I believe WA state just changed the law to now allow rain barrels.
Which seems okay to me, in western Washington the average holding is less than 1 acre, most suburban homes are on .25 acres, they can get by with gutter harvesting into a 55 gallon drum to sustain their home garden through a summer, which is usually dry. If we all respond by starting up 2-3 month gardens, which is the average growing season here, many will fail but at least they won't consume too much water and a number of us can supplement our veggies for what is now too costly to produce inexpensively in California. Blueberries from Peru are popular in stores at 7.99 for ~2 pints. We're used to it. A fair amount of food production has already shifted to Mexico and points south which actually have more sustainable weather patterns compared to Calif drought. Until the costs of transportation go up. There's no free lunch. People have been telling us for quite a while...
This year I'm planting hops, which is about the only crop I've succeeded in growing in 98004 in the past 20 years. Hops smell really nice in hot weather, and with my coffee roasting in the garage my neighbors say they get really thirsty all the time. I know a network of home brewers who will buy my hops, or trade them for some nice veggies. Or I could go back to my college days and homebrew.