Southern California receives an average rainfall of about 15 inches annually. Two-thirds of Southern California's water supplies must be imported. The average rural family uses about 500 - 600 gallons of water daily or 3/4 of an acre foot per year while the average urban family using about 800 - 900 gallons of water daily or 1 acre foot per year. It pays to conserve - not only for the environment but for your pocketbook as well.