Cal. Wat. Code § 1485
Any municipality, governmental agency, or political subdivision operating waste disposal plants producing disposal water meeting the requirements of the appropriate regional board, and disposing of said water in the San Joaquin River may file an application for a permit to appropriate an equal amount of water, less diminution by seepage, evaporation, transpiration or other natural causes between the point of discharge and the point of recovery, downstream from said disposal plant and out of the San Joaquin River or the Sacramento-San Joaquin Delta. A permit to appropriate such amount of water may be granted by the board upon such terms and conditions as in the board's judgment are necessary for the protection of the rights of others. Water so appropriated may be sold or utilized for any beneficial purpose. The right to the use of water granted by this section shall not include water flowing in underground streams.
The Legislature finds and declares that the problems incident to the full utilization of the waters of the San Joaquin River and the Sacramento-San Joaquin Delta into which it flows, are unique and that a general law cannot be made applicable thereto.
Ca. Water Code § 1485