Ariz. Rev. Stat. § 48-1822
The district may apply the proceeds from the sale of any of its bonds to further any of its lawful purposes including to pay all costs and estimated costs of the issuance of the bonds, of feasibility studies, of all engineering, inspection, fiscal and legal expenses and of the cost of interest estimated to accrue on money borrowed or that will be borrowed as the board of directors may determine, reserve funds, including those for debt service and working capital, costs and fees related to credit enhancement and costs of the services of agents, consultants or experts retained or employed in the planning, preparation, supervision, financing and completion of the activity financed by the bonds. In addition, the district may expend bond proceeds either as a loan to the United States or as a contribution, in aid of the United States in constructing, repairing or rebuilding any project for which the district acts as a contractual party to assist in the delivery of electricity.
A.R.S. § 48-1822