20 November 2012: The US and Mexico have signed a five-year agreement to share Colorado River water during periods of both drought and surplus. The agreement also creates an Intentionally Created Mexican Allocation (ICMA) program, where surplus water from certain conservation and water source projects could be held by the US on Mexico’s behalf, for later delivery to Mexico.

The agreement, which was signed in Coronado, California, provides for several cooperative actions. During certain high elevation reservoir conditions at Lake Mead, the US will provide additional Colorado River water to Mexico. During low elevation reservoir conditions at Lake Mead, water deliveries will be reduced to avoid greater cuts in the future.

The agreement also calls for, inter alia: generating water for the Colorado River limitrophe and delta through conservation projects; providing investment by the US in Mexican water infrastructure and environmental projects that will benefit both countries; implementing joint efforts to address the salinity of the Colorado River; committing the US and Mexico to expedite consideration of issues involving the possible construction of a link between the All-American Canal in the US and the Colorado River-Tijuana Aqueduct in Mexico; and outlining areas for possible future cooperation, including on environmental restoration, water conservation, system operations and new water sources projects.

US International Boundary and Water Commission (IBWC) Commissioner Edward Drusina hailed the agreement as providing Mexico and the US with “new tools to address the impacts of drought and climate change.” Mexican IBWC Commissioner Roberto Salmon said the agreement paves the way for cooperation that can “guarantee sustainability” in the border region, particularly on future water supply for Mexican border communities.

While the US-Mexico Water Treaty created the IBWC in 1944, the IBWC can trace its roots back to a bilateral International Boundary Commission created in 1889. Among other things, the 1944 Treaty made the IBWC responsible for the exercise of rights and obligations involving the limitrophe portions of the Rio Grande and Colorado Rivers and the settlement of all disputes that may arise under the treaty. [IBWC Press Release]