WSP04002

• File Number: 8270.100
• Description: Colorado River Basin Water Quality/Salinity -- Misc Water Quality
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1974
• Author: USDOI
• Title: Colorado River Water Quality Improvement Program - Status Report
• Water Supply Pro - Doc Type: Report/Study

potentials for salinity control are discussed. The EPA
study describes salinity conditions in the basin,
W evaluates the nature and magnitude of damages to
o water users, examines alternative salinity c;:ontrol
l'\._:. measures, and provides recommended measures and
0- programs for control of the salinity levels. The
Colorado River Board of California report defines the
nature and magn itude of the problem and presents a
plan for controlling the salinity at or near present
levels. The Water Resources Council reports draw
heavily on the prior studies, develop estimates of
future salinity conditions, and identify potential
control measures. Utah State University performed a
computer simulation of the hydrologic-salinity flow
system in the Upper Colorado River Basin.

Differences in findings among the various studies
occurred, particularly as related to quantitative
displays of historic salinity conditions, salt loading,
concentrating effects, contributions from various
sources, and economic impacts. Because there was
nonuniformity in assumptions, data sets, and
procedures, the quantitative findings should be
expected to differ. On the other hand, the conclusions
derived are generally similar. The major sources of
salinity were identified as arising from natural point
and diffuse sources, irrigation, evaporation,
out-of-basin transfers, and municipal and industrial
uses. The largest portion of the mineral burden and
water supply was found to originate in the Upper
Colorado River Basin. The natural sources were
thought to be the major contributors to the salinity.
Salinity was projected to continually increase unless
control programs are implemented. The impact of the
increasing salinity levels was found to be primarily
economic. While salinity levels increased over time, the
composition of the water with respect to individual
ions remained relatively stable.

WATER RESOURCES OF THE UPPER
COLORAOO BASIN.BASIC
DATA (USGS)

In 1964, the U.s, Geological Survey published its
report entitled "Water Resources of the Upper
Colorado Basin-Basic Data" as Professional Paper No.
442. This report is based on data for the 1941.1957
period. I n summary, the report states that- if the
developments of 1957 had not been in existence then:
(1) the hypothetical average yearly water yield at Lees
Ferry would have been about 15,2 million acre.feet
rather than the 12.7 million measured, (2) the
hypothetical average concentration would have been
about 250 mg!1 rather than observed values of about
500 mg!l, and (3) the hypothetical dissolved solids

discharge would have been about 5.2 rather than
observed amounts of about 8.7 million tons annually.
Substantially all the increase in dissolved solids
discharge was construed by the investigators to be an
effect of irrigation on 1.4 million acres of land. They
estimated the average increase to be 2.5 tons per
irrigated acre per year. F rom one part of the area to
another, this average was said to range from about 0.1
to 5.6 tons. The report did not indicate which portion
of this increase was due specifically to irrigation and
which to natural sources.

UPPER COLORADO RIVER BASIN
COOPERATIVE SALINITY CONTROL
STUDY (USBR)

In cooperation with the Federal Water Pollution
Control Administration (now the Environmental
Protection Agency). the Bureau of Reclamation in July
1969 completed a report entitled "Upper Colorado
River Basin Cooperative Salinity Control Study," The
report has been given to the EPA for review and study
and has not yet been released. It deals with the control
of salinity from specific identified sources, appraises
potential salt-load reduction values, and evaluates the
status of the economic feasibility of salinity control.
The need for a coordinated salinity control program
for the entire Colorado River is stressed.

NEED FOR CONTROLLING SALINITY
OF THE COLORADO RIVER (CRBC)

The Colorado River Board of California published a
report entitled "Need for Controlling Salinity of the
Colorado River" in August 1970. Using available data,
the report traces the average annual salinity principally
at Hoover, Parker, and Imperial Dams and makes
projections for the years 1980, 2000, and 2030, The
historical average is based on the years 1963-1967 and
shows values below Hoover Dam to be 730 mg!1 and at
Imperial Dam 850 mg!1. 8elow Hoover Dam, values of
830 and 1,090 mg!1 are projected for the years 1980
and 2030, respectively. Comparable projections for
Imperial Dam suggest 1,070 mg!1 in 1980 and 1,390
mg!1 in 2030. The Salinity is estimated to cause $8 to
$10 million damage annually for each salinity increase
of 100 mg!1 for water users in California. The report
identifies a number of potential salinity control
projects which, if constructed, might serve to maintain
salinity near present levels. The studies by the Board
indicate that unless action is taken to control salinity
and with the Upper Basin continuing to develop, the
total economic impact in California from salinity

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