Paragraph 22 I1

Except so far as may be unavoidable in the construction of a tidal work, the undertaker shall not, without the written consent of the Port Authority (which consent shall not be unreasonably delayed or withheld), deposit or permit the deposit of any material on or in the river or on the bed, shores or banks of the river; and the undertaker shall within 7 days after receipt of written notice to that effect from the Port Authority remove any material so unavoidably deposited without the written consent of the Port Authority under paragraphs 18 and 19, as in the reasonable opinion of the Port Authority is necessary for facilitating or preserving safety of navigation.