The International Boundary and Water Commission (IBWC) has its roots in the 1848 Treaty of Guadalupe Hidalgo and the Gadsen Treaty of 1853, both of which established (and re-established) the U.S.-Mexico border, and also established commissions to survey and map the new U.S.-Mexico border, designating landmarks to mark the border. As the rivers that created the borders changed their courses naturally, land changed jurisdiction, and the International Boundary Commission (IBC), the IBWC's predecessor, was established in 1889 to apply rules that resulted from the Rio Grande and Colorado Rivers' roles as the boundaries between the two countries. In 1906, the two countries signed their first water distribution treaty, the Convention of March 1, 1906, which designated portions of the rivers to each country. In 1933, the two countries began joint river projects to stabilize the Rio Grande, and in 1944, the countries formed the IBWC to enforce allocations of the river and began work on dams that would be operated and maintained by both countries. The IBWC has been integral in resolving boundary disputes for the two countries over the following decades and in constructing dams and reservoirs that stabilize the boundary rivers, keeping them on course to maintain consistent borders and benefits for the U.S. and Mexico.
The Amistad Dam is an international dam on Rio Grande River built in 1969 to create a reservoir of 5,250,000 acre-feet for flood control, conservation, hydroelectric generation, and recreational uses. The Amistad is the largest of the U.S.-Mexico operated storage dams and reservoirs on the Rio Grande at 6.1 miles long and 254 feet above the riverbed. The dam has 16 spillway gates that can release up to 1,500,000 cubic feet of water per second. The reservoir runs about 75 miles up the Rio Grande, has a surface area of 65,000 acres, and a volume of 3,124,260 acre feet. The dam was constructed by the International Boundary and Water Commission (IBWC) as a joint investment of the United States and Mexico. Both companies are responsible for the operation and maintenance of Amistad, as it benefits and protects regions on both sides of the border. President Richard M. Nixon and Mexican President Diaz Ordaz jointly dedicated the dam in 1969.