(1)The Executive may use for the discharge of any water pumped or found during the construction of the authorised works any available stream or watercourse, or any sewer or drain of the relevant authority, and for that purpose may lay down, take up and alter conduits, pipes and other works and may make any convenient connections with any such stream, watercourse, sewer or drain.
(2)(a)The Executive shall not—
(i)discharge any water into any sewer or drain vested in or under the control of the relevant authority except with the consent of that authority and subject to such terms and conditions as that authority may reasonably impose; or
(ii)make any opening into any such sewer or drain except in accordance with plans approved by, and under the superintendence (if given) of, the relevant authority.
(b)Consent to a discharge, or approval of plans submitted, under this subsection shall not be unreasonably withheld.
(3)(a)Section 85 of the [1991 c. 57.] Water Resources Act 1991 shall apply to, or to the consequence of, a discharge under this section into any controlled water within the meaning of section 104 of that Act as if this section were excluded from the reference to any local statutory provision mentioned in section 88 (1) (f) of that Act.
(b)In the exercise of their powers under this section the Executive shall not damage or interfere with the bed of any watercourse forming part of a main river or the banks thereof within the meaning of section 72 of the [1991 c. 59.] Land Drainage Act 1991.
(4)The Executive shall take all such steps as may be reasonably required to secure that any water discharged under this section shall be as free as may be reasonably practicable from any gravel, soil or other solid substance or matter in suspension.
(5)Any difference arising between the Executive and the National Rivers Authority or the relevant authority, as the case may be, under this section shall be determined by arbitration.
(6)In this section “the relevant authority” means the Council or any sewerage undertaker within the meaning of the [1991 c. 56.] Water Industry Act 1991.