End of semester field visit – the re-watered River Garry (Perthshire)

The exams are all finished now, so what better than a field visit to revisit some of the key themes of the semester just passed?  More so when there’s the offer of a guided tour from Scottish & Southern Energy’s biologist Dr Alasdair Stephen, and a shining yellow thing in the sky all day long!

Struan Weir photo
Visiting Struan Weir – now mostly removed to once again permit fish to ascend the Garry above its confluence with the Errochty Water.

The focus for our day was the River Garry, which has been dry for most of the past 60 years thanks to a diversion of the upper river to supply water to Loch Errochty, for renewable power generation at Errochty Power station.  SSE concluded an agreement with the Scottish Environment Protection Agency (SEPA) and the Tay District Salmon Fishery Board to allow the new provision of environmental flows, commencing in autumn 2017.  We spent some time in class talking about in-stream habitat and ecosystems: the role of water depths, velocities and wetted perimeter.  The works allow SSE to put the demands of the Water Framework Directive into practice.

Calvine Falls Photo
Falls below Calvine. If you were a salmon, would you be able to jump that? At least now the fish get the chance – and observations show that salmon are indeed migrating beyond this natural barrier.

But the trip soon revealed that a lot more was required than ‘just’ hydraulic and ecological modelling.  Our discussion turned to questions of scientific evidence, stakeholder benefits, partnership working, people as much as policy, and balancing acts – how best to protect the local freshwater environment without causing unnecessary losses of generation water?

River Garry sediment downstream of intake
Heavily Modified! Sediment in the foreground has been excavated from the headpond above the Garry Intake, and is deposited adjacent to the river to allow sediment to be entrained in spates – providing a source of suitable bed sediment downstream.

A few photos here give a flavour of the day.  Many thanks, Alasdair, for sharing your knowledge, many experiences and insights.

Loch Garry Weir
Dry river bed at the outlet (east end) of Loch Garry. This is the next phase of the Garry restoration project, to provide a continuous environmental flow here.
Loch Garry inflow - east end
The flow of the Allt Coire Luidhearnaidh joins the Allt Dubhaig and normally flows west into Loch Garry. These watercourses will provide the water planned to re-water the upper Garry.
Sediment traps
Sediment traps on the Allt Coire Luidhearnaidh. Why?

Read more about the Garry re-watering here from:

Garry below Calvine: photo
River Garry downstream of Calvine. The bed is dominated by bedrock. Has it always been like that, or do we see here a result of sediment starvation?
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2 thoughts on “End of semester field visit – the re-watered River Garry (Perthshire)”

  1. An informative day out which gave us (students aspiring to hydrology involved environmental work) the opportunity to get an insight into professional inter-institutional relationships and trust which is needed for environmental collaborations. You can’t learn that in a lecture theatre. It was also interesting and inspiring to see one of the most successful projects in Scottish environmental history, i have found field visits like this to be fantastic, thanks Andrew.

  2. A very interesting field trip with great insights into the project to re-water The river Garry.

    Being on site and being talked through parts of the project and the relationship between all those involved was a great learning experience.

    It also showed that the needs of government, private land, owners, and SSE can all be negotiated for a good outcome for the environment.

    Go on every field trip you can as reading or viewing pictures is no substitute for in the field experience.

    A big thank you to Dr Black for the opportunity to go with him and Alisdair from SSE for explaining the project and answering our questions.

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