61.—(1) Subject to the provisions of this Part of this Schedule and except to the extent that the Agency or another person is liable to maintain any such work and is not precluded by the exercise of the powers of the Order from so doing, Network Rail shall 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 or on land held by Network Rail for the purposes of or in connection with the specified works, whether or not the drainage work is constructed under the powers of the Order or is already in existence.
(2) If any such drainage work which Network Rail is liable to maintain is not maintained to the reasonable satisfaction of the Agency, the Agency may by notice in writing require Network Rail to repair and restore the work, or any part thereof, or (if Network Rail so elects and the Agency in writing consents, such consent not to be unreasonably withheld), to remove the work and restore the site (including sea defences) to its former condition, to such extent and within such limits as the Agency reasonably requires.
(3) Subject to paragraph 64, if, within a reasonable period being not less than 28 days beginning with the date on which a notice in respect of any work is served under sub-paragraph (2) on Network Rail, Network Rail has failed to begin taking steps to comply with the reasonable requirements of the notice and has not thereafter made reasonably expeditious progress towards their implementation, the Agency may do what is necessary for such compliance and may recover any expenditure reasonably incurred by it in so doing from Network Rail.
(4) In the event of any dispute as to the reasonableness of any requirement of a notice served under sub-paragraph (2) , the Agency shall not except in a case of emergency exercise the powers of sub-paragraph (3) until the dispute has been finally determined.