We’re developing proposals for a vital new drought resilience project for London.
We’re inviting communities, customers and stakeholders to share their views on our updated proposals for the Teddington Direct River Abstraction (TDRA) project, a vital drought resilience project for London with key activities – including building tunnels, new structures and shafts – at Mogden Sewage Treatment Works, Ham Playing Fields and near Teddington Weir.
Our statutory consultation will last 10 weeks, running between 17 June to 26 August 2025. The feedback we receive will help us shape our proposals to keep water flowing for the future. You can find everything you need to respond to the consultation on our dedicated TDRA statutory consultation page, including a range of consultation materials which explain our proposals and information about how you can submit your feedback and join our events.
We forecast to supply drinking water to nearly 13 million people by 2050 in the Thames Water area, including over 10 million people in London.
Additionally, with the UK set to experience more extreme heat events, we need to plan ahead to develop new water supply solutions. One of the vital new projects we’re proposing for London is a new river abstraction on the River Thames. This will ensure a reliable water supply during drought periods for residents, businesses, schools, hospitals and other essential services.
Working with Water Resources South East (WRSE), we’ve identified that the Teddington Direct River Abstraction (TDRA) project is the right solution to help protect London from the risk of drought.
We’re proposing a new river abstraction on the River Thames, supported by water recycling. The TDRA project could provide up to 75 million litres of water each day during periods of prolonged dry weather.
Water would be abstracted from the river upstream of Teddington Weir and transferred along a section of new connecting pipeline to an existing underground tunnel to our reservoirs to become drinking water.
The abstracted water would be replaced with recycled water from Mogden Sewage Treatment Works in Isleworth, transferred to the river along a new underground pipeline to an outfall structure upstream of Teddington Weir. This way, we’d be able to access additional supplies of water from the river, while ensuring river levels are maintained and the river environment and ecology protected.
At the heart of this project is the use of water recycling, a tried-and-tested method. Rainwater flows into our lakes, rivers, and streams, as well as being absorbed into the ground. We abstract water from rivers and groundwater sources and treat it in our water treatment works to turn it into top-quality drinking water. We pump that to your taps via our network of 20,000 miles of water pipes.
Once water’s been used, we call it wastewater. It goes down your drain or plughole into our network of sewer pipes. These lead to our sewage treatment works, where we treat the water until it’s clean enough to go back into the rivers.
There would be rules governing when the project could be used. We’d only use it during periods of prolonged dry weather, typically between late summer and late autumn, on an intermittent basis.
In order to keep the treatment facility in good working order at other times, we’d need to run water through it, at a low volume, called a “maintenance flow”.
Over the next couple of years, reflecting on feedback that we receive during our engagement and public consultations, we’ll be developing designs for the proposed tertiary treatment facility, new pipelines and shafts, and intake and outfall structures.
Our proposals for the TDRA project are overseen by RAPID (Regulators’ Alliance for Progressing Infrastructure Development), a consortium of water industry regulators. RAPID has implemented a ‘gated’ regulatory process to ensure that all new strategic water supply options are considered in a fair, consistent and transparent way, and that customers’ money is spent wisely. More information about RAPID and the gated process can be found here, where you'll also find the technical reports, additional information provided to RAPID and feedback from RAPID relating to the project.
In December 2023, the Secretary of State confirmed that the TDRA project should be treated as a development of national significance for which a Development Consent Order (DCO) is required. Details of the Request and the Decision are available on the Defra website.
The DCO process provides opportunities for people to have their say on the proposals before a final decision is made by the Secretary of State. Before formally applying for a DCO, Thames Water must carry out public consultation and consider feedback.
Find out more about the DCO process in our factsheets. More information is also available on the Planning Inspectorate website.
