WSP02457

• File Number: 8276.400
• Description: McElmo Creek Unit - Colorado River Salinity Control Program
• State: CO
• Basin: Colorado Mainstem
• Water Division: 7
• Date: 5/1/1981
• Title: Draft Status Report - McElmo Creek Unit
• Water Supply Pro - Doc Type: Report/Study

.

.

SUMMARY

The Regional Director's proposed feasibility report for the McElmo

Creek Unit of the Colorado River Water Quality Improvement Program

is scheduled for completion in 1983. Until then, this status report

will inform concerned interests of the costs and impacts associated with

the alternatives currently being considered.

The McElmo Creek Unit investigation in southwestern Colorado was

authorized by Public Laws 93-320 and 96-375 to determine the most cost-

effective way to reduce the 115,000 tons of salt entering the San Juan

River annually from the McElmo Creek drainage, which, in turn, flows into

the Colorado River. An increase in salinity at Imperial Dam of about 12

milligrams per liter (mg/L) results from both off-farm and on-farm

agricultural activities.

Most of the Montezuma Valley Irrigation Company (MVI) facilities

were constructed before 1900, and much of the system was cut directly

into the saline soils and rock. Conveyance system seepage from the

unlined canals picks up these salts and discharges them into McElmo Creek

and, eventually, the Colorado River. The Soil Conservation Service, an

agency of the Department of Agriculture, is conducting an on-farm program

for salinity reduction, while the Water and Power Resources Service is

involved in the off-farm salinity control efforts.

Following the initiation of the study in December 1976, a public

involvement program aided in developing and evaluating a number of

potential alternatives. From these potential alternatives candidate

plans were selected and divided into two stages for future stuny. The 71
0014
first stage consists of three plans for reducing the salt load from