467. Memorandum Prepared by the Government of Mexico, Tlatelolco, Mexico City, June 25, 1971.1 2

[Page 1]

EMBAJADA DE MEXICO
MEMORANDUM

An examination of the last negotiations between Mexico and the United States of America on the salinity of the water of the Colorado River in order to reach a new temporary agreement in substitution of Minute No. 218, permits us to establish:

I. That the two countries are in agreement to:

a) It is to the advantage of both countries, for their mutual relations, to improve the conditions established in Minute No. 218 for handling the Wellton Mohawk waters.

b) This improvement can be obtained by using the waters extracted from wells drilled in the Yuma Mesa.

c) The antagonistic interpretations of the stipulations of the Water Treaty must be conciliated inasmuch as they constitute the true problem of the salinity in order to make possible its definitive solution and,

d) They should make an effort to attain a temporary agreement in substitution of Minute No. 218.

II. That the differences between the two countries can be appreciated by:

a) The United States offered as an additional measure to the agreements in Minute No. 218, to deliver to Mexico 50,000 acre-feet of waters extracted from wells in the Yuma Mesa, to substitute an equal amount of drainage water [Page 2] from Wellton Mohawk that are charged to Mexico. The United States would diminish water deliveries from the wells in the Yuma Mesa in accordance with the salinity balance of its lands;

b) Mexico proposed also as an additional measure to the agreements contained in Minute No. 218, that the United States by drilling additional wells as necessary, deliver 150,000 acre-feet of water per year from the wells in the Yuma Mesa, to substitute uninterruptedly all the drainage waters of Wellton Mohawk charged to Mexico;

c) The United States considers that with the measures that it proposes, Mexico should have no need to waste any water from Wellton Mohawk, to control the salinity at 1300 parts per million;

d) Mexico considers that it is imperative to improve the quality of the waters in the Morelos Dam, and has decided to let flow into the sea, without using it, all the drainage water of Wellton Mohawk, carried by the conveyance channel constructed by mandate in Minute No. 218. Mexico also considers that with the measures that it proposes, the salinity of the waters in the Morelos Dam could be reduced to 1120 parts per million, which is more acceptable, even though it is considerably above the 900 parts per million found in the waters of the same River utilized [Page 3] by users in the United States;

e) The United States considers inconvenient to undertake a commitment to examine the substance of the problem in the agreement that should substitute Minute No. 218, and

f) Mexico considers that it is necessary to establish this commitment to guarantee whatever action is decided upon. Considering the foregoing and the good disposition that the negotiators of both countries have shown, it is believed that in an effort to reach agreement, it would not be difficult to arrive to the following conciliatory conditions:

1) That the United States deliver to Mexico 100,000 acre-feet per year of water from the wells of the Yuma Mesa, drilling for its own account whatever additional wells are necessary to substitute for an equal amount of drainage water from Wellton Mohawk which at present is charged to Mexico;

2) That this annual delivery be uninterrupted during the time the agreement is in force, so that any reduction of salinity in the waters from the wells delivered to Mexico by the United States result in a reduction of salinity in the waters used by Mexico from the Morelos Dam. This will be in accordance with the spirit of the negotiation which prevailed in the agreement that was reached in Minute No. 218, without introducing new criteria such as the salinity [Page 4] balance that may prejudge on the rights of one or the other country.

3) That the new minutes or agreement contain a commitment to proceed to the examination of the substance of the problem, so as to reach a definite solution during the time the agreement is in force, and that the procedure be set forth for both countries to follow toward that end;

4) That the United States in order to avoid contamination of the subterranean waters that are used for irrigation in the Mexicali Valley extend through its territory the conveyance channel for the drainage waters of Wellton Mohawk up to the land border at San Luis Rio Colorado, and

5) That the new minutes or agreement will be for a minimum of six years, with ample legal reservations.

Tlatelolco, D. F., June 25, 1971.

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[Map: Colorado River and Wellton-Mohawk Conveyance Channel]

  1. Source: National Archives, RG 59, Central Files 1970–73, POL 33–1 MEX–US. No classification marking. A handwritten note on the first page indicates that Secretary of Foreign Relations Rabasa gave the note to Secretary of State Rogers on June 28. Another handwritten note indicates that Rogers replied on July 24.
  2. The Government of Mexico proposed a 6-year agreement to deal with the Colorado River salinity issue.