That is a problem, but not an intractable one. The first easy win would be to just stop wasting so much water. CA could be a lot more careful with water than it is by just leaning on industry and ag to cut wasteful water use harder than it leans on the suburbs. Don’t get me wrong, green lawns in our Mediterranean climate are a stupid waste too, but it pencils out to less than a percent of all water use, where ag and industry are both in the double digits.