Paragraph 19 I1

Subject to the provisions of this Part of this Schedule, a tidal work shall not be constructed or carried out except in accordance with such plans as may be so approved or deemed to be approved by the Port Authority or determined by arbitration or in such other manner as may be agreed, and in accordance with any reasonable conditions subject to which approval is so given or determined and to the reasonable satisfaction of the Port Authority.

A tidal work shall be so constructed and thereafter maintained as to ensure that the traffic on the river is not interfered with except with the written approval of the Port Authority (which consent shall not be unreasonably withheld but may be given subject to reasonable conditions) and in any event no more than is reasonably necessary for the construction or maintenance of a tidal work; and, subject to the foregoing, that at all times during construction of the tidal works an unobstructed main navigation channel within the tunnel area for the safe passage of vessels is maintained and kept dredged by the undertaker to such depth as the Port Authority may reasonably require and to a width of not less than 60 metres.