Hopefully, you can expand on Marc Reiser's "Cadillac Desert", the Bible of water in the West. I suppose the problem in the West is storage...not enough when there's a heavy rainfall year. I'm not an expert, but groundwater aquifer recharge seems held back by the "really good aquifers are deep and under impermeable layers" problem (ie hard to recharge). The Central Valley aquifers recharge easily (the whole valley is a big sponge) but seems as such to deplete rather easily through evapotranspiration. Your are so right that changes to diet and ag are key to water management (and many other environmental issues)

https://scottvern.medium.com/the-most-important-article-you-will-ever-read-about-future-ag-food-and-environment-5fb8d9fdcc85

https://scottvern.medium.com/how-does-california-better-capture-precious-storm-water-3b17a0fdbaf