An expanded Leigh Flood Storage Area and new Hildenborough defences, costing £42 million in total, are designed to cut flood risk for 1,870 homes and 575 businesses along the River Medway.
Residents in Tonbridge and Hildenborough now have significantly stronger flood protection after a £42 million scheme officially opened on 29 September 2026. The project expands the Leigh Flood Storage Area — a large earthwork basin that holds back River Medway floodwater during severe storms — and adds a new embankment, pumping station and flood wall in Hildenborough.
The expanded storage area can hold around 7.4 million cubic metres of floodwater. That’s roughly 2,880 Olympic-sized swimming pools. Capacity has grown by about 23 per cent, achieved by raising the maximum water level at the control structure by 55 centimetres, with three new 12.5-tonne gates installed alongside updated lifting, electrical and maintenance systems.
Around 180 Hildenborough homes that flooded in 2013 are expected to benefit directly. A 98-metre embankment, a new pumping station on the Hawden Stream and a sheet-piled wall are designed to stop the River Medway backing up into the village — without pushing flood risk onto anywhere else.
Simon Curd, Flood Risk Manager at the Environment Agency, said the increased storage capacity and improved gate systems were intended to maintain flood-risk reduction for the next 50 years. Councillor Matt Boughton, leader of Tonbridge and Malling Borough Council, described the council’s £500,000 contribution as an investment in local protection and resilience. Jamie Henderson, Kent County Council cabinet member, said the scheme would strengthen resilience across the Medway catchment.
The original Leigh Flood Storage Area opened in 1982 and had been operated 75 times between 1981 and summer 2026. The three-year expansion was completed while the storage area stayed operational throughout — something the Environment Agency described as a complex engineering challenge.
One addition sits outside the flood-defence brief entirely: an eel pass was built into the structure to help protected eels move through it freely.
The scheme was delivered by the Environment Agency in partnership with Kent County Council and Tonbridge and Malling Borough Council, and is intended to protect communities further downstream along the Medway as well.
The Environment Agency will monitor the scheme’s performance over the coming decades, with the defences designed to remain effective for the next 50 years.
£42m flood scheme opens to protect Tonbridge and Hildenborough Quiz
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