Water’s New Mega Reservoir Project Near Abingdon Draws Public Attention
A major new reservoir project planned by Thames Water near Abingdon, Oxfordshire has sparked both interest and concern among local communities. The project, known as the South East Strategic Reservoir Option (SESRO), is expected to become one of the largest reservoirs in the UK, designed to meet the growing water demands of around 15 million people across southern England.
Public Consultation Underway
An 11-week public consultation for the project—estimated to cost between £5.5 billion and £7.5 billion—will continue until 13 January. Thames Water plans to apply for government planning consent in autumn 2026.
According to Leonie Dubois, Head of Engagement at Thames Water, the company aims to ensure transparency by addressing public questions and concerns throughout the consultation period.
Why Such a Large Reservoir?
The proposed reservoir will cover approximately 4.5 square miles (7 sq km), roughly equivalent in size to Gatwick Airport.
Dubois explained that the scale reflects the region’s pressing need for water security, serving customers of Thames Water, Southern Water, and Affinity Water.
She added, “Climate change, population growth, and environmental protection mean we must secure more reliable water resources for the future.”
Could Fixing Leaks Replace the Need for a Reservoir?
Thames Water has faced repeated criticism over its aging infrastructure and leaks, but Dubois said both challenges must be addressed together.
“About 80% of our water strategy focuses on fixing leaks and encouraging customers to use less water,” she said. “However, the remaining 20% requires new infrastructure like this reservoir to ensure long-term resilience.”
Can Thames Water Deliver After Past Controversies?
Earlier this year, Thames Water was fined £122.7 million for violations related to sewage spills and shareholder payments—the largest penalty ever imposed by industry regulator Ofwat.
Dubois acknowledged public skepticism but pointed to the successful delivery of the Thames Tideway Tunnel, completed on time and within budget.
She explained that the same delivery model will be used for the reservoir: private investment funds the construction, which is repaid over 100 years by customers through regulated charges.
Flooding and Safety Concerns
Dubois reassured residents that safety is central to the project’s design.
“Reservoirs in the UK are built under some of the world’s strictest safety legislation,” she said. “This project will follow all national regulations to ensure the structure’s long-term stability and protection against flooding.”
Why Not Use Existing Quarries Instead?
Some residents have questioned whether abandoned quarries across the Thames Valley could serve as water-storage alternatives.
Dubois responded that more than 2,000 options were reviewed during feasibility studies, but the Abingdon site proved most suitable.
“The location’s natural clay is ideal for constructing embankments,” she noted. “It also allows us to draw water from the River Thames during wet months and release it back during drier periods, helping the environment.”
How Will Oxfordshire Benefit?
While the reservoir will supply water to customers across southern England, Oxfordshire will also gain local advantages.
“The project will include green spaces, wildlife corridors, and new habitats,” Dubois said. “Over time, it will become an environmental hub that the community can enjoy while enhancing regional biodiversity.”
Source: Information adapted from BBC News reporting
