The next stage of investment in London
At Thames Water, we know how much our customers care about London’s rivers - because we do too. That’s why we’ve been working hard to make real improvements, but there’s more to be done.
On 13 March 2025, we announced the next big step in our efforts. An £1.8 billion investment between 2025 and 2030 to improve river health across London. This follows the connection of the Thames Tideway Tunnel, a huge step forward for our waterways.
This new investment comes as the London Tideway plan nears completion. The three key phases of that plan have delivered major upgrades and improvements. Together, these projects have reduced annual sewage overflow volumes by a huge 95%.
Image credit: Crane Valley Partnership
How London’s rivers are already improving
We’ve already made huge strides in protecting the Thames and its tributaries:
Major sewage works upgrades
We're upgrading sewage treatment works (STW) at sites including Beckton and Crossness. These are now preventing 40 million tonnes of sewage entering the river each year.
Lee Tunnel
This scheme tackled the single biggest sewage overflow at Abbey Mills in Newham. Opened in 2016, it's transforming Channelsea Creek into a much healthier ecosystem. A 10lb sea bass was even found there in 2022 - something very rare in central London.
Thames Tideway Tunnel
The £5 billion Thames Tideway Tunnel is now operational. It's diverting 5.5 million tonnes of sewage from the Thames, making a massive impact on water quality.
What's next
We’re not stopping there. Our next phase focuses on smaller rivers and tributaries, such as the Roding, Wandle, Lee, and Brent. We'll be upgrading 26 sewage overflows, ensuring these waterways are cleaner and healthier. As part of our Storm Overflow Reduction Plan, we’ll prioritise actions which tackle surface water. We'll use nature-based solutions where possible, as well as increased storage.
We plan to reduce pollution from private drains illegally connected to surface water sewers. This will improve water quality at 200 surface water outfalls on over 45 watercourses.
We’re also launching a brand-new £20 million River Health and Community Fund. This will support local environmental and community groups. This follows our successful Smarter Water Catchments programme along the River Crane. We’re excited to see even more positive change.
London’s rivers are getting cleaner and healthier. We look forward to announcements on plans for the Thames Valley and Home Counties.
