A £42m flood-defence scheme to reduce flood risk in Tonbridge and Hildenborough, Kent, has officially opened, the Environment Agency has announced.
The project expanded the Leigh flood storage area and added new defences at Hildenborough. Environment Agency figures indicate that the combined works will reduce flood risk for about 1,870 homes and 575 businesses along the River Medway and in downstream communities.
Leigh storage capacity increased
The Leigh flood storage area, which was originally completed in 1982, has been enlarged by approximately 23%. The maximum stored-water level at its control structure has been raised by 55cm, increasing capacity to about 7.4Mm³.
Work was carried out over three years while the storage area remained operational. It included the installation of new 12.5t steel gates, lifting and electrical systems, and improved access platforms for maintenance. An eel pass was also installed.
The Environment Agency said the Leigh structure had been used 75 times between 1981 and summer 2026 to manage flood risk.
New defences at Hildenborough
At Hildenborough, the scheme includes a 98m embankment across the floodplain, a new pumping station on the Hawden Stream and a sheet-piled wall to prevent the River Medway backing up into the village.
The measures are intended to protect 180 homes that were affected by flooding in 2013, alongside other properties benefiting from the additional storage capacity at Leigh.
The upgraded facilities are expected to continue reducing flood risk for the next 50 years. Principal contractor VolkerStevin delivered the works, with a trained operator set to monitor conditions around the clock and operate the structure when properties are at risk.
Funding and climate resilience
The scheme cost approximately £42m to design and construct. Funding included £36.6m from Flood Defence Grant in Aid, with additional contributions from Kent County Council, the South East Local Enterprise Partnership, Tonbridge and Malling Borough Council and local levy funding.
The works are estimated to deliver more than £155m in benefits to downstream communities. The Environment Agency said the investment formed part of a broader response to climate change, including more frequent and intense storms and wetter winters.
Environment Agency flood risk manager in Kent Simon Curd said: “This is a major investment in the safety and resilience of communities along the River Medway. The original Leigh flood storage area has protected Tonbridge and Hildenborough for more than 40 years, but climate change means we must be prepared for more severe storms and wetter winters.”
He added: “By increasing the amount of floodwater the area can store by around 23 per cent and improving the reliability of its gates and operating systems, we have made sure this vital structure can continue reducing flood-risk for the next 50 years.”
Leigh is one element of flood-risk management for Tonbridge, alongside town walls and natural floodplains at nearby sports pitches.
Kent County Council cabinet member for environment, coastal regeneration and public health Jamie Henderson said the expanded storage area and Hildenborough defences would provide “greater protection for communities across the Medway catchment” and help safeguard homes and businesses.
Tonbridge and Malling Borough Council leader Matt Boughton said the council had invested £500,000 in the improvement works.