Holding Objection (Part 3) – Technical Objection Summary

Ness DSFB object to the Glen Earrach Pumped Storage Hydro/ ECU00005121 scheme on the following grounds:

1. Identification of multiple pathways by which wild Atlantic salmon migrating through Loch Ness would be adversely impacted, including, but not limited to those emanating from the River Moriston SAC. The pathways identified included, attraction towards intakes during pumping, disruption of the natural hydrology of Loch Ness, depletion of the invertebrate ecology of Loch Ness, and proposed changes to water management in Loch Ness and River Ness.

2. Harmful changes in water management in Loch Ness, and the River Ness, arising from the proposed modifications to Dochfour Weir

3. The impoverishment of the shoreline invertebrate ecology of Loch Ness due to the rapid and frequent drawdown of water levels in Loch Ness. This impact is considered to be adverse, significant, and unmitigable.

4. Wider ecological impacts consequential to a reduction in the Ness salmon population, including impacts of the presence of Bottlenose dolphins predating on returning wild Atlantic salmon at Chanonry Point, Moray Firth.

5. Construction impacts, including noise from blasting.

6. Limitations of the 2025 Loch Ness smolt tracking study

7. Concerns over the regulation of multiple PSH and the impact of frequent Loch Ness water level drawdowns.

8. The visual impact of the industrialisation of the west shores of Loch Ness and its proximity to the A82.

9. The presence of alternative locations and technologies to provide the storage required.

Introduction

The Ness District Salmon Fishery Board is an organisation established under statute and is responsible for the protection and enhancement of salmon and sea trout fisheries in the Ness District. It was constituted under the 1862 and 1868 Salmon Fisheries Legislation, subsequently amended in the Salmon Act 1986 and the Salmon Conservation (Scotland) Act 2001 and more recently amalgamated under the Salmon and Freshwater Fisheries (Consolidation) (Scotland) Act 2003. The Ness DSFB is a member of Fishery Management Scotland, the representative body for Scotland’s District Salmon Fishery Boards.

The Ness DSFB District covers the entire Ness catchment, as well as coastal burns on the north and south shores of the Inner Moray Firth. The District limits extend eastwards from Kessock, to the boundary with the Nairn DSFB district to the east of Ardersier. The Ness DSFB are involved in a number of conservation projects within the catchment including the Upper Garry Salmon Restoration Project.

Ness DSFB staff report to an elected Board comprised of proprietors, mandates and representatives from external organisations.

In order to better inform its response to the Kemp PSH Ness DSFB commissioned an expert opinion by the Norwegian Institute of Nature Research (NINA). A report titled ‘A review of the environmental impacts of proposed pumped storage hydropower projects in Loch Ness: implications for migrating Atlantic salmon’ was published in August 2023, and the issues identified in the report informs our response to the Glen Earrach pump storage hydro application.

Ness DSFB also commissioned a report by MTS-CFD to investigate the hydrological impact of multiple PSH schemes on Loch Ness.

In June 2024, Ness DSFB submitted a petition to the Scottish Government Citizen Participation and Public Petitions Committee titled “Halt any further pump storage hydro schemes on Scottish lochs holding wild Atlantic salmon” with the following sub-text “Calling on the Scottish Parliament to urge the Scottish Government to create a moratorium on any further development of pump storage hydro operations on Scottish lochs holding wild Atlantic salmon until the impact of such developments on wild Atlantic salmon migrations is understood”. The Petitions Committee considered the petition on November 2024, when the committee kept the petition open and agreed to write to relevant PSH developers, asking for information regarding research they have commissioned on the interaction between PSH and wild Atlantic salmon. The committee also agreed to contact the UNESCO Centre for Water Law for information on the wider context of PSH developments.

In due course all developers, and the UNESCO Centre for Water Law, with the notable exception of Statera, responded to the Petitions Committee. None of the developers were able to highlight any new research findings regarding the impact of PSH on Wild Atlantic salmon, with only Glen Earrach able to detail the proposed 2025 smolt tracking study in Loch Ness. This paucity of research by the major developers of PSH highlights the knowledge gaps identified by NINA and Ness DSFB regarding PSH in sensitive environments such as Loch Ness. Other countries have taken a more strategic approach to PSH with Canada and USA seeking to only develop closed-loop PSH schemes due to environmental concerns (Stantec, 2023 & Hydrowires, 2022).

Qualifying statement

A number of issues arising from recent planning application hearings are of relevance to the Glen Earrach pump storage application.

Firstly, there is no organisation dedicated to the protection of Loch Ness. Considering the significance of Loch Ness as an iconic destination, it remains remarkably unprotected from potentially harmful developments. Existing public bodies appear to be conflicted or under-resourced to provide such a role. The establishment of a National Park Authority, covering Loch Ness, would potentially provide the protection it deserves, but that seems an unlikely prospect at present. In the absence of any appropriate public body, it is essential that apposite responses to applications such as this receive the appropriate weighting by decision makers.

Secondly, when it comes to planning concerns, NatureScot do not represent all of Scotland’s nature, as is often assumed, and sometimes stated by NatureScot. Regarding planning matters the circumstances where they will respond are quite narrowly defined, see How and when to consult NatureScot Checklist | NatureScot. Developments affecting protected sites will receive a response, but protected species are covered mainly through the provision of standing advice.

Given the narrow focus of NatureScot’s advice, planners should be prepared to give more weight to comments and responses from appropriate non-statutory organisations or individuals, otherwise huge swathes of Scotland’s nature and biodiversity are effectively ignored.

Thirdly, the system of Environmental Impact Assessment Reporting adopted in the UK involves developers commissioning consultants to produce the various reports required. Such a system will inevitably tend to favour the developer/applicant. Consultant reports usually appear credible, and are presented as the expert view, which can carry considerable weight amongst those whose role it is to assess applications. It is the view of Ness DSFB that consultants commissioned to produce these reports rarely see the full picture, often perpetuate errors, can provide distorted and contrived arguments to suit a particular narrative, and lack access to reports available to local staff tasked with responding to applications, such as this. It is essential that planners and regulators tasked with considering complex applications such as this have access to specialist staff who can provide the level of scrutiny required for every aspect of an application.

