The permanent International (Water) Boundary Commission, United States and Mexico, succeeded three earlier international commissions designed to establish the boundary between the United States and Mexico. The first, established in accordance with the Treaty of Guadalupe Hidalgo, was headed by John R. Weller (who was succeeded by John C. Frémont, then by John R. Bartlett) and Andrew B. Gray (who was succeeded by William H. Emory) for the United States and Pedro García Conde and José Salazar y Larreguí for Mexico. This commission surveyed the California-Baja California boundary and then skipped across the desert to establish the New Mexico-Chihuahua boundary. After beginning the survey of this section of the boundary near El Paso, the commission soon encountered difficulty in interpreting the treaty, which was solved only when abolished by the Gadsden Purchase treaty. A second boundary commission was then established, headed by William H. Emory for the United States and José Salazar y Larreguí for Mexico. This commission reported, informally, the completion of the entire survey on December 18, 1855 (having spent nearly $100,000 less than its appropriation), and Emory submitted a four-part, two-volume report, later published by Congress, which included elaborate illustrations and descriptions of climate, flora, fauna, topography, and anthropology made by scientists who accompanied the commission. In time many of the markers placed by the Emory commission became obliterated, and in order to reestablish the line and settle some disputed territory, a third boundary commission was established through a series of treaties in 1882, 1885, 1889, and 1894. A commission, headed by J. W. Barlow for the United States and Jacobo Blanco for Mexico, was appointed and submitted a report on the relocation of markers in 1896.
The functions of the commission were defined and extended through various treaties in 1905, 1933 and 1945. Over the years, the commission was charged with the elimination of cut-offs, or bancos, flood control, and river-rectification problems. Its biggest achievement was in the peaceful settlement of the Chamizal dispute with the signing of the Chamizal Treaty in 1963. The treaty provided for forcing the Rio Grande through a concrete channel that prevents it from changing course. The Water Treaty of 1944 transformed the commission into the International Boundary and Water Commission. Along with the new name came expanded duties. Aside from settling boundary disputes, commissioners were charged with the planning, construction, and operation of three international dams, as well as additional hydroelectric-power and flood-control projects to benefit both countries. To date, two dams, Falcon and Amistad, have been completed (see INTERNATIONAL FALCON RESERVOIR, and AMISTAD RESERVOIR). In addition to the functions outlined by treaties dealing with the water boundary, the permanent commission succeeded the Barlow-Blanco commission and took on the functions of the previous land commissions. Because of its permanence and unusual character and function, the commission occupies a unique place in international arbitration. See also MEXICAN-UNITED STATES BOUNDARY COMMISSION.