Cal. Wat. Code § 55501.5
A district may, pursuant to the notice, protest, and hearing procedures in Section 53753 of the Government Code, fix a water service standby or immediate availability charge to be applied on an area or frontage or parcel basis, or a combination thereof, within the district to be charged to areas to which water service is made available for any purpose by the district, whether the water service is actually used or not. The district may establish schedules varying the charge according to the land uses and the degree of availability or quantity of use of the water service to the affected lands, and may restrict the charge to lands lying within one or more zones or areas of benefits established within the district. The district may not, however, except as is otherwise provided in this section, fix a charge in excess of thirty dollars ($30) per acre or for a parcel of less than one 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 of the Government Code).
If the procedures set forth in this section as it read at the time a standby or availability charge was established were followed, the district 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 district shall comply with the notice, protest, and hearing procedures in Section 53753 of the Government Code.
The maximum charge which may be fixed by the district may be increased from one fiscal year to the next by the same percentage increase as reflected by the Consumer Price Index, as issued by the United States Bureau of Labor Statistics, relative to the immediately preceding fiscal year.
If a person for more than one year obtains substantially all of his or her water requirements for the contiguous parcels of land which the person occupies from rainfall, springs, streams, lakes, rivers or wells, and if the person's primary economic activity on the land is the commercial extraction or processing of minerals, the land is exempt from any water standby or availability charges.
The district may collect the standby or availability charge by billing the charged lands on a fiscal year basis or by other means available.
The district may collect the standby or availability charge as a part of the annual general county tax bill if the district furnishes 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, in sufficient time to meet the schedule established by the county for inclusion of those items on the county general tax bill. The parcel description may be the parcel number assigned by the county assessor to the parcel. In that case, the standby or availability charge is a lien against the parcel of land to which it is charged in the same manner as the county general taxes. Penalties may be collected for late payment of the standby or availability charge, or the amount thereof unpaid, in the manner and at the same rates as that applicable for late payment or the amount thereof unpaid of county general taxes. All laws applicable to the levy, collection, and enforcement of municipal ad valorem taxes are applicable to those charges, except that, if any real property to which the lien would attach has been transferred or conveyed to a bona fide purchaser for value, or if a lien of a bona fide encumbrancer for value has been created and attaches thereon, prior to the date on which the first installment of the taxes would become delinquent, then the lien which would otherwise be imposed by this section shall not attach to the real property and the charge relating to the property shall be transferred to the unsecured roll for collection.
If the district 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. Water Code § 55501.5