UK: Dredging Is Not the Solution, WWT Says

As flood waters recede, Worcestershire Wildlife Trust (WWT) is calling for long-term sustainable solutions to deal with flooding for both people and for wildlife.

Peter Case, Water and Wetlands Officer for the Trust, explained: “Our sympathy is with those individuals and local communities that have been affected by the recent flood events and we are very supportive of the fantastic effort made by the Environment Agency and others at this difficult time.

“It is vital to build resilience into Worcestershire’s landscape if this is the sort of weather we can expect more frequently.”

The Trust acknowledges that dredging in appropriate places is effective but rejects that this should be seen as a panacea to flooding.

A recent, independently produced, report by the Chartered Institute for Water and Environmental Management (CIWEM) documents how dredging sections of a river will move water faster downstream, compounding the flood issue elsewhere. A healthy river works to move sediment along; dredging can increase siltation by encouraging the river to deposit material elsewhere as it tries to reach equilibrium.

Peter continued: “It is widely recognised that dredging a river to make it deeper won’t stop flooding – the volume of water is too great to be contained in the channel. If we simply dredge we run the risk of further isolating rivers from their floodplains and making them solely a way of conveying water from A to B.

“We also shouldn’t forget that trees and other bankside vegetation will help alleviate flooding by stabilising the riverside banks and helping to reduce erosion.

“Dredging and siltation isn’t great for people and it’s bad news for wildlife too – it all impacts negatively on fish, vegetation and waterborne creatures.”

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Press Release, February 24, 2014