Cal. Pub. Util. Code § 13263

In lieu of the immediate levy of a tax to pay the interest or any part thereof on any bonded indebtedness incurred in accordance with this division, the board may in the estimate of the amount of money necessary to be raised by the bonds include a sum sufficient to pay interest on all of the bonds or part thereof during the period of acquisition, construction, or completion, but for no period in excess of five years.