Paragraph 21 I1

Nothing in this Order shall authorise or empower the undertaker without the previous written consent of the Port Authority (which consent shall not be unreasonably withheld but may be given subject to reasonable conditions), to embank, encroach upon or interfere with any part of the bed, shores or banks of the river except as is expressly authorised by this Order or authorised by the Port Authority pursuant to paragraphs 18 and 19.