WSP06981

• File Number: 8276.110
• Description: Grand Valley Unit-Colorado River Basin Salinity Control Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/16/1978
• Title: Negative Determination of Environmental Impact: Stage One of the Grand Valley Unit - Colorado River Basin Salinity Control Project
• Water Supply Pro - Doc Type: EIS

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2.

Economic and Social Conditions

The improved water quality resulting from the Stage One development
would have total economic benefits of about $667,000 annually in the
Lower Colorado River Basin, based on an estimated reduction in salinity
of 2.9 mg/L at Imperial Darn and a benefit value of $230,000 per mg/L of
reduction. These benefits would accrue to municipal, domestic, indus-
trial, and agricultural water users, primarily from. decreased costs for
water treatment, reduced pipe corrosion and appliance wear, decreased
use of soaps and detergents, improved palatability of drinking water,
and improved agricultural conditions.

Stage One construction would create new employment opportunities for
about 3 years but would result in negligible population increases since
the existing labor force in the Grand Valley is adequate to satisfy con-
struction needs. In the peak construction year, an estimated 188 people
would benefit directly from construction-related employment by the direct
creation of about 75 jobs, but no immediate change in demand for housing
or community services is anticipated. Increased income due to construc-
tion, however, might promote upgrading of homes and increased revenue
from taxes might be used to improve community services.

An estimated $2,260,000 in wages from direct employment would have
its greatest impact in the trade industry, principally in Mesa County.
Direct stimulus to trade would also be realized with the purchase of
miscellaneous supplies used in construction. The development would pro-
vide a temporary stimulus to freight industries by requiring shipments
of pipe and other construction materials and supplies into the area.
Irrigation water deliveries would be maintained throughout the normal
season during the construction period, so agricultural income would be
maintained.

3. Water Resources

Approximately 200 acre-feet of water would be added to the Colorado
River as a result of reduced consumptive use by phreatophytes along the
canals and laterals to be altered by Stage One. This would amount to
only 0.005 percent of the present annual flow in the river at the lower
end of the valley. The Stage One improvements would result in a 28,000-
ton reduction in salt loading which, in turn, would reduce salinity
levels at Imperial Dam by 2.9 mg/L or 0.26 percent. The reduction in
salinity at the Colorado-Utah state line would amount to about 5.0 mg/L
or 0.88 percent.

4. Fish and Wildlife

The Stage One development would have a very minimal impact on fish,
since the improvement of water quality and flow in the Colorado River
would not be enough to measurably alter fish habitat or biological

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