The deal spreads the costs of conservation and the pain of future droughts and shortages across the river’s millions of users north and south. The river supplies water to about 40 million Americans from Denver to Los Angeles.

Whenever drought forces the U.S. to impose cuts under a planned drought contingency plan, the International Boundary and Water Commission said Wednesday, Mexico will agree to cut its take of the river “in parity with U.S. savings.” Read the full article.