Wild Atlantic salmon context

The policy framework and context for wild Atlantic salmon has changed in recent years, significantly since 2021, when Red John PSH was granted planning permission on Loch Ness. At the same time Scottish salmon rod catches have declined, with the 2023 rod catch the lowest on record.

In December 2023, the IUCN (International Union for the Conservation of Nature) assessed wild Atlantic salmon in most of Great Britain, including within the Ness catchment, as ‘endangered’, as a result of a 30-50% decline in British populations since 2006 and a 50-80% projected decline between 2010-2025.The previous assessment classed the UK population as being “at least risk”. Among the threats to the species highlighted by IUCN are ‘natural system modifications’, including dams and water management/use, and other ecosystem modifications.

In 2022, the Scottish Government published its Scottish Wild Salmon Strategy, which sets out the vision, objectives and priority themes to ensure the protection and recovery of Scottish Atlantic wild salmon populations. This was followed by the Wild salmon strategy: implementation plan 2023 to 2028 which included themed actions such as Improving the condition of rivers and giving salmon free access to cold, clean water.

At the end of 2022, the Scottish Government published its draft Biodiversity strategy to 2045: tackling the nature emergency which sets out a clear ambition for Scotland to be Nature Positive by 2030, and to have restored and regenerated biodiversity across the country by 2045.

The IUCN designation, the Scottish Wild Salmon strategy, and Implementation plan, and the ambitious aspirations of the Biodiversity Strategy defines the context within which all applications now have to be considered.

Grounds for objection

1. Impact on Wild Atlantic Salmon smolt migration

Ness DSFB have identified the following pathways by which the migration of wild Atlantic salmon smolts may be affected by the development of ever larger PSH schemes on Loch Ness. The cumulative impact of multiple PSH developments will magnify these impacts. These pathways are listed and discussed below:

• Attraction towards screened intakes

• Disruption to the natural hydrology of the loch by cyclical pumping and generation

• Impoverishment of the shoreline ecology

• Changes in water management due to modifications to Dochfour Weir

1.1 Attraction towards screened PSH intakes

In recent years advances in tracking technology have highlighted the difficulties wild Atlantic salmon smolts encounter as they travel through lochs and lakes seeking the outlet on the migration to the sea. Even in natural waterbodies the mortality rate amongst salmon smolts as they migrate downstream through still waters can be high. Ness DSFB are concerned that salmon smolts migrating past the zone of influence of Glen Earrach PSH, and other PSH schemes on Loch Ness, will be attracted to the intakes during pumping, even with screening. Salmon smolts respond to environmental cues via rheotactic sensory capabilities, which means they will be drawn to a flow of water out of Loch Ness. As far as a salmon smolt, seeking the exit from Loch Ness, is concerned, PSH offtakes will function as a proxy for the River Ness. Ness DSFB are concerned that if salmon smolts are attracted towards PSH offtakes, they will be delayed, and potentially subject to enhanced predation by the resident populations of trout, pike, fish eating birds, or mammals such as otters and seals. The presence of multiple PSH intakes around the shores of Loch Ness will only accentuate the problem.

To put the potential for this attraction to PSH intakes to occur in context, the mean flow down the River Ness during the smolt run period (mid-April to Mid-June) in the years 2019 to 2022 was 61.4m3/s (mean annual range 35.1 to 138.8m3/s). The volume of water pumped out of Loch Ness by Glen Earrch PSH would be 382m3/s during the abstraction phase. In addition, the existing Foyers scheme pumps at 167m3/s, the consented Loch na Cathrach scheme will pump at 170m3/s and the proposed Loch Kemp scheme has a pumping volume of 370m3/s. When pumping synchronously, the cumulative pumping rate of these schemes would be 8 to 31 times greater than typically present in the outflowing River Ness during the smolt run period. The cumulative volume of water pumped out of Loch Ness by the four PSH schemes would be 1089m3/s, orders of magnitude higher than the typical, natural flow in the River Ness during the smolt run period.

Glen Earrach proposes to install screens, 53m out from the intakes, in order to avoid impingement of smolts on the screens. The volume of water abstracted during pumping will still act as an attractant to migrating smolts, with inevitable delays and enhanced predation. An additional negative factor is that Glen Earrach PSH will be situated 7.5km from the mouth of the River Moriston SAC, and on the same shoreline that salmon smolts from the Moriston may be expected to take on their migration towards the sea.

Glen Earrach commissioned a smolt tracking study in Loch Ness in spring 2025. The aims of the study were “The proposed study aims to assess Atlantic salmon smolt passage through Loch Ness and at Ness Weir / Caledonian Canal before construction of the Development and the two other proposed developments. Specific project objectives are to use acoustic telemetry to assess route, passage efficiency, and delay of downstream migrating smolts in the area of the Development and Ness Weir, including Loch Ness, Loch Dochfour, River Ness, and the Caledonian Canal”. 200 Atlantic salmon smolts migrating into and through Loch Ness were tagged with acoustic tags. These smolts emanated from the River Morison and River Garry, with the tagged Moriston smolts released at Moriston Estuary and the Garry smolts released into the River Oich. Receiver arrays were placed in Loch Ness, at the smolt entry points, and in four lines across Loch Ness in the vicinity of Foyers, as well as around the Dochfour river/canal bifurcation.

The report from this study is still awaited but it appears that Foyers PSH was not operational, or operating with limited capacity only, during the period of the 2025 smolt migration. This study may increase our understanding of salmon smolts migration routes through Loch Ness, but it unlikely to provide any meaningful information on the impact of PSH. It has always been the position of the Ness DSFB that no further PSH schemes should be permitted in lochs supporting an Atlantic Salmon population until the impact of offtakes on smolt migration are understood.

Due to the lack of knowledge regarding the effect of PSH intakes on migrating salmon smolts, the impact on wild Ness Salmon smolts, and in particular those emanating from the River Moriston SAC is considered adverse and significant.

1.2. Disruption to the natural hydrology of Loch Ness

Loch Ness is a long, linear loch aligned with the prevailing SW winds. Loch Ness is a well-studied loch and in the early years of the 20th century was at the centre of the emerging science of Limnology. Consequently, the natural hydrology of Loch Ness is relatively well understood. The loch is classed as being a warm monomictic waterbody with thermal stratification in the summer and complete mixing during the winter when the entire loch becomes isothermal. What is not understood is the impact of large-scale, cyclical lateral movements of water entering and leaving the loch in the upper 10m+, on the natural hydrology of the loch.

