Exchange of notes constituting an agreement concerning the loan of waters of the Colorado River for irrigation of lands in the Mexicali Valley. Done in Mexico City, 24 August 1966

The American Ambassador to the Mexican Secretary of Foreign Relations
No. 291
Mexico City, August 24,1966

Excellency:
I have the honor to refer to the recent request of the Mexican Commissioner on the International Boundary and Water Commission for additional waters of the Colorado River to relieve the critical shortage of water available for irrigation of lands in the Mexicali Valley. I have the honor to inform Your Excellency that the Government of the United States of America is prepared to provide the needed waters to Mexico and for this purpose to conclude with the Government of the United Mexican States an Agreement on the following terms :

1. The United States shall, during the months of September and December 1966, release to Mexico, in accordance with a schedule to be agreed upon by the International Boundary and Water Commission, 40,535 acre-feet of Colorado River waters in addition to the waters of the Colorado River allocated to Mexico annually under Article 10 of the Water Treaty signed in Washington on February 3, 1944 (United Nations, Treaty Series, Vol. 3, p. 313).

2. The United States will retain 40,535 acre-feet of water from its annual scheduled deliveries to Mexico under the 1944 Water Treaty in calendar year 1967, in accordance with a schedule to be agreed upon by the International Boundary and Water Commission before January 1, 1967, unless it is determined by the United States in the May 1, 1967 forecast, to be issued about May 15, 1967, that the runoff of Colorado River Waters in the United States from April through July, 1967 is expected to be 8.5 million acre-ft or more, in which event the 40,535 acre-feet will be retained over a period of three years including 1967, in accordance with a schedule to be agreed upon by the Commission before July 1, 1967. In the event that either of the aforesaid schedules cannot be agreed upon by the Commission, the United States must reserve the determination to itself.

3. The releases and retention of waters agreed to in paragraphs 1 and 2 shall be effected within the maximum and minimum schedules of delivery by months set forth in Article 15 of the 1944 Water Treaty.

4. The United Mexican States agrees to reimburse the United States at market value for any actual decrease in power generation at either Hoover or Glen Canyon Power Plant, caused by the loss of power head resulting from the release of the said 40,535 acre-feet to Mexico.

5. This Agreement shall not be regarded as a precedent for deliveries of water in the future in addition to the waters of the Colorado River allotted to Mexico annually under Article 10 of the 1944 Water Treaty.If this proposal is acceptable to the Government of the United Mexican States, this Note and Your Excellency's reply concurring therein shall constitute an Agreement between our two Governments, which shall enter into force on the date of your Excellency's reply.Accept, Excellency, the renewed assurances of my highest consideration.

Fulton FREEMAN
His Excellency Antonio Carrillo Flores
Secretary of Foreign Relations
Mexico, D. F.

Ministry of Foreign Relations
United Mexican States
Mexico
No. 11205Mexico, D.F., August 24, 1966

Mr. Ambassador:
I have the honor to acknowledge the receipt of Your Excellency's note No. 291 dated today, the text of which, translated into Spanish, reads as follows:[see above]

In reply I have the honor to inform Your Excellency that my Government considers the proposals contained in the note transcribed above to be acceptable, and consequently, it agrees that the aforesaid note and this reply shall constitute an agreement between the Government of the United Mexican States and the Government of the United States of America, which shall enter into force on date.

I avail myself of this opportunity to renew to Your Excellency the assurances of my highest consideration.

Antonio CARRILLO FLORES
His Excellency Fulton Freeman
Ambassador Extraordinary and Plenipotentiary
of the United States of America