London's Victorian sewerage system was designed to overflow into the River Thames during extreme weather when the sewers reached capacity, to prevent homes and streets from flooding.

The system is struggling to cope with the demands of 21st century London, and discharges are now happening much more frequently - around once a week on average.

We've developed three major engineering schemes to help stop sewer overflows and improve water quality in the River Thames.

This includes upgrades to all five of our major sewage treatment works in London, the construction of the Lee Tunnel and the proposed Thames Tunnel.