Pumping by PSH will result in large scale abstraction of water from Loch Ness, into higher altitude upper reservoirs, where it will be stored for varying periods of time until released back into Loch Ness during generation. These movements could affect physical attributes of the water such as temperature. During periods of sunny weather water temperatures will be warmed by direct thermal transfer from exposed, rocky shorelines of upper reservoirs, conversely this water could be exposed to cooling during the winter. Unquantified, thermal inputs from frictional losses during pumping and generation will also occur.

The cumulative maximum impact on water levels arising from Foyers, Loch na Cathrach and Loch Kemp PSH, is a rise and fall in water levels of 0.72m, potentially more if the capacity of the consented Loch na Cathrach scheme is increased. The addition of a further 0.52cm drawdown from Glen Earrach means that the maximum drawdown of Loch Ness could be 1.24m. That in itself would be extremely harmful to the ecology and amenity of Loch Ness but the consequences of the water movements associated with that drawdown on the hydrology of Loch Ness are less well understood.

In order to investigate this issue Ness DSFB commissioned MTS-CFD Limited to develop a hydrodynamic model of Loch Ness to assess the effects of four pumped storage hydroelectric (PSH) schemes on the loch’s ecosystem (Scanlon & Stickland, 2025). A generating and pumping schedule was applied in which water was either delivered to or pumped from the loch over a 48-hour time period, with environmental parameters representative of May conditions applied. The model was run for a 48-hour period and the results show that the sequence of water extraction and delivery can disturb the vertical temperature profile of the thermocline as deeper, colder water is entrained into the warmer upper layers. Animations were provided which highlighted the horizontal, and vertical scale of water movements.

The results of this study were striking, including the potential for cross-loch currents, thermal gradients, the formation of a vortex in Dores Bay. No allowance was made in this initial study for any temperature changes arising from direct solar radiation, e.g. as upper reservoirs are filled on a warm sunny morning, nor for thermal inputs from frictional losses.

This initial study was funded by Ness DSFB but further research is clearly required to investigate the impact of massively increased PSH activity, on the famously stable temperature profile of Loch Ness.

We note that Glen Earrach have proposed funding a PhD: Evaluating the influence of a Pumped Storage Hydropower plant on the hydro-environmental characteristics of Loch Ness, Scotland and monitoring buoys have been deployed in two locations in Loch Ness. Clearly Glen Earrach agrees with our assessment that further research is required. Given the 3 or 4-year timescale associated with a PhD study, Ness DSFB are of the opinion that no further planning consents should be granted for PSH in Loch Ness until this study is complete. To do otherwise risks irreversible changes to the unique freshwater ecology of Loch Ness.

The significance of these hydrological changes for salmon smolts should be self-evident. The existing, relatively straightforward hydrology of Loch Ness, with the prevailing wind generating surface currents towards the River Ness at the north end of the loch, aligning with the dominant inflows, from the Oich and Moriston, at the south end of the loch. With multiple PSH schemes on Loch Ness the hydrology of Loch Ness is going to become much more complex which is almost certain to impact wild salmon smolt migration through Loch Ness. The complete lack of published research on this issue means it would be unsafe to grant consent for any further PSH on extremely sensitive, and biodiverse rich, lochs such as Loch Ness

1.3 Impoverishment of the shoreline ecology

The impact of large and frequent loch level drawdowns on the shoreline ecology is known and understood. The result will be the impoverishment of the existing rich and diverse shoreline ecology of Loch Ness (Smith et al, 1987). That rich, and diverse, invertebrate ecology is the foundation of large part of the Loch Ness ecology as the profundal/abyssal habitat of Loch Ness is much less productive than the shallow littoral zone. Given the low ratio of littoral to abyssal habitat in Loch Ness, the loss of the most productive part of the invertebrate ecology is highly significant. The Glen Earrach EIAR absurdly dismisses the impact of the cumulative drawdown on shoreline invertebrates in Loch Ness as negligible.

The rich and diverse invertebrate shoreline ecology supports the brown trout population of Loch Ness for large parts of the year. The regular hatches of different mayfly, stonefly or caddis species provide feeding opportunities for fish and bird populations around the entire shoreline.

During the salmon smolt migration, Loch Ness provides an important transitional environment for the, predominantly, tributary origin, salmon smolts. The 2022 “Missing Salmon” tracking project found that the time taken by tagged smolts to transit Loch Ness ranged from 3.5 days to 43 days with a mean residency time of 14 days (Lothian, A.J., 2022). The transition period through Loch Ness will be an important phase in the smolt migration staging, with a progression of the smoltification developmental status, prior to entering the marine environment.

Salmon smolts on Loch Ness will also feed and grow during this period, therefore any diminution to the shoreline ecology will have a direct impact on the size and health status of all Ness smolts entering Loch Ness, including those from the Moriston SAC. Anglers on Loch Ness in May 2025 noted extensive accumulations of smolts on the east side of the Loch, with smolts attracted to anglers’ flies, over an area of shoreline extending to approximately 3km (Angus MacGruer, pers. Comm, 2025). The majority of Ness catchment salmon smolts will be produced in the tributaries entering Loch Ness, therefore this impact pathway can be considered to have an unmitigable, population scale effect on the Ness salmon population.

1.4 Changes in water management due to modifications to Dochfour Weir

Glen Earrach PSH propose to modify Dochfour Weir with the installation of tilting gates along the full length of the weir in order to store water in Loch Ness, regulate flows in the River Ness, and to isolate the River Ness from the fluctuations in flow that would occur in the absence of mitigation. It is worth noting the original operators of Foyers were required to install, and operate, by-pass gates at the south-eastern end of Dochfour Weir at the outflow from Loch Ness when Foyers PSH was built in the 1970s. These gates (SSE sluices) were designed to ensure that, “during periods when the natural inflow to Loch Ness is low, that the control gates to be provided at Dochfour Weir are operated in such a manner that the flows in the River Ness are not adversely affected by the discharge of water from, or the pumping of water to, Loch Mhor”. There is a sensor in the River Ness downstream of Dochfour Weir, which detects changes in river levels, automatically triggering adjustments in the gate opening to minimise variation in flows in the River Ness. This system generally works well, now, although in 2023 a sudden reduction in the flow in the River Ness occurred in response to changes in the sluice opening. One such an example resulted in a fish kill in summer 2023. We understand that an agreement between the owners of Loch na Cathrach PSH and SSE, regarding the joint use of the sluices, has been reached. It is worth noting that whilst there was no requirement to mitigate variations in flow at high river levels, the typical drawdown by Foyers is <150mm.

