The Cumbrian floods – a bit of context

December 27, 2015

Glenridding in Cumbria

 

All rivers flood occasionally, bursting their banks and inundating the surrounding flood plains. That’s why the flat areas around rivers are called flood plains. In 2000 the UK was required to accept the European Water Framework Directive (EWF) into UK law. Until 2000 and the EU directive, for all of recorded history, it almost went without saying that a watercourse needed to be big enough to take any water that flowed into it even during exceptionally wet periods, otherwise it would overflow and inundate the surrounding land and houses. The alternative to managing the river course would be to abandon any building on river flood plains but this would mean abandoning very large areas that are currently inhabited and a lot of the most fertile farming lands (which are fertile precisely because they are occasionally flooded with nutritious river silt).

When the UK adopted the European Water Framework Directive in 2000 authorities were no longer charged with a duty to prevent flooding. Instead, the emphasis shifted, in a reversal of policy driven by Green ideology, to a primary obligation to achieve ‘good ecological status’ for our national rivers. This is defined as being as close as possible to ‘undisturbed natural conditions’.

Heavily modified waters’, which include rivers dredged or embanked to prevent flooding, cannot, by definition, ever satisfy the terms of the EU directive.

So, in order to comply with the obligations imposed by the EU the UK authorities had to stop dredging and embanking and allow rivers to ‘re-connect with their floodplains’, as the currently fashionable jargon has it.

And to ensure this is done, the obligation to dredge has been shifted from the relevant statutory authority (now the Environment Agency) onto each individual landowner, at the same time making sure there are no public funds for dredging. And any sand and gravel that might be removed is now classed as ‘hazardous waste’ and cannot be deposited to raise the river banks, as it used to be, but has to be carted away.

The climate is changing, as it has always changed, and we have to live with it. But there are sensible and stupid ways to cope with extreme or unusual weather events and changing patterns of weather. The reason the UK authorities have to erect expensive and largely ineffective flood defences, at say Carlisle and Keswick, is because such work does not interfere with the flow of the river in its bed, so it does not infringe the EU Water Framework Directive.

There is EU money available for flood ‘defences’, but none for the very measure that would do some good, namely removing the huge build-up of gravel from the river bed.

sue beardon December 27, 2015

the other problem in Lake District is the use of the uplands primarily for grazing and the removal of trees and other vegetation that would help water to be absorbed on the watersheds rather than flowing into the streams and rivers. And this strategy is of course subsidised. Much as I love to see the little lambs gamboling on the fellsides and the broad sweep of bare mountaintops, it is really time for a new approach. But no one much talks about this because of the vested interests involved.

Tony December 27, 2015

I completely agree, the changes in land use and the spread of sheep grazing to uplands has played a big part in some of the recent flooding episodes.

Julie December 27, 2015

Our town was flooded catastrophically yesterday. All the shop/businesses both schools in the bottom and lots of people’s homes. It’s not possible, however much you dredge and build walls, to contain all the water coming off the hills. We’ve had flood works in the valley, but nothing effective to stop the water running off the Tops. In fact farmers are subsidised to run sheep and the owners of grouse moors are grant aided to destroy the upland habitat, both of which activities increase run off. The big trouble here is age old deforestation, and present day destruction of the blanket bog, by over burning and increasing the number of drainage channels. Giving the river somewhere to go, Todmorden has sluice gates that let the river into the park, does make sense. We’ve had flood walls built up, and they’ve just finished a drainage system where a blockage last time in 2012, caused a huge load of water to come into town. None of that can help that
much in the face of a huge deluge. We need to try and keep the water on the Tops, letting it enter the valley more slowly, it’s the fast reacting streams that rise so fast when they are in spate that’s our big problem. Have a look at http://www.hebdenbridge.co.uk for some idea of what has happened.

Tony December 30, 2015

I hope Hebden is recovering – it sounds ghastly. I came across this interesting article about the history of floods in the Calder Valley.

http://eyeoncalderdale.com/past-floods-in-the-calder-valley

MaryP January 6, 2016

Dredging is sometimes worthwhile, but more often than not it’s a short-term fix that simply passes the problem downstream to the next bottleneck. The move away from dredging was completely sound from a hydrological perspective, and when the EA was bullied into dredging in the wake of the Somerset floods a few years ago it was little reason more than to please the mobs. For some reason I can’t fathom, ignoramuses and the tabloids have decided to politicise dredging. As for “green ideology”, the idea that hydrological engineers are tree-huggers is just laughable. Flood defence and alleviation plans are drawn up based on what will work best given the increasingly limited funds provided. Not much to do with being “green”.

MaryP January 6, 2016

As for the EU WFD, while it does speak of establishing a “good ecological status” but nowhere does it say this should be at mutually exclusive with flood control. (Assuming other goals can be achieved, what harm is done if we attempt to clean up Europe’s rivers, anyway?) And you’re completely wrong to assert that modified channels are incapable of being ecologically beneficial. It just so happens that, as a very general rule, modified channels do not help with basin-wide flooding control – they just pass the problem on – and are also more expensive than the alternatives.

FWIW you’re right that recent floods in Britain aren’t really much to do with climate change. The problems are, for now anyway, much more to do with land use and basin management.

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