Gov. Code, § 57384

(a) Except as provided in subdivision (b), whenever a city has been incorporated from territory formerly unincorporated, the board of supervisors shall continue to furnish, without additional charge, to the area incorporated all services furnished to the area prior to the incorporation. Those services shall be furnished for the remainder of the fiscal year during which the incorporation became effective or until the city council requests discontinuance of the services, whichever occurs first.

(b) This subdivision applies only to incorporations for which the petition or resolution of application for incorporation is filed with the commission on or after January 1, 1987. Prior to the commission adopting a resolution making determinations, the board of supervisors may request that the city reimburse the county for the net cost of services provided pursuant to subdivision (a). The commission shall impose this requirement as a term and condition of its resolution. The city shall be obligated to reimburse the county within five years of the effective date of the incorporation or for a period in excess of five years, if the board of supervisors agrees to a longer period. As used in this subdivision, “net cost of services” means the total direct and indirect expense to the county of providing services, as determined pursuant to paragraph (2) of subdivision (c) of Section 56810, adjusted by any subsequent change in the California Consumer Price Index, less any revenues which the county retains that were generated from the formerly unincorporated territory during the period of time the services are furnished pursuant to subdivision (a). This subdivision applies only to those services which are to be assumed by the city.

(c) At the request of the city council, the board of supervisors, by resolution, may determine to furnish, without charge, to the area incorporated all or a portion of services furnished to the area prior to the incorporation for an additional period of time after the end of the fiscal year during which the incorporation became effective. The additional period of time after the end of the fiscal year during which the incorporation became effective for which the board of supervisors determines to provide services, without charge, and the specific services to be provided shall be specifically stated in the resolution adopted by the board of supervisors.