FLOOD08649

• County: Ouray
• Community: Ridgway
• Stream Name: Uncompahgre River & Cottonwood Creek
• Basin: Gunnison
• Title: Hydrology Addendum to FIS Town of Ridgway
• Date: 9/27/1985
• Prepared For: Ouray County
• Prepared By: Montgomery Watson
• Floodplain - Doc Type: Floodplain Report/Masterplan

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. . STUDY AREA DESCRIPTION

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. Community Description
. The Town of Ridgway, Colorado is located in the southwest portion of the state at the junction of
. U.S. Highway 50 and State Route 62 approximately 10 miles north of the Town of Ouray. The
. Town is located in the Uncompahgre Valley at an elevation of 6,985 ft.
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. Estimates by the Ridgway Area Chamber of Commerce in 2000 estimated the population of the
. Town and its surrounding area at 820.
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. Because of its centralized location, Ridgway has historically been a commercial service center,
. initially serving mining related activities. The Town was established in 1891 and was named
. after Rio Grande Southern Railroad Superintendent Robert M. Ridgway. Today, much of the
. economy of the Town is based on recreation and tourism.
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. Watershed Descriptions
. The September 27, 1985 Ridgway FIS provides flood hazard information for two flooding
. sources; the Uncompahgre River and Cottonwood Creek. The FIS provides detailed mapping
. for the Uncompahgre River while Cottonwood Creek has been studied only by approximate
. methods.
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. The Uncompahgre River flows from south to north along the eastern edge of the corporate limits
. of the Town. The headwaters of the river are located in the San Juan Mountains between Ouray
. and Silverton from where it flows approximately 70 miles to its confluence point with the
. Gunnison River near Delta.

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. Cottonwood Creek is a tributary to the Uncompahgre River just south of State Route 62 in the
. southeast portion of the Town of Ridgway. The creek is paralleled by County Road 5 and drains
. a portion of the lower slopes of Mount Sneffels (14,150 ft) southwest of the Town. The drainage
. basin generally lies below elevations of 9,000 ft and the tributary drainage area at the confluence
. with the Uncompahgre River is approximately 4.2 sq mi.

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. Floodinl! Problems and Floodinl! History
. The 1985 FIS though found no newspaper articles or other historical documentation for severe
. flooding on either the Uncompahgre River or Cottonwood Creek. The FIS though notes that
. flood flows on the Uncompahgre River are generally the result of rapid melting of mountain
. snowpack during the period from May to early June. Small tributaries to the Uncompahgre River
. such as Cottonwood Creek are subject to cloudburst-type flooding but these flood flows are
. generally not large enough to affect peak flows on the main channel of the Uncompahgre River.

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. Previous Studies
. The September 27, 1985 FIS is the first flood insurance study carried out for the Town of
. Ridgway and has not been revised since its issuance. The study supercedes a Flood Insurance
. Rate Map produced for the Town by FEMA dated October 13, 1981. Reference information for
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