Cal. Gov. Code § 50603
At the hearing the legislative body may order changes in the proposed maintenance or the proposed boundaries of the district by the elimination of any portion thereof which will not in its opinion be benefited by the work proposed to be done.
If the legislative body proposes a change in the boundaries to include additional land in the district, the legislative body shall adopt a resolution briefly describing the change proposed to be made and giving notice of the time and place when and where any interested person may object to such change. The clerk shall mail a copy of a notice of intention to do so to each person described in Section 50598 included in the area proposed to be added, within the time and in the manner set forth in Section 50598. The notice shall describe the proposed change and specify the time for hearing objections. The notice shall also be published in the time and manner provided for in Section 50597.
Ca. Gov. Code § 50603