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

e
!oM
t::)
(,t~ 2
~
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

BACKGROUNO

HISTORICAL

Salinity ultimately becomes a major problem in many irrigated areas. In

areas with high saline soils, such as the Grand Valley in west central

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

delivered in 1882. The irrigated land in the Grand Valley and the

diffused source areas with highly saline soils and subsoils are large

contributors of saline return flows. In recent years salinity concen~

trations in the Lower Colorado River have adversely affected .rrigated.

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

water delivered to California, Arizona, and Mexico.

The Colorado River system naturally carries a large load of ~alts

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

resulting from transbasin diversions, and for irrigation, municipal and

industrial uses has significantly reduced the supply of water available

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

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

available for dilution, and in most cases the development projects will

themselves increase the salt loadings in the Colorado River system.

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

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

Water Quality Control Project was established in 1960 by the Division of

Water Supply and Pollution Control, U, S, Public Health Service (pre~

decessor to the Federal Water Quality Administration). Their studies

4