Cal. Elec. Code § 21000
The county elections official in each county shall compile and make available to the Legislature or any appropriate committee of the Legislature any information and statistics that may be necessary for use in connection with the reapportionment of legislative districts, including, but not limited to, precinct maps indicating the boundaries of municipalities, school districts, judicial districts, Assembly districts, senatorial districts, and congressional districts, lists showing the election returns for each precinct, and election returns for each precinct reflecting the vote total for all ballots cast, including both vote by mail ballots and ballots cast at polling places, compiled pursuant to Section 15321 in the county at each statewide election. If the county elections official stores the information and statistics in data-processing files, he or she shall make the files available, along with whatever documentation shall be necessary in order to allow the use of the files by the appropriate committee of the Legislature and shall retain these files until the next reapportionment has been completed.
Ca. Elec. Code § 21000