Last reviewed: 28.5.2011 - 6.05pm
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.
In this section
London's Victorian sewer system
Find out why London's sewer system is struggling to cope with the demands of the 21st century.
Sewage Works Upgrades
We're cleaning up the River Thames by increasing the amount of sewage we can treat, and improving the standards to which we treat it.
Lee Tunnel
We're building a new four-mile sewer to capture sewage that would otherwise overflow into the River Lee during heavy rainfall.
Thames Tunnel
The proposed Thames Tunnel will run up to 20 miles from west to east London, helping prevent sewage entering the River Thames.
Latest news and project updates
Get the latest news and updates on our London Tideway Improvements project.
Frequently asked questions
Read answers to the questions we frequently get asked about the London Tideway Improvements project.
Photo gallery
View a selection of images of our London Tideway Improvements projects and see how the sewers looked over 100 years ago.
Contact us
How to find out more about the London Tideway Improvements.



