What is the Thames Tideway Tunnel?

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We’re working to improve the water and sewer networks across London and the Thames Valley to make sure they can cope with current and future demands.

Thames Tideway Tunnel route (image courtesy of Tideway)

Thames Tideway Tunnel

One of the biggest projects to improve and future-proof our network is the Thames Tideway Tunnel (also known as the “super sewer”).

This is a 15-mile-long sewer, the width of three London buses, which is being bored under the River Thames. It’s designed to prevent millions of tonnes of sewage from overflowing into the tidal Thames every year from the capital’s overloaded Victorian sewer system.

The new tunnel will pipe sewage to our Beckton works. After that, we’ll return clean water to the environment – and use the sewage waste to generate more renewable energy too.

At 15 miles long, seven metres wide and up to 65 metres deep, the Thames Tideway Tunnel is the biggest infrastructure project ever undertaken by the UK water industry. Most of the engineering work is being carried out by a separate company independent to Thames Water, known as Tideway, who will finish construction by 2024, and hand over the tunnel for Thames Water to operate.

It’s all part of our long-term plan to future-proof London’s whole water and sewerage system, which also includes the new Lee Tunnel, upgraded treatment works and Sustainable Drainage Systems (SuDS).

The Thames Tideway Tunnel is designed to serve the needs of Thames Water customers for many generations to come.