Operations for the construction of a tidal work, and operations for the maintenance or improvement of such a work affecting the river, shall be completed as soon as reasonably practicable after they have been commenced.

As soon as reasonably practicable after the completion of operations for the construction, maintenance or improvement of any part of a tidal work, the Secretary of State shall remove all temporary works and all materials on site placed for the purposes only of those operations and shall make good the site to the reasonable satisfaction of the Port Authority.