FLOOD10395 ‎(2)‎

• County: Montezuma
• Community: Dolores
• Stream Name: Dolores River
• Title: Dolores River near Dolores, Colorado, Flood Insurance Study
• Date: 5/1/2004
• Prepared For: Dolores
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

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5. Descriptive Information
5.1 General Characteristics. The Dolores River basin is located in southwest Colorado.

The river flows southwest out ofthe San Juan Mountains, an extension of the Rocky Mountains.

Downstream ofthe city of Dolores, the Dolores River, joined by its major tributary, the San

Miguel River, flows north through the Colorado Plateau and then into the Colorado River at a

point west ofthe Utah-Colorado state line. The Colorado Plateau extends across the Four Corners

area of southeast Utah, southwest Colorado, northeast Arizona and northwest New Mexico. The

San Miguel River is the major tributary to the Dolores River downstream of Dolores. See Plate 2

for basin topography.
The Dolores River watershed above McPhee Reservoir is about 40 miles long with a

maximum width of 30 miles. The upper Dolores River is formed by the confluence of its two

forks, the upper mainstem and the West Dolores River. The headwaters of the upper mainstem

Dolores River are above 12,000 feet on Sliderock Ridge, northeast ofthe city of Dolores, and

west of the Animas River headwaters (tributary to the San Juan River), and south ofthe San

Miguel River headwaters (tributary to lower Dolores River). The upper mainstem Dolores River

flows through the mountain community of Rico (elevation approximately 8,800 feet) in Dolores

County before entering Montezuma County. Bear Creek, the major tributary to the upper

mainstem Dolores Fiver, flows northwest out of the La Plata Mountains to join the upper

mainstem Dolores River about halfway between the Montezuma County line and the confluence

with the West Dolores River. Bear Creek can contribute large flows to the Dolores basin during

rainstorm events as well as during the snowmelt season. Roaring Forks and Stoner creeks are two

other upper mainstem Dolores River tributaries. The West Dolores River flows out ofthe east-

west-oriented San Miguel Range ofthe San Juan Mountains.

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