In the UK, dredging and desilting have historically been carried out for a broad range of reasons including: to prevent flooding, to drain land, to maintain flows to mills, to abstract sand or gravel for construction or to improve navigation.
When used with other flood risk management measures as part of a catchment based approach dredging and desilting can be effective and justified.
In the majority of cases, they are not the most efficient or sustainable ways of reducing flood risk and may actually increase flood risk to downstream communities.
Dredging and desilting are an important part of the Environment Agency’s river maintenance programme, which is why the EA spent around £5 million on these activities in 2019/20.
This is in addition to the approximately £40 million the EA spend on other works in channels such as weed clearance and blockage removal to keep them flowing.
For more info on the Environment Agency’s approach to dredging, please click here.