17.—(1) A tidal work shall not be constructed, altered or replaced except in accordance with plans and sections approved by the Secretary of State and subject to any conditions and restrictions imposed by him before the work is begun.
(2) If a tidal work is constructed, altered, replaced or re-laid in contravention of this article or of any condition or restriction imposed under this article—
(a)the Secretary of State may by notice in writing require the Council at its own expense to remove the tidal work or any part thereof and restore the site thereof to its former condition; and if, on the expiration of a period of 30 days from the date on which the notice is served, it has failed to comply with the requirements of the notice, the Secretary of State may execute the works specified in the notice; or
(b)if it appears to the Secretary of State urgently necessary so to do, he may remove the tidal work, or part of it, and restore the site to its former condition,
and any expenditure incurred by the Secretary of State in so doing shall be recoverable from the Council.