The governing body of the municipality shall set the rates for municipal charges, rents, and leases and for services rendered by the municipality in connection with a harbor improvement or facility, the revenue of which is pledged, in an amount sufficient to:
(1) pay the expense of operating and maintaining the improvement or facility;
(2) pay the interest on the bond as it accrues;
(3) pay the principal of the bond as it matures; and
(4) maintain the reserve and other funds as provided in the bond authorization, unless otherwise specifically provided for in the bond authorization.