WSP10898

• File Number: 8273.100
• Description: Colorado River Basin Salinity Control - Federal Agency Reports - BOR
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 8/27/1974
• Title: Supplement to the Environmental Statement - Colorado River International Salinity Control Project - Draft
• Water Supply Pro - Doc Type: EIS

'"
o
'"
w

S UM~'AR Y
(X) Draft

() Final

Environmental Statement

'.

Prepared by the United States Department of the Interior and Depa, ~~ent
of State as a Supplement to the Draft Environmental Statement, INT DES 74-39,
April 1, 1974, Colorado River International Salinity Control Project, to
provide for Protective and Regulatory Ground Water Pumping.

1. Type of Action:

(X) Administrative

() Legislative

2. Brief description of action: A protective and regulatory ground-
water pumping project is proposed to be implemented under authority
of the Colorado River Basin Salinity Control Act of 1974 (Public
Law 93-320). The proposed project, located in the extreme southwest
corner of Yuma County, Arizona, within 5 miles of the International
Boundary, includes acquisition of approximately 23,500 acres of land
on the Yuma Mesa and the construction, operation, and maintenance of
two well fields capable of pumping 160,000 acre-feet of ground water
annually for use in the United States and for delivery to Mexico in
satisfaction of the United States-Mexico Water Treaty of 1944 and
consistent with Minute No. 242 of the International Boundary and
Water Commission. The purpose of the project is to protect and
utilize the United States ground-water resource for the benefit of
United States' interests.

",

3. Summary of environmental impact and adverse environmental effects:
Delivery of 125,000 acre-feet per year of pumped ground water to
Mexico will have a beneficial impact in that it will maintain flow
to Mexico at the Southerly International Boundary as required under
Minute No. 242 and will conserve a corresponding amount of Colorado
River water in upstream storage reservoirs for use in the United States.
Future use of approximately 34,400 acres of unimproved Yuma Mesa land
will be limited. Operation of the project's 35 pumps will require
52,000,000 kWh of electrical energy per year. Lowering of water levels
in the ground-water reservoir by pumping will adversely affect riparian
vegetation in and along the extreme lower Colorado River and approxi-
mately 60 miles of open agricultural drains, and may cause some
localized land subsidence. Substantial losses of fish and wildlife
will occur thereby reducing recreational opportunities in the area.
The impacts associated with the lowering of the ground-water level
will eventually occur even without the project as a result of continued
pumping of the existing Mexican well field. The pumping will benefit
agriculture by improving the drainage in areas with a high water table.

4. Alternative considered: No action

5. List of entities who received copy of Draft Environmental Statement:
See attached list.

6. Date draft statement available to CEQ and the public: April 1, 1974,
HIT DES 74-39.

AUG 27 IS14