FLOOD10329

• Designation Number: 581
• County: Hinsdale
• Community: Hinsdale County
• Stream Name: Los Pinos, Weminuche, Middle Fork Piedra, E. Fork
• Title: Floodplain Information Report, Hinsdale County, Colorado
• Date: 9/1/2004
• Prepared For: Hinsdale County and CWCB
• Prepared By: Love and Associates, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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STUDY AREA DESCRIPTION

Community Description

Hinsdale County is located in the southwest corner of Colorado. Please refer to the
Vicinity Map, Figure 1. The County occupies approximately 1124 square miles, and
approximately 96 percent is public land, including portions of Gunnison, San Juan, and
Rio Grande national forests. The Continental Divide snakes through the middle of the
County. The population of Hinsdale County is approximately 800 people. About half the
population of the County lives in Lake City, the county seat. Numerous lakes, streams,
and reservoirs are located within the County. Hinsdale County has an alpine climate
which typically has short cool summers with sporadic summer thunderstorms and cold
winters with heavy snowfall. Average annual precipitation within the County ranges
from 11 to 55 inches per year.

In Lake City, the average temperature in January is approximately 170 F and the average
temperature in July is approximately 610 F.

Watershed Description

Hinsdale County is located in the high country of Colorado. Much of the County is
located within public lands which are not open to development. The continental divide
criss-crosses the County and, as a result, the County is located within three river basins:
the north in the Colorado River Basin, the center in the Rio Grande Basin and the south in
the San Juan River Basin. All watersheds are characterized by high elevation, steep
slopes, and rugged topography. Elevations within the County range from about 8000 feet
to over 14,000 feet msl.

Flood peak discharges can be moderated by numerous lakes and reservoirs located on
many streams. Annual flood peaks are generally the result of snowmelt. Summer
thunderstorms can cause localized flooding. Flooding can also result from rain on
snowmelt events in late spring. Flooding can be aggravated by sediment transport and
deposition, debris flows and channel obstructions.

Floodin2: Problems and Floodin2: History

Because of the low population density within much of the County, reported flooding
events are rare. Flooding is reported in Henson Creek and Lake Fork near Lake City in
mid June of 1921, a result of a rain falling on melting snow. During 1984, minor
flooding occurred within the 100-year floodplain in the Lake City area caused by a year
of high snowfall.

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