While the private sector assumes responsibility for capital costs and the risks involved such as cost and timeoverruns in construction or failure to deliver an agreed level of service, the local authority in return commits to regular payments.
These consortia, which would have the clout to raise debt finance at low rates, would assume the risk of cost overruns and the responsibility for finishing projects on time.
Building them was a major headache at the time, and utilities and ratepayers paid dearly to cover construction cost overruns throughout the 1970s and 1980s.