The Environment Agency’s proposal to increase the maximum level of water that can be stored in the Leigh flood storage area has been approved by the Secretary of State for Environment, Food and Rural Affairs.

Image shows three gates located between four pillars stretching across a body of water. The middle gate is partially raised.

Increasing the amount of water that can be held in the Leigh flood storage area will reduce the flood risk on the River Medway and help the county to be resilient to climate change, meaning more properties can be better protected from flooding.

Currently the Environment Agency can legally store water to a maximum level of 28.05 metres above ordnance datum (AOD), as measured at the control structure. Investigations showed that storing water to 28.6 metres AOD will reduce flood risk to more properties.

Increasing the maximum stored water level required permission from the Secretary of State for Environment, Food and Rural Affairs which has now been received.

The Environment Agency can now start work to enable the Leigh flood storage area to store more water, increasing its capacity by nearly a quarter. Enlarging the reservoir also means that a new flood embankment can be constructed in Hildenborough. Once complete, over 1,400 homes and businesses in Tonbridge and Hildenborough will be better protected from flooding.

Sally Harvey, Environment Agency Area Director, Kent, South London and East Sussex, said:

“We are pleased to confirm that the Secretary of State for the Environment, Food and Rural Affairs has approved our application to increase the maximum stored water level in the Leigh flood storage area.

“This decision means that we will now be able to proceed with the Leigh expansion and Hildenborough embankment scheme which will reduce flood risk to over 1,400 homes in Tonbridge and Hildenborough.”

The scheme is being delivered by the Environment Agency in partnership with:

• Kent County Council
• Tonbridge and Malling Borough Council
• South East Local Enterprise Partnership

Cllr Robin Betts, Tonbridge and Malling Borough Council Cabinet member for environment and climate change, said:

“This project is an important step in response to climate change and the increased risk of flooding in the coming years. We know only too well that many homes and businesses have been seriously flooded in the past and the fear of this happening again still exists for many. Once complete the new flood defence measures will offer reassurance to communities and considerable improvement to reduce the risk of flooding in the future.”

Christian Brodie, South East Local Enterprise Partnership Chair, added:

“This is a complex scheme, which has taken time to design, and a strong partnership has been developed with a range of funding sources and key partner agencies. We are pleased to invest in protecting existing homes and businesses, especially Tonbridge high street which is the life blood of the community. But crucially, this scheme will unlock new sites for homes and businesses in strategically important locations for the area and create new jobs and employment space, which is vital for the future economy.”

Funding is through the government’s Flood Defence Grant in Aid (FDGiA), with contributions from Tonbridge and Malling Borough Council, Kent County Council and the South East Local Enterprise Partnership.

The Environment Agency expects to appoint contractors in spring 2022. Work is expected to start on site in summer 2022 and the scheme completed in autumn 2024.

In 1982, the Southern Water Authority completed the Leigh flood storage area (FSA). The FSA reduces the risk of flooding to around 1,200 homes and businesses in Tonbridge and Hildenborough. It works by storing the peak of a flood upstream and releasing it in a controlled manner once the peak has passed.

The flood storage area sits between the villages of Leigh and Penshurst in Kent. When full, it covers approximately 278 hectares. It is formed of a 1.3 kilometre long, 5 metre high earth embankment across the Medway valley. The River Medway itself passes through 3 steel gates built into the embankment. These gates control the amount of water flowing downstream by either letting the river flow normally, or restricting the flow to hold water in the storage area.

The FSA is an ‘online’ storage reservoir, which means that the river is always flowing through it.

Since 2019, the Environment Agency has been working with organisations and landowners who are affected by the proposal. The Environment Agency submitted its application to increase the maximum stored water level to the Secretary of State in early June 2020. A number of objections to the application were submitted to Defra which were unable to be resolved, therefore an inquiry took place between April and May 2021 to allow concerns to be heard.

The Environment Agency responded to the concerns raised by all respondents at the inquiry and the inspector submitted a report with recommendations to the Secretary of State in July 2021.