NatureScot interim response – Holding Objection
This is a partial response produced at the request of the applicant; it includes our advice on most protected areas and nationally important nature interests that could be affected by the proposal with the exception of North Inverness Lochs SPA and the River Moriston SAC. In relation to this SAC, we advise below on just one aspect of the proposal; our full response will follow later.
- Summary
• River Moriston Special Area of Conservation (SAC): We have not yet undertaken a full appraisal of the implications for this SAC, but in relation to the proposed seasonal variable weir we conclude the proposal could affect internationally important natural heritage interests and we therefore object to this proposal until further information is provided. This will enable us to carry out an appraisal of these effects and help you determine this proposal. Even with this additional information, there is a risk that it may not be possible to show with the certainty required by the Habitats Regulations that the conservation objectives of this SAC will not be undermined. We will provide full advice on this SAC in due course.
•Urquhart Bay Woods SAC: The proposal could affect internationally important natural heritage interests and we therefore object to this proposal until further information is provided. This will enable us to carry out an appraisal of these effects and help you determine this proposal.
•North Inverness Lochs Special Protection Area (SPA): The proposal could affect internationally important natural heritage interests. We have not yet completed our appraisal of the implications for this SPA and other associated Slavonian grebe SPAs. We will advise in due course.
•Ness Woods SAC: There are natural heritage interests of international importance on the site, but our advice is that these will not be adversely affected by the proposal. Annex A contains full details of our appraisal.
•Moray Firth SAC: There are natural heritage interests of international importance on the site, but our advice is that these will not be adversely affected by the proposal. Annex A contains full details of our appraisal.
2. Background
We understand the role of pump storage hydro in Scotland’s transition to net zero, and welcome the applicant’s willingness to engage in pre-application consultation on the implications for protected areas.
At your request, our appraisal below is based on the proposal as described in the application, including the off-site seasonal variable weir at Dochfour the applicant proposes as mitigation for significant effects on sensitive receptors associated with water level variation in Loch Ness and downstream flows in the River Ness. The weir, however, is not part of this application and has not yet been subject to a separate application. We understand it will be applied for by a third party who is yet to be identified. We note here a risk that what appears to be a negative suspensive condition is not enough to give a competent authority sufficient certainty that the required mitigation will be implemented when they carry out their appropriate assessment. HRA requires that details of the confirmed mitigation are available to the competent authority.
3. Appraisal of the impacts of the proposal and advice
The proposal is to build a new pumped storage hydro (PSH) scheme near Loch Ness, centred on national grid reference NH 45255 22395, about 9.5 km south of Drumnadrochit and 6.5 km north of Invermoriston.
The Proposed Development will have a capacity of 1,800 MW. The upper reservoir, the Headpond, is at Loch nam Breac Dearga which is about 480 m above sea level with Loch Ness as the Tailpond.
The development has underground and over ground components, including the main Power Cavern Complex, dry and wet tunnels, access tracks and control works.
The proposal also includes the promise of future works to apply for a variable weir as part of the mitigation package. This is not part of this application and has yet to be applied for.
The project could affect a number of designated European sites: North Inverness Lochs SPA, River Moriston SAC, Urquhart Bay Woods SAC, Moray Firth SAC and Ness Woods SAC.
These sites’ status means that the requirements of the Conservation (Natural Habitats, &c.) Regulations 1994 as amended (the ‘Habitats Regulations’) apply. Consequently, Energy Consents Unit (ECU) is required to consider the effect of the proposal on the SACs and SPA before it can be consented (commonly known as Habitats Regulations Appraisal). The NatureScot website has a summary of the legislative requirements (https://www.nature.scot/doc/legislative-requirements-european-sites ).
The applicants have carried out an assessment of impacts on North Inverness Lochs SPA, River Moriston SAC, Urquhart Bay Woods SAC, Moray Firth SAC and Ness Woods SAC in their shadow Habitats Regulations Assessment (HRA). We generally agree with the conclusions set out in the assessments for Moray Firth SAC and Ness Woods SAC.
- River Moriston SAC
We include partial advice in relation to this SAC below and will follow up with comprehensive advice in due course.
The SAC is designated for Atlantic salmon and freshwater pearl mussel and lies approximately 8km south-west of the proposed outfall/ intake. For part of their lifecycle, freshwater pearl mussel are dependent upon a healthy population of salmon which act as host species. Atlantic salmon smolts from the River Moriston migrate through Loch Ness, and the River Ness, to spend a year or more at sea before returning as adults to spawn in their natal river. Elements of the scheme that could affect the water environment in Loch Ness, and/or the Rivers Moriston and Ness, therefore have the potential to affect both qualifying interests.
The population of Atlantic salmon in this SAC is in unfavourable condition, with suboptimal and declining resilience to threats and pressures. Nationally, Atlantic salmon in Great Britain have recently been assessed as being ‘Endangered’ and threatened with extinction at the regional level. In the Moray Firth, recent research indicates that around half of the Atlantic salmon smolts in the overall catchment are being lost during their downstream migration before they reach the sea. Of the seven river catchments involved in this study, the Ness Catchment, of which the River Moriston is a component, had the lowest survival percentage of smolts reaching the sea at just 18% across the three study years.
Freshwater pearl mussels are also in unfavourable condition at this site due to poor recruitment and the small size and aged status of the population, especially in the upper reaches of the river.
