11.—(1) Where the authorised works are abandoned or suffered to fall into decay, the Secretary of State may by notice in writing require the Commissioners at their own expense either to repair and restore the relevant part of the authorised works, or to remove the authorised works and restore their site to its former condition, to such an extent and within such limits as the Secretary of State thinks proper.
(2) Where works, consisting—
(a)partly of authorised works; and
(b)partly of works on or over land above the level of high water,
are abandoned or suffered to fall into decay and the works mentioned in sub-paragraph (b) are in such condition as to interfere or to cause reasonable apprehension that they may interfere with the right of navigation or other public rights over the foreshore, the Secretary of State may include those works, or any portion thereof, in any notice under paragraph (1).
(3) If, on the expiration of 30 days from the date when a notice under this article is served upon the Commissioners, they have failed to comply with the requirements of the notice, the Secretary of State may execute the works specified in the notice and any expenditure incurred by the Secretary of State in so doing shall be recoverable from the Commissioners.