Cal. Pub. Resources Code § 5788.15
On or before July 1 of any year, the city council of a city which is located wholly or partially within a district may adopt a resolution ordering the transfer of funds from the city to the district in an amount equal to the entire or partial amount of property tax revenue that would have been allocated to the district from the territory that is located both in the city and the district. The city shall file certified copies of its resolution with the district and the county auditor. Pursuant to Section 96.8 of the Revenue and Taxation Code, the county auditor shall compute and implement an effective tax rate reduction. A city's decision to pay funds to a district in lieu of property tax revenues is effective only for the fiscal year for which it is made.
Ca. Pub. Res. Code § 5788.15