(a) Before any expenditures as authorized by § 14-89-903 shall be made, the commissioners of a municipal improvement board shall provide from the operation of an electric power plant or waterworks system adequate depreciation and reserve accounts.
(b) Adequate provisions shall also be made for such alterations, improvements, or extensions of the electric power plant or waterworks system as, in the judgment of the commissioners of the board, will be necessary during the ensuing year.