Subject to the provisions of this section, nothing in any of the provisions of this Act to which this section applies authorises a highway authority or any other person to use or interfere with any watercourse (including the banks thereof), or any drainage or other works, vested in or under the control of F1the National Rivers Authority or other drainage body within the meaning of the F2Land Drainage Act 1991without the consent of F3the National Rivers Authority or that body.

A consent required for the purposes of subsection (1) above shall not be unreasonably withheld, and if any question arises whether the withholding of a consent is unreasonable either party may require it to be referred to an arbitrator to be appointed, in default of agreement, by the President of the Institution of Civil Engineers.

This section applies to sections 45, 100, 101, 110, 294 and 299 above and to the provisions specified in Schedule 22 to this Act.

In its application to sections 100, 110, and 299 above this section applies in relation to a navigation authority as it applies in relation to F2the National Rivers Authority or other drainage body within the meaning of the F4Land Drainage Act 1991.