S.C. Code Ann. § 31-3-1560

An authority may issue bonds from time to time in its discretion for any of its corporate purposes. An authority may also 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 (a) exclusively from the income and revenues of the housing project financed with the proceeds of such bonds or with such proceeds together with a grant from the Federal Government in aid of such project, (b) exclusively from the income and revenues of certain designated housing projects whether or not they were financed in whole or in part with the proceeds of such bonds or (c) from its revenues generally. Any of such bonds may be additionally secured by a pledge of any revenue or a mortgage of any housing project, projects or other property of the authority.