Paragraph 20

If any permanent or temporary alterations or additions to the waterway are reasonably necessary in consequence of the construction of a specified work, or during a period of 24 months after the completion of that work in order to ensure the safety of the waterway, the continued safe operation of the waterway or the prevention of a detriment such alterations and additions may be carried out by the Trust upon the giving of reasonable notice to the undertaker and the undertaker must pay to the Trust the reasonable cost of those alterations or additions including, in respect of any such alterations and additions as are to be permanent, a capitalised sum representing the increase of the costs which may be expected to be reasonably incurred by the Trust in maintaining, working and, when necessary, renewing any such alternations or additions.

If during the construction of a specified work by the undertaker, the Trust gives notice to the undertaker that the Trust desires itself to construct that part of the specified work which in the opinion of the Trust is endangering the stability of the waterway or the safe operation of any waterway then, if the undertaker decided that part of the specified work is to be constructed, the Trust shall assume construction of that part of the specified work under paragraph 4(3) of this Part of this Schedule and the undertaker must pay to the Trust all reasonable expenses to which the Trust may be put and compensation for any loss which it may suffer by reason of the execution by the Trust of that specified work.

The Trust must, in respect of the capitalised sums referred to in this paragraph and the other provisions of this Part of this Schedule, provide such details of the formula by which those sums have been calculated as the undertaker may reasonably request in writing within 14 days of Trust notifying the undertaker of the amount of the capitalised sums.

If the cost of maintaining, working or renewing the waterway is reduced in consequence of any such alterations or additions, a capitalised sum representing such saving is to be set off against any sum payable by the undertaker to the Trust under this paragraph.