FLOOD10349

• County: Gunnison
• Community: Marble and Vicinity
• Stream Name: Crystal River
• Title: Floodplain Information Report - Crystal River - Marble and Vicinity
• Date: 5/1/2004
• Prepared For: Marble and CWCB
• Prepared By: ICON Engineering, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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around 6,100 feet where the Crystal River discharges into the Roaring
Fork River, near Carbondale, Colorado.

The Crystal River is approximately 30 miles long, extending from the
Town of Crystal, located approximately 5 miles upstream of Marble, to
the Town of Carbondale. The channel gradient is very steep, ranging from
a 3.8% slope near Crystal to 1.4% slope upstream of Carbondale.

Vegetation within the Crystal River watershed reflects a sparsely
developed mountain climatology. Between Marble and Carbondale, the
watershed is densely vegetated with evergreen and aspen trees, along with
other natural mountain vegetation. Above Marble, the watershed reflects a
high alpine environment with more dense woody vegetation, such as aspen
and evergreen trees along with rock outcroppings, below 11,200 feet.
Rock talus and steep mountains are prevalent above 11,200 feet.

The Crystal River basin is a semiarid mountain environment with cool
summers and long winters. Runoff is attributed to intense thunderstorm
rainfall events during the summer months and heavy snowfall during the
winter months. The following table provides climatological data for
Aspen, Colorado, located approximately 20-miles northeast of Marble and
Crested Butte, Colorado, located approximately 41 miles southeast of
Marble. Aspen and Crested Butte are the closest National Weather
Service Station locations to Marble.

Table 1: Crystal River Vicinity Climatology Datal

Mean Annual July Mean January Mean
LOCATION Precipitation Temperature Temperature
(Inches) (0 F) (0 F)
Aspen, Colorado 23.3 61.7 20.7
Crested Butte, Colorado 23.9 56.0 8.4

IThis data was compiled from National Weather Service records from year 1971 to 2000.

2.4 Flooding History

The history of flooding from the Crystal River in the vicinity of the Town
of Marble has been well documented in 1941 and 1945. Flooding is
attributed to flash floods from the Crystal River and nearby Carbonate
Creek. In addition to flooding, mudflow conditions occur annually in
Marble. In one situation, a structure, the Horace Williams House, has
been documented to have moved over 30 feet as a result of the 1941
mudflow. Photographs of the flood in 1945 are shown in Figure 1 and
Figure 2,

ICON Engineering, Inc.
May 2004

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