The municipal council may, in its discretion, additionally secure bonds by a pledge of the net revenues which it may derive from any municipally owned public utility. In making a pledge of such revenues the municipality may reserve the right to place other bonds, general obligation or revenue, on a parity with the bonds additionally secured in the manner provided for by this section.
If the net revenues of any municipally owned utility shall be pledged and such utility shall be under the management of commissioners, the commissioners shall give their consent to the issuance of bonds and to the pledge and covenants securing them.