60. Memorandum From the President’s Assistant for National Security Affairs (Kissinger) to President Nixon1


  • Settlement of the Colorado River Salinity Problem

Your Personal Representative, Herbert Brownell, has reached agreement with his Mexican counterpart on a solution to the problem of salinity in Colorado River waters delivered to Mexico under the 1944 Water Treaty. The proposed solution is in accord with the proposal made to you by Mr. Brownell last December which you subsequently approved. The agreement is subject to final approval by you and President Echeverria.

This is a major breakthrough in our relations with Mexico. It promises an end to a problem that has gone unsolved for twelve years. And it removes the largest single irritant in our relations with this important neighbor.

Mr. Brownell will be submitting a detailed report in a few days. But the essential elements of the agreement are as follows:

U.S. Undertakings

—a commitment to deliver to Mexico most of its treaty allotment of waters with a salinity level of no more than 115 parts per million higher than that of water at Imperial Dam. The commitment begins when Congress has authorized funds for a desalting plant and relining of the Coachella Canal;

—agreement to pay for lining a drainage channel that would carry outflows from the Welton-Mohawk Irrigation District and brine from the desalting plant from the Mexican border to the Gulf of California;

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—support for Mexican efforts to get financing on favorable terms for improving and rehabilitating the Mexicali Valley;

—on a basis to be negotiated, to provide modest grants to assist Mexicali rehabilitation related to the salinity problem, including tile drainage and technical assistance.

MEXICAN Undertakings:

—specific acceptance as part of its water allocation of 140,000 acre-feet of water delivered at San Luis but not heretofore covered by agreement;

—acceptance of pumped drainage water as part of its allocation, so long as the salinity differential is not exceeded;

—acceptance by Mexico of this agreement as the “permanent and definitive solution” foreseen in the Nixon-Echeverria communiqué of June 1972.

Mutual Undertakings:

—agreement to limit groundwater pumping within five miles of the Arizona-Mexico border to 160,000 acre-feet a year by each party;

—agreement to consult regarding any water development programs in the border area that might affect the other party.

You will note that Mexico has agreed to consider this the “definitive” solution and that no provision was offered or demanded regarding the payment of cash damages.

I believe the agreement is a favorable one for the United States. It will be costly (the current estimate is between $110 and $130 million over the next four years). But Mr. Brownell believes, and I agree, that there are no known politically feasible, less expensive alternatives within the United States. And the international alternative of going to court would cost the United States considerably more financially, while creating a substantial, unnecessary and long-lasting strain in our relations with Mexico.

The Mexicans expect to have President Echeverria’s prompt approval of the proposed agreement and would like us to inform them of your approval by Tuesday, August 28. They propose to make a public announcement of the agreement on August 31, and we would make our announcement that same day.

We shall, of course, inform key members of the House and Senate of the essential elements of the agreement in advance of the public announcement. Mr. Brownell’s consultations over the past months with Congress, especially with Foreign Affairs, Foreign Relations, and Interior Committees, indicate they are basically favorable to an agreement along the lines now achieved. We expect an effort by representatives of some Basin States to link their approval of the agreement with support [Page 195] for some of their favorite water and development projects in home States. But we believe the basic outlook regarding Congressional reaction is favorable.

The proposal submitted to the Mexicans and now accepted by them was worked out in close consultation with Interior Secretary Morton and Mr. Ash of OMB.


That you approve the agreement reached with Mexico and announcement of that Agreement on August 31.

That you approve the attached directive (Tab A) instructing the Departments and Agencies involved to prepare a legislative package promptly to carry out the terms of the agreement, including appropriation of an initial $2 million for study and design of the physical works.

  1. Summary: Kissinger summarized the key points of an agreement on the Colorado River salinity issue reached by Brownell and Rabasa on August 21. He recommended that President Nixon approve both the agreement and a directive instructing U.S. Agencies to prepare a legislative package for the implementation of its terms.

    Source: National Archives, Nixon Presidential Materials, NSC Files, Country Files, Box 788, Latin America, Mexico, Vol. IV, 1973. Confidential. Sent for urgent action. Nixon initialed his approval of Kissinger’s recommendations. A note on the memorandum reads: “Wash. notified 8–28.” Notations on a draft of the memorandum indicate that Nixon conveyed his approval to the White House through a phone message from San Clemente, California, on August 28. Attached as Tab A, but not published, is a draft memorandum from Kissinger to the Secretaries of State and the Interior and the Director of OMB. In telegram 6497 from Mexico City, August 31, the Embassy noted that the accord was formalized with an August 30 exchange of notes. (Ibid., RG 59, Central Foreign Policy File, [no film number]) In telegram 134951 to Mexico City, June 24, 1974, the Department reported that President Nixon signed legislation implementing U.S. commitments under the agreement on that date. (Ibid., D740165–0734)