Ariz. Rev. Stat. § 37-1121
B. Members of the commission are public officers for the purposes of title 38, chapter 3, article 8 and title 38, chapter 3.1. A person who has advocated for or expressed a desire that a watercourse in this state be determined to have been navigable or nonnavigable may not serve as a commission member. A commission member who is a witness, gives evidence or makes statements of personal knowledge of the characteristics of navigability of a watercourse for the commission's consideration shall not participate as a commission member in proceedings relating to that watercourse. A commission member shall not: