Michael Gardner has a nice summary of what’s at stake in the litigation blocking the complex deal under which California agrees to throttle back its use of Colorado River water:

Southern California’s water managers insist it should be easy to overcome the latest challenge to a landmark, seven-state pact to share the Colorado River that also produced a vast new supply of water for the San Diego region.

But nearly a century of litigation and political turmoil has shown that when it comes to water-use conflicts in the West, there are few easy remedies.

The deal includes water transfers from Imperial Valley ag to urban users on the coast, along with money for shoring up the Salton Sea ecosystem. The legal problem is narrow – the question of whether the deal’s open-ended fiscal commitment to the Salton Sea violates the state constitution. But if that is invalidated, essentially the whole complex deal unravels.