Ariz. Const. art. 13, § 4

No municipal corporation shall ever grant, extend, or renew a franchise without the approval of a majority of the qualified electors residing within its corporate limits who shall vote thereon at a general or special election, and the legislative body of any such corporation shall submit any such matter for approval or disapproval to such electors at any general municipal election, or call a special election for such purpose at any time upon thirty days' notice. No franchise shall be granted, extended, or renewed for a longer time than twenty-five years.