Federal Inland Waterways Administration Act - Establishes a Federal Inland Waterways Administration in the Department of Transportation. Declares that such administration shall initiate and coordinate programs for the development, regulation, and improvement of inland waterways and transportation thereon. Provides that such functions of: (1) the Maritime Administration of the Department of Commerce; (2) the Federal Maritime Commission; (3) the Corps of Engineers of the Department of the Army; (4) the Tennessee Valley Authority; (5) the Interstate Commerce Commission; (6) the Coast Guard; and (7) the Saint Lawrence Seaway Development Corporation which relate to inland waterways shall be transferred to and administered through such Administration. Stipulates that all orders, rules, contracts, and licenses which have been issued by organizations affected by this Act shall remain in effect until modified by the Secretary of Transportation. Provides that the provisions of this Act shall not afect hearings or suits commenced prior to the date this Act takes effect. (Amends 5 U.S.C. 5314)