Paragraph 23 I1

The undertaker shall not, except for the purpose of constructing the authorised works, remove any gravel, soil or other material from the bed, shores or banks of the river without the previous written consent of the Port Authority (which consent shall not be unreasonably delayed or withheld), but nothing in this paragraph shall prevent the use by the undertaker of any gravel, soil or other material so removed for the purposes of the construction of other authorised works.