Summary
- Dredging has a limited but important role in flood management and drainage, but it should be used only where there is a clear need and not as the default solution.
- Dredging can provide short-term local benefits, but it is expensive, requires ongoing maintenance, and does not address the underlying causes of flooding or sediment build-up.
- Dredging can have a significant environmental impact, including damage to river habitats, poorer water quality, increased erosion, and greater flood risk downstream. Flooding and sedimentation are best addressed by tackling the causes at source through better land management and reducing soil erosion.
- The Rivers Trust recognises that dredging will continue to be necessary in some specific situations, but it should not be relied upon as the primary response to flooding and sedimentation.
- Long-term resilience depends on tackling problems at their source through catchment-scale planning, nature-based solutions and sustainable land and water management.
Our position on dredging
Learn more about dredging for flood management and agriculture and our position in our full statement.
FAQs
Why doesn’t the Rivers Trust support widespread dredging?
We recognise that dredging can reduce flood risk in some locations and may be necessary in specific circumstance. However, it is generally a short-term measure that requires ongoing maintenance and does not address the root causes of flooding or sediment build-up. We advocate for longer-term, catchment-scale solutions that are more sustainable and cost-effective.
Is the Rivers Trust against dredging altogether?
No. We recognise that dredging has an important role in some locations, particularly in low-lying, heavily-modified drainage systems where maintaining water conveyance is essential. We acknowledge it can be part of a long-term plan where there is clear evidence it is the most appropriate solution and where environmental impacts have been carefully assessed.
Does dredging reduce flooding?
It can, but usually only in the short term and often only in the immediate area where it takes place. By increasing the speed at which water moves downstream, dredging can increase flood risk elsewhere. Long-term flood resilience is better achieved by slowing water across the landscape and increasing natural water storage.
What are the environmental impacts of dredging?
Dredging can:
- Damage fish spawning grounds and aquatic habitats.
- Disturb wildlife and river ecosystems.
- Release pollutants trapped in sediments.
- Increase erosion and riverbank instability.
These impacts need to be carefully considered before dredging takes place.
What does the Rivers Trust support instead of dredging?
We support integrated catchment management, combining:
- Natural flood management.
- Wetland and floodplain restoration.
- Healthy soil and regenerative farming.
- Buffer strip creation.
- Improved soil management to reduce erosion.
These measures help reduce flooding while also improving water quality, biodiversity and climate resilience.