WSPC04953

• File Number: 8272
• Description: Colorado River - Colorado River Basin Salinity Control Program - CRBSCP
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 4/1/1990
• Author: Joseph F Friedkin
• Title: International Problem with Mexico Over the Salinity of the Lower Colorado River - Excerpted from Water and the American West - Essays in Honor of Raphael J Moses
• Water Supply Pro - Doc Type: Publication

02;;,239

32/Friedkin

creased level of salinity in the water received in the Mexicali
Valley. claiming a violation of international law.
The increase in salinity was caused principally by the
discharge to the Colorado River of 6,000 ppm waters from the
lITigation drain of the Wellton-Mohawk Irrigation. District in
Arizona. a project of the United States Bureau of Reclamation
that began operating in 1952. A reduction in total Colorado
River flows reaching Mexico in 1961 contributed to the in-
crease in salinity. The Wellton-Mohawk District drain enters
the river downstream of Imperial Dam but upstream of Mex-
ico's diversions. An extensive drainage system was constructed
for the District by the Bureau of Reclamation to relieve a water-'
logged condition that had developed from heavy irrigation of
the District lands for over ten years. Wells pump water from
the highly saline aquifer that underlays the District into col-
lector drains. The system maintains groundwater levels below
the root zones of crops so that groundwater does not impair
agricultural production.

The 1944 Water Treaty with Mexico
The 1944 Treaty provides that "[o]f the waters of the Col-
orado River, from any and all sources. there are allotted to
Mexico: (al A guaranteed annual quantity of 1.500.000 acre
feet..} in accordance with certain other provisions of the treaty.
The treaty is silent on water quality. In .hearings before the
United States Senate concerning ratification of the treaty.
California officials vigorously insisted that the absence of a
provision relating to the quality of lITigation return 'flows and
allowing them to be the source of deliveries to Mexico.under the
treaty could lead to objeetions from Mexico on water quality
grounds. In response. State Department representatives testi-
fied that water quality had been extensively discussed in the
negotiations with Mexico. and that the Mexican represen-
tatives understood that the treaty required that Mexico accept
irrigation return flows. They further testified that this under-
standing was incorporated by the provision in article 10 of the
treaty that said that Mexico's annual allotment of 1.5 million
acre-feet is "from any and all sources. . ."2. and a provision in
article 11 that "waters shall be made up of the waters of the said
liver. whatever their oligin . . ....3 '
In 1942, the United States formed the "Committee of
Fourteen," comprised of two representatives of each of the
Colorado River Basin states. to advise the Department of State
on the states' concerns and their conditions for supporting any
agreement with Mexico allocating Colorado River water. The
water quality issue was partly responsible for California's
strong dissent and Nevada's abstention from the Committee's