(1) For the purposes of this section and §§ 14-361-119 — 14-361-122, unless the context otherwise requires, the term “public agency” includes municipality, as defined in this chapter, any agency of the state government and of the United States, and any municipality, political subdivision, and agency of another state; and
(2) The term “governing body” means the governing body of the municipality, and the head of the agency if the public agency is other than a municipality.
(3) All powers, privileges, and authority granted to any municipality by this chapter may be exercised and enjoyed jointly with any public agency of any other state or of the United States to the extent that the laws of such other state or of the United States permit such joint exercise or enjoyment.
(4) If not otherwise authorized by law, any agency of the state government, when acting jointly with any municipality, may exercise and enjoy all of the powers, privileges, and authority conferred by this chapter upon a municipality.