California Code, Education Code - EDC § 5023

(a) Whenever an elementary, high school, or unified school district, or a portion of any such district, is annexed to another school district in which trustee areas have been established, the county committee on school district organization of the county having jurisdiction over the annexing district shall study and make recommendations with respect to trustee areas of the annexing district as enlarged.  If the recommendations include moving territory from an existing trustee area in the annexing district to another trustee area of the annexing district, the recommendations shall comply with the criteria and requirements in Section 21130 of the Elections Code.  Procedures contained in Section 5019 shall be used for purposes of this section.

(b) Recommendations adopted under provisions of subdivision (a), if approved by the electors, shall become effective on the same date that the annexing district as enlarged becomes effective for all purposes.