The scale of the Kemp and Glen Earrach PSH has resulted in both developers suggesting that modifications to Dochfour Weir are required in order to mitigate the impact of their schemes, but also to provide a mechanism for storing water in Loch Ness, in order to limit curtailment during periods of low water. Both Statera and Glen Earrach are proposing major modifications to Dochfour Weir including the provision of tilting gates. Glen Earrach plans to operate the weir seasonally (May to September).

Ness DSFB have a number of concerns regarding the Glen Earrach proposal for Dochfour weir in relation to the Ness salmon population (other, non-fish related, concerns regarding the weir will be discussed later in this document). These fish related concerns are listed, and discussed below:

• Out with the proposed operation season (Oct to April) flows in the River Ness will vary enormously over the course of a day, resulting in the River Ness becoming a hydro-peaking river. Hydro-peaking is widespread in Norway with detrimental impacts on salmon populations, including fish stranding, loss of rearing habitat and disruption to spawning. Changing river levels will also result in amenity and safety issues. Such a scenario would be completely unacceptable to Ness DFSB and would be a retrograde step considering the protective measures implemented in the 1970s to mitigate PSH flow variations in the River Ness.

• The seasonal operation of the proposed Dochfour Weir tilting gates results in an increase in levels in Loch Ness in May (GE Additional Information June 2025). The inevitable consequence of storing, or holding back water in Loch Ness, during the summer (to avoid curtailment of PSH), means that flows down the River Ness will be reduced. Reduced downstream flows during the wild salmon smolt run is completely unacceptable and would have a population level effect on the entire Ness salmon smolt run, including those emanating from the River Ness. Salmon smolts respond to environmental cues with a key response being attraction to downstream flows though rheotaxis. Lower flows down the River Ness means a weaker attractant flow towards the only viable migratory outlet from Loch Ness. This is yet another example of an extremely harmful impact of PSH on the Ness wild salmon population.

• Ness DSFB has requested detailed information on river levels in River Ness, similar to the request by NatureScot for water levels in Loch Ness during defined periods. Additionally, Ness DSFB have requested river flow data during the important April/May smolt migration.

That information is still awaited. This issue of reduced river flows in the spring will be discussed further below.

2. Proposed modifications to Dochfour Weir and impacts on fish passage

In order to mitigate the impacts of the operation of Glen Earrach on loch and river levels, and in order to reduce PSH curtailment due to lack of water, the developer proposes to modify Dochfour Weir. The aims of the proposed modifications are listed in Volume 5: Appendices Appendix 2.1: Dochfour Weir Upgrade Description, Para. 3.1.3, of the EIAR. In that list of aims Glen Earrch omit what is clearly one of the main objectives of the weir upgrade, that is the ability to store water in Loch Ness in order to avoid curtailment of PSH in Loch Ness during periods of dry weather.

When Foyers PSH was constructed in the 1970s the then Fisheries Committee required the construction of the “SSE sluices” on the south end of the weir in order to smooth out fluctuations in River Ness flows due to variations in Loch Ness levels. The operation of the gates is controlled via a feedback sensor in the river downstream of Dochfour Weir. This system was updated in 2024 and now seems to work well. The SSE sluices are twin undershot gates, each 8m in length. What is now proposed by Glen Earrach is on a completely different scale.

Detail is lacking in the application but it is clear that what is proposed is without precedent in Scotland. The entire length of Dochfour Weir will be converting into pneumatically operated tilting gates with a design criterion to regulate water levels up to 1.1m (Appendix 2.1, Figure 2.1.1). This will involve major engineering to Dochfour Weir, a Scheduled Ancient Monument, and a simple cobbled structure design to withstand water flowing over. Figure 2.1.1 shows a total of seven supporting abutments but does not show the intermediate supporting piers. Figure 2.1.1., Section C, shows an overhead structure, presumably running the full length of the gated weir.

It was little wonder that the proposed Weir modifications were the subject of much discussion at the roundtable meeting at Highland Council HQ on the 28th July. The proposed modifications will transform Dochfour Weir from an existing low profile, virtually organic structure, that provides the unique vision akin to an infinity pool from the A82, with anglers appearing to walk on water as they fish. This will be replaced by a technical structure with vertical supporting structures along the length of the weir, tilting gates and a horizontal superstructure.

The applicant states that failsafe mechanisms will be incorporated to ensure that catastrophic failure cannot occur; something that would be essential considering the potential flood risk to Inverness. Inverness residents will be aware of the regular issues with the operation of the new swing bridge over the canal at Torvean and realise that mechanical issues can beset even relatively simple structure such as that. Even if effective and reliable failsafe mechanisms were incorporated the failure of one, or more of the gates ( which is inevitable) would negate the ability of the weir to function as conceived, and introduce the novel risk of water pouring through a malfunctioning gate with associated erosion risks to specific areas of the weir, something it was not designed to withstand.

The pneumatic bladders that will inflate to lift the tilt gates are an obvious vandalism risk. Does that mean that the publicly accessible weir will need to fenced off? This will have implications for angling, or canoeing access, for example.

In para. 3.2.1, the applicant states that the existing character of the weir will be maintained i.e. a curtain of water passing over the full length of the weir. That is a consequence of the existing simple, level crest structure of the original Telford Weir. The maintenance of a curtain of water passing over the proposed tilting gate structure, with potentially 80, or more, 6m long tilting gates, at two different levels will be challenging.

Clearly there are many unresolved issues associated with the unprecedented proposals for Dochfour Weir but issues relating to fish passage are more straightforward. In Chapter 9: Aquatic & Marine Ecology, of the Glen Earrach PSH EIAR, there is extensive discussion regarding the assessment of operational effects on fish passage at Dochfour Weir. We have a number of comments to make on this chapter, and similar comments on other chapters, with our concerns summarised below.

