13For protection of relevant undertakers
(1)The Board shall as soon as possible inform all relevant undertakers of the carrying out of emergency operations likely to affect them and shall thereafter give notice as soon as possible to the relevant undertakers of any such operations.
(2)A person authorised by the Board to enter on land in pursuance of section 6 (Power to enter land and carry out relevant operations pursuant to notice of entry) of this Act shall not exercise any of the powers of that section unless notice of his intention to do so has been served by the Board, not less than 28 days before he does so, on any relevant undertakers.
(3)This section shall have effect subject to any agreement between the Board and any relevant undertakers.