9.—(1) If any berth approach within the Harbour becomes subject to sedimentation, scouring, currents or wave action which is wholly or partly caused by the construction or carrying on of the tidal works (including any temporary works) and which occurs during the period beginning with the commencement of the construction or carrying on of the tidal works and ending with the expiration of five years after the date on which the last of those works is completed or the removal of such temporary works, as the case may be, the Company shall either—
(a)pay to the Authority any additional expense which the Authority may reasonably incur for the preservation or proper maintenance of the berth approach—
(i)in dredging the Harbour to remove the sedimentation,
(ii)in taking such action as the Authority considers to be necessary for the purpose of making good such scouring or the effects of such currents or wave action, or
(iii)as a result of increased frequency of maintenance dredging; or
(b)take the necessary action at their own cost subject to prior approval of the Authority, such prior approval not to be unreasonably withheld or delayed.
(2) Where dredging is undertaken under sub-paragraph (1) the Company shall pay for or carry out such dredging as may be necessitated by further sedimentation, scouring or wave action occurring within five years after completion of the dredging undertaken under sub-paragraph (1).