It is stated in 9.8.52, that “during consultation with NDSFB, concerns were raised over the effectiveness of fish pass provision currently installed on Dochfour Weir due to insufficient flows under baseline conditions”. No source is provided but that is not something that can be attributed to the Director of Ness DSFB. In 9.8.53, it goes on to say that “…views of NDSFB that there is currently a high probability that some adult salmon, especially the smaller specimens, are unable to navigate the existing weir and fish pass under current conditions”. Again, this statement is unattributed and not supported by any evidence. There is absolutely no evidence of size selection in the adult salmon population upstream of Dochfour Weir.

The value quoted in 9.8.54, for the compensation flow in the River Ness is incorrect. There is no minimum compensation flow in the River Ness. This factual error has been perpetuated throughout multiple pump storage hydro applications. The only defined flow relevant to the minimum flow in the River Ness is contained within clause 4.2.9 of the SSE Hydro Ness CAR licence REF-HYDR-COMN-009, where it states “A combined daily flow of not less than 772,836m3 /d shall be maintained in the River Garry as measured immediately below the Invergarry generating station tailrace and the River Moriston as measured immediately below the Glenmoriston Power Station tailrace). This equates to 8.94m3/s, which, combined with additional incoming flows from other tributaries forms the low water flow in the River Ness.

In 9.8.55, it is stated “These lift gates are also potentially harmful to downstream smolt movements due to velocities through the lift gates when open”. Ness DSFB disagree completely with this statement. The existing lift gates are simple, undershot, structures with approximately 1m of head. There is no significant pressure differential and it is highly unlikely that smolt will be harmed by passing through this structure. Again, there is no evidence, nor references, provided to substantiate this statement. We do agree that the erosion associated with the 2017 sheet piling at the foot of the fish pass is undesirable, but there is no evidence that this presents any barrier to upstream migration at present.

The salmon run timings provided in 9.8.56 are completely incorrect, for almost all salmon rivers in Scotland, let alone the River Ness. The peak migration period for salmon in the River Ness is the summer, with July and August being the most important months numerically. The Ness catchment has a significant spring run; indeed, it has the best early spring run in the Highlands. This run commences in January and extends through May, merging with the early summer fish in June. Few salmon enter the River Ness in September and October nowadays.

Table 9-12 shows that the impact of Glen Earrach will be reduced flows in the River Ness at all except the highest flows.

The conclusion of this section, much of which is unsubstantiated, is that “the weir and existing fish pass are not conducive to successful migration of Atlantic salmon upstream”. This was based on an analysis of depth and flows. To consider this further, it is very informative to compare this conclusion with the summary from a report titled – Red John Pumped Storage Hydro Scheme Assessment of Fish Passage at Ness Weir, July 2019, which stated that “The analysis of the passability of the fish pass to adult salmon based on the SNIFFER (2010) guidance shows that the fish pass acts as a partial barrier – low impact due to velocities when it is running full. However, as water levels drop, velocities fall resulting in the fish pass acting as no barrier, based on velocities alone. The depth of flow at the downstream part of the barrier remains such that again it is not regarded as a barrier.” In contrast to the 2024 Glen Earrach EIAR assessment, the 2019 Red John report concluded that the Dochfour Weir fish pass was no barrier, based on flow velocities, and depth.

Both reports were produced by the same consultants, AECOM, although acting on behalf of different Loch Ness PSH clients. The authors of the reports were different, however the 2019, Red John PSH report was checked by the same person that verified the 2024 Glen Earrach report. Little wonder Ness DSFB are, at times, sceptical of the neutrality of consultants tasked with producing EIA reports. 9.9.13 details several supposed proposed improvements associated with the planned upgrade to Dochfour Weir,

• including resolving the supposed issues for upstream fish migration (multi species),

• the installation of a smolt deterrent device,

• the creation of a more natural flow regime in the River Ness.

As stated above, the first of these points is largely a construct of the Glen Earrach application. For fish such as eels the current weir, with its organic structure, well vegetated weir face, and mossy, damp surface presents an ideal fish passage solution along its entire length. The same would apply to lamprey as there are a multitude of potential routes for upstream passage. There is absolutely no evidence that the weir forms a barrier to the upstream migration of salmon, indeed it has served that purpose for 200 years.

Regarding the issue of smolt entrainment in the Caledonian Canal Scottish Canals have just published an optioneering study (Envirocentre, March 2025), which ranks resolving the smolt entrainment issue at Dochgarroch, as the number one priority at the six locations studied. This study was commissioned by Scottish Canals in response to a specific action against them in the Scottish Government Wild Salmon Strategy Implementation Plan 2023 – 2028. Action 1.17 of that plan requires Scottish Canals to: Undertake a review of the risk to fish migration of the canal network and associated management structures [By 2025] (Scottish Canals – DSFBs and Trusts, SEPA, NatureScot).

Ownership of that action rests with Scottish Canals and, now that the report has been published, we expect that delivery will follow at pace.

The statement in 9.9.13, about creating a more natural flow regime in the River Ness has to be qualified by stating that this would be in comparison to one driven by PSH fluctuations. The natural regime Glen Earrach purport to create in the River Ness, is in response to the unnatural regime created by Glen Earrach. The claim to create a more natural flow regime in the River Ness is not supported by the evidence provided in the flow duration curves presented. In the Additional Information provided in June 2025, Table 2-11: The Proposed Development, Loch na Cathrach & LK Annual and Seasonal Impact with Seasonal Variable Weir, it can be seen that the Q95 spring flows in the River Ness would be 20m3/s with PSH operation, compared to the baseline of 34m3/s. This same reduction in spring flows is repeated across all except the highest Q10 flows. This significant reduction on spring flows in the River Ness would be exceptionally harmful to smolt migration. At the very time when wild Atlantic salmon smolts are trying to find their way downstream, flows down the River Ness will be cut by over 40%.

Ness DSFB refute the claim made in Chp 2, 2.13.1, that the proposed modifications to Dochfour Weir would “support improved ecological outcomes (notably for migratory salmon)”. As detailed above the EIAR claims about the problems for adult salmon at Dochfour Weir are a false argument constructed by the consultants, with their own report from 2019 for the Red John PSH application, arriving at the opposite conclusion. Smolt passage at Dochfour Weir will be resolved with the implementation of the recommendations made by Scottish Canals in the Fish Migration Optioneering Studies 2025 report.

