187. Memorandum of conversation, February 16, between Rusk and Ambassador Carrillo1

[Facsimile Page 1]


  • Geneva Disarmament Conference and Salinity of Colorado River Water


  • The Secretary
  • Ambassador Antonio Carrillo Flores, of Mexico
  • Mr. Sayre—CMA
  • Mr. Baker—ACDA


  • SINR/D
  • UARA—Mr. Woodward
  • HIBWC—Colonel Hewitt—2
  • GAmembassy MEXICO CITY
  • S/SAmconsulate MEXICALI
  • S/PCMA—2
  • Department of Interior—3
  • ACDA

The Mexican Ambassador called on the Secretary at the former’s request. He informed the Secretary that the Mexican Government agreed with the position of the United States (as outlined to the Mexican and Brazilian Ambassadors by the Secretary on February 12), on the Soviet proposal to have the heads of government open the March 18 Geneva Conference on Disarmament. The Ambassador asked for clarification of the US-UK proposal that the Foreign Ministers of the US, UK and USSR meet at Geneva prior to convening the conference and that the conference be attended by Foreign Ministers. The Secretary explained that it had been originally agreed that the conference be attended by the Permanent Representatives. The United States and the United Kingdom proposed that it be attended by Foreign Ministers. The Soviet Union responded by suggesting that the heads of government open the meeting. The United States hoped that the Soviet Union would agree to our proposal that it be a Foreign Ministers meeting and that as many Foreign Ministers as possible, in addition to those of the US, UK and USSR, would attend. The Mexican Ambassador said that Mexico desired to be represented at the conference by its Permanent Representative PADILLA Nervo and that the Mexican Foreign Minister did not plan to attend.

[Facsimile Page 2] [Typeset Page 447]

The Mexican Ambassador then discussed with the Secretary Mexico’s serious preoccupation with the quality of Colorado River waters being delivered to Mexico under the terms of the 1944 Water Treaty. He said that the Mexican Government viewed the situation with grave concern. He recalled that the Mexican Foreign Minister had discussed the problem with the Secretary at Punta del Este. He showed the Secretary the February 13 issue of Excelsior which he described as a conservative, pro-American newspaper. The newspaper headline and lead story were to the effect that the Mexicali Valley faced a catastrophe because of the salt water problem. He said that he realized it was a complex problem and that the International Boundary and Water Commission is urgently considering it. He wanted to suggest that the immediate problem be separated from the long range solution and that action be taken within the next week or two to provide good quality water for the February irrigation of the wheat crop in the Mexicali Valley. He asked whether the United States could agree during the next two or three months to deliver water to Mexico from storage through the All American Canal. The drainage water in the Colorado River would be permitted to waste to the Gulf except to the extent that it might be diverted by Mexico and mixed with the high quality water. Mexico would reserve its position on whether the water wasted would be counted as part of the Treaty allotment.

Mr. Sayre explained that the Treaty allots Mexico 1,500,000 acre feet of water. He noted that delivery to Mexico of any quantity above that amount would create a serious internal domestic political situation because of the strong feelings of the 14 Colorado Basin State Senators and others on the division of Colorado River water. He said that the source of the drainage apparently responsible for the high salt content of the water is the Wellton-Mohawk irrigation district in Arizona. The water Mexico is receiving from the River has a salt content of some 2,500 parts per million of salt, whereas deliveries to Mexico before this year had a salt content of about 1,500 p.m.m. He noted that US irrigation experts had advised us that the water now being delivered is usable for irrigation of wheat.

The Mexican Ambassador discussed briefly the salt water situation on the Rio Grande River which the United States complained about to Mexico in 1960 but on which no action [Facsimile Page 3] has been taken. He said that the United States had asked on December 2, 1961, that the water behind Anzalduas Dam be wasted because of its high salt content and that Mexico had agreed within 24 hours. He hoped that the US could agree as promptly to the Mexican request. (The Mexican Ambassador had made this same point to Mr. Sayre before his conversation with the Secretary, at which time Mr. Sayre noted that the lower Rio Grande farmers had wanted to irrigate seedling vegetable plants which [Typeset Page 448] required water of a low salt content. If wheat had been involved the water would have been used. The US counted the released water as part of its Treaty allotment. The quantity of water was negligible in contrast to the thousands of acre-feet involved on the Colorado River.)

Mr. Sayre noted that the quality of Colorado River waters was discussed during the negotiation of the 1944 Water Treaty and that it was realized at the time that the salt content of the water would increase. He said that in return for a higher quantity of water than that to which the United States considered Mexico entitled, Mexico had accepted provisions in the Treaty which required Mexico to take and count drainage water as part of its allotment. The Mexican Ambassador interposed that this was the point on which Mexico had reserved its legal position because it disagreed with the United States. He said that the only record of which he was aware that this had been discussed was in the hearings before the United States Senate.

The Secretary inquired what might be done to meet the Mexican request. Mr. Sayre said that we had received a similar proposal from the Mexican Commissioner but that we had understood the Mexican Commissioner, in effect, to suggest it as a long term solution. We had already prepared a reply to the Mexican Commissioner. He said the Mexican Ambassador’s proposal was for emergency action and that he would take it up immediately with the Department of the Interior. The Secretary said that he would call the Secretary of the Interior and promised the Mexican Ambassador a prompt reply.

Note: The Ambassador’s proposal was discussed with the Department of the Interior and an instruction was sent on February 15 to the United States Commissioner that he could accept the proposal if Mexico (1) understood the United States would count all waters delivered whether [Facsimile Page 4] in the River or through the Canal as part of its allotment under the Treaty, (2) understood that the United States could not guarantee deliveries through the Canal at a level higher than provided in the Treaty because the capacity of the Canal is only sufficient to handle the requirements of US users plus the amount specified in the Treaty for Mexico and (3) paid the cost of delivery through the Canal in accordance with the formula worked out in 1950 when emergency deliveries were made through the Canal.

  1. Geneva Disarmament Conference and salinity of Colorado River water. Confidential. 4 pp. DOS, CF, 397.5611–GE/2–1662.