The big little salt war between the U.S. and Mexico was finally over. On both sides of the border, there were cheers for the long-awaited settlement of a minor but highly abrasive issue: U.S. pollution of the Colorado River.
The Colorado is a life-giving stream for much of the arid U.S. Southwest and for Mexico's Mexicali Valley. Under a 1944 treaty, the U.S. promised to share the river for irrigation. Mexico built a dam one mile below the border, spider-webbed the once desolate Mexicali Valley with irrigation canals. Then in 1961, under the Wellton-Mohawk reclamation project in Arizona's Yuma Desert,...