London builds new 'super-sewer' to end Thames pollution blight

A 25 kilometre long 'super sewer' is near completion in London after years of building work. The Thames Tideway Tunnel will divert water from drains which used to flood into the River Thames during heavy rainfall, making the waterway much cleaner for wildlife and river users.

The infrastructure is being broadly welcomed by environmental groups, but sewage outflow is a nationwide problem which is going largely unchecked outside the capital.