California should aim for enough desalination capacity to sell surplus to AZ and Nevada. One plant in Carlsbad is cool, but building a few more would really help find some unknown/unexpected cost savings the world really needs right now.

Nevada isn't really in need of imported water. Almost every drop of water that hits a drain in Vegas is treated and re-used so Nevada's use of water from Lake Mead is very low. It's one of the most water efficient places on Earth.

Outside of Vegas and Reno the state's pretty much depopulated, so that's the whole usage.

If California would just build the desalination plants and support Californian needs without hitting the supply from the Colorado so hard Nevada would be fine.

Arizona, on the other hand... yes. They could probably use some imports.