Cal. Pub. Util. Code § 60152

Limited tax bonds shall be issued pursuant to a resolution adopted at any time by a two-thirds vote of the district. Each resolution shall provide for the issuance of bonds in the amounts as may be necessary, until the full amount of bonds authorized have been issued. The full amount of bonds may be divided into two or more series and different dates of payment fixed for the bonds of each series. A bond need not mature on its anniversary date.