Paragraph 2.13.1, also states that Scottish Canals and Glen Earrach have “shared objectives to modernise the weir to increase resilience to climate change, support improved ecological outcomes (notably for migratory salmon), and maintain the navigability of the Caledonian Canal.” As stated above Ness DSFB refute the claims about improved outputs for migratory salmon, and when asked what would happen to Dochfour Weir if the proposed PSH schemes on Loch Ness did not go ahead, the answer was the weir would just continue as is, providing safe navigation through the Canal (Richard Millar, pers comm). The sheet piling installed by Scottish Canals were designed to protect Dochfour Weir for the next 100 years. Scottish Canals clearly have no concerns about the durability of Dochfour Weir, nor any concerns regarding the navigability of the weir.

It is hard to imagine a more disastrous scenario for smolt migration through Loch Ness, than the post-PSH scenarios emerging from these PSH applications. Loch Ness, a key feature on the downstream migration of all upper Ness salmon smolts will have its hydrology totally disrupted, and downstream flows in the efferent river will be reduced by 40%, during the peak smolt run period. Loch Ness is going to become an extremely challenging transitional zone for salmon smolts with almost certain significant, adverse impacts.

Dochfour Weir, fish passage summary

• The arguments presented regarding adult fish passage at Dochfour Weir are contrived and are at complete variance with the findings of the 2019 assessment.

• The fish passage assessment is based on modelling with no actual measurements taken to confirm model data.

• There is no evidence of size selection in the adult salmon population upstream of Dochfour Weir with small grilse often caught above.

• Salmon delayed at structures during migration would often display tell-tale signs such as constant leaping, build up in numbers, agitated behaviour etc. There is absolutely no evidence that this occurs at Dochfour Weir, whatsoever.

• The seasonal operation of the proposed Dochfour Weir will result in hydropeaking flows in the River Ness during the winter and water storage in Loch Ness during the summer will have significant impacts on protected species and habitats.

3. Littoral zone invertebrates

Pumped Hydro Storage (PHS) schemes typically increase the frequency of fluctuations in water levels. Depending on the demand for pumping operations, either for replenishing the upper storage reservoir or for power generation, these short-term fluctuations may occur on a weekly, daily or hourly basis. They are likely to be more rapid and more frequent than natural fluctuations which are more gradual (Patocka, 2014).

Regarding the impact on the littoral invertebrate fauna of Loch Ness, Smith et al. (1987) found that the richest littoral invertebrate communities were found in lochs with annual water level fluctuations (AWLF) of less than 5 metres and weekly water level fluctuations (WWLF) of less than 0.5 metres (this applies to Loch Ness at present). Where the AWLF is greater than 5 metres, or the WWLF is greater than 0.5 the invertebrate community was impoverished, and where both the AWLF and WWLF are greater than these figures the invertebrate community was extremely poor. Trotter et al. (2022) also found that hydropower schemes impact invertebrate communities. Invertebrate richness in dams and reservoirs impacted by hydropower operations was significantly lower than in natural waterbodies.

With the potential for a daily drawdown > 0.5m the invertebrate fauna of Loch Ness will become impoverished. This would be significant as Smith et al. (1987) found that the littoral invertebrate fauna of Loch Ness was in the top six of twenty-seven lochs sampled for diversity and abundance of the littoral fauna.

The shallow littoral habitat within Loch Ness is limited in extent, but is considered to be vital habitat for brown trout, for migrating salmon smolts, and for a wide range of shoreline birds such as sandpipers, wagtails and dippers.

Section 9.6.31 of Chapter 9 concludes that “On this basis, there are no other species considered greater than negligible nature conservation value and therefore the macroinvertebrate assemblage is considered of Local value.” This statement refers to the impoverishment of the invertebrate ecology of the entire, 80km+, shoreline of Loch Ness. Sub-surface ecological destruction on this scale, in terrestrial terms, is equivalent to slashing and burning the entire riparian woodland of Loch Ness, yet it is concluded in 9.8.65 as “assessed as a Low magnitude impact on aquatic macrophytes, macroinvertebrates, and other fish species in Loch Ness, and the impact of fluctuating water levels is considered to result in a Negligible effect”. No mitigation at all is provided.

Contrast this with the extravagant mitigation proposed for the loss of 1.27ha of native woodland at the lower control works location. There are no rare trees in the area of native woodland that will be lost, rather the species present are indicative of a typical W9 woodland community. According to NPF4 there is a presumption against the loss of ancient woodland and semi-natural woodland with compensation required to offset. As mitigation for the loss of 1.27ha of woodland the applicant proposes a comprehensive planting scheme within Balmacaan Estate, i.e. in-house. The mitigation plan will result in the establishment of 674ha of new native woodland, all designed to maximise biodiversity gain.

In return for the impoverishment of the currently rich and diverse invertebrate shoreline ecology of Loch Ness no mitigation whatsoever is proposed. No mitigation is proposed for the destruction of Loch nan Breac Dearga either, yet these are the receptors that will be damaged the most by this harmful development. This may be an oversight, or more likely that the impact on these receptors is unmitigable, in which case this harmful development cannot be approved.

This selective and skewed form of mitigation cannot be considered satisfactory by regulators; it is certainly not for Ness DSFB. This impoverishment of the rich and diverse shoreline ecology will not be mitigated by extensive tree-planting elsewhere, and the ecology of one of Scotland’s largest, and most important lochs will be permanently damaged, if this harmful development is allowed to proceed.

