New U.S.-Mexico water-sharing agreement for Colorado River emphasizes preservation

Lake Mead's water level is at a historic low. (Desert Sun photo by Jay Calderon)

"Mexican and American officials are finalizing a water-sharing deal for the Colorado River, and a newly released summary of the accord’s key points shows negotiators have agreed on a cooperative approach geared toward boosting reservoir levels and trying to stave off a severe shortage," Ian James reports for The Desert Sun in Palm Springs, Calif.

The river is shrinking because of overuse and a 17-year drought, and scientists predict that climate change will cause the river's flow to go down 35 percent or more in this century. Lake Mead, the country's largest reservoir, is only 38 percent full. All of this threatens the nearly 40 million people and 5 million acres of farmland in the Southwest that depend on the Colorado and its tributaries.

The current five-year agreement expires Dec. 31; the new one, titled Minute No. 323 to the 1944 Mexican Water Treaty, builds on that and would remain in effect through 2026. It is expected to be signed this fall. Though relations between Mexico and the U.S. have been tense at times during President Trump's administration, negotiations on the river agreement within the International Boundary and Water Commission have gone smoothly. Talks began on the new agreement during President Barack Obama's administration and were mostly finished a year ago. The commission includes members of both the Mexican and American governments, and representatives of affected U.S. states have also participated in the talks.

Central Basin Municipal Water District map

"The agreement itself has not yet been publicly released. The summary provided by the U.S. Bureau of Reclamation was presented Wednesday at a board meeting of the Imperial Irrigation District, which holds the biggest single entitlement to water from the river," James reports. The accord lays out a plan for Mexico and the U.S. to cooperate to reduce water use, secure water for environmental purposes, restore and monitor habitats along the Colorado River, and reduce the risk of Lake Mead hitting a critically low level. A too-low Lake Mead would affect not only water supply but hydroelectric power generation from Hoover Dam. The agreement also calls for the U.S. and Mexico to establish several joint working groups to focus on specific issues such as river salinity.

Imperial Irrigation board members said in a memo that several agreements must be made between states, water agencies and the Department of the Interior in order for the U.S. to implement the commitments it would be agreeing to in the deal. "Those agreements include a U.S.-funded program to invest $31.5 million in water conservation projects in Mexico, including infrastructure upgrades such as concrete lining for leaky canals and other improvements to reduce water losses from distribution systems," James reports.