22.—(1) After the purpose of any temporary works has been accomplished, the undertaker must with all reasonable dispatch, or after a reasonable period of notice in writing from Neath Port Authority requiring the undertaker so to do, remove any such temporary works or any materials relating to them which may have been placed below the level of high water within the harbour or the approaches to the harbour by or on behalf of the undertaker.
(2) If the undertaker fails to do so within a reasonable period after receiving such notice, Neath Port Authority may remove the same and may recover the reasonable costs of doing so from the undertaker.