We could do a lot to make water usage more sustainable.

Most places in the US get at least ten inches of precipitation annually. Very few get less than that.

With that much rainfall, a lot of homes can be self supporting with catchment systems, grey water reuse, etc.

Edit: Anyone interested in some best practices should look at what Fresno County is doing. They get an average of 11 inches of rain annually and they were basically desert before a canal system was built in the late 1800s.

In some years, their ground levels have risen because of their water policies and practices. In contrast, much of the rest of California and the Midwest are experiencing subsidence as water tables permanently and steadily fall.