California Code, Public Resources Code - PRC § 49032

(a) Prior to adoption of the initial ordinances prescribing the fees provided for in Section 49031, the board of supervisors shall place before the voters of the district the question whether the district shall be authorized to prescribe fees.  If the voters do not approve that authorization, a subsequent election to secure that approval shall not be held within one year of the date of the prior authorization election.

(b) The approval of the voters may be secured at a district or countywide election or by a ballot mailed to each registered voter of the district.

(c) The board of supervisors shall determine what majority of the voters voting on the proposition shall be required to approve the proposition.