The trick is to conserve the valuable state resource, make wise decisions about how to use it and cut waste.
Conservation. (Drought-tolerant plants. Metering. Smart watering systems.)
Store groundwater more efficiently. (Especially during years with surpluses)
Reuse wastewater (Right now, it all flows into the ocean. Use it for irrigation, industry, let it seep into aquifers) )
Stop throwing away storm water. (Build parks and storage areas and let it seep into the soil.)
Cut agricultural water use. (Israel has already done this. Step One. Eliminate subsidies of marginal water-hungry crops.)
Tip: Western Water Blog