Paragraph 7 I1

After the purpose of any temporary works has been accomplished the Agency must with all reasonable dispatch, or after a reasonable period of notice in writing from the Harbour Authority requiring the Agency so to do, remove any such temporary works or any materials relating thereto which may have been placed below the level of high water by or on behalf of the Agency; and, on failing to so do within a reasonable period after receiving such notice, the Harbour Authority may remove the same and may recover the reasonable costs of so doing from the Agency.