(1) The payment of operating and maintenance expenses, the rendition of efficient service, and the creation of adequate depreciation reserves sufficient to maintain the investment in facilities;
(2) The payment of the principal and interest on outstanding obligations;
(3) The payment of dividends on stock issued and outstanding, if any;
(4) The creation of such reserves for improvements, construction, and contingencies as the board from time to time may prescribe; and
(5) Any other purposes authorized by law.