Cal. Sts. & Hy. Code § 10351
Unless the power to proceed shall have ceased at the conclusion of the hearing on the proposed improvement because of a majority protest, at any time before completion of the improvement proceedings, the legislative body may make changes in, to or from the boundaries of the proposed assessment district, the improvement ordered to be made or acquired, the assessment (including the amounts of any of the individual assessments therein), or in the proceedings, or any act, determination or provision made, or permitted to be made, by the legislative body under and pursuant to this division, which act, determination or provision does not affect the jurisdiction of the legislative body to order the improvement. The legislative body shall not change the boundaries to include any territory which will not, in its judgment, be benefited by the improvement.
Ca. Sts. and High. Code § 10351