Cal. Elections Code § 12260

(a) The elections official may change or alter any precinct boundaries. (b) If any changes or alterations are made the elections official shall prepare new detail maps or exterior descriptions thereof, or both. The county surveyor shall, if so requested, provide assistance to the elections official in the preparation of the detail maps or exterior descriptions. (c) The elections official shall provide, at the request of any interested person, the following information: (1) All precinct boundary changes and alterations made within the current calendar year and the immediately preceding two calendar years. (2) All precinct consolidations made within the current calendar year and the immediately preceding two calendar years, specifying the election or elections in which the consolidations were made. (d) The information provided to persons pursuant to subdivision (c) shall include the precinct numbers before the change or alteration and then a description, including precinct numbers, of the changes or alterations. The description may include maps. (e) The information described in subdivisions (c) and (d) shall be compiled for each calendar year and shall be kept and filed so as to be accessible to any person upon request. (f) The elections official may charge a person requesting information the amount needed to reimburse the jurisdiction for the actual expenses incurred in providing copies of the information required under this section.