Cal. Gov. Code § 61026

In the case of a board of directors elected by divisions or from divisions, the board of directors shall adjust the boundaries of the divisions before November 1 of the year following the year in which each decennial census is taken. If at any time between each decennial census, a change of organization or reorganization alters the population of the district, the board of directors shall reexamine the boundaries of its divisions. If the board of directors finds that the population of any division has varied so that the divisions no longer meet the criteria specified in subdivision (d) of Section 61025, the board of directors shall adjust the boundaries of the divisions so that the divisions shall be as nearly equal in population as possible. The board of directors shall make this change within 60 days of the effective date of the change of organization or reorganization.