Cal. Pub. Res. Code § 5785

(a) In the case of a district with an elected board of directors, the directors may be elected:
1. (1) At large.
2. (2) By divisions.
3. (3) From divisions.
(b) As used in this article:
1. (1) “By divisions” means the election of each member of the board of directors by voters of the division alone.
2. (2) “From divisions” means the election of members of the board of directors who are residents of the division from which they are elected by the voters of the entire district.
(c) A board of directors may be elected by any one of the methods described in subdivision (a) if a majority of the voters voting upon the question are in favor of the question at a general district or special election.
(d) The board of directors 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 board of directors shall adopt a resolution placing the question on the ballot.
(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.
(f) If the majority of voters voting upon the question approves the election of directors either by divisions or from divisions, the board of directors shall promptly adopt a resolution dividing the district into five divisions. The resolution shall assign a number to each division. Using the last decennial census as a basis, the divisions shall be as nearly equal in population as possible. In establishing the boundaries of the divisions, the district board may give consideration to the following factors:
1. (1) Topography.
2. (2) Geography.
3. (3) Cohesiveness, contiguity, integrity, and compactness of territory.
4. (4) Community of interests of the divisions.
(g) If the majority of voters voting upon the question approves of the election of directors either by divisions or from divisions, the members of the board of directors shall be elected by divisions or from divisions. Each member elected by division or from division shall be a resident of the election division by which or from which he or she is elected. At the district general election following the approval by the voters of the election of directors either by divisions or from divisions, the board of directors shall assign vacancies on the board of directors created by the expiration of terms to the respective divisions and the vacancies shall be filled either by or from those divisions.
(h) If the majority of voters voting on the question approves of the election of directors at large, the board of directors shall promptly adopt a resolution dissolving the divisions that had existed.