Authority to set aside revenues for operation and maintenance,

a depreciation account, and payment of bonds Sec. 6. The board may fix and set aside: (1) the proportion of the revenues of the waterworks department necessary for reasonable and proper operation and maintenance; (2) the proportion of the revenues for a proper and adequate depreciation account; and (3) the fixed proportion of the revenues to be applied to the payment of the principal and interest of the authorized bonds. As added by Acts 1982, P.L.74, SEC.1.