Cal. Sts. & High. Code § 35402.2

If at any time the legislative body finds that the proceeds of the bonds first issued will be insufficient to make all of the acquisitions and improvements described in the ordinance declaring the district formed and to pay the additional items specified in Section 35402, it may at one time or from time to time issue additional bonds to the extent permitted by the provisions, conditions and covenants contained in the ordinances, resolutions or indentures providing for the issuance of any bonds previously issued.