Cal. Gov't Code § 61027

(a) This section applies only to a district where the board of supervisors is the district’s board of directors and more than five years have passed since the effective date of the district’s formation.
(b) Upon receipt of a petition signed by at least 10 percent of the voters of the district, the board of directors shall adopt a resolution placing the question on the ballot. Alternatively, the board of directors may adopt a resolution placing the question on the ballot. The petition or resolution shall specify whether the board of directors will be elected at large, by divisions, or from divisions.
(c) If a majority of the voters voting upon the question at a general election or special election are in favor, the district shall have an elected board of directors.
(d) At the election, the voters shall also elect members to the district’s board of directors. Those persons shall take office only if a majority of the voters voting upon the question of having an elected board of directors are in favor of the question.
(e) If the question is submitted to the voters at a general district election, the notice required by Section 12112 of the Elections Code shall contain a statement of the question to appear on the ballot. If the question is submitted to the voters at a special election, the notice of election and ballot shall contain a statement of the question.