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.

1. print 10,000 flyers and hand them out to people. (at 100/day thats gonna take a while)
2. pay for online ads targetting the geographic area which point to water saving website.

bonus:

1. offer a glass of "saved" water to politicians. "This water was not wasted on ugly grass so that now we can drink it. This water was saved because we handed out shower timers, isn't it great that water is freely available and we treat our resources with respect"
2. call local politicians; encourage them to put out water saving propaganda. create a mockup and offer to them for free.

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.