1(1)The following provisions of this Part of this Schedule shall, unless otherwise agreed in writing between the Secretary of State and the protected authority, have effect for the protection of land drainage works and sewers.
(2)In this Part of this Schedule—
“drainage work” means any work vested in or under the control of the protected authority for the purposes of their land drainage functions as defined in the [1976 c. 70.] Land Drainage Act 1976 and includes a watercourse as so defined;
“plans”, in relation to any specified work, means detailed plans, drawings, sections and specifications describing the position and manner in which, and the level at which, the work is proposed to be carried out and the position of all drainage works and sewers of the protected authority within the limits of deviation for that work, and shall comprise detailed drawings of every alteration which is to be made in any such drainage works and sewers by carrying out of the specified work;
“the protected authority” means the Anglian Water Authority and the Southern Water Authority, or either of them, in their capacities as—
authorities responsible for sewerage and sewage disposal; and
authorities responsible for land drainage, including defence against sea water;
“sewer” includes any main used for the conveyance of sewage sludge or sewage effluent, any drain or sewer forming or intended to form part of the general sewerage system of the protected authority, and any storm outflow or outfall or any other apparatus or structure vested in, or maintained by, the protected authority for the purposes of sewerage or sewage disposal; and
“specified work” means Work No. 3, and any works carried out within the limits of deviation for that work for the purpose of or in connection with the construction, maintenance or improvement of any part of the crossing which comprises that work or the tunnels;
but in paragraphs 2 and 5 to 7 below references to a specified work are references to so much only of any such work as is over, or within 15 metres of, any drainage work or sewer.