WSP03020

• File Number: 8278.400
• Description: Title I - Mexican Treaty and Minute 242
• Basin: Colorado Mainstem
• Date: 1/1/2000
• 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, 2000

This report presents the results of operations from January 1 through December 31, 2000 under the
agreement with Mexico entitled, "Permanent and Definitive Solution to the International Problem
of the Salinity of the Colorado River," dated August 30, 1973 of the International Boundary and
Water Commission, United States and Mexico (IBWC). 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 for the United States and
Mexico by the IBWC, with support from the United States Bureau of Reclamation (USBR), the
United States Geological Survey (USGS) and Mexico's National Water Commission (CNA).
Locations and features referred to in this report are shown in Exhibit 1.

The records show that the United States operations comply with salinity standards in Minute No.
242.

Deliveries Upstream of Morelos Dam

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. :t 30
p.p.m. U.S. count (121 p.p.m.:t 30 p.p.m. Mexican count) over the annual average
salinity of Colorado River waters which arrive at Imperial Dam . . ."

The records show that during 2000:

1) Scheduled deliveries of water from the Colorado River in the quantity of 2,096,931 ,000
cubic meters (1,700,000 acre-feet) were made to Mexico in accordance with Article 10 of
the 1944 Water Treaty consisting ofl,953,281,000 cubic meters (1,583,540 acre-feet) at the
river bed above Morelos Dam and 143,650,000 cubic meters (116,458 acre-feet) across the
land boundary near San Luis, Arizona and at the limitrophe section of the river below
Morelos Dam. Other waters delivered to Mexico in the limitrophe section amounted to
415,859,000 cubic meters (337,140 acre-feet).

2) During 2000, the annual flow weighted average salinities of the waters of the Colorado
River a) upstream of Morel os Dam, b) arriving at Imperial Dam, and the resulting salinity
differentials were as follows:

U.S. Count" Mexican Count'
Waters Umml Umm)
a) Upstream of Morel os Dam 778 843
b) Arriving at Imperial Dam 659 725
Salinity Differential 119 118