Sewerage undertakers may construct, on their own or on another's land, drainage systems for the purpose of reducing the volume of surface water entering public sewers or the rate at which it does so.
A sewerage undertaker may maintain and operate a drainage system constructed by it under subsection (1).
In this section—
"drainage system" means a structure designed to receive rainwater and other surface water, other than a natural watercourse;
"natural watercourse" means a river or stream;
"rainwater" includes snow and other precipitation;
"structure" includes—
(a)any part of an existing or proposed structure, and
(b)any feature or aspect of a design that is intended to receive or facilitate the receipt of rainwater or other surface water.
The powers conferred by subsections (1) and (2) are not to be regarded as functions of a sewerage undertaker for the purposes of section 155 (compulsory purchase of land required for the purposes of carrying out functions of relevant undertakers).