Quoich Dam, River Garry, Scotland
Poutès Dam, River Allier, France
February 13, 2019
Case Study Number: 4
Dam name: Quoich Dam
River name: Garry
AMBER TOOLS: Molecular toolkit (D2.5), MesoHABSIM (D2.6), Ecosystem Services Survey, Social survey (D3.5)


The case study focused on the assessment of ecosystem restoration needs arising from the presence and operation of hydroelectric dams on the River Garry, one of the main tributary rivers within the Ness catchment.

The two dams in the catchment are two of the five hydropower dams comprising the Great Glen Hydropower Scheme, the other three being located on the River Moriston. A very significant reduction in the salmon population of the River Garry following installation of the dams, and the ongoing efforts at mitigating these impacts, prompted the choice of this river system as the case study for applying the barrier impact tools and adaptive management framework developed within AMBER.

Understanding the conservation challenge of this iconic and economically important fish species requires consideration of broader river ecology and connectivity issues, as well as of the social, cultural and economic context.


  • Reduced river connectivity
  • Reduction in salmon population
  • mitigation of barrier impacts


The Ness catchment has been under intense study for the past five years, through AMBER and other initiatives, and there is great potential for a comprehensive adaptive management framework to be developed, bringing together researchers and relevant stakeholders.

AMBER Developed use of the eDNA tool for barrier assessment, carried out drone survey and sediment analysis, implemented MesoHABSIM habitat assessment, placed temperature sensors below barriers in collaboration with the Scotland River Temperature Network initiative, discussed barrier management practices , investigated the historical, cultural and linguistic background for the case study, conducted interviews and workshops with members of the local community and carried out water quality sample collection and analysis in parallel with eDNA water sample collection.


  • Molecular toolkit (D2.5)
  • MeshoHABSIM D2.6, Ecosystem Services Survey (D2.7)
  • Social survey (D3.5)


Within the constraints of the primary focus of the project on the Upper Garry, a catchment-wide approach (the hallmark of any adaptive management strategy) was sought, and the core eDNA analysis of barrier impacts for the Great Glen Hydro Scheme was extended to eDNA analysis of Loch Ness and eDNA analysis of the presence of salmon in the Caledonian Canal.

Flooding due to hydro dams has eliminated 40% of salmon habitat and some of the remaining habitat has been altered in character. Alterations on the Gearr Garry below Quoich Dam are hypothesised to arise from sourcing of compensation flows from the bottom of the reservoir affecting water temperature and chemistry, stream sediments and, thus, habitat quality and biodiversity. No salmon spawning or juveniles now occur in the Gearr Garry and salmon production from the remaining accessible habitat is lower than expected.

This AMBER case study, a partnership with SSE and NDSFB, aims to put the UGSRP, and other initiatives, into a comprehensive biological-socio-economic barrier assessment and ecosystem restoration framework to advance understanding of biodiversity impacts, mitigation needs and optimal management solutions.


Development of the case study was made possible through a variety of different partnerships. At the onset of the project, the RLI partnered with the Ness District Salmon Fishery Board and with Scottish and Southern Energy (SSE), the hydropower company that owns the Great Glen Hydropower Scheme.

As the case study progressed, more partnerships evolved including with the Scotland River Temperature Network initiative, Marine Scotland Science (MSS), the scientific division of Marine Scotland, the Scottish Environmental Protection Agency (SEPA), the National Centre for Gaelic Language and Culture - Samhal Mor Ostaig College, UHI), Glengarry Heritage Centre, the Environmental Research Institute UHI (ERI), the Funaqua consortium, the Loch Ness Hunters project and the Missing Salmon Project.


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