Paragraph 51
Subject to sub-paragraph (5) the undertaker must from the commencement of the construction of the specified works maintain in good repair and condition and free from obstruction any drainage work which is situated within the limits of deviation and on land held by the undertaker for the purposes of or in connection with the specified works and any protective work, whether or not the drainage work is constructed under the powers conferred by this Order or is already in existence.
If any such drainage work which the undertaker is liable to maintain is not maintained to the reasonable satisfaction of the relevant drainage authority, the relevant drainage authority may by notice in writing require the undertaker to repair and restore the work, or any part of such work, or (if the undertaker so elects and the relevant drainage authority in writing consents, such consent not to be unreasonably withheld or delayed), to remove the specified work and any protective work and restore the site to its former condition, to such extent and within such limits as the relevant drainage authority reasonably requires.
Subject to sub-paragraph (4) and paragraph 10, if, within a reasonable period, being not less than 28 days beginning with the date on which a notice in respect of any drainage work is served under sub-paragraph (2) on the undertaker, the undertaker has failed to begin taking steps to comply with the reasonable requirements of the notice and has not subsequently made reasonably expeditious progress towards their implementation, the relevant drainage authority may do what is reasonably necessary for such compliance and any reasonable expenditure incurred by the relevant drainage authority in so doing is recoverable from the undertaker.
In the event of any dispute as to the reasonableness of any requirement of a notice served under sub-paragraph (2), the relevant drainage authority must not, except in the case of an emergency, exercise the powers conferred by sub-paragraph (3) until the dispute has been finally determined in accordance with paragraph 11.
This paragraph does not apply to—
drainage works which are vested in the relevant drainage authority, or which the relevant drainage authority or another person is liable to maintain and is not prevented by the powers of the Order from doing so; and
any obstruction of a drainage work for the purpose of a work or operation authorised by this Order and carried out in accordance with the provisions of this Part of this Schedule provided that any obstruction is removed as soon as reasonably practicable.