Cal. Water Code § 71882

The purpose or amount of bonded debt or the boundaries of the proposed improvement district shall not be changed by the board except after notice of its intention to do so, given by publication pursuant to Section 6061 of the Government Code in a newspaper printed and published in the district, if there is a newspaper printed and published in the district, and by posting in six public places within the proposed improvement district. The notice shall state the changed purpose and debt proposed and that the exterior boundaries as proposed to be changed are set forth on a map on file with the secretary which map shall govern for all details as to the extent of the proposed improvement district, and shall specify the time and place for hearing on such change, which time shall be at least 10 days after publication or posting of the notice.