Widespread dredging could make flooding in some communities worse in the future – not better – according to a new report.
The report, by The Chartered Institution of Water and Environmental Management (CIWEM), suggests solely relying on the method could make some communities more vulnerable to flooding.
Critics have blamed a lack of dredging of the rivers Tone and Parrett for the prolonged flooding on the Somerset Levels.
Deputy Prime Minister Nick Clegg conceded a visit to Langport that the lack of it was a “mistake”.
However, others, such as the RSPB, have questioned its necessity.
The report instead calls for the promotion of sustainable measures of controlling flood crises, rather than what it calls “politically-motivated, knee-jerk reactions”.
Nigel Hendley, CIWEM’s interim chief executive, said flood risk management is an increasingly challenging balance of measures and decisions which require a sound evidence base and expert judgment.
He said: “Dredging can be successfully employed to reduce flood impact under certain conditions, and alongside other measures to protect river ecology, but it can also have serious impacts on downstream flood risk so requires very careful consideration as an option.
“We should seek sustainable alternatives wherever possible and assess these as well as dredging on a site by site basis."
Janina Gray, from the Salmon & Trout Association and chair for the Blueprint for Water coalition, which has endorsed the report, said leadership was essential in tackling the crisis.
She said: “People across the breadth of southern Britain have been swamped by devastating floods.
“These people are looking for solutions and our report shows those encouraging dredging as a simple solution to a complex problem are offering false hope.
“We need the Prime Minister to show leadership not just now but into the future, working with evidence and experts to make the right long-term decisions for people, businesses and wildlife.”
The CIWEM argued that a longer-term, evidence-based policy of land use management is needed to address both flooding and drought at catchment-scale.
Martin Salter, National Campaigns Coordinator at the Angling Trust, said dredging was not a “silver bullet” but that proper catchment management can “make a difference”.
He said: “Rivers establish flood plains for a purpose and we abuse them at our peril. The government also needs to toughen up rather than weaken planning protection for vulnerable floodplains.
“It's worrying hear that there is currently a 30 per cent increase in applications in locations designated as high flood risk by the Environment Agency.”