The UK's largest water and wastewater company, Thames Water, has announced today, 17 September 2024, that it will make further changes to its proposed Teddington Direct River Abstraction (TDRA) project following consultation feedback from over 2,000 people.

The initial project planned to build a river abstraction shaft upstream of Teddington Weir and to replace the abstracted water with an equal amount of recycled water from new tertiary treatment facilities located in Mogden Sewage by 2033.

Thames Water's initial plans for their TDRA project inlcuded a method of pipe-jacking (Credit: Tilly O'Brien)

Thames Water undertook non-statutory public consultations from 17 October 2023 to 11 December 2023 to seek feedback on the site options for shafts and infrastructure associated with the drought resilience project. 

The new changes respond to feedback from these consultations.

The changes include switching from pipe-jacking to tunnel boring methodology to reduce visual impacts for the local community and re-directing the maintenance flow at Isleworth, which keeps the water recycling process in good working order, using existing infrastructure.

Pipe-jacking is a method of construction that occurs underground and tends to create less noise and dust than other methods.

The project is vital in protecting London's drinking water supply during periods of drought.

Proposals for the project are also outlined in the company's Water Resource Management Plan (WRMP), which recently secured government approval to publish. 

The plan outlines the company's strategy to provide a secure and sustainable water supply for the next 50 years.  

The new infrastructure project is of national significance and would safeguard the drinking water supply to millions of households and businesses across London.

Thames Water forecasts a shortfall of 1 billion litres of water per day by 2050, and it expects to be supplying an additional two million customers in London by that time, up from eight million to ten million.   

 To address the water shortage, Thames Water is also planning record investment in new infrastructure and upgrades to its water network, alongside a commitment to more than halve leakage by 2050 and roll out a further 1.1 million smart meters to customers in the next five years.  

In addition, the company is hosting four community information events throughout October where local people can find out more about the project and design changes.

 Thames Water is accepting interview bids and can offer you time between 2-4pm tomorrow for a pre-record with Leonie Dubois, Head of Engagement, Land and Consents at Thames Water.

The TDRA project would only be used during periods of drought to protect drinking water supplies. 

Water abstracted from the River Thames, upstream of Teddington Weir, would be transferred along a new connecting pipeline to an existing underground tunnel.

Water will be abstracted from the River Thames (Credit: Thames Water)

It would then join the Lee Valley reservoirs in East London, ready to become drinking water. 

 To replenish the river, highly treated recycled water, which has gone through an additional cleaning stage known as 'tertiary treatment' would then be transferred from Mogden sewage treatment works and released into the River Thames at a new discharge location upstream of Teddington Weir.

This would compensate for water taken to help protect the environment and local wildlife. 

Strict rules set by the Environment Agency would govern its operation and the project is designed to ensure there would be no untreated sewage transferred into the river. 

 If approved, the project could provide up to 75 million litres of water each day, sparing London's economy from the effects of a severe drought which could cost as much as £500 million a day. 

This graphic shows the proposed plans for Thames Water's TDRA project (Credit: Thames Water)

 Over 2,300 people responded to Thames Water's non-statutory public consultation in autumn 2023.

To address the public's most pressing concerns about surface-level impacts in Hounslow, Richmond and Kingston, the company announced in July 2024 that it would change the proposed construction method for its new recycled water pipeline. 

The move from pipejacking to tunnel boring significantly reduces visual impacts, as four ventilation shafts and construction compounds are removed from the project design.

This also reduces the number of traffic movements that would have been associated with the original shaft and associated compound sites. 

 As it continues to act on feedback, Thames Water has today set out a solution that would remove the need to continually discharge treated water upstream of Teddington Weir.

It would instead discharge the maintenance flow, which keeps the water recycling process in good working order, at Isleworth, using existing infrastructure.

As a result of this change, treated water would only be discharged upstream of Teddington Weir when the TDRA project is in operation; on average, once every two years. 

 Leonie Dubois said: "We take feedback from communities extremely seriously and are focused on ensuring our design proposals deliver improvements every step of the way.  

 "We have a long way to go before we reach the final design stage, and there will be further opportunities for people to have their say and help shape our proposals."

She continued: "I hope local communities feel reassured that we are listening and acting on their feedback. Minimising impacts and disruption where we can, while protecting future water resources, is our absolute priority." 

Thames Water were previously questioned about their potential plans to build under people's homes in Twickenham.

The water company were also being investigated by water regulator Ofwat in August, who made suggestions for Thames Water to improve its TDRA plans.

Thames Water's community information events will be held on the following dates, and those interested in attending are encouraged to register their attendance in advance:   

•  Tuesday 1 October 2024, 2pm – 7pm, Isleworth Public Hall. 
• Saturday 5 October 2024, 10am – 4pm, St Richards Church, Ham. 
• Wednesday 9 October 2024, 2pm – 8pm, Doubletree by Hilton, Kingston on Thames. 
• Monday 14 October 2024, 2pm– 8pm, York House, Twickenham. 

 Find out more about the TDRA proposals and changes here or visit Teddington Direct River Abstraction (TDRA) - Thames Water Resources Management Plan (thames-wrmp.co.uk). 

Consultation feedback documents and plans will be uploaded from midday onwards today.

Thames Water has robust plans in place to reduce water leakage, and the Government has pledged to support water companies to encourage customers to use less water.

However, the water company does not believe that this is enough and suggests that it must look at new ways to use water more wisely.

It said: "Abstraction, supported by water recycling, is a viable solution to the challenge we face."  

Government policy requires that Thames Water improve its resilience to extreme drought events to 1 in 200 years on average in the 2030s, and 1 in 500 years on average by 2040. 

A severe drought would have extensive economic and social impacts, potentially devastating the environment and affecting the health and quality of life of all those who live and work in the city.