WSP08103

• File Number: 8278.400
• Description: Title I - Minute 242
• Basin: Colorado Mainstem
• Date: 1/1/2002
• Author: INBWC
• Title: Minute 242 2002 Annual Report
• Water Supply Pro - Doc Type: Annual Report

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Groundwater

Point 5 of Minute No. 242 provides that:

.Pending the conclusion by the Governments of the United States and Mexico of a
comprehensive agreement on groundwater in the border areas, each country shall
limit pumping of ground waters in its territory within five miles (eight kilometers) of
the Arizona-Sonora boundary near San Luis to 160,000 acre-feet (197,358,000 cubic
meters) annually."

In 2002, Mexico pumped 135,687,000 cubic meters from its San Luis Mesa well field located
within five miles (eight kilometers) of the boundary near San Luis. The annual volumes pumped
from these well fields from 1975 through 2002 are shown in Table S.

The USBR has completed 21 of the allowed 35 wells on the United States side, all located within
eight kilometers (five miles) of the Arizona-Sonora boundary near San Luis, for protective and
regulatory pumping. Construction of the remaining 14 allowed wells has been deferred until
additional water supply needs make it necessary. Of the 21 completed wells, 6 were pumped during
2002 for municipal and irrigation uses. The annual volumes pumped from 1975 to 2002 are shown
in Table 6.

Under Minute No. 242, the Commission is continuing its program for exchange of groundwater data
for the major groundwater basins lying partly in the United States and partly in Mexico, including
the Colorado River delta area. The objective of the exchange is to make available hydrologic,
geologic and water quality data in either country to both Sections of the Commission to enable
evaluation of the conditions of the international groundwater basins.

Consultations and New DeveloDments in the Rel!ion

Point 6 of Minute No, 242 provides that:

". . . . . the United States and Mexico shall consult with each other prior to
undertaking any new development of either the surface or the groundwater
resources, or undertaking substantial modifications of present developments, in its
own territory in the border area that might adversely affect the other country."

The United States and Mexico began informal IBWC talks related to conveyance of a portion of
Mexican treaty water in a lined All-American Canal.

Similarly, binational technical work groups of the IBWC continued to develop joint cooperation
options concerning salinity peaks in the southern boundary deliveries and removal of sediment in
the international reach of the Colorado River.

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