WSP12542

• File Number: 8282.400
• Description: Colorado River Operations and Accounting - Deliveries to Mexico
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 5/1/2001
• Author: David and Lucille Packard Foundation
• Title: Immediate Options for Augmenting Water Flows to the Colorado River Delta in Mexico - RE-Colorado River-Mexican Delta Issues - 05-01-01
• Water Supply Pro - Doc Type: Report/Study

002017

governmental entities to provide an interim water supply for the Delta while needed research
continues.

'Ibis report proposes two sources of water that could be secured in the short-run for
furnishing a sustainable, annual supply of water to some of the ecosystems in the Delta. One source
involves the purchase of marginal agricultural land with water rights in Mexico, and the dedication
of those water rights for establishing specific areas of cottonwood and willow habitat in the river
corridor below Morelos Dam. Appropriate parcels have been identified for this purpose, and the
acquired water could amount to as much as 15,000 AFY. Legal research conducted for this report
confirms that water rights in the Mexicali and San Luis Rio Colorado Valleys can be purchased and
transferred for ecological purposes with the concurrence of local and federal Mexican officials.

The second proposed source of water is agricultural runoff from farmland near Yuma,
Arizona. This runoff is unrelated to the 125,000 AFY of brackish water already by-passed from
Wellton-Mohawk to Mexico. Currendy, the Yuma agricultural drainage water is returned to the
Colorado River at the Northerly International Boundary and to the Southerly International
Boundary where it is counted as part of Mexico's 1.5 million AFY annual treaty entidement. As
much as 75,000 acre-feet of Yuma irrigation runoff is available for diversion. This report proposes
that facilities be constructed to divert an appropriate amount of Yuma brackish flows directly into
targeted ecological areas in Mexico and, in particular, the agricultural land purchased and retired as
part of this proposal. The Yuma brackish water would not be counted against Mexico's 1.5 million
AFY entidement, and thus Mexico would receive deliveries of an equivalent amount of higher
quality substitute Minute 242 Well Field groundwater or mainstream Colorado River water released
from Lake Mead. '

The options proposed in this report are bilateral measures that can be implemented without
significant delay if the responsible parties are' amenable to solving the problem. Based on the
research and interviews conducted for this report, these options are likely to encounter the fewest
practical, political, and financial challenges and arouse less controversy than many other options.
Nevertheless, implementation of the options will require. coordinated action and funding from
public and private sources and should have the concurrence of the two nations. through a Minute to
the 1944 Treaty. A comprehensive, long-term solution, on the other hand, will require considerable
research as well as negotiations among multiple stakeholders.

The actions proposed in this report could constitute important first steps in addressing the
ecological needs of the Delta. Moreover, implementation of the proposals could help to sustain and
to restore important habitat in the short-term while the scient$c and diplomatic processes seek a
comprehensive, long-term Delta management strategy. The actions proposed in this report are,
therefore, intended to complement and build upon the ongoing work of government agencies, non~
government organizations and universities to better understand the Delta ecosystems and promote
their restoration.2 Implementing these proposals in the short-term will result in benefits to. both
countries and, most importandy, the ecology of the Delta.

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