Yes, California needs more water. So,the largest desalination plant in the northern hemisphere has been approved for Carlsbad, California.
But how feasible is it? Desal requires enormous amounts of energy to operate and dumps the salt back into the ocean, which can’t be healthy for it long-term.
Reclaiming gray water and intelligent conservation would go a long way to helping the water shortage. Why are people in semi-arid areas with water shortages allowed to have lush green lawns? Perhaps drought-resistant lawns should be mandated (and in fact some cities already do this.)