The drought-busting scheme would allow water to be moved from the River Severn to the River Thames to safeguard long-term supplies to the South East.

Two options are being explored—either laying a new pipeline or restoring sections of the historic Cotswold canals.

The JV will lead conceptual design work as Thames Water ramps up long-term planning to avert a supply crunch forecast to hit by 2050.

Without new infrastructure, the company is predicting a shortfall of up to 1bn litres of water a day for its 10m customers across London and the Thames Valley.

The project forms a key part of Thames Water’s approved Water Resources Management Plan 2024. Alongside the transfer link, the plan also backs a new reservoir in Oxfordshire and a water recycling plant in West London.

Thames Water said the JV team will develop design and engineering options to ensure the project is “ready to go” if and when construction gets the green light.

No final cost has been confirmed, but industry benchmarks suggest a price tag in the £1bn–£2bn range depending on route and capacity.

The Cotswold canal option could bring added heritage and engineering challenges, but potentially greater environmental and amenity benefits if it stacks up.

The Severn–Thames scheme is one of several nationally significant infrastructure options under investigation to futureproof the UK’s water supply.

Thames Water’s current portfolio of strategic resources options (SRO) projects includes, the South East Strategic Reservoir Option (SESRO), Severn to Thames Transfer (STT), London Water Recycling (LWR) projects, Thames to Affinity Transfer (T2AT) and Thames to Southern Tra transfer (T2ST).