(a) The use of nonpotable water, including recycled water, in accordance with this part is subject to all applicable state regulation.
(b) This part only applies to a use of water within the district’s service area that is not the subject of a determination pursuant to Article 7 (commencing with Section 13550) of Chapter 7 of Division 7.
(c) This part is in addition to, and not a limitation upon, any powers of a public agency or a court to prevent the waste or unreasonable use of water.