The undertaker may, for the purposes of constructing, operating, maintaining, repowering and decommissioning the tidal works from time to time deepen, dredge, scour, cleanse, alter and improve so much of the bed, shores and channels of the land within the offshore Order limits as adjoin or are near to the authorised works and may use, appropriate or dispose of the materials (other than wreck within the meaning of Part 9 of the Merchant Shipping Act 199520) from time to time dredged by it.