5.—(1) Subject to paragraph (3), in constructing or maintaining any of the scheduled works, the Agency may deviate—
(a)laterally from the lines or situations shown on the works plan to any extent within the limits of deviation; and
(b)vertically from the levels shown on the sections to any extent upwards or downwards.
(2) Without limiting the scope of paragraph (1), in constructing or maintaining the scheduled works the Agency may, within the limits mentioned in paragraph (1)—
(a)deviate from their points of commencement and termination as shown on the Order plans; and
(b)deviate from the design shown on the Order plans.
(3) The scheduled works must be constructed so that the unobstructed opening between the walls of the barrier, as shown on the Order plans, measures 25 metres wide.
(4) Nothing in paragraphs (3) or (4) of article 4 (power to construct and maintain works) authorises the Agency to execute any works in contravention of the restrictions imposed by paragraph (3).