For the purposes of any section of this Act that confers powers on local authorities to construct, lay or maintain sewers, drains or pipes, Part VI of the Third Schedule to the [1945 c. 42.] Water Act 1945 is incorporated with this Act, with such adaptations as may be necessary to make that Part applicable to the construction and maintenance of sewers and drains as well as to the laying and maintenance of water mains and pipes.

The Part so incorporated with adaptations as aforesaid applies in relation to any person not being a local authority who is empowered by this Act to construct, lay or maintain a sewer or drain as if, so far as his powers extend, he were the undertakers.