fastest 2 ways to get the word out; Make a website describing drought and some good solutions to help out. brand it as a NFP, i.e. shower heads, not running a tap while brushing your teeth, aethetic lawns that are not grass, water saving technology for farming systems. maximise for "saving water is saving money is saving the environment" win-win-win messages.
bonus:
existing resource: http://www.savewater.com.au/how-to-save-water/in-the-home
TL;DR; Push a public message about it; be loud about it.
I think we need a discussion thread for the californian drought going on. I would like to compile information in the main post and would like help compiling it. If we really are proud to be effective altruists then this is an area we should really figure out.
Any one have any good ideas on how we can help?