As someone from Australia who's quite accustom to experiencing droughts, I can tell you such a scenario is handled very differently overseas. Off the top of my head, this is how I've seen it approached in Melbourne:

1. No outdoor water use, whatsoever. That includes washing the car, the dog, watering the garden, hosing down a sidewalk. If you're caught doing any of these, you're in for a $500 fine 2. You're not allowed to fill a swimming pool and all public fountains are turned off 3. The water company will go door-to-door exchanging water restricting shower heads for those currently installed. Egg timers for use in the shower are also given away 4. A marketing campaign is launched promoting the 4 minute shower (the duration of the above-mentioned egg timer) 5. Water saving products receive government subsidies. I.e. rainwater tanks, low water use toilets, etc

I see almost none of this happening in CA and, for the life of me, I can't understand why.