Cal. Sts. & High. Code § 18160

The procedure in this chapter shall be an alternative procedure for levying and collecting assessments, and the city council may by resolution determine, in its discretion, that this procedure shall be followed. Such determination may be made, with respect to the procedures governing the organization of the district, at the time when the city council shall order the making and filing of a report as provided in Section 18040. Such determination may be made in any succeeding year during the period of time for which the improvement is ordered to be continued, at least 60 days prior to the making of the general tax levy for city purposes.