Garfield Counties.

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