Cal. Pub. Resources Code § 5356
If any protests are against the extent of the district or against the inclusion of property in the district, then the legislative body shall have power to make such changes in the boundaries of the proposed district as it shall find to be proper and advisable, and shall define and establish such boundaries, but such boundaries shall not include any territory which will not be benefited by the improvement or work. The legislative body shall not modify the boundaries except after notice of its intention given in the same manner as publication of the ordinance of intention to call the bond election, describing the proposed modification, and specifying a time for hearing objections to such modification, which time shall be at least 10 days after the publication of the notice, and the objections shall be heard and determined as are objections to the proposed improvement or work.
Ca. Pub. Res. Code § 5356