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

002033

Rio Hardy. The fresh water would be used, primarily during winter and spring, to establish new
stands of riparian vegetation on an ongoing annual basis.

The following issues must be addressed:

. Additional due diligence and the execution of various agreements would .be required
before these alternatives can be implemented, including CNA's commitment to
maintain control over the purchased water.

. Assessing the economic and social implications of purchasing and retiring
agricu1turalland.14

. Addressing the competing uses for this water. It should be recognized that the
communities of Mexicali, San Luis Rio Colorado, Tijuana, Tecate and Rosarito need
additional water for their growing communities. Also, drainage return flows to the
Delta could be margirially impacted through a land retirement program.

. Securing the ecological ~e of parcels of land within the riparian river corridor
through long-term leases.

. Addressing the implications of possible US reservoirs associated with lining the All
American Canal that could diminish the volume and frequency of operational over-
deliveries of Colorado River water to Mexico.

. Identification of a bi-national institutional framework that will have an advisory and
support role for implementation and operation of the project.

B. Brackish Water Sources

'This alternative would involve transportation, at least during the term of the ISC, of brackish
agricultural drain water from the Yuma area to an area in Mexico lying south of the Compaction
Zone, west of the Cienaga de Santa Clara and east of the confluence of the Colorado River and the
Rio Hardy. This area is currendy targeted by CNA for elimination of irrigation activities. Once
irrigation is no longer being practiced, the CNA drainage wells that now lower groundwater in the
area would no longer be operated. Without the drainage wells operating, the area is expected to
become swiunplike. The brackish water from the Yuma area is of such a salinity that it can be used
to establish open water ,areas and support other marsh species that are already established in the
area.

The brackish water would be transported from the Yuma area to this area by the Bypass
Drain and would be in addition to the 125,000 acre-feet per year of agricultural drain water from the
Wellton-Mohawk area that now is delivered to die Cienaga. The limitation on the quantity of
additional brackish water that can come from the Yuma area is the total unused conveyance capacity
in the Bypass Drain. The Bypass Drain can carry a maximum of about 200,000 acre-feet per year.
The brackish drainage water would be transported through the existing Bypass Drain to a newly
constructed 4-mile long connector canal. The connector canal would take water from the Bypass
Drain to the Plan Ayala Drain at a location about 10 miles south of Colonia Esperanza. Figure 5

24

I
I
I
)
I

I
I
I
I
I

I
I
I

I
I
I
J
I

I