Foreign Relations of the United States, 1964–1968, Volume XXXI, South and Central America; Mexico

354. Memorandum From the President’s Special Assistant for National Security Affairs (Bundy) to Secretary of State Rusk and Secretary of the Interior Udall¹

Washington, April 6, 1965.

The President has approved the proposed agreement with Mexico, which the Departments of State and Interior recommended, as the best attainable measures we could take now to settle the salinity problem. The Wellton–Mohawk problem is a special case, but it would be desirable to look at projected future operations on the Colorado River so that we will avoid the possibility of a future dispute with Mexico.

We should consider whether projected future operations will serve the basic interests of the United States. The basic interests here involved are, of course, protection of the water rights of the United States and the maintenance of friendly relations with our nearest southern neighbor. The example of excellent relations with Mexico also has a bearing on our world posture.

I know that some of the Basin States continue to be dissatisfied with the 1944 Water Treaty itself and believe that our policy should be conditioned by the fact that Mexico was guaranteed a quantity of water larger than it should have been given. I should think our best interests are served by carrying out in good faith the bargain made in 1944. I gather that the Mexican response to comments that the 1944 Treaty was a bad bargain for the United States has been that Mexico made bad bargains in 1848 and 1853.

One of the conclusions that the two Departments have apparently reached, after more than three years of work on the Wellton–Mohawk problem, is that the United States has an obligation to act reasonably in conducting irrigation in the United States. In technical terms, this translates itself into a requirement that U.S. irrigation districts maintain approximate salt balance. This fairly well defines our legal view of the 1944 Water Treaty.

On the other hand, Mexico has from the first held to the view that the Treaty divided the waters of the Colorado and that it was, therefore, entitled to the same treatment as users in the United States. In short, it asserts that the United States has no right to deliver all of the drainage water to Mexico, but should divide it proportionally among all the users on the lower Colorado.

If, as is apparently generally expected, the overall quality of water in the lower Colorado continues to deteriorate, it would be to Mexico’s interest to test its legal theory. On the other hand, it is in our interest to avoid such a test. But if we are to do so, we need complete data on projected developments as the basis for developing an agreed strategy.

The Department of the Interior should take the leadership in developing data on the following points and any others that the two Departments consider appropriate. I would hope we could have the study before the end of the year. The study should assume that the Department of the Interior will in the course of the next few years be able to limit flows to Mexico to its guaranteed annual allotment of 1,500,000 acre feet:

1. What will the quality of water delivered to Mexico be each year over the next twenty years? This should consider existing projects, those contemplated in the Pacific Southwest Water Plan, and others that might be developed over the next twenty years.

2. What will the quality of water delivered to U.S. irrigation projects below Imperial Dam be overall and by project for these same years?

3. What quantity and percentage of Mexico’s guaranteed annual amount will be drainage return flow for these same years?

4. What U.S. irrigation districts in the lower Colorado River now use drainage return flow for irrigation? Is it contemplated that these amounts will increase or decrease over the next twenty years?²

McGeorge Bundy

1. Source: Johnson Library, National Security File, Country File, Mexico, Vol. I, Cables, 12/63–12/65. Confidential.
2. The proposed study has not been found. In a memorandum to Rusk, March 22, 1966, Sayre complained: “The Interior Department ought to have been able to furnish us before now the results of studies on the salinity of water to be delivered to Mexico that the White House requested in April 1965.” (National Archives and Records Administration, RG 59, Central Files 1964–66, POL 33–1 MEX–US)