WSP03614

• File Number: 8270.100
• Description: Colorado River Basin Water Quality/Salinity -- Misc Water Quality
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1981
• Author: USDOI
• Title: Quality of Water - Colorado River Basin - Progress Report No. 10 - January 1981 -- Part 1 of 2 -- Title Page through Part IX - page 98
• Water Supply Pro - Doc Type: Report/Study

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extremes as well as average conditions are reflected in the resultinR
probabilities of occurrence, thereby providing a more complete view of
future salinity conditions.

It has been assumed for purposes of this stuny that the average annual
rate of pickup of dissolved solids from newly irrigated lands would be in
the range of zero to 2 tons per acre (zero to 4.5 t/ha) per year. This
assumption is baserl upon previous detailed studies. Where comprehensive
studies showed a different rate, the different figure was usen. The effect
of salt contrihuted from new lands is thus evaluated by co~putations of
salinity concentrations using these rates. It was also assump.d no increase
in the rate of pickup of dissolved solids would occur for lands already
under irrigation. Large industries such as powerplants were considered to
have no return of salts or water, and SAlt load changes dlJe to mllnicipal
ann minor industries were a~sumed negligible.

The estimated concentrations in milligrams per liter prujected for
1990, 2000, and 2010 conditions, without salinity control measures, are as
follows:

1990 2000 2010
Zero Two Zero T'NO Zero Two
T/A T/A CRSS T/A T/A CRSS T/A T/A CRSS
. Lees Ferry 670 690 592 703 730 656 709 736 680
Hoover Dam 831 853 697 883 913 766 898 928 805
Parker Dam 853 878 730 912 946 808 928 %3 851
Imperial [)am 1021 1055 859 1093 1141 969 1112 1161 1019

Since the above figures from Table D and Table E wer~ computed by us-
ing average values, they show only average conditions. Actual conditions
will produce years of higher flow, producing better quality water, or years
of lower flow producing, poorer quality water.

The depletions used in this report ar.e for the projects, both author-
ized and proposed for authorization together with present developments and
other proposals for developments as presently planneci.

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This report includes discussions of the effect of salinity on water
uses and potential salinity control measures. Investigations of the poten-
tial for water quality improvement on the Colorado River were initiated by
the Water and Power Resources Service (formerly the Bureau of Reclamation)
in fiscal year 1972. A report, "Colorado River Water Quality Improvement
Program," dated February 1972, describes potential projects for controlling
the salinity of the Colorado River. A second reportJ "Colorado River Water
Quality Improvement Program, Status Report," was published by the Water and
Power Resources Service in January 1974. This report, with appropriate
updating by current investigations, is the basis for the discussion of the
Colorado River Salinity Control program presented in Part VIII. This
evaluation of the program is made in accordance with requirements of the
Colorado River Salinity Control Act, Public Law 93-320. The Final Environ-
mental Impact Statement for the Colorado River Water Quality Improvement

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