California needs to actually do something about their water supply problem. They are now talking about cutting off Central Valley farmer's water supply. This is some of the most productive agricultural land in the US. The state needs to build a lot of desalination plants all along the coast. The Carlsbad plant has several years of experience of producing 50 million gallons of pure fresh water per day. My water district buys part of their output, and note that the California Water Authority has no plans to cut water for San Diego.
Now there certainly is some stupid water use in Central Valley agriculture raising crops that require a lot of water, like the almonds that are mostly exported to China. But I think the growers could actually change their prices enough to cover their water costs of a changed model that does not depend on Sierra snowpack. We have thousands of square miles of desert East of the Sierras and Southern mountain ranges, that have extremely abundant sunshine. PV panels are the cheapest way of generating electricity now, often as low as 2 cents per KWHr. We could build those solar farms, the transmission lines needed to carry the power to the coast, and the desalination plants to make the fresh water. This would give us a totally-predictable water supply.
Instead of two desalination plants, we should have 30. Pumping the water to the Central Valley would be pretty cheap, as most of the Central Valley has low elevations. Done right, we could even run the canals now carrying water South backwards. Sending it that way would actually be downhill!
We're flying electric helicopters on Mars yet you can't turn on your clothes dryer in Texas. That's because scientists are in charge of Mars, and Republicans are in charge of Texas.