The board, in addition to the moneys which may be received by it from the sale of bonds and from the collection of revenues, rents, and earnings derived under the provisions of this chapter, shall have the authority to accept from any public or private agency, or from any individual, grants for or in aid of the construction of any planned development, or for the payment of bonds, and to receive and accept contributions from any source, of 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.