Cal. Streets and Highways Code § 22605

The legislative body, either in a single proceeding or by separate proceedings, may order one or any combination of the following changes of organization: (a) The annexation of territory to an existing assessment district formed under this part. (b) The detachment of territory from an existing assessment district formed under this part. (c) The dissolution of an existing assessment district formed under this part. (d) The consolidation into a single assessment district formed under this part of any combination of two or more of any of the following: (1) An existing assessment district formed pursuant to this part. (2) An existing lighting, street lighting, maintenance, or tree planting district formed pursuant to Chapter 26 (commencing with Section 5820) of Part 3 of Division 7, Part 1 (commencing with Section 18000), Part 2 (commencing with Section 18300), Part 3 (commencing with Section 18600), or Part 4 (commencing with Section 19000) of Division 14, or Part 1 (commencing with Section 22000) of this division, or pursuant to any procedural ordinance adopted by a charter city. (e) The legislative body shall not, by annexation, detachment, dissolution, or consolidation, alter the obligation of property owners to pay the principal of, and interest on, bonded debt or notes issued pursuant to Section 22662.5. This section does not prevent the lawful refunding of the bonded debt or notes or the apportionment of assessments upon the division of properties assessed.