Conservation has to start with agriculture since that's the vast majority of usage. The simplest and most effective step would be to stop subsidizing that water usage so heavily. Last I looked the average farmer paid about 1/10 the price per gallon as residents, but it varies a lot and some pay less than 1/100. That leads to exactly the behavior you would expect: completely unsustainable high water usage crops being grown in large amounts.
If you don't mind the presentation style, https://www.youtube.com/watch?v=XusyNT_k-1c is great presents an even direr situation: because water rights are "use it or lose it", we are actively encouraging water misuse, beyond just "it's cheap enough to misuse it".
