My blog seems big on dredging these last few months, but with the government’s DIY dredging schemes recently unveiled the issue has taken on some urgency. Politicians from all sides have been keen to believe that, in the second wettest year on record, floods were caused not so much by lots of rain as natural river morphology
This is the text from a notice placed in our local paper by Stuart Agnew MEP, a farmer and member of UKIP.
“The River Wensum is a special-scientific site and is “protected” by Natural England. Sadly this agency is despoiling the river by dumping thousands of tonnes of stone into it, reducing its ability to discharge into the sea. Having wasted over £10 million on this folly, Natural England compounds the problem by refusing to clear (or allow anyone else to clear) the accumulation of fallen trees, dead vegetation and general debris from the river. Taken Together Natural England’s activities are seriously degrading the river bank, converting adjacent meadows from occasional flood plains into semi-permanent swamp and creating serious implications for ground nesting birds and disease in livestock. Serious changes are needed at this agency.”
The River Wensum flows east through central Norfolk towards Norwich and the Broads. In its upper reaches around Raynham, Fakenham, Guist and Bintree, it is a small chalk-stream. Once upon a time a fishing club existed on this upper river that was the rival of any in Hampshire, tended by full-time keepers and almost as old as the Houghton Club. Once, in the late 1980s when I was trying to find some trout fishing in Norfolk I got in touch with the sole remaining member of that ancient club and he told me that his river, the bit he rented, wasn’t worth the bother nowadays. And when I moved back years later he was still there, a stalwart of the stream hanging on out of loyalty more than anything.
Finally the life-long dreams of that man, to see the restoration of a chalk-stream that has fallen on very hard times, are becoming a reality. The Wensum is a Site of Special Scientific Interest and a European Special Area of Conservation and this status has catalysed some ambitious restoration schemes, not to say a level of environmental protection that the river could surely have done with forty or fifty years ago when it was so comprehensively destroyed by dredging.
You see the reason why that old fishing club dwindled away and the reason why Natural England is “dumping” stone into the Wensum is because more or less the entire length of the stream was dredged in the post-war years, and the legacy of that work was a ruined river, flowing insipidly along the base of an incised and over-wide canal. Chalk-streams all over southern England have been destroyed by dredging, but none more so than the Wensum. It was all done in the name of intensifying the farming effort on the waterside meadows, but the problem with dredging, is that it takes a very crude mechanism and applies it to a very complex system – its like adjusting your TV signal with a hammer. It doesn’t always, or even very often, yield the results intended … but it does always ruin the system.
The other day I had lunch with a university professor who has spent his entire life studying the morphology of rivers, the way they erode and deposit, the complex relationships between flow, slope and meander. At one point he said that there is a lot that we still don’t fully understand about the patterns of their flow. If that is the case, if our foremost fluvial hydrologist feels there is still stuff to learn, how much can we reasonably expect Stuart Agnew to know already?
He writes that dumped stone (gravel in fact) is “reducing the ability of the river to discharge into the sea”. He also writes that Natural England is refusing to allow anyone to clear fallen trees, dead vegetation and general “debris” from the river and finally that this policy is “degrading” the stream.
Clearly one man’s degraded river is another man’s enhanced river. The thousands of tons of gravel are designed to replace those gravel shallows that were taken out by dredging. The retention of fallen trees is a vital part of allowing the river to regenerate a dynamic morphology. Anyone who knows anything about spring-fed rivers knows why Natural England is doing these things, and yet Stuart Agnew calls the restored gravel riffles “folly” and classifies the river’s natural vegetation as “debris”.
We can all cope with a difference of opinion, but Agnew’s argument is so disingenuous. Gravel riffles, no matter what you may think of them, cannot possibly stop a river discharging water into the sea: only abstraction and crop irrigation can do that. Trees are not debris, whereas tractor tyres, old bits of barbed wire and fertiliser bags are. One might even say that excessive nitrates and phosphates and the sediment that washes in off fields are also a kind of debris. And finally I would love to know what species of ground nesting bird is bothered by an un-dredged river: whereas there are many whose populations are troubled by insecticide and the destruction of hedgerows.
Stuart Agnew’s argument sets farming interests against conservation interests, but he never admits as much. Not only that, but I’m sure many farmers would take exception to his arguing in such a polarised way on their behalf. No one could reasonably argue that the intensification of farming which occurred in the post-war years (and in a very different socio-economic climate) did not take its toll on our environment. But we are living in a different world now, one where many farmers and many conservationists feel that it is possible to work together to the same ends: a living, working countryside in which rivers can be rivers and wildlife can thrive.
On this issue Mr Agnew appears to be living in the 1950s. It’s not Natural England which needs to change.