Yeah not getting a glass of water at restaurants won't solve jack. Limiting oil/gas industry from fracking (which we don't need if you looked at oil supplies/stock prices lately) which wastes billions of gallons of water which gets used on our food is one solution for sure imho.
http://www.latimes.com/local/california/la-me-drought-oil-water-20150503-story.html#page=1
I got no beef with almonds. Cali if the perfect climate. Alfalfa, rice, tomatoes, lettuce etc., on the other hand, can be grown in areas with plenty of water. Most of the alfalfa as pointed out by lurking goes to China. And having lawns in the desert is nuts. But I'm biased since my business is growing and selling native/drought tolerant plants.