4. Linkage between Ness salmon population and dolphins feeding at Chanonry Point

Chapter. 9. Aquatic & Marine Ecology, Section H. Indirect Impacts to Marine Mammals through Impacts to Prey Species, focusses on the relationship between Ness salmon and the presence of Bottlenose dolphins feeding on salmon at Chanonry Point, Fortrose. The Glen Earrach EIAR acknowledges that there is a relationship, but considers it to be of low magnitude, and a minor adverse effect on the local seal and dolphin populations. NatureScot, in their response to the Loch Kemp PSH application, also noted that potential for an adverse impact on the Bottlenose dolphin feature of the Moray Firth SAC but advised that the Kemp proposal will not adversely affect the integrity of the site. NatureScot acknowledged that salmon provide an important component of their diet when they are available as they have a high nutritional and calorific value, but as dolphins are opportunistic feeders they would be able to substitute other prey species, if salmon were to decline. Even if this were the case, both NatureScot, and the Glen Earrach EAIR, completely miss the point raised by Ness DSFB regarding Ness salmon and the Moray Firth dolphin population. Our concerns focus on what is widely regarded as the greatest wildlife spectacle in the Highlands: – the sight of large Bottlenose dolphins feeding on returning wild Atlantic salmon, within metres of the shore, at Chanonry Point. As with all predator/prey relationships, if the inner Moray Firth salmon population declines, then the number of dolphins engaging in this specific feeding opportunity at Chanonry Point will decline, as well as the frequency of visits. It is worth noting that the frequent presence of dolphins at Chanonry Point, thus far in 2025, with multiple social media accounts posting photos of dolphins feeding on salmon, on a daily basis.

A 2019 tracking study involving netting adult salmon Chanonry Point (Newton & Conroy, 2020). Captured salmon were tagged and released. The study found that 92.8% of adult salmon tracked back to rivers were destined for the Ness or Beauly, with the remainder detected entering the Spey and Conon, nearby Moray Firth Rivers. This highlights the significance of the Ness salmon as a prey source for dolphins at Chanonry Point.

There can be no better demonstration of a direct linkage between the freshwater and marine ecosystem than the Chanonry Point Ness salmon/bottlenose dolphin relationship, which creates such a popular wildlife viewing destination. Given the decline in wild salmon in Scotland it is imperative that the freshwater habitat, upon which the salmon depend, is nurtured, not harmed, none more so than Loch Ness. This is indeed Scottish Government policy. Chanonry Point, and the dolphins feeding there on returning wild Atlantic salmon, is the greatest wildlife spectacle in the Highlands, and is symbolic of the high-quality natural environment the Highlands are famous for.

This response from Ness DSFB to the salmon/dolphin relationship, compared with that of NatureScot, with their primary focus on Moray Firth SAC, population level impacts, highlights the requirement of decision makers to heed to the views of a range of bodies, when it comes to biodiversity, and not just rely on the narrow focus of NatureScot, an organisation that focusses on specific aspects of protected species and does not represent all of Scotland’s nature. This point is of particular important in relation to the biodiversity aims of NPF4.

5. Impacts during construction

The EIAR notes (9.9.7) that significant avoidance behaviour is calculated to occur out to 2.1km of the LCW. As the width of Loch Ness is 1.2km at that point the impact on salmonid behaviour within the loch is likely to be significant. Adult salmon migrate along both shores of Loch Ness as they home to their natal river. Adult salmon use Loch Ness as resting habitat during the summer quiescent phase and they can be caught by angling around the entire perimeter of Loch Ness, including at the location of the proposed Glen Earrach intake structures.

6. Smolt tracking study 2025

The significance of the 2025 smolt tracking study with regard to PSH operation may be limited as it appears that the operation of Foyers PSH was curtailed in the weeks following the onset of smolt tagging. There is no direct access to Foyers operational data but SEPA gauges in the River Ness & Loch Ness showed that levels were unusually stable. Analysis of publicly available data from the energy balancing network showed that there was no generation at Foyers for 17 of the 25 days following the commencement of smolt tagging (Westcoast Consulting, 2025).

9.9.11 suggests potential mitigation measures, for example when smolts are known to be present in the vicinity of the LCW. Establishing the presence of smolts in the loch would require sophisticated monitoring equipment, e.g. sonar. It is worth noting that Ness DSFB received a report on the 9th May 2025 noting the presence of large numbers of smolts on the east side of the loch from an area known as the “Beaches” (location of proposed Kemp PSH) to near Foyers, a shoreline distance of approximately 3km. The smolts were noticed by anglers with “small groups” of smolts following the anglers’ flies. Such accumulations of migrating smolts can occur anywhere around the shoreline of the loch during April & May.

7. PSH constraint due to operation of multiple PSH schemes

It is obvious that if multiple PSH schemes operate with the same, shared lower reservoir, then periods of constraint will occur as water levels become limiting. The mean water level of Loch Ness is 0.58m above the legal limit below which abstraction must stop (15.27m). With a combined drawdown of 1.24m from the four consented or proposed schemes, it is clear that loch levels in Loch Ness will fluctuate quickly and frequently and that water levels are likely to be at the legal limit on a daily basis for much of the year.

The present approach by SEPA is to allocate tiered stop pumping levels, via a Controlled Activities Regulations (CAR) licence, to each of the PSH in Loch Ness. At present the only schemes with CAR licences are Foyers and Loch Na Cathrach PSH. The stop pumping limit is not defined in the Foyers CAR licence, but the Loch Na Cathrach CAR licence stop pumping limit is set at 15.33m. Neither Loch Kemp, nor Glen Earrach, have yet been granted a CAR licence although the figure of 15.42m has been quoted by Glen Earrach.

We do not know how SEPA will approach the consenting of further PSH on Loch Ness. We understand SEPA are currently developing guidance for PSH but this has not yet been issued for public consultation. Regulation of multiple schemes is going to be challenging as the pumping power of these PSH schemes is such that the risk of overshooting stop pumping levels is high. There is no precedent, that Ness DSFB are aware of, for SEPA regulating multiple abstractors in a single loch, certainly not on this scale. The risks of non-compliance with whatever systems are put in place is inevitably high.

There was an incident in May 2023 when the level, of an already low, Loch Ness fell by over 100mm in a period of 24hours, falling well below the legal minimum water level and reaching record low levels. It is not possible for the loch level to drop, during low water conditions, at that high rate by natural means, and, at the time, there was only one facility on the loch capable of pumping water at that rate. If there are multiple PSH schemes on the loch, all operated by different private companies, each competing for a limited water resource, it is likely that breaches of the legal limit will occur more frequently, impacting all other users of the loch. It is not clear if current, or planned, monitoring will mean that responsible parties could be identified and taken to task.

