California Code, Water Code - WAT § 75610

The district, after the levying of the ground water charge, shall give notice thereof to each operator of each water-producing facility in the zone or zones as disclosed by the records of the district, which notice shall state the rate for each class of water of the ground water charge for each acre-foot of water to be produced during the ensuing water year. The notice may be sent by postal card or by other first-class mail and with postage prepaid by the district.