Tuesday, 29 November 2011

Be careful what you wish for...

It's poured down here ever since I wrote yesterday's blog, welcoming the rain. I went out first thing this morning to see how the Allan Water was looking. I found it had morphed from Mr Hyde to Gargantua, consuming the fields on either side of its banks to become a vast, writhing body of water at least a quarter of a mile wide.

In the submerged field opposite there were a group of black-faced sheep marooned on two small hummocks of higher ground, but still up to their bellies in mud-thick water. They were so densely huddled together that at a distance I had thought they were a couple of large straw bales that had been washed down the river. It took the binoculars to pick out their bedraggled bodies and anxious fidgetting. The river must have risen pretty swiftly to trap them like that.

When I got back to the house I phoned a friend who knows the farmer, and caught him just as he was driving off to let him know. So later this morning I went back to see if the sheep had been rescued. It was still raining. A small digger and quad bike were down by the edge of the water. Most of the sheep were safely back on higher ground, still clinging together as if traumatised by their ordeal.

But I arrived just in time to see a small drama unfold. Black-faced sheep are, apparently, very flighty, and one sheep had obviously taken fright when the farmer and his helpers had tried to coax it off the rapidly disappearing island. It was heading towards me, struggling along the submerged fenceline on the opposite bank. It seemed to be pushed along by the flow, getting deeper into the water as it went, until it was actually swimming, its heavy fleece dragging it down. Someone - I guessed the farmer - was following it at the lapping edge of the water, trying to turn it back, until eventually he was forced to wade across to it, thigh deep in the roiling water. The pair disappeared behind trees for a few heartstopping moments, before the farmer reappeared gripping the sheep by the horn with one hand, while picking his way along the fence line with a stout stick in the other. It looked a dangerous place to be. I was glad when he managed to lift the sheep over the fence before climbing over himself and wading back to the 'shore'. I heard later that one of the sheep had been drowned, and I felt guilty for wishing for the rain.

Of course flooding is a natural part of the seasonal cycle. It's vital for wetland birds and plants. It has been used for centuries by farmers for water meadows. What's not natural is the speed with which water courses like the Allan Water now change from gentle lowland river to destructive tide. The Scottish Environmental Protection Agency (SEPA) can explain why better than I:

'Alterations to the course and morphology of the River Allan and its tributaries have changed its character. These have changed the natural dynamics of the watercourse, in many cases affecting the ecological processes important for sustaining biodiversity. In places, alterations to the catchment and watercourses have increased the rate at which rainfall reaches the river by increasing the speed of overland flow. This is a common aim of land drainage practices. However this results in higher river levels. Additionally straightening and dredging of channels associated with improvements to agricultural production on floodplains and the construction and upgrade of transport links. Combined, these changes result in fast accumulation of water in low gradient areas or where flow is constricted including both rural and urban areas such as Greenloaning, Dunblane and Bridge of Allan.'

Basically, we've been mucking around with the land surrounding the river for agricultural and commercial gain, and the river has bitten back, affecting farmers further down the line, and making flooding much more likely in properties in towns and villages built before the 'improvements' were made.

SEPA has been working with the Centre for River EcoSysyems Science (CRESS) at Stirling University on a scoping exercise to establish the best way to rectify the chaos this has caused. Unsurprisingly solutions include putting back the trees, damming up the drains, restoring the channel meanders and allowing the river to flood again where it won't damage properties. It's great that they are looking at ways to redress the problem - let's hope they can translate the planning into action.

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