Cal. Education Code § 5019.5

(a) Following each decennial federal census, the governing board of each school district or community college district in which trustee areas have been established shall adopt trustee area boundaries pursuant to Chapter 2 (commencing with Section 21100) of Division 21 of the Elections Code. (b) Notwithstanding subdivision (a) of Section 21130 of the Elections Code, if a school district or community college district has one or more multiple-member trustee areas, the governing board shall adopt the boundaries of the areas of the district so that the population of each area is substantially the same proportion of the total population of the district as the ratio that the number of governing board members elected from the area bears to the total number of members of the governing board, as required by the United States Constitution. Substantial proportionality of population shall be based on the total population of residents as provided in paragraphs (1) and (2) of subdivision (a) of Section 21130 of the Elections Code. (c) Except as provided in subdivision (a), the authority to establish or abolish trustee areas, rearrange the boundaries of trustee areas, increase or decrease the number of members of the governing board, or adopt any method of electing governing board members may be exercised only as otherwise provided under this article and Division 21 (commencing with Section 21000) of the Elections Code, as applicable.