Cal. Sts. & Hy. Code § 35402.4
At any time prior to the issuance of bonds, the legislative body may change the boundaries of the district after notice and hearing in the same manner as provided in Sections 35270 to 35272, but no such change shall be made unless following such hearing the legislative body shall determine that all of the territory within the district as changed will be benefited by the acquisitions and improvements originally ordered or the acquisitions and improvements as changed pursuant to Section 35402.3, as the case may be. Any such change in boundaries shall be effected by an ordinance amending the ordinance declaring the district formed. Proceedings under this section may be combined with proceedings under Section 35402.3.
Ca. Sts. and High. Code § 35402.4