From the Guardian (a British newspaper) today: London's super sewer causes a stink. Most agree the 24-mile, £3.6bn 'super sewer' is necessary. But Londoners are furious that Thames Water is planning to drill in public parks and gardens.
The scale of the giant drain, said Phil Stride, Thames Water's engineer in charge, is necessary. "It ranks with the building of the underground, Crossrail and the Channel tunnel itself. But it will solve the problem of pollution in the Thames for 100 years. At the moment, 39m tonnes of sewage goes into the Thames every year; this tunnel will collect 96% of it." The intention is not to replace Joseph Bazalgette's innovative but overwhelmed 160-year-old sewage system, but to augment it.
It's amazing that Bazalgette's sewers lasted as long as they did. If he hadn't doubled the size he thought necessary they would have become overwhelmed and need replacing in the sixties. So they lasted an extra half century because of his foresight.