WSP08073

• File Number: 8277.100
• Description: Salinity Projects Not Located in Colorado - Colorado River Salinity Control Forum
• Basin: Colorado Mainstem
• Date: 9/1/1981
• Title: Salinity Control and Environmental Assessment - part 1
• Water Supply Pro - Doc Type: EIS

Additional Research and Demonstration Needs

Research on channel erosion, sedi~ntation, and consumptive use of
crops and phreatophytes in the valley would be beneficial. Field
research on consumptive use could refine the irrigation analyses, and
the salt and water budgets. Studies are being conducted by the
University of Nevada Extension Service on the consumptive use of alfalfa,
Farmers are not fully aware of potential benefits from optimizing soil-
water-air proportions in the root zone, and a demonstration project
would be very helpful, Additional study to define the flow paths of
deep percolating irrigation water would also be beneficisl,

Effects of Recommended Plan

Effects of the recommended plan are analyzed as if no new agri-
cultural water development were to take place, Downstream salinity
benefits are indexed to reduced salt concentration in the Colorado river
at Imperial Dam, Benefits are derived from the.effects of reduced
salinity on municipal water supplied to Las Vegas, Los Angeles, San
Diego, Phoenix, etc. and on agriculture in Imperial Valley, Palo Verde,
Cochella, Colorado River Indian Reservation, etc, These benefits are
based on $499,009 (1980) price index) for each milligra~per-liter
salt reduction,l The recommended plan will reduce salinity at Imperial
Dam by about 4 milligram-per-liter,

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Increased crop production and efficiency of production as a result
of improved irrigation water management results in $119,800 average
annual onfarm net benefits.

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Long-term adverse effects on wildlife habitat within the area will
be minimal. It is anticipated that within the evaluation period after
implementation there will be a slight improvement in the quantity and
quality of all wildlife habitat systems,

The measures of effects were summarized in three accounts, Economic
Development, Environmental Quality, and Other Social Effects, See
Tables 10, 11 and 12, The Environmental Quality Account includes im-
pacts to wildlife habitat, The improvements in water quality and quan-
tity will not have a measurable effect on the fisheries in Lake Mead
and downstream.

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Implementation Program

USDA recommends that ongoing conservation programs be accelerated
for needed improvements, Implementation plans should be prepared as
a Long-Term Agreement (LTA) with the farmer as part of a conservation
plan of operations for each farm,

An LTA provides for dealing directly with the landowner. The local
conservation districts will play a key role in helping determine prior-
ities for assistance, coordinating onfarm improvements with conveyance

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Adjustment to 1980 prices was made using the Consumer Price Index,
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