WSP09507

• File Number: 8276.350
• Description: Lower Gunnison Basin Unit - Colorado River Basin Salinity Control Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 4
• Date: 5/1/1979
• Title: News Articles/Press Releases May 1979 - March 17 1994
• Water Supply Pro - Doc Type: News Article/Press Release

BACKGROUND

The Lower Gunnison River Basin, an area with
180,000 acres of Irrigated farmland In west
central Colorado, Is the subject of a
salinity control study to reduce salinity In
the Colorado River System. The Irrigated
land and highly saline soils In the basin
contribute about 800,000 tons of salt to the
Colorado River annually.

Follow Ing passage of PL 92-500, the Federal
Water Pollution Control Act Amendments of
1972, the Environmental Protection Agency
Issued regulations requiring states of the
Colorado River Basin to adopt water quality
5 tandards and a p I an of Imp I emen1-at i on for
sal inity control.

Section 203 of the Act requires feasibility
studies on twelve sal iofty control units,
including the Lower Gunnison as an irrigation
source control unit.

The So II Conservat Ion Serv I ce of the
States Department of Agr I cu I ture
cooperating agency by law.

Un Ited
is a

PURPOSE OF STUDY

As Its part of the sa II n I ty contro I study,
SCS has eva I uated the present cond I t Ion of
on-farm irrigation systems and management
practices and determined what can be done to
reduce salt in the river. Our activities
attempted to answer these questions:

1. What Is the magnitude of on-farm irriga-
tion Improvement needs?

2. What are the total Installation costs and
annual levels of funding required to
Implement the program?

3. What wll I be the reduction In salinity to
the Colorado River?

SALT BUDGET ANALYSIS

Salt In the Colorado River accumulates through
sol I erosion, deep percolation from field
irrigation, and seepage losses from ditches
and canals. Permeability and depth of solis
are major characteristics affecting the volume
of water passing through the soli prof lie and
carrying salt to the river. The salt budget
attributed to on-farm Irrigation for the
present condition and for three possible
levels of Improved irrigation water management
are shown In the table. Presently, 270,000
tons of salt are delivered annually to the
river from on-farm Irrigation. Other sources
contribute an estimated 530,000 tons of salt.

LOWER GUNNISON SALINITY STUDY
PROJECT LOCATION MAP

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