Michel Hiltzik in the LA Times anticipates the upcoming water war. Here is the problem.
If the Western drought continues, Arizona would have to bear almost the entire brunt of water shortages before California gives up a drop of its appropriation from the river. Few observers of Western water affairs believe that's politically practical, but few have offered practical alternatives.
The original agreement and subsequent legislation were optimistic about the continuance of sufficient water in the Southwest. But:
The [Central Arizona Project] bill's drafters probably never thought supplies would become so tight. But the bill from nearly a century of overuse is on the verge of coming due. During the last 50 years, according to figures from the Reclamation Bureau, the population served by the river has grown from 12 million to 30 million. Over that period, the average flow on the river has fallen from 15.5 million acre-feet to as low as 12 million. (An acre-foot serves two households a year.)
Hoping for a few wet years, building desalination plants, or constructing more dams are not likely to be long term solutions.
This is likely to be grim.
What will be necessary is a fundamental reconsideration of 100 years of water-appropriation practices and patterns.