Thames Water’s has launched a public consultation on its proposals for a new reservoir near Abingdon in Oxfordshire– the nationally significant infrastructure project that is vital to securing the South East’s future water supply.

Image: illustration showing the view of the proposed Oxfordshire reservoir from the north

The reservoir will secure the future water supply of 15 million people across the South East, supplying Thames Water, Southern Water and Affinity Water customers. Communities across the region are being encouraged to respond.

The National Infrastructure Commission (NIC) says around nine nationally significant water resource projects are needed before 2030 to prepare for anticipated water scarcity, with the findings set out in its second National Infrastructure Assessment. If the Oxfordshire reservoir is given the green light by the Government it is expected to take at least 15 years to complete, with a target opening date of 2040.

The water company has now unveiled a new interim masterplan and design concepts since the autumn 2023 proposals were shared with local communities - a significant amount of design and development work has taken place since then.

Thames Water is part way through the process of preparing designs for the new reservoir and is on track to submit an application for development consent to the Planning Inspectorate in 2026, seeking the powers to build the new reservoir.

Proposals for the reservoir, known as SESRO (South East Strategic Reservoir Option), have been developed in conjunction with Southern Water and Affinity Water, as the reservoir is designed to secure future water supplies for all three company’s customers, a projected 15 million people –including customers in Oxfordshire.

The UK has not built a new reservoir for over 30 years and Thames Water forecasts that across London and the Thames Valley it will need an extra 1 billion litres of water every day by 2050 to protect against the effects of climate change and population growth.

The water company said it is estimated that a severe drought could cost London’s economy alone as much as £500 million a day.

Thames Water said investing in the construction of a new large-scale 150Mm3 reservoir would ensure there is enough water to meet the needs of a growing population into the next century and beyond, while simultaneously protecting against the effects of climate change. More than 19 million people currently live in the South and East of England, and this is forecast to grow by 2 million across London and the Thames Valley by 2050.

Leonie Dubois, Thames Water’s Head of Engagement, Land and Consents said:

“Our water resources are under threat, and the consequences of not investing in a new reservoir could be to the detriment of millions of people, the environment, and the economy, so it’s vital we take action. Investing in SESRO would provide a drought insurance policy for households and businesses right across the South East.

“We have a unique opportunity ahead of us to address the water shortage risk, whilst seizing the chance to create a new, much-loved community resource with leisure, employment and recreational benefits for those that live nearby."

With the reservoir supplying people living far beyond the Oxfordshire border, Thames Water is encouraging individuals and communities across the South East to have their say and to respond to the public consultation.

In addition to assuring water supplies, the reservoir will also help to improve the environment by reducing abstractions from rivers and groundwater sources, including Hampshire’s rare and sensitive chalk streams, the Test and Itchen.

The interim masterplan for SESRO is separated into seven different zones, which the public are being asked to comment on. This includes information about the opportunities for leisure, which could include nature trails, a visitor centre, cafés, a water sports centre, recreational lakes and an education centre.

Feedback is also sought on potential changes to the local road network as part of wider plans to better connect communities to the reservoir and each other. New public rights of way (PROWs) and an enhanced road network would help to ensure that residents in the nearby villages of East Hanney, Steventon, Drayton, Marcham and Garford could all access the new open spaces with ease.

Lee Dance, Organisational Director at Water Resources South East, said:

“It’s important that we make the right decisions for the whole of the region. SESRO is a critical part of the forward-looking programme of investment in our water supplies, set out in WRSE’s regional plan, which will provide water to people across the South East.

“It will provide a new strategic water resource, producing up to 270 million litres of water per day that will be moved across the region, providing additional water supplies to 15 million people.

“It’s critical we have the right infrastructure in place to meet the challenges ahead, including climate change and population growth, and to help us leave more water in our rivers and streams to help protect our region’s environment.”

The SESRO public consultation will be supported by a series of community events which will help visitors to contextualise the visual layout proposed for the reservoir. This will include a new virtual reality headset experience, which enables people to view the reservoir from different vantage points, 3D models and new computed generated images.

Community events will be held in Oxfordshire on the following dates, and those interested in attending are encouraged to register their attendance in advance:

Thursday 27 June, 2pm to 8pm, Sutton Courtenay Village Hall, Sutton Courtenay

Saturday 29 June, 10am to 4pm, Royal British Legion, East Hanney

Monday 1 July, 11am to 5pm, Abingdon Guildhall, Abingdon

Friday 5 July, 11am to 5pm, Loyd Lindsay Rooms, Wantage

Tuesday 9 July, 2pm to 8pm, Didcot Civic Hall, Didcot

Monday 15 July, 2pm to 8pm, Milton Hill House, Steventon

Thursday 18 July, 2pm to 8pm, Marcham Centre, Marcham

The 12-week public consultation is now open and those wishing to respond are invited to submit their feedback by Wednesday, 28 August 2024. All consultation responses will be considered, and feedback will help to inform future design stages. Local communities and stakeholders will be invited to have their say on the revised proposals at a second public consultation in 2025.

Click here for more information about the public consultation and the community events programme