WSP09883

• File Number: 8273.100
• Description: Colorado River Basin Salinity Control - Federal Agency Reports - BOR
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 9/1/1973
• Title: Colorado River International Salinity Control Project - Special Report - Executive Summary
• Water Supply Pro - Doc Type: Report/Study

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between the City of Yuma and the Colorado River. This flume, now in a
deteriorated condition, will be replaced with a concrete siphon to assure
continuous operation of the desalting plant.

1. Product Water Costs. Based on the desalting plant I s production
of 90 mgd or 101,000 acre-feet per year of desalted water, the unit costs
for the desalted water will be:

Dollars per acre-foot
Capital cost .
Operating cost .

136
(42)
(94 )
42
(13)
(29)

Cents per 1,000 gallons
Capital cost .
Operating cost

2. Power Requirements. The desalting plant will have a demand of
about 35 mw and require about 216 million kilowatt-hours of electric energy
annually. Electric energy will be provided by entities operating within
the Bureau of Reclamation's Lower Colorado Region, an area served by private,
public-non-Federal, and Federal systems using thermal and hydroelectric units.
Fossil-fuel generating capacit1 is predominant.

A 161-kv switchyard to serve the complex will be located onsite.
Right-of-way will be required for the construction of 8-1/2 miles of
161-kv transmission lines.

B. Wellton-Mohavk Drainage

The size of the desalting plant depends upon the quantity of the
drainage water 1'urnished for treatment. The quantity of drainage water
depends upon the size of the area irrigated and the irrigation efficienc-
ies, and therefore can be partially controlled.

The Wellton-Mohavk Division of the Gila Project was authorized for
a total of 15,000 acres, although only about 65,000 acres have thus far
been developed for irrigation. Of this acreage, about 80 percent are
valley lands where irrigation efficiencies are relatively high. The
remainder are mesa lands with much lover efficiencies. In recent years,
drainage from these lands has ranged from 210,000 to 220,000 acre-feet
annually, and in 1912 the average annual salinity of these flows was
about 3,100 ppm.

C. Reduced Drainage Flows

By reducing the volume of drainage flows from the Wellton-Moha\/lt
District from their present level of about 220,000 acre-feet annually,
the size of the desalting plant can also be reduced.

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