An authority shall have power to issue bonds from time to time, in its discretion, for any of its corporate purposes. An authority shall also have power to issue refunding bonds for the purpose of paying or retiring bonds previously issued by it. An authority may issue such types of bonds as it may determine, including bonds on which the principal and interest are payable:
Any of such bonds may be additionally secured by a pledge of any revenues or a mortgage of any housing project or projects or of any other property of the authority.
OCGA § 8-3-70