The declaration under subsection (a) shall apply only to those parts of the areas described in subsection (a) of this section which are or will be bulkheaded and filled or otherwise occupied by permanent structures, including marina facilities. All such work is subject to all applicable Federal statutes and regulations, including, but not necessarily limited to, sections 401 and 403 of this title, section 1344 of this title, and the National Environmental Policy Act of 1969 [42 U.S.C. 4321 et seq.].
If, 20 years from November 17, 1988, any area or part thereof described in subsection (a) is not bulkheaded or filled or occupied by permanent structures, including marina facilities, in accordance with the requirements set out in subsection (b) of this section, or if work in connection with any activity permitted in subsection (b) is not commenced within 5 years after issuance of such permits, then the declaration of non-navigability for such area or part thereof shall expire. Notwithstanding the preceding sentence, the declaration of nonnavigability for the area described in subsection (a)(5), or any part thereof, shall not expire.