David Cameron's dredging pledge 'a cruel offer of false hope'

David Cameron has been accused of indulging in amateur environmental science as a hard-hitting new report says his promise to step up river dredging is offering flood victims “a cruel offer of false hope”.

A report out Friday concludes that, in most cases, dredging does little to alleviate flooding in the immediate area – and can exacerbate flooding of communities downstream.

This is in stark contrast to the Prime Minister’s criticism of the Environment Agency for opposing dredging. Mr Cameron has pledged to spend tens of millions of pounds clearing silt from rivers to reduce flooding by speeding up their flow, and told BBC Radio Berkshire on Thursday: “Expert bodies have decided [dredging] should not be part of the picture. Clearly it needs to be a big part of the picture in the future.”

Nigel Hendley, of The Chartered Institution of Water and Environmental Management, which produced the report, said on Thursday: “Dredging can be successfully employed to reduce flood impact under certain conditions… but it can also have serious impacts on downstream flood risk so requires very careful consideration as an option,”

The report was commissioned by 13 wildlife organisations including the Angling Trust, RSPB and Buglife. It found that the amount of extra water a river can carry away following dredging is so small compared to the volume of water pouring into it that the banks would still become inundated if the technique was employed. Furthermore, the increased volume of water flowing away from the area means communities further down the river have to contend with even more water.

Martin Salter, a former Labour MP who now serves as national campaigns coordinator at the Angling Trust, said: “The Prime Minister should start looking at the evidence and stop behaving like an armchair hydrologist in search of a soundbite.” Janina Gray, of the Salmon & Trout Association added: “Our report shows those people encouraging dredging as a simple solution to a complex problem are offering false hope.”

Environment Agency figures show that about 1.1 billion tonnes – or 242 billion gallons – of water has cascaded through the Windsor stretch of the Thames since 1 January – more than four times the norm. Opponents of dredging argue that even a sizeable 20 to 30 per cent increase in the river’s capacity in the Upper Thames through dredging would make little difference, while piling an extra 100 million to 150 million gallons of water a day on to Lower Thames communities.