Protecting London’s new Silvertown Tunnel from flooding
London’s new Silvertown Tunnel is a critical response to one of the city’s most pressing challenges: chronic congestion. The new crossing eases pressure on traffic-clogged routes, improving reliability and public transport access. But keeping the tunnel dry is just as important as keeping traffic moving. Xylem helped protect this vital connection with a custom flood prevention system, installing six pumping stations to collect and return rainwater safely back to the Thames River.
The Silvertown Tunnel officially opened in April 2025, providing a critical new river crossing underneath the River Thames. Located between North Greenwich and Silvertown, the 1.4-kilometer, twin-bore road tunnel includes two lanes in each direction, with dedicated space for public buses.
The new tunnel eases pressure on the aging Blackwall Tunnel, which opened back in 1897 and wasn’t built for today’s traffic.
By adding another way to cross the river, the Silvertown Tunnel makes journeys more reliable for commuters, businesses, and public transport users across East and Southeast London.
The Riverlinx consortium developed this major infrastructure project for Transport for London (TfL). The mission was not only to improve traffic flow but also to boost safety, sustainability, and long-term maintenance. TfL brought in Xylem to design and deliver a flood management solution for the tunnel that quickly removed rainfall and runoff.
Managing flood risk in a busy urban tunnel
As with any tunnel, water presents a constant threat. In this case, the large road surface areas leading to the tunnel entrances act as catchment zones for heavy rain and runoff. Without proper drainage and pumping, this water could enter the tunnel and cause serious delays, damage, or safety hazards.
The varying levels of water buildup across multiple low points within and around the tunnel added complexity. Any pumping solution needed to be robust, reliable, and engineered to run continuously without interruption – no matter the weather.
Six pumping stations with Flygt technology
To tackle this challenge, Xylem designed and installed six pumping stations along the tunnel route – four inside and two outside. Each station was equipped with Flygt submersible pumps suited to different parts of the tunnel, including NZ 3301 (70kW), NP 3171 (18.5kW), and NP 3085 (1.3kW) models.
The pumps take turns running and support each other as needed, so there's always enough power to handle rising water levels. This setup helps prevent flooding by making sure water is removed quickly, even during heavy rain.
Beyond just equipment supply, Xylem handled the full project scope: from design and installation to commissioning and pressure testing. The team also installed over one kilometer of 300mm ductile iron pipework to transport the pumped water, safely returning it to the Thames after filtration.
Supporting the future of London’s transport
With Xylem’s flood prevention system, the Silvertown Tunnel can stay open and dry, even during the heaviest rainstorms. The pumps quickly collect and remove water, keeping traffic flowing and protecting one of London’s most important new transport routes.
As a trusted partner to infrastructure projects around the world, Xylem brings deep expertise in water management to help cities build safely and sustainably.
In Silvertown, that means reducing the risk of flooding, delays, and costly maintenance – while supporting the long-term resilience of London’s transport network.
Learn more about Xylem’s pumping solutions and services supporting infrastructure around the world.