WSP09080

• File Number: 8276.150
• Description: Grand Valley Unit - Colorado River Basin Salinity Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 7/1/1982
• Title: Monitoring and Evaluation Plan -- Colorado River Basin Salinity Control Program for Grand Valley Unit and Uinta Basin Unit, Utah -- PART I
• Water Supply Pro - Doc Type: Report/Study

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Basin-Wide Salinity Mon~toring and Evaluatio~

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Installation of structural measures, cultural practices, and improvement of

irrigation water management are expected to impact basin-wide salinity

concentrations. During the planning process for each salinity control unit,

estimates were made of salt load reductions which would result from

implementation of the recommended USDA program. Monitoring of changes in deep

percolation and seepage from irrigation improvements are to be translated into

estimates of basin-wide impacts.

In approaching the basin-wide monitoring studies for this plan, SCS recognizes

four premises:

Premise 1 - Colorado River system is highly complex, subject to seasonal and

annual variations in the flow and salinity, and modifie,:l by existing reservoirs

and man's use.

Premise 2 - Basin-wide salinity is presently being monitored through an

extensive network of sampling stations maintained by U.S. Geological Survey.

This basin-wide monitoring is supplemented by an extens:lve network of surface

and ground water sampling stations maintained by U.S. Geological Survey, U.S.

Bureau of Reclamation, and other federal agencies. USDA wIll not duplicate the

ongoing monitoring.

Premise 3 - Determination of average concentrations of total dissolved solids in

a long-term process canplicated by river depletions resulting from present and

proposed developments.

Premise 4 - The onfarm irrigation monitoring efforts described in this plan, and

the resulting estimates of deep percolation, seepage and salt load reductions,

are considered to be evidence of basin-wide salinity impacts.

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