7983

• UCREFRP Catalog Number: 7983
• Author: U.S. Department of the Interior.
• Title: Quality of Water, Colorado River Basin.
• USFW Year: 1993.
• USFW - Doc Type: Progress Report No. 16,
• Copyright Material: NO

Chapter 2

Description of Basin

The construction and filling of the main stem
reservoirs of the Colorado River Basin (figure 1)
have brought about significant changes in the
flow patterns of the river. The Colorado River
Basin encompasses portions of seven States:
Wyoming, Utah, Colorado, Nevada, New Mexico,
Arizona, and California. The river flows over
1,400 miles from its headwaters in Wyoming and
Colorado. It joins with tributaries from Utah
and New Mexico; flows through the Grand
Canyon; provides State boundaries for Nevada,
Arizona, and California; flows through the
Republic of Mexico; and terminates in the Gulf
of California. The Colorado River provides
municipal and industrial water for more than
18 million people and irrigation water to
1. 7 million acres in the United States.

NV

CA

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CLIMATE

Extremes of temperature in the Colorado River
Basin range from -50 to 130 degrees F. The
northern portion of the Basin is characterized by
short, warm summers and long, cold winters;
and many mountain areas are blanketed by deep
snow all winter. Much of the area consists of
high basins or valleys with cold winters and hot,
dry summers. The southern desert portion of
the Basin has long, hot summers, practically
continuous sunshine, and almost complete
absence of freezing temperatures. Rainfall
averages 2.5 inches per year in the southern end
of the Basin, while total precipitation in the
mountains reaches 40 to 60 inches annually.

GREEN RIVER

WY

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SAN JUAN R.

UTILE COLORADO R.

NM

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Figure 1.-Map of Colorado River Basin.