23.—(1) This paragraph applies during the specified period if, in consequence of the construction of the specified works (including any dredging in connection with the construction, or to afford vessels access to those works), any accumulation of silt or other material, or any scouring or alteration of the tidal flow in the river is caused or created within the protected area.
(2) If the accumulation, scouring or alteration of tidal flow referred to in sub-paragraph (1) causes or creates a relevant concern, the protected interests may, within the specified period, request that the Company carry out such works or take such action to address that relevant concern.
(3) The Company, if so requested by the protected interests under sub-paragraph (2), shall carry out such works or take such action necessary to address that relevant concern, including without prejudice to the generality—
(a)repairing such damage;
(b)removing such accumulation of silt or other material; and
(c)restoring safe navigation and berthing,
within the protected area.
(4) If the Company fails to take the requested steps under sub-paragraph (3), the protected interests may themselves cause the work to be done and may recover from the Company the reasonable cost incurred by them in doing so.
(5) In this paragraph—
“the specified period” means the period—
during which the specified works on the foreshore or bed of the river are being constructed, ending five years after they have been completed; and
during which any temporary structures in connection with the specified works are being constructed, ending five years after they have been removed.
“a relevant concern” means—
damage to the harbour works of the protected interests;
an impediment to the free navigation of the protected area; or
prejudices safe navigation or berthing in that area.