Cal. Water Code § 75354

If bonds have been voted but not sold, and the board expects to sell such bonds prior to the end of the ensuing fiscal year, there shall be included in the annual estimate an amount estimated to be sufficient to provide for the payment of all principal and interest of such unsold bonds which the board believes will come due during the ensuing fiscal year and also during that part of the following fiscal year before the proceeds of an assessment tax levied at the time for making the general tax levy in such following fiscal year can be made available for the payment thereof.