WSP10235

• File Number: 8281.910
• Description: Colorado River Studies and Investigations -- Grand Valley Salinity Study
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1976
• Author: Soil Cons Serv
• Title: Grand Valley Salinity Study - draft
• Water Supply Pro - Doc Type: Report/Study

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Because many natural and manmade factors affect the river's salinity,

the actual salinity will vary above and below the recommended numeric

criteria. However, under the assumptions of streamflow equivalent to

the long~term average, a reasonable rate of increase in water depletions

and full implementation of needed salinity control measures, the average

salinity can be maintained at or below 1972 levels during the study

period of the next 15 years.

The federal regulations provide for temporary increases above the 1972

levels if control measures are included in the plan. Should water

development projects be completed before control measures are identified

or brought on line, temporary increases above the criteria could result

and these increases will be in conformance with the regulation. With

completion of control projects, those now in the plan or those to be

added subsequently, salinity would return to or below the criteria

level.

AUTHORITY

On November 16, 1973, the Colorado Water Conservation Board requested

the assistance of the Soil Conservation Service, under authority of

Section 6 of Public Law 566, to make feasibility studies of possible

improvements of on-farm irrigation systems and improvements in the

upland watershed condition for the purpose of controlling saline

return flows to the Colorado River from the Grand Valley Unit.

23 Public Law 93-320 (88 Stat. 266) dated June 24, 1974, entitled

24 "Colorado River Basin Sal inity Control Act" authorized the U. S.

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