California Code, Government Code - GOV § 53187

(a) Levy an assessment which is contingent upon the development of land and which may be made payable at the time of approval of a tentative subdivision map, vesting tentative subdivision map, final subdivision map, or zoning change that makes or proposes to make a significant change in the use of the land, as determined by the legislative body by ordinance. The contingent assessment may be made payable upon receipt of a building permit for any parcels which have already received all other required approvals for development. The developer shall pay for any contingent assessment payable over time while the developer holds title to the property. The amount of the contingent assessment shall be in proportion to the benefit to be received by each parcel, and shall be specified as a fixed dollar amount per unit of area for parcels developed into each of several land use categories, as determined by the legislative body, except that the legislative body may provide that the fixed dollar amount may be adjusted annually by an interest rate, as determined by the legislative body by ordinance. The amount of the cumulative interest rate adjustment shall not exceed 100 percent of the fixed dollar amount. The contingent assessment may be made payable as a capital amount or over time, with interest as provided by the legislative body by ordinance.

(b) Levy a contingent assessment pursuant to subdivision (a) together with a noncontingent assessment or special tax levied pursuant to the financing act such that after all levies have been paid, the total of contingent assessments and levies made pursuant to the financing act which are expected to be paid on behalf of each parcel will be in proportion to the portion of project benefits expected to be received by each parcel, as determined by the legislative body.

(c) The proceeds of a contingent assessment may be used for any of the following purposes:

(d) Enter into and enforce a reimbursement agreement pursuant to Article 4 (commencing with Section 53190).