Cal. Gov. Code § 38743
A city may, pursuant to the notice, protest, and hearing procedures in Section 53753, fix, on or before the first day of July in each calendar year, an annual water service standby or immediate availability charge to be applied on an area or frontage or parcel basis, or a combination thereof, within the city to be charged to such areas to which water service is made available for any purpose by the city, whether the water service is actually used or not. If the procedures set forth in this section as it read at the time a standby charge was established were followed, the city council may, by resolution, continue the charge pursuant to this section in successive years at the same rate. If new, increased, or extended assessments are proposed, the city council shall comply with the notice, protest, and hearing procedures in Section 53753. The city council of a city which fixes such a charge may establish schedules varying such charge according to the land uses and the degree of availability or quantity of use of such water service to the affected lands, and may restrict such charge to lands lying within one or more zones or areas of benefits established within such city. The council may not, however, fix a monthly charge in excess of ten dollars ($10) per acre, either on an area or frontage basis, or in excess of five dollars ($5) for a parcel or frontage of less than an acre unless the standby charge is imposed pursuant to the Uniform Standby Charge Procedures Act (Chapter 12.4 (commencing with Section 54984) of Part 1 of Division 2 of Title 5).
A city may collect the standby or availability charge by billing the charged lands on a monthly or fiscal year basis.
A city may collect the standby or availability charge as a part of the annual general county tax bill provided the city furnishes, on or before August 10, in writing to the board of supervisors and to the county auditor the description of each parcel for which a charge is to be billed together with the amount of the charge applicable to each parcel. The parcel description may be the parcel number assigned by the county assessor to the parcel.
If the city collects standby charges through the county general tax bill, the amount of the standby charge and any applicable penalty shall be stated on the tax bill separately from all other taxes, if practicable.
Ca. Gov. Code § 38743