The Secretary of State to President Roosevelt

My Dear Mr. President: In his letter to you of March 18, 1944, the Secretary of the Interior raised certain questions respecting the administration of the water treaty with Mexico.

Your instructions to me in regard to this matter were that the Department of State, acting through the United States Section of the International Boundary Commission, is to supervise and control the construction and operation of all works and facilities situated on the boundary, such as the international dams and appurtenant works on the Rio Grande, and of all works and facilities, wherever situated, that are to be used exclusively for the delivery of water allocated to Mexico. That supervision and control in these instances should be [Page 1370] in this Department and the United States Section of the Boundary Commission is made obvious by the fact that such activities require constant cooperation between those agencies of the two Governments established by treaty and law for such purposes, that is, the two national sections of the International Boundary Commission, United States and Mexico. Your reply of April 3 to Secretary Ickes set forth this general principle, with the further statement that, in accordance with established policy, the Department of the Interior should construct and operate those interior facilities used only partly for the delivery of Mexico’s water.

At my suggestion, several conferences have been held between representatives of the two Departments. Although agreement has been reached in part, I regret to say that two fundamental aspects remain unsettled, one of substance, the other of procedure.

Substance. Interior is not disposed to accept the broad rule laid down in your letter of April 3, as summarized above. This rule has heretofore been successfully applied in jurisdictional matters between the two agencies. Interior now wants to take over certain important international functions provided for in the proposed treaty. Of course, work of this kind has been one of the prime functions of the Boundary Commission since 1889. An International Commission had to be set up at that time precisely because both countries had found that this was the only way practically and effectively to work together. The simple fact is that Mexico’s agreement to the treaty signed on February 3, 1944 was obtained only by incorporating provisions that continued in the future what had prevailed in the past in similar situations, namely, that jurisdiction over international water matters and facilities along the boundary be in the Department of State of this country and the Ministry of Foreign Relations of Mexico, acting through the two national sections of the International Boundary Commission, United States and Mexico.

It is equally clear that all activities within the United States, except those devoted exclusively to the carrying out of treaty provisions, should be performed by the regular agencies, principally Interior. It is, moreover, the intention of the Department of State and of the United States Section of the Boundary Commission, acting in accordance with Article 20 of the treaty, to make use of these agencies to the fullest extent possible in the design and construction of works allotted this Government along the boundary. These works must be constructed in cooperation with Mexico, which is to bear a proportionate part of the cost, hence they would of necessity have to be under the supervision and control, so far as we are concerned, of the United States Section of the Commission, since obviously only that Section can deal with the Mexicans. Furthermore, the Mexicans would not have it any other way. Interior, as I understand it, desires to take [Page 1371] over what are primarily functions of the United States Section of the Commission.

Form. Interior desires that the agreement on substance, when reached, be accepted by Mexico, either through an exchange of notes, by a protocol, or by a Senate reservation. The use of any of these devices seems improper and unnecessary. Mexico has no concern with the allocation of functions within the United States devolving upon the United States Government. Our Government should decide that for itself. Resort to any of these devices is necessary only when the treaty itself requires modification, and that is not the case here.

It is thus apparent that there is no question of an encroachment by this Department upon the jurisdiction of interior agencies but, rather, of a threatened encroachment by interior agencies upon purely international functions such as would imperil the treaty itself.

At such time as may be convenient to you, I should like to go over this with you at greater length.

Faithfully yours,

Cordell Hull