Cal. Water Code § 521

The Legislature further finds and declares all of the following: (a) Water furnished or used without any method of determination of the quantities of water used by the person to whom the water is furnished has caused, and will continue to cause, waste and unreasonable use of water, and that this waste and unreasonable use should be identified, isolated, and eliminated. (b) Water metering and volumetric pricing are among the most efficient conservation tools, providing information on how much water is being used and pricing to encourage conservation. (c) Without water meters, it is impossible for homeowners and businesses to know how much water they are using, thereby inhibiting conservation, punishing those who conserve, and rewarding those who waste water. (d) Existing law requires the installation of a water meter as a condition of water service provided pursuant to a connection installed on or after January 1, 1992, but the continuing widespread absence of water meters and the lack of volumetric pricing could result in the inefficient use of water for municipal and industrial uses. (e) The benefits to be gained from metering infrastructure are not recovered if urban water suppliers do not use this infrastructure. (f) This chapter addresses a subject matter of statewide concern. It is the intent of the Legislature that this chapter supersede and preempt all enactments and other local action of cities and counties, including charter cities and charter counties, and other local public agencies that conflict with this chapter, other than enactments or local actions that impose additional or more stringent requirements regarding matters set forth in this chapter. (g) An urban water supplier should take any available necessary step consistent with state law to ensure that the implementation of this chapter does not place an unreasonable burden on low-income families.