Water Code § 23673
ARTICLE 4. Formation and Assessment
Upon a change or resubdivision upon the assessment book of the district of any parcel of land in an improvement district, the board upon its own initiative or upon a petition of the owner of the parcel so changed or resubdivided, may reapportion the improvement district assessment upon the parcel, and the order of reapportionment shall be recorded in the same manner as the order levying the original assessment.