Health & Saf. Code, § 13845

(a) Except in the case where a county board of supervisors or a city council has appointed itself as the district board, the number of members of a district board may be increased or decreased if a majority of the voters voting on the question are in favor of the question at a general district or special election. The question shall specify the resulting number of members of the district board.

(b) The district board may adopt a resolution placing the question on the ballot. Alternatively, upon receipt of a petition signed by at least 25 percent of the registered voters of the district, the district board shall adopt a resolution placing the question on the ballot.

(c) 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 the ballot shall contain a statement of the question.

(d) If the voters approve of increasing the number of directors, the new members shall be elected or appointed pursuant to this chapter. If the district board is elected, the additional members may be elected at the same election.

(e) If the voters approve of decreasing the number of directors, the members of the district board continue to serve until the end of their current terms.

(f) The number of members of a district board may be changed by the local agency formation commission as a term and condition of approval by the commission of any change of organization or reorganization. Unless the Cortese-Knox-Hertzberg Local Government Reorganization Act of 2000, Division 3 (commencing with Section 56000) of Title 5 of the Government Code, otherwise requires voter approval, the change ordered by the commission does not require approval by the voters of the district.