WSP13037

• File Number: 8280.10
• Description: CREST - Colorado River Enhancement Snowpack Test
• State: CO
• Author: Unknown - Crest members/BOR?
• Title: Briefing Document for the Colorado River Enhancement Snowpack Test
• Water Supply Pro - Doc Type: Report/Study

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III. ENVIRONMENTAL CONSEQUENCES

A. Description of the Physical Environment

The Colorado River Basin encompasses a rich array of the most diverse aesthet1c
and productive resources in the United States. The seven Basin States are
Wyoming, Utah, Colorado, Nevada, New Mexico, Arizona, and California.
However, the productivity of the Basin1s lands 1s tempered and controlled by
its arid and semiarid climate. For all practical purposes, water resources
development has dictated the future of the Basin since the turn of the
century. A 1979 report by the Comptroller General describes the Basin
succinctly.

liThe ColoradO River originates in the Rocky Mountains of Colorado
and Wyoming, flows southwest about 1,400 miles, and empt1es into
the Gulf of California. It drains an area of 242,000 square miles
in seven States, which represents one-twelfth of the area of the
United States, excluding Alaska. The basin has climatic extremes
of year-round snow cover and heavy precipitation on the high peaks
of the Rockies and desert conditions with very low precipitation
in southeast California and southwest Arizona. The Colorado River
is controlled by several dams and reservoirs. The Glen Canyon Dam
and Lake Powell store most of the Upper Basin's water and control
releases to the Lower Basin. The Hoover Dam and Lake Mead store
most of the Lower Basin's supply and control the amount of water
released to Lower Basin users."[4]

Review ~f alternatives by project scientists indicates the San Juan Mountains
may be the scient1fically desirable location to initiate the Colorado River
Basin Augmentation Demonstration proposal. The Upper Colorado Region Compre-
hensive Framework Study describes the area as follows:

. .

liThe main tributary of the Colorado River in the subregion is the
San Juan River, second largest tributary in the Colorado system.
The San Juan heads on the western slope of the Continental Divide
in southwestern Colorado and enters the main stream about 80 miles
upstream from Lee Ferry. Three small rivers, Dirty Devil, Escalante,
and Paria, drain the eastern side of the Wasatch Plateau in Utah
and join the Colorado from the west.

liThe largest towns of the subregion are Durango and Cortez in
Colorado, Monticello and Blanding in Utah, and Farmington in
New Mexico. Page at Glen Canyon Dam is the only community of
significant size in the Arizona portion of the subregion. Most
of the remaining Arizona portion is in the Navajo Indian
Reservation.

liThe subregion is served by U.S. Highways 84, 89, 160, 164, 550,
and 666 and by an extensive system of State highways ana secondary
roads. The subregion has no int2rstate highways at present, but
Interstate 70 when completed will traverse the headwaters of the
Dirty Devil River. Service by the narrow-gage brdnch line of the
Denver & Rio Grande Western Railroad in the eastern part of the

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