FLOOD11354 ‎(2)‎

• County: Eagle
• Community: Eagle County and Incorporated Areas
• Basin: Colorado Mainstem
• Title: FIS - Eagle County and Incorporated Areas
• Date: 12/4/2007
• Prepared For: Eagle County
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

the 100-year floodplain and floodway, beginning at the Garfield/Eagle County boundary
and extending upstream through the Wingo Bridge. A HEC-RAS model was developed,
and floodplain mapping was prepared for submittal to FEMA.

The Town of Basalt contracted with McLaughlin Water Engineers, Ltd. (MWE), to
review and modify the HEC-RAS model in the reach between the Lower and Upper
Basalt Bypass Bridges as part of a river master plan for the town. The Town of Basalt
also contracted with Matrix to review and modify the HEC-RAS model in the reach
between Willits Lane and the Lower Basalt Bypass Bridge, including the River Oaks
subdivision. The reach between the Wingo Bridge and the Upper Basalt Bypass Bridge
was modeled by the Roaring Fork Club for its river restoration project, and a LOMR was
accepted by the CWCB and issued by FEMA in 1998. In 2000, Pitkin County contracted
with Matrix to model the reach from the Wingo Bridge upstream to the confluence with
Snowmass Creek. The Town of Basalt then contracted with Matrix in 2000 to
coordinate and finalize the four floodplain studies into one complete Floodplain
Information Report for all the reaches and to model the 10-, 50-, and 500-year
floodplains. This report was dated July 24,2000.

This Floodplain Information Report was republished on November 14, 2001, to include
detailed floodplain mapping with Base (l-percent-annual-chance, or 100-year) Flood
Elevations (BFEs) in the area south of the Town of Basalt, known as South Side, where
floodwater splits at the Upper Basalt Bypass Bridge and flows overland. The report also
included new topographic mapping for the Basalt area that was obtained in January 2001
from Aero-Metric, Inc. The new report also includes a floodway delineation that was not
in the earlier edition.

The Brush Creek original detailed study, Contract No. H-4549, was completed by
Gingery and Associates Inc. in October 1978 and was revised based on a LOMR,
Case No. 04-08-0l45P. The hydraulic analyses were performed by Icon Engineering Inc.
for the Town of Eagle, and were completed in August 2003 (Reference 2).

Previous hydrologic and hydraulic analyses affecting Eagle County and the incorporated
communities are listed in the following chart.

2