WSP03161

• File Number: 8276.150
• Description: Grand Valley Unit-Colorado River Basin Salinity Control Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1976
• Title: Draft - Grand Valley Salinity Study
• Water Supply Pro - Doc Type: Report/Study

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BACKGROUND

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2 HISTORICAL

3 Sal inity ultimately becomes a major problem in many irrigated areas. In

4 areas with high sal ine soils, such as the Grand Valley in west central

5 Colorado, salinity has been a problem since irrigation water was first

6 del ivered in 1882. The irrigated land in the Grand Valley and the

7 diffused source. areas with highly saline soils and subsoils are large

8 contributors of sal ine return flows. In recent years sal inity concen-

9 trations in the Lower Colorado River have adversely affected irrigated

10 crop production and other uses. This problem is especially severe for

11 water del ivered to Cal ifornia, Arizona, and Mexico.

12 The Colorado River system naturally carries a large load of salts

13 (dissolved solids) and suspended sediment. The depletions in streamflow

14 resulting from transbasin diversions, and for irrigation, municipal and

15 industrial uses has significantly reduced the supply of water available

16 for dilution of the salt loads in the lower river system. Future develop-

17 ment of water by the Upper Basin states will further reduce the water

18 available for dilution, and in most cases the development projects wil I

19 themselves increase the salt loadings in the Colorado River system.

20 Recognition of the water quality problem in the region has caused a

21 number of studies to be made since about 1960. The Colorado River Basin

22 Water Qual ity Control Project was establ ished in 1960 by the Divis ion of
23 Water Supply and Pollution Control, U. S. Public Health Service (pre-
24 decessor to the Federal Water Qual ity Administration). Their studies

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