California Code, Streets and Highways Code - SHC § 22591

During the course or upon the conclusion of the hearing, the legislative body may order changes in any of the matters provided in the report, including changes in the improvements, the boundaries of the proposed assessment district and any zones therein, and the proposed diagram or the proposed assessment. The legislative body may, without further notice, order the exclusion of territory from the proposed district, but shall not order the inclusion of additional territory within the district except upon written request by a property owner for the inclusion of his property or upon the giving of mailed notice of hearing to property owners upon the question of the inclusion of their property in the district.