The Mexican Ambassador ( Castillo Nájera ) to the Department of State



My Government has carefully considered the memorandum relative to negotiations to conclude a Treaty on International Waters which was handed to me by Mr. Duggan75 on February 11, 1942.

The Government of Mexico is happy to recognize the good disposition of the Government of the United States which has been shown by its accepting, in general terms, the proposal which my aforesaid Government submitted to the Department of State for consideration.

As I have on previous occasions taken the liberty of explaining, the problem of the international waters and, in particular, that referring to the Colorado River, has been the subject of prolonged studies on the part of Mexican experts and on the basis thereof, my Government instructs me to make certain comments on the memorandum of [Page 549] February 11 and, at the same time, to insist on the points of view on which Mexico’s requests are based.

1. Amount of Water Needed by Mexico. The request for a volume of 2,000,000 acre-feet annually is the minimum to satisfy the foreseeable needs to a very near future. The latest studies of the Mexican Section of the International Boundary Commission between Mexico and the United States show that the furnishing of the indicated amount of 2,000,000 acre-feet, which are indispensable for Mexican needs, would not cause difficulties in the execution of present and future irrigation programs in American territory.

The aforesaid volume of 2,000,000 acre-feet annually is the absolutely necessary volume for the irrigation of 200,000 net hectares, which may be cultivable, of the 300,000 good-class, gross hectares, subject to gravity control in the Mexican section of the delta of the Colorado River. The volume of 1, 150,000 acre-feet offered in the memorandum of February 11 would be insufficient for the irrigation of a great area of cultivable lands in the Colorado delta, lands which constitute the only important agricultural zone in Lower California. It is well to add that, in addition to the 200,000 net hectares to which I have just referred, there is an area of approximately equal size, formed of good quality lands, which could be watered by pumping if sufficient water from the Colorado were available. There are also salt lands which could be washed or improved if sufficient water were available. Despite these considerations, the aforesaid possibilities had to be discarded in formulating the plan in the terms in which it was presented to the Department of State.

The offered volume of 1, 150,000 acre-feet would not, I repeat, suffice to meet minimum needs. Acceptance of that volume would create in Lower California a situation similar to that existing in the Juárez Valley in which, as is well-known, the area of cultivable lands amounts to 17,000 hectares, of which only half are irrigated. The Government of Mexico cannot agree that the permanently bad situation and the continual international difficulties prevailing in the Juárez Valley should be reproduced, with greater seriousness, in the Colorado zone, where the area of lands to be irrigated is ten times greater than in that Valley and the agricultural significance is of capital importance for all Lower California.

From the studies made by the Mexican Section to which I referred above, it is shown that the volume of the Colorado River amply provides for the uses of both countries and, accordingly, an equitable division of the waters would specify a minimum of 2,000,000 acrefeet for Mexico. Account has been taken of future possibilities in both countries in setting this figure.

In the conclusions reached by Engineer Adolfo Orive Alba as member of the Mexican Section of the International Water Commission, [Page 550] in his “Hydrological Study of the Colorado River”, it is stated that, in accordance with most recent American data and taking into consideration the development, in the United States, of all possible projects, Mexico could receive up to 2,300,000 acre-feet annually without any scarcity being felt in the United States even in periods of drought which, apparently, are produced by the climacteric regime of the region.

According to investigations made in 1930 by Mr. E. B. Debler, engineer of the Reclamation Service—who made use of data of official origin in his studies—the United States requires an annual average of 16,000,000 acre-feet to satisfy its needs in accordance with its foreseeable plans in maximum development. This means a surplus of 2,400,000 acre-feet annually, which amount could be allowed to Mexico without injury to its northern neighbor.

A more recent estimate, published in 1939 in the “Engineering New Record”, places American maximum needs at a lower figure than that estimated by Engineer Debler. According to the said calculations, those needs could be met with 14,200,000 acre-feet annually. If the calculation is correct—and everything leads to the belief that this is the case—the surplus would be sufficient not only to satisfy our country’s demands but to constitute a margin of safety, in years of scarcity, when the average flow of the Colorado drops from the 19,000,000 acrefeet which statistics consider as the regular flow and which is what has been taken as the base of all studies on the subject.

Despite the fact that, on the basis of the data set forth, Mexico could request, as equitable, a volume between 2,400,000 and 2,500,000 acre-feet, our petition is limited to 2,000,000, an amount indispensable to satisfy the minimum needs of the region.

2. Procedure for Delivering the Water. The American proposal to furnish the water controlled according to a fixed table, cannot be accepted by Mexico since it would certainly mean a repetition of the situation in the Juárez Valley, where practice has shown that delivery made in such way gives rise to serious injuries, both with respect to the crops and with respect to a large amount of waste of water occasioned by the method of the fixed table. At present it is not possible to foresee the crops, systems of labor and fluctuations of climate which may occur within 50 or more years, but it can be foreseen that, in the future, deliveries under a fixed table, if accepted today, would cause future friction and difficulties which must be here and now avoided. To this end, the Government of Mexico suggests as being more practicable the delivery of the water according to an annual table which the International Commission would determine, every December, and which would govern during the following year.

3. Excess of Flow. With respect to volumes of water which might reach Mexico in excess of the guaranteed amount, the Mexican Government’s [Page 551] point of view differs from that of the United States in some aspects of practical application, but it considers it preferable to defer the technical discussion thereof that it may be undertaken when the two parties agree on the basic part of the question, to conclude the friendly arrangement which is desired.

As I had the honor of stating previously, the Mexican Government concurs in the American proposal to give to the present International Boundary Commission between Mexico and the United States of America the powers and duties specified in the draft treaty.

  1. Laurence Duggan, Adviser on Political Relations.