WSP01897

• File Number: 8270.100
• Description: Colorado River Basin Water Quality/Salinity -- Misc Water Quality
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1977
• Author: USDOI
• Title: Quality of Water - Colorado River Basin - Progress Report No. 8 - January 1977
• Water Supply Pro - Doc Type: Report/Study

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SUMMARY (Continued)

This is because reservoir operations including releases and storage have
not been considered.

It has been assumed for purposes of this study that the average
rate of pickup of dissolved solids from ney irrigated lands ~ould be in
the range of zero to 2 tons per acre. ~~ere comprehensive studies
showed a different rate, the different figure was used. The effect of
salt contributed from new lands is thus evaluated by computations of
salinity concentrations using these rates. It was also assumed no
additional pickup of dissolved solids would occur for lands already
under irrigation.

The estimated concentrations in milligrams per liter projected for
1980, 1990, and 2000 conditions, assuming negligible salinity control
measures. are as follows:

1980 1990 2000
Zero Zero Zero
riA 2T/A riA 2T/A riA 2T/A
Lees Ferry 629 635 697 726 716 747
Hoover Dam 781 788 886 919 920 957
Imperial Dam 923 938 1118 117~ 1154 1214

Since the above figures from Table E, Part VII were computed by
using average 1941-1974 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 are for the projects. both
authorized and proposed for authorization together with present develop-
ments and other proposals for developments as presently planned.

This report includes discussions of the effect of salinity on water
uses and potential salinity control measures. Investigations of the
potential for water quality improvement on the Colorado River were
initiated by the Bureau of Reclamation in IT 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 report, "Colorado River Water Quality Ioprovement Program,
Status Report," was published by the Bureau of Reclamation in January
19i4. 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 Environmental Impact Statement for the
Colorado River Water Quality Improvement Program is expected to be completed
by ~larch 19ii.

Other phases of ~ater quality, including sources of pollution. and
parameters such as dissolved oxygen, te~perature, pH. heavy metals.
toxic materials, nutrients, bacteria, radioactivity. mercury, and
sediment, are discussed.

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