A new report from a group of Colorado River experts is calling for a change in the way the United States shares water with Mexico. The paper’s authors write that the change would give water managers a new degree of flexibility during record-breaking dry times.
Currently, the U.S. is required to send a fixed amount of water to Mexico every year. The new paper instead recommends sending a percentage of the water that is actually in the Colorado River each year. It comes at a time when states that use the river are stuck in tense negotiations about sharing its shrinking supply, and the region’s water policy stands at the precipice of potential change.
The paper, co-authored by a group of academics and former policymakers, writes that the old rules no longer make sense as drought and climate change have greatly reduced the amount of water in the river and its reservoirs.
“As usage patterns and hydrology change in the 21st century,” the authors wrote. “Fixed volumes no longer work. A shift to a percentage-based split between the United States and Mexico on the Colorado River, based on the river's actual natural flow, would provide a solid foundation for the two countries' joint management of the Colorado in the decades to come.”
Eric Kuhn, the former director of the Colorado River District, served as the paper’s lead author. He said managing water based on percentages would reduce some of the U.S.’ risk during exceptionally dry times.
“If the flows go down,” Kuhn told KJZZ, “Mexico naturally gets less. If we can arrest that, and it goes back up, Mexico's share goes up. So we're operating more as partners on the river with a percentage allocation.”
While U.S. states are at an impasse about how to share the river amongst themselves, Kuhn believes that federal diplomats from both countries are still focused on sharing water across the international border and can draw up new rules even if the states can’t agree.
In fact, he said, new percentage-based water sharing rules would help “insulate” Mexico from the impacts of potential litigation between Colorado River states, which appears to be getting likelier amid stalled negotiations.
Kuhn said he has seen support from state officials for a percentage-based deal with Mexico since the paper went public. The idea mirrors a short-lived proposal by some Colorado River states, under which U.S. states would determine the amount of water they can take from the Colorado River based on a percentage of annual flows.
While that idea fizzled out as a solution for the standoff between the states, Kuhn said a successful implementation of percentage-based sharing between the U.S. and Mexico could show states that it might work as a solution for their own conundrum.
Jennifer Pitt, Colorado River program director for the Audubon Society, said the authors of the recent paper “make a compelling case” and that it would not be unprecedented for American and Mexican diplomats to reach a decision for sharing water before the states agree amongst themselves. The last time similar talks were underway, negotiators from the two countries agreed on binational rules in 2017, and states didn’t adopt their set of plans until 2019.
Pitt, a leading expert on U.S.-Mexico Colorado River sharing, said the amount of water sent downstream from the U.S. has historically only been one component part of agreements between the two countries.
“The breadth of those agreements was important,” she said, “And each component of the agreements was influenced by that full package.”
Future agreements, she said, should contain a broad set of terms. That might include measures to control the salinity of that water, work with nonprofits to restore ecosystems in the parched Colorado River Delta and opportunities to study strategies that might help add water to the system, such as desalinating ocean water.
