18.—(1) Before beginning to construct any specified work, Network Rail must submit to the drainage authority plans of the specified work and such further particulars available to it as the drainage authority may within 28 days of the submission of the plans reasonably require.
(2) Any such specified work must not be constructed except in accordance with such plans as may be approved in writing by the drainage authority, or determined under article 40.
(3) Any approval of the drainage authority required under this paragraph—
(a)must not be unreasonably withheld;
(b)is deemed to have been given if it is neither given nor refused within 2 months of the submission of the plans for approval and, in the case of a refusal, accompanied by a statement of the grounds of refusal; and
(c)may be given subject to such reasonable requirements as the drainage authority may make for the protection of any drainage work or the fishery, or for the protection of water resources, or for the prevention of flooding or pollution or in the discharge of its environmental duties.
(4) The drainage authority must use its reasonable endeavours to respond to the submission of any plans before the expiration of the period mentioned in sub-paragraph (3)(b).