FLOOD07952

• County: Fremont
• Community: Canon City
• Stream Name: Four-mile Creek, Mud Gulch
• Basin: Arkansas
• Title: Floodplain Management Study - Four-Mile Creek and Mud Gulch at Canon City
• Date: 10/1/2002
• Prepared For: Canon City, Fremont County
• Prepared By: USDA Soil Conservation Service
• Floodplain - Doc Type: Floodplain Report/Masterplan

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USGS gauges on the Arkansas River at Pueblo and Canon City. An area proportion

was then applied between the Pueblo and Canon City station results to obtain the

peak flows in the town of Florence and in Fremont County. The discharges obtained

in CDM's regional analysis fell within the 90 percent confidence limits of the Corps

of Engineers Canon City gauge station analysis discharges in Reference 1 and,

therefore, the hydrologic analysis, as presented by the Corps of Engineers in the

Florence Flood Plain Information Report, was adopted for use in estimating the

flood boundaries for the Arkansas River.

The peak discharges for the Arkansas River at Canon City and Florence are
presented in Table 3 and Figure 4.

TABLE 3
PEAK DISCHARGES AT SELECTED LOCATIONS
Peak Discharges (cfs)

Drainage Area
Location (square miles) lO-Yr 50-Yr 1Oo-Yr 500-Yr
Arkansas River
at Canon City 3,117 8,850 16,500 20,500 32,200
at Florence 3,546 11,000 21,000 28,000 71,000

For a detailed description of the hydrologic analysis, refer to the Albuquerque

District Corps of Engineers Flood Pla1lJ Information, Arkansas River Basin, Florence.

Colorado (Reference 1). A detailed technical addendum has also been prepared by
Camp Dresser & McKee (Reference 10).

Hydraulic Analysis

Hydraulic analyses conducted in this study were done using the U.S. Army

Corps of Engineers computer model HEC-RAS Water Surface Profiles, Ver. 3.0.1,

March 2001. All flows were set up as sub-critical flows in compliance ,\1th FEMA's

1985 guidelines and specifications.

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