Have you reduced the lawn on your property?
In its Audubon at Home program, NAS says:
Our choices of plants, landscape materials and design, and garden practices have an enormous impact on our outdoor water use. Lawns require two-and-a-half to four times more water than shrubs and trees. Indeed, it is estimated that in the course of a single year, a typical suburban lawn uses 10,000 gallons of water over and above that provided by rainfall.That's a sobering thought, particularly in this dressed-up desert in which I live.