The All-American canal channels water from the Colorado river to Californian farmland. But seepage from the canal helps irrigate land across the border in Mexico’s Baja California state, Mexicans and environmentalists say.

Eugenio Elorduy, the governor of Baja California, has accused the US of ignoring its neighbours’ interests.

“This situation will blow in our faces if it is not attended to by the U.S government,” Elorduy told the media.

“We are astonished as to why the Department of Interior does not look into this situation and set up a working group to solve this situation. This must not be underestimated. When you get farmers in Mexico against their water it makes any farmer very mad,” he said.

Concreting in the leaks along 37 km of the 129 km canal will save the US enough water to supply 130,000 households in San Diego. But that will be at the expense of Mexican farmers, wetlands and wildlife, a development council from Mexicali, Mexico, has argued in a US court, together with two Californian green groups.

The federal district court in Arizona rejected all but one of the claims, saying that Mexican farmers have no standing in a US court. One count remains, concerning violations of the US National Environmental Policy Act, and will be heard in mid-March.

Rene Acuna, the Mexicali council’s executive director, said in a statement: “It is very disappointing that the judge believes the U.S. can steal our water without due process simply because we are Mexicans.”

Mexico’s president Vincente Fox has reportedly raised the issue with US President George W Bush twice last year.

The Mexican environment secretary, Enrique Villegas, has warned that opposition parties were using the affair in anti-US campaigns ahead of the Mexican presidential elections in July.

By Goska Romanowicz

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie

Subscribe