Water wins

Water agencies in three Western states will soon be trading money for water with Mexico, after officials signed a pact Tuesday updating the terms of the 1944 agreement that dictates what portion of Colorado River water our southern neighbor receives each year.

At a cost of $10 million, regional agencies in the thirsty states of Southern California, Arizona, and Nevada will get almost 100,000 acre-feet of water from Mexico, according to the 5-year deal. (An acre-foot is roughly enough to supply two homes a year; one acre of alfalfa typically uses between 2.5 and 7 acre-feet of water per year) Mexico will use the money to repair irrigation systems destroyed by the magnitude 7.2 quake that hit the Mexicali Valley, a key agricultural area, in 2010.

The agreement, named Minute 319, also tasks Mexico with taking less water from the Colorado in periods of shortage, (before the signing the seven U.S. states that share the river’s water were bound to this, but Mexico was not), and allows our southern neighbor to take a cut of surplus water in years there’s more available. Mexico can also store up to 250,000 acre-feet of water per year in Lake Mead, the key reservoir for the lower basin states, for use at a later time, an option it has not had in the past.

Officials hailed the pact as a neat piece of diplomacy. Speaking to reporters at a telephone conference Tuesday, Secretary of the Interior Ken Salazar called it “the most important bi-national agreement on the Colorado River since the 1944 U.S. – Mexico Water Treaty.”

“We have chosen collaboration over conflict” and “cooperation and consensus over discord,” said Salazar. “What we are doing now in the Colorado River Basin provides an international model of how to resolve water issues.”

The pact is an important part of addressing the challenges facing users of the Colorado River (who currently number more than 33 million people) if future demand for water outstrips the available supply, said Michael Connor, Bureau of Reclamation Commissioner. By the year 2060, the deficit between how much water the river can supply and how much states demand could be as much as 3.2 million acre-feet per year, he said.

The U.S. and Mexico also agreed to release about 100,000 acre-feet of water in a one-time pulse, to help raise water levels in the beleaguered Colorado River Delta, parts of which have been practically dry since about 1998. A coalition of conservation groups (the Environmental Defense Fund, the Nature Conservancy, the Sonoran Institute, and Pronatura Noroeste, a Mexican non-profit) are also collaborating to buy 10,000 acre-feet of water per year from Mexican farmers to bump up river levels in the delta. While this is not enough water to simulate historical flows, it will help re-establish trees, like cottonwoods, and provide crucial habitat for migratory birds and wildlife, says Pat Graham, Arizona State Director for the Nature Conservancy.

The groups will also be hiring people in communities close to the river to plant vegetation along the riverbank, and work on restoration efforts, says Graham.

While conservationists and state officials on both sides of the border welcomed the pact, California’s Imperial Irrigation District chose not to sign it. This is due to its concerns over not being able to store its own surplus water in Lake Mead, as well as the requirement that it would have to negotiate with the Metropolitan Water District in Los Angeles for a share of the water bought from Mexico.

For the Southern Nevada Water Authority, which sources 90 percent of the drinking water for Las Vegas from Lake Mead, however, the possibility of higher lake levels is a bonus. And if Mexico does store some of its water in Mead this could help keep lake levels high enough to allow the current intake pipes to keep working. Lake levels are now at 1,116 feet, and below 1,075 feet the existing intakes stop working. As a result, SNWA is in the midst of constructing the so-called “third straw,” a low-lying intake pipe scheduled for a 2014 completion that would allow the agency to continue to draw water at lake levels up to 1,000 feet.

As SNWA general manager Pat Mulroy says, “That project [the pipe] is our protection from catastrophe. It’s our safety net. As long as we can continue to defer it, we will.”

Brendon Bosworth is a High Country News intern.

Photo courtesy wikimedia user Luca Galuzzi.