Cal. Wat. Code § 74468
Directors to fill vacancies in new divisions in the event the redivision is approved by the voters shall be nominated and elected at the same election in the same manner as for election of directors of a district so far as applicable. If one incumbent director resides within a proposed new division his term of office shall not be affected by the approval of the redivision by the voters of the district. If two or more incumbent directors reside within a proposed new division, the term of office of each of them will terminate on the approval of such redivision unless only one is duly nominated, in which case his term of office shall not be affected by the approval of such redivision. A candidate who is a director of the district shall be permitted to have the word "Incumbent" or words equivalent thereto placed after his name on the ballot.
Ca. Water Code § 74468