The authority, in addition to the moneys which may be received from the sale of revenue bonds and from the collection of revenues and earnings derived under this chapter, shall have authority to accept from any federal agency grants for or in aid of the construction of any project or for the payment of bonds and to receive and accept contributions from any source of either money or property or other things of value, to be held, used, and applied only for the purposes for which such grants or contributions may be made.