WSP02976

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1979
• Title: An Economic Evaluation of the Salinity Impacts From Energy Development - The Case of the Upper Colorado River Basin
• Water Supply Pro - Doc Type: Report/Study

W
tv
1-'
C)l

<l ct iv i ties
botb salt
processes.

increase salinity levels through
loading and salt concentrating

The salinity of streams in the Upper
Basin varies from day to day and month to
month with fluctuations in the streamflow and
sdlt loadings. Total annual salt load,
outflow, and average salinity concentration
level of each WRSA (Utah State University
1975) are presented in Figure 6.

Since the increases in salinity levels
cause economic damages to the Lower Colorado
River Basin and Mexico, a need for mitigation
has lead to the salinity-control efforts
described in three important documents:

1) The Federal Water Pollution Control
Act Amendments of 1972 (Public Law 92-500)
and the Clean Water Act of 1977 (Public Law
95-217) seek to restore and maintain the
chemical, physical, and biological integrity
of the nation's waters. Public Law 92-500
declares that the national goal is to elimin-
ate discharge of po'11utants into navigable
waters by 1985. This legislation has been
interpreted by the Environmental Protect ion
Agency (EPA) to require that numerical
standards for maximum allowable salinity
concentrations on the Colorado River be set.
An agreement reached between EPA and the
Upper Basin states in 1974 calls for the

2,250 IT
5,673 TAF
.40 T/AF

3,601 IT
4,817 TAF
.75 T/AF

9,580 IT
12,790 TAF
.75 T/AF

4,833 IT
5,428 TAF
.89 T/AF

maintenance of salinity at or below 1972
levels. Later, in 1976, EPA issued standards
for three locations (723 mg/l below Hoover
Dam, 747 mg/l below Parker Dam, and 879 m~/l
at Imperial Dam).

2) Minute No. 242, an agreement made in
1973, promises that the salinity of water
delivered to Mexico will not exceed ll5 parts
pe r mi II ion (ppm) + 30 ppm over the annua 1
average salinity 'Of Colorado River water
which arrives at Imperial Dam.

3) The Colorado River Basin Salinity
Control Act (Public Law 93-320) authorizes
the Secretary of the Interior to construct
several projects for the improvement, en-
hancement, and protection of the quality of
water available in the Colorado River for use
in the United States and the Republic of
Mexico.

Under Public Law 93-320, the Colorado
River Salinity Control Program has been
established, and several projects are autho-
rized for planning or construction to reduce
salt loading from natural sources. Whether
these public investments prove economically
feasible will depend on their cost and the
benefits received. A list of the proposed
projects with associated costs, water losses,
and salt reductions is shown in Table 8.

1,994 IT
4,945 TAF
.403 T/Ai7

2,514 IT
3,541 TAF
.71 T/AF

1,764 IT
6,419 TAF
.326 T/AF

Figure 6. Thousand tons (TT) of salt load, thousand acrewfeet (TAF) of outflow, and
ton per acre foot (T/AF) of salinity level of each WRSA.

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