Flooding poses a threat to people and property, especially in urban river catchments, and this risk is increasing due to climate change. In Greater London, thousands of us live or work in areas threatened by flooding from a range of natural and non-natural sources.
The natural springs and waterways of the upper Silk Stream in Harrow form the headwater catchments of the River Brent. From here water flows downstream through Barnet towards the Welsh Harp reservoir. Flood risk along the whole Silk Stream valley increases downstream as the river grows in size and drains an ever-increasing catchment area.
The upper Brent headwaters 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, NFM techniques could involve creating semi-natural water brakes with large wood, such as leaky dams; wetlands; planting trees; or reducing soil compaction to make it easier for rainwater to infiltrate and be stored in the ground.
The upper Brent headwaters Community NFM project will engage with local people to raise awareness of how flooding happens, and create more flood water storage in the upper part of the Silk Stream catchment at Stanmore Country Park and Bentley Priory in Harrow.
Working closely with the Harrow Nature Conservation Forum and the wardens at each site, we will identify suitable locations to slow down the flow and store water using large wood and materials found within each reserve. These measures will be designed to increase habitat diversity and help deliver existing site management plans.
At agreed locations we will use some of the large wood (logs, tree trunks) generated by habitat management to create naturalised flow check points otherwise known as leaky dams. Using a specially designed Community NFM recording app and the MoRPh citizen science survey method we will work with local people to monitor how the new flood check points are working and check whether habitats are attracting more varied species.