Even if the level did not routinely breach the legal limit, having multiple PSH schemes competing for a limiting resource, especially in the summer, means that the level of Loch Ness would be at, or close to, the legal limit (15.27m) at some point in the day, virtually every day. This will result in even more difficulties for existing users of the loch, many of which are long-established indigenous businesses. The proposed modifications to Dochfour Weir will provide a means to store water in Loch Ness and allow PSH companies to operate during periods when they would otherwise have been constrained by the lack of water. A consequence of the proposed modifications to Dochfour Weir will be even more frequent fluctuations in water levels in the loch in particular when water levels are below mean loch levels. Rather than providing a buffer of water the main outcome of the proposed Dochfour Weir modifications will be even more frequent fluctuations in loch levels with loch levels at, or approaching the legal, minimum, limit more often.

8. Visual impact

Loch Ness is one of the top tourist attractions in Scotland and an iconic destination known worldwide. Tourism related developments, attractions and access are concentrated on the west side of the loch which means that views of the relatively undeveloped east shoreline are a memorable part of the visitor experience.

Foyers PSH powerhouse is one of the few industrial buildings on the shore line of Loch Ness. It presents an unabashed, and incongruous, presence on the east shoreline. The white façade of the Foyers powerhouse is highly visible during daylight, and at night the light pollution associated is visible for miles. Hydro promoters often cite the established nature of, and cultural importance of hydro infrastructure in the Highlands, with some justification, but Foyer’s power station remains, unashamedly, an industrial building in a prominent, and highly visible location for travellers on the A82.

Glen Earrach PSH is located in the west side of the loch, with the water intakes, and associated infrastructure, in extremely close proximity to, and will be highly visible from the A82. The smolt screen infrastructure will extend 53m out from the intakes according to Para. 9.7.2. However, figure 2.16: Lower Control Works Plan, shows the smolt screen structures to be ~33m out from the intake structures. Clearly there is an error in one, or both of the above statements. Figure 2.17 shows that the outside edge of the smolt screens to be 98m distant from the A82, and will be very prominent to A82 travellers as an industrial structure next to that busy road.

There will clearly be challenges associated with building such a large structure in a very confined space between the busy A82 and Loch Ness. The construction of a 400m long retaining wall below the A82 is itself a major undertaking likely to require blasting. Construction on this scale, including tunnelling, in close proximity to the A82 presents potential risk to the trunk road, plus extended periods of traffic management on a road not otherwise free of traffic management measures for other activities, including forestry.

9. Alternatives to PSH, or alternative locations

Ness DSFB would like to reiterate that we are not against PSH per se. We recognise that the switch to renewable generation means a requirement for more storage. However, we consider that Loch Ness is absolutely the wrong place for this scale of PSH for the reasons detailed above.

The recently approved Earba PSH does not affect migratory fish and is a semi-closed loop system which has a lower environmental impact. There are also other PSH in the planning system which are located upstream of existing hydro dams where there are no direct impacts on migratory fish species.

The battery storage sector continues to evolve with cost reductions and increases in efficiency stimulating huge growth of this technology. A report by industry commentators +LCPDelta has highlighted the prominent role that battery energy storage schemes will provide in the future https://insights.lcp.com/rs/032-PAO-331/images/LCP-Delta-Value-of-long-duration-BESS-April-2025.pdf. This report envisages a significantly reduced role for PSH.

The question must be asked, why are we considering consenting more harmful pump storage schemes when the majority of those with planning permission, such as the Cruachan Power Station Expansion in Argyll and the long-consented Coire Glas scheme in Lochaber, are currently not progressing?

10. Conclusion

As an organisation the Ness DSFB can state quite categorically, that the proposed Glen Earrach PSH would be damaging to the Loch and River Ness, it’s ecology, including the threatened wild salmon population, would impact negatively on the many other users of Loch Ness and would degrade an iconic tourism destination, with a complete lack of appropriate mitigation and no net biodiversity gain.

Energy storage may be required but PSH should be located in the least environmentally damaging location. Alternative storage technologies are likely to fulfil much of the storage requirement. Loch Ness is simply not the right place for such a proliferation of pump storage hydro.

Brian Shaw

Director, on behalf of the Ness District Salmon Fishery Board

References

Angus MacGruer, Proprietor River Oich, Ness DSFB Board Member and Loch Ness angler.

Bailey-Watts, A.E. and Duncan, P. (1981). The ecology of Scotland’s largest lochs: Lomond. Awe.

Ness. Morar and Shiel. Ed. P. S. Maitland. Chemical characterisation. A one-year comparative study. p67-89.

Envirocentre, 2025. Scottish Canals Fish Migration Optioneering Studies. March 2025.

HydroWires, 2022. Closed-Loop Pumped Storage Hydropower Resource Assessment for the United States Final Report on HydroWIRES Project D1: Improving Hydropower and PSH Representations in Capacity Expansion Models.

Lothian, A. J. Moray Firth Tracking Project 2011 – Ness.

Newton, M., & Conroy, C., 2020. Moray Firth Adult Salmon Acoustic Tracking Project 2019

Patocka, F. (2014). Environmental Impacts of Pumped Storage Hydro Power Plants. Norwegian University of Science and Technology.

Scanlon, T., & Stickland, M. (2025). Modelling of Pumped Storage Hydroelectric Sites in Loch Ness.

Smith, I.R., Lyle, A.A. and Rosie, A.J. (1981b). The ecology of Scotland’s largest lochs: Lomond. Awe. Ness. Morar and Shiel. Ed. P. S. Maitland. Comparative physical limnology. p28-65. Richard Millar, Chief Operating Officer, Scottish Canals.

Smith, B.D., Maitland, P.S. and Pennock, S.M. (1987). A Comparative Study of Water Level Regimes and Littoral Benthic Communities in Scottish Lochs. Biological Conservation 39: 291-316.

Stantec, 2023. Technical and Economic Potential Assessment Pumped Storage Hydropower in Canada, 2023.

Trotter, G., Turgeon, K., Boisclair, D., Bulle, C. and Margni, M. et al. (2022). The impacts of hydropower on freshwater macroinvertebrate richness: A global meta-analysis. PLoS ONE 17(8): e0273089.

Westcoast Consulting, 2025. Report on generation at Foyers based on publicly available balancing mechanism generation data.