Salmons Brook: Cutting flood risk in Enfield

Flooding poses a threat to people, property and productive farmland, and this risk is increasing due to climate change. Thousands of us live or work in areas threatened by flooding in Greater London.

Parts of the borough of Enfield, north London, have suffered from severe flooding in the past. The Salmons Brook Flood Alleviation Scheme was completed in 2016 at a cost of £15.3 million and protects more than 2500 homes. However, some areas still remain at risk. Now, a natural flood management scheme is being trialled in Enfield to meet that need.


The Salmons Brook Natural Flood Management project

Natural Flood Management (NFM) is the practice of using and enhancing the natural landscape’s ability to store and slow flood waters. Depending on the local area, that could involve planting trees, reducing soil compaction, creating wetlands or leaky dams.

The Salmons Brook NFM project will concentrate on the upper, higher area of the Salmons Brook catchment; north of Enfield Road, through Trent Park and as far as the Ridgeway Road, where there is a large amount of agricultural and park land. This includes the Merryhills Brook and the Leeging Beech Gutter.

A leaky dam: one example of natural flood management
The Salmon’s Brook Catchment

By installing many small NFM interventions appropriate to location, we aim to slow the flow and store water higher in the rural areas of the Salmons Brook catchment, especially in and after periods of heavy rainfall.  Allowing more water to infiltrate into the ground will reduce the amount of water flowing downstream and compliment existing flood defence structures – giving an increase in flood protection to property and infrastructure.

We are turning to land owners, farmers, Friends of Groups, and other interested parties to help us plan and install these interventions. Local communities have valuable local knowledge of the land which statutory organisations can learn from., and we believe that by working together we can create better solutions to flooding issues.


Cutting flood risk and boosting biodiversity

This project (alongside the other three Thames21 is working on) will be intensively monitored and evaluated over the next three years, and the results fed back to DEFRA and the wider public. We aim to demonstrate the costs and benefits of carrying out natural flood management in the urban fringe  – and this will inform best practice nationally.

As well as increasing protection from flooding for at least 20 more properties in Enfield, our vision for the Salmons Brook is that the scheme will help improve the health of the river, the soil, and enhance the value of the green space for wildlife and people.

The Salmons Brook Natural Flood Management programme is a partnership between the London Borough of Enfield Council, the Environment Agency, the Greater London Authority, Brunel University, and Thames21.