California Code, Streets and Highways Code - SHC § 22660

(a) The legislative body may, by resolution, determine that the estimated cost of any of the proposed improvements described in subdivisions (a) to (d), inclusive, of Section 22525 is greater than can be conveniently raised from a single annual assessment and order that the estimated cost shall be raised by an assessment levied and collected in installments over a period not to exceed five fiscal years.

(b) The legislative body may, by resolution, determine that the estimated cost of the proposed improvements described in Section 22525 is greater than can be conveniently raised from a single annual assessment and order that the estimated cost of those improvements, other than the costs of maintenance and servicing, be raised by an assessment levied and collected in installments over a period not to exceed 30 years.

(c) The resolution adopted pursuant to subdivision (a) or (b) shall generally describe the proposed improvements, set forth the estimated cost thereof, specify the number of annual installments and the fiscal years during which they are to be collected, and fix or determine the maximum amount of each annual installment.