WSP00515

• File Number: 8271.200.60
• Description: Colorado River Basin Salinity Control Program - Development and History - Ann Rpts-Reviews
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1982
• Title: 1982 USDA Annual Report - Colorado River Basin Salinity Control Program
• Water Supply Pro - Doc Type: Annual Report

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More importantly, the Act instructed the Secretary of Interior "to coordinate
and cooperate wit~ the Secretary of Agriculture and the Administrator of the
!PA" regarding diffuse and non-point source areas of salinity. Title II
further instructed the Secretary of Agriculture to use "existing programs"
available to that Department to assist with salinity control.

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USDI assigned leadership responsibilities for the Act to the BR, and USDA
assigned program leadership to the SCS. USDA's involvement is documented
in a 1974 Me$orandum of Understanding with USDI and in a 1975 Memorandum of
Agreement between the SCS and the BR.

E. Benefits

Benefits related to water quantity, water quality, and reduced salt loadings
are major factors in the onfarm salinity control projects. Completed reports
indicate onfarm irrigation efficiency improvements and salinity control
practices will reduce salt loads by 19,000 tons per year in Moapa Valley and
to as much as 335,000 tons per year in Lower Gunnison. Table 11-1 shows the
salt load reductions and salinity concentration reduction impacts at Imperial
Dam for six onfarm salinity control projects. USDA has not recommended a plan
for the Big Sandy unit because of the continued off-farm salinity control
planning being conducted by the BR.

Table 11-1 ~ Salinity Control Impacts at Imperial Dam
for Recommended Plan

Irrigation Unit
Areaa

Salt Load
Reduction,
(Tons)

Reduced Salinity
Concentration
(mg/l)

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Grand Valley (CO)
Uinta Basin (UT)
Moapa Valley (NV)
, Lower Gunnison (CO)
Virgin Valley (NV, AZ)
McElmo Creek (CO)
Big Sandy (WY)

230,000
76,000
19,000
335,000
37,000
38,000
No Recommended

24
10
2
35
4
4

Plan

These reductions provide significant water quality benefits based upon
$513,000 average annual downstream damages for each mg/l increase in salinity
concentration at Imperial Dam.

The major benefits from the CRBSCP are national and regional in scope. The
national need is to maintain the salinity differential in the Colorado River
water delivered to Mexico in accordance with the 1973 agreement (Minute No.
242 of the International Boundary and Water Commission, United States and
Mexico). The regional need is to maintain current salinity levels in Colorado
River water withdrawn for downstream use while allowing the Basin States to
further develop its compact-apportioned waters.

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