WSP00824

• File Number: 8278.400
• Description: Title I - Mexican Treaty and Minute 242
• Basin: Colorado Mainstem
• Date: 1/1/1997
• Author: IBWC
• Title: Minute 242 Annual Report
• Water Supply Pro - Doc Type: Annual Report

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A REPORT ON SALINITY OPERATIONS
ON THE COLORADO RIVER UNDER MINUTE NO. 242

January 1 - December 31, 1997

This report presents the results of operations from January 1 through December 31, 1997, under the
agreement with Mexico entitled, "Permanent and Definitive Solution to the International Problem
of the Salinity of the Colorado River", incorporated in Minute No. 242 dated August 30, 1973, of
the International Boundary and Water Commission, United States and Mexico. The operations
began on June 25, 1974, immediately following approval of the Enabling Legislation, Public Law
93-320.

This report is based upon records of flows and salinities determined jointly by the United States and
Mexican Sections of the International Boundary and Water Commission, the U.S. Bureau of
Reclamation and the U.S. Geological Survey. Locations and features referred to in this report are
shown on the map, Exhibit 1.

The records show that the United States 9perations resulted in compliance with the agreement in
Minute No. 242.

The Salinity Differential

Minute No. 242 provides in Point 1 that:

"The United States shall adopt measures to assure that . . . the
approximately 1,360,000 acre-feet (1,677,545,000 cubic meters)
delivered to Mexico upstream of Morelos Dam, have an annual
average salinity of no more than 115 p.p.m. ~ 30 p.p.m. U.S. count
(121 -p.-p-.fii::t 30'p~p.fii.- Mexican count) -6vefthe- annuM-average
salinity of Colorado River waters which arrive at Imperial Dam, . . ."

The records show that during 1997:

1) Scheduled deliveries of water of the Colorado River in the quantity of 1,850,234,000 cubic
meters (1,500,000 acre-feet) were made to Mexico-in accordance with Article 10 ofthe 1944
Water Treaty consisting of 1,708,221,000 cubic meters (l ,384,872 acre-feet) in the river bed
above Morelos Dam and 142,013,000 cubic meters (115,131 acre-feet) across the land
boundary near San Luis, Arizona and in the limitrophe section of the river below Morelos
Dam.

Other waters delivered to Mexico in the limitrophe section amounted to 1,692,905,000 cubic
meters (1,372,455 acre-feet).

2) The annual average salinities of the waters of the Colorado River a) upstream of Morel os
Dam, b) arriving at Imperial Dam, and the resulting salinity differential were as follows:

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