The reservoir will be an above-ground reservoir which will be contained by walls between about 30 metres high with building starting in 2025. It will cover 4 square miles between the A338 and the A34 north of the railway line. The surface of the water will be covered with solar panels. There will be no space around the reservoir for leisure facilities.
It would hold about 150 million cubic metres of water and be capable of providing 600 million litres per day.
To see the draft map of the new reservoir see this page from the Thames Water Reservoir - Technical Report.
For more background
Since 1975, Thames Water has considered options to increase the water available to London residents and the Abingdon Reservoir between Steventon, East Hanney and Drayton has been one of those options.
In 2010 a Public Enquiry ruled that Thames Water had not proven the case for a reservoir of 100 million cubic metres of water to supply the South East.
The Thames Water's draft Water Resources Management Plan includes building an above-ground reservoir just to the north of us which will be contained by walls between 15 and 25 metres high. That’s about the height of an 8 storey block of flats and higher than anything else in the Vale. It would hold about 150 million million cubic metres of water and be capable of providing 600 million litres per day.
Thames Water are looking to find an additional 660 million litres of water per day by 2080, mostly for London. They have the worst leakage record of all water companies – they were even fined by OFWAT for missing targets. The plan proposes to reduce leakage by 15% by 2025. However, if their leakage per property was as good as that of Southern Water or Anglian Water they could save about 260 million litres per day rather than the 110 million in the plan.
The plan states that by 2025 Thames Water will install a further 700,000 smart meters in customers’ homes, expecting to save 49 million litres of water per day. How much more could be saved after that from the remainder of the 15 million customers? A very conservative estimate would be at least 200 million litres more per day from a further 10% of customers.
By 2025 Thames Water plan to visit nearly 300,000 customers’ homes and businesses to promote water efficiency. This programme is estimated to save 24 million litres of water every day. Once again how much more could be saved in future years from the remainder of the 15 million customers? We think it would be a minimum of 100 million litres per day from an additional 10% of customers.
The plan proposes a new river abstraction scheme at Teddington generating 270 million litres per day. Yet GARD show that, by changing the way the scheme is operated, it could deliver 315 million litres per day. As water use grows the scheme output will grow so could reach 470 million litres per day by 2050 never mind 2080.
The plan will also obtain up to 285 million litres per day from the Beckton Re-use scheme yet GARD see no reason for a limit of less than 350 million litres.
Thames Water also suggest that transferring water from the River Severn could provide 180 million litres per day yet GARD believe that over 300 million litres per day is possible.
Adding all of these things up, they should be able to obtain 1,580 million litres per day. Much more than the 660 million they are looking for and without the financial and environmental cost of building a reservoir.
Action organisation GARD (Group Against Reservoir Development) has battled for years against Thames Water's proposals for an "Abingdon reservoir".
They believe that other options are less costly, less damaging to the environment, less disruptive to local communities and more robust against climate change than the reservoir.
We submitted our objections to the plans pointing out that the reservoir was unnecessary in 2019 and the document can be accessed here ( our submission)