18.—(1) Before beginning to construct any specified work, the undertaker shall submit to the consenting authority plans of the specified work and such further particulars available to it as the consenting authority may within 28 days of the receipt of the plans reasonably require.
(2) Any such specified work shall not be constructed except in accordance with such plans as may be approved in writing by the consenting authority, or determined under sub-paragraph (1).
(3) Any approval of the consenting authority required under this paragraph—
(a)shall not be unreasonably withheld or delayed;
(b)shall be given within 8 weeks of the submission of the plans submitted under sub-paragraph (1) or where the consenting authority has requested further particulars for approval (such request must be made within 2 weeks of receipt of the plans submitted under sub-paragraph (1)) within 8 weeks of the submission of such plans;
(c)shall be deemed to have been given if it is neither given nor refused within 8 weeks of the submission of the plans or receipt of further particulars if such particulars have been required by the consenting authority for approval; and
(d)may be given subject to such reasonable modifications to the plans as the consenting authority may request and such reasonable requirements as the consenting authority may make for the protection of any drainage work or for the protection of watercourse, or for the prevention of flooding or pollution or in the discharge of its environmental duties.