3.—(1) After the date on which this Order comes into force the applicant and any person authorised by the applicant may extinguish or interfere with the enjoyment of any right of navigation to the extent only that such extinguishment or interference is necessary for the purposes of constructing, using and maintaining the works shown indicatively on the deposited plan.
(2) After the date on which construction of the works is completed any right of navigation on the affected area shall be enjoyed only by persons and vessels capable of passing safely beneath, and without interference with, the works shown indicatively on the deposited plan.