Wat. Code, § 35504

A district may not exercise any of the powers granted a district by this article unless the board first submits to the voters of the district at an election a proposition as to whether or not the powers may be exercised by the district and a majority of the votes cast on the proposition are in favor of the proposition. Such proposition may be submitted at, or at an election consolidated with, the election at which a proposition to issue bonds of the district, or for an improvement district therein, for the purposes specified in this article is submitted. A proposition to issue bonds of the district, or for an improvement district therein, for the purposes specified in this article which has been submitted at, or at an election consolidated with, an election under this section before the effective date of the amendment of this section enacted at the 1964 First Extraordinary Session of the Legislature is hereby ratified and confirmed and any bonds authorized at said election may be issued as legal obligations of the district or improvement district. Only one election need be held to authorize a district to exercise any of the powers granted by this article or any later amendments thereof.