Keep The Cattle Out!

J

Jonathan Louis

Guest

Keep The Cattle Out!​


By Chris Thomas, Trustee of the Forth Rivers Trust

Virtually all the physical problems our rivers and their riparian margins face are the result of human activity – damming, straightening, dredging, levees, culverting, bank-clearing, climate-change… the list goes on and on. It doesn’t much matter if the river is urban or rural, the effects are much the same. There’s another: poaching by livestock. One might think that cattle having access to rivers is natural and perhaps we think that way: the canon of romantic landscape painting commonly features cattle standing in water in idyllic scenes. And sure it is – if your cattle and rivers are truly wild. But where rivers and riparian margins are already hugely compromised through agriculture, livestock having unrestricted access to water is a major cause of river habitat degradation.

Cattle degrade the riparian margins through erosion induced by trampling the soft sediment of river banks. Channels are widened and shallowed, fine sediment is released excessively into the water course, and, of course, cattle add excessive nutrients through their faeces and urine. Destabilised banks are highly susceptible to erosion during high flows, introducing yet more fine sediment.

The solution is simple: keep the cattle out of the water and away from the immediate riparian margins with fencing. One might think that substantial structures are required for large animals, but a simple post and electrified wire fence will do the trick, even in a field full of excitable and inquisitive bullocks.

Here’s an example…

A few years ago, it was clear that cattle poaching by summer bullock herds along a stretch of the East Lothian River Tyne was causing very significant problems. Banks were destabilized and eroding, and riparian vegetation was virtually non-existent through grazing. River gravel bars were similarly left bare.

Following evidence present by East Lothian Angling Association and the Forth Rivers Trust in early 2017, discussions between the local landowners and SEPA eventually resulted in the installation in 2019 of a very simple post and single wire electric fence, isolating the riparian margins of the Tyne and its tributary, the Coulston Water, from the fields.

Within months, the vegetation on the riparian margins was beginning to recover, and bars were naturally vegetating. Banks began to stabilize. The promising start has been realized over the three years since the fence was installed. In that time, trees are naturally regenerating profusely on lateral and median gravel bars and on the banks – mostly willows and alders. Herbaceous vegetation is capturing sediment during high flows, adding to the volume of the bars and stabilizing them. Banks are much less susceptible to erosion; although some very local erosion is occurring, it is natural, increasingly a function of the river, not induced by the cattle, and it keeps one or two areas clear for the sand martins that nest along this stretch.

In ten years, this stretch of river will be unrecognizable; it will share more of the natural physical character of the river upstream and downstream. Historically, the river has meandered significantly in this stretch. Now, it will do so less. Once the trees build up, the river will be much more shaded and be kept cooler – a significant advantage for aquatic and riparian terrestrial life as climate change increases average temperatures. Habitat will be more abundant and diverse, not only for invertebrates and fish, but also birds and mammals. Trees will begin to add woody debris to the river, which will enhance instream habitat, biologically and physically. Stabilised gravel bars will help maintain a narrow channel, which will be deeper, providing better, cooler and more energetic oxygenated habitat for river life.

In three years, the recovery has been spectacular, boding well for the future. And it all results from installing a simple electric fence to keep the cattle out, and letting the river get on with what it does. While fixing some problems on rivers can be complex and costly, cattle poaching is easily and cheaply sorted.



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Before: Cattle used to cross the Coulston water causing significant damage to the riverbanks and in stream habitat.

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After: riverbanks fenced off and now recovering. instream habitat is improving with less fine sediments entering the river.

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Before: cattle used to enter the river at this point causing significant erosion. During spates, the banking would give way.

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After: Vegetation has grown on the banks now it is excluded from grazing. Erosion has stopped and river more resilient. Willow and alder have started to grow along the river margin.

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Before: cattle used to be able to cross the river and graze the riverbank on the other side. majority of this field was arable so no real loss to grazing area.

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After: Riverbank starting to recover on opposite side of the river now that cattle can’t reach it.

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After: instream bars have developed narrowing an artificially over widened channel creating more flow and habitat diversity.

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After: Side bars starting to vegetate. River was over widened due to the erosion caused by the cattle, and it has now started to recover.

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