11. Floating Pennywort removal, Denham
Aim: Control invasive non-native species
Water body: River Colne
Project description
Programme to remove Floating Pennywort from the Colne at Denham
Floating Pennywort is an invasive species that was first naturalised in 1990 as a result of discarded plants from garden ponds. It can grow up to 20cm per day and may quickly dominate a waterbody forming thick mats and impeding water flow and amenity use. May out-compete native species by blocking out light, causing deoxygenation, obstructing air breathing insects from reaching the water surface and reducing water temperatures.
Project lead: Environment Agency
Project end: 2013
Funding source: Environment Agency