Our advice is that this proposal is likely to have a significant effect on the Atlantic salmon and freshwater pearl mussel qualifying interests of the River Moriston SAC as a result of the following impact pathways:
Atlantic salmon
1. Construction and dewatering of the coffer dam
2. Increased sedimentation / turbidity (non-toxic) in areas adjacent to the construction site during construction
3. Risk of contamination (toxic) from fuel / chemical leakages / and concrete spills during construction
4. Risk of noise disturbance from heavy machinery, sediment movement, temporary cofferdam
5. Salmon may become impinged on intake screen during periods of abstraction
6. Capture of salmon smolts at the intake during periods of abstraction
7. Intake flow attracting downstream migrating salmonid smolts and/or kelts, delaying migration and resulting in additional mortality
8. Outlet flow attracting adult salmonids migrating upstream
9. Changes to the thermal regime in Loch Ness affecting salmon growth and survival, and food supply
10. Reduction of water levels in Loch Ness impeding migration
11. Reduced productivity of the littoral zone as a consequence of changes to the water level regime in Loch Ness
12. Changes to the flow regime in the River Ness impeding migration
13. Construction of the proposed Dochfour seasonal variable weir impeding migration
14. Operation of the proposed Dochfour seasonal variable weir impeding migration
Freshwater pearl mussel
1. Decrease in Loch Ness water level during periods of water abstraction may lower water levels in the mouth of the River Moriston placing mussels outwith preferential habitats
2. Impacts on the population as a consequence of impacts to the Atlantic salmon host species
Consequently, Energy Consents Unit, as competent authority, is required to carry out an appropriate assessment in view of the site’s conservation objectives for the qualifying interests. To help you do this, we propose to carry out an appraisal to inform your appropriate assessment.
To enable us to carry out this appraisal, further information is required. At this stage, we are only advising on some information requirements associated with the proposed seasonal variable weir, which include:
1. Demonstration it is possible in principle to design, construct and operate a seasonal variable weir in a manner which will maintain or improve passage over the weir for upstream and downstream migrating salmon from the R Moriston SAC
2. Demonstration it is possible in principle to operate the variable weir to meet the other stated objectives, whilst avoiding adverse effects on the integrity of European sites, and taking climate change predictions into account
3. Demonstration it is practically feasible to secure agreement of all the necessary stakeholders to construct and operate the weir to meet the stated objectives
4. Provision of assurance from all relevant consenting authorities that a seasonal variable weir with the attributes necessary to demonstrate (1) – (3) above would be consented.
This information is required because, as the weir is not part of this, or another, application, relatively few details are available. There is currently no certainty that it could be consented, constructed and operated in the manner described. In contrast, guidance on Habitats Regulations Appraisal (Ref 1) states that competent authorities must be sure that mitigation will be effective at the time they give their permission and that ‘each mitigation measure must be described in detail, with an explanation based on scientific evidence of how it will eliminate or reduce the adverse impacts which have been identified. Information should also be provided of how, when and by whom they will be implemented, and what arrangements will be put in place to monitor their effectiveness and take corrective measures if necessary’. We would be pleased to advise on draft proposed approaches to demonstrating these points.
There are likely to be additional further information requirements to demonstrate that all the impact pathways listed above, and any other that may be identified in future, will not undermine the conservation objectives of the qualifying interests of this SAC, both individually and in combination with other proposals. We will provide further advice in due course.
Even with the additional information requested above, there is a risk that it may not be possible to show with the certainty required by the Habitats Regulations that the conservation objectives of this SAC will not be undermined.
b) Urquhart Bay Woods SAC
We mostly agree with the conclusions set out in the applicant’s Urquhart Bay Woods SAC sHRA (as amended). However, we do not agree with the in-combination assessment conclusion (section 7.4, p 34).
The SAC is designated for alder woodland on floodplains, and lies approximately 10km downstream from the tailrace.
Our advice is that this proposal is likely to have a significant effect on Alder woodland feature of the SAC. Consequently, Scottish Government Energy Consents Unit as competent authority, is required to carry out an appropriate assessment in view of the site’s conservation objectives for these qualifying interests. To help you do this, we propose to carry out an appraisal to inform your appropriate assessment. To enable us to carry out this appraisal, further information is required.
• Details of how much woodland will be inundated and for how long each inundation event will last above the current median summer level. This should be accompanied a detailed fine scale map which clearly shows the areas of woodland likely to be inundated, together with current NVC type, colour coded to show the areas with the highest impacts.
Our full assessment of the impacts on Urquhart Bay Woods SAC is provided in Annex A
c) North Inverness Lochs SPA
The SPA is protected for breeding Slavonian Grebe. A small part of the proposed development site boundary is within the SPA. In addition, there other lochs close to the proposed development that are used by Slavonian Grebe likely to be connected to the SPA population.
Our advice is that this proposal is likely to have a significant effect on Slavonian grebe of the North Inverness Lochs SPA. Consequently, the Scottish Government Energy Consents Unit, as competent authority, is required to carry out an appropriate assessment in view of the site’s conservation objectives for its qualifying interests. To help you do this, we propose to carry out an appraisal to inform your appropriate assessment. We will provide further advice once we have completed our appraisal.
d) Priority peatland habitat
This proposal will result in the loss of 125ha of nationally-important high quality priority peatland habitat which is in good condition. As the majority of the site at the head pond is classed as blanket bog, the applicant has been unable to avoid impacts on peatland here. Elsewhere, infrastructure has avoided areas of high value peatland. In order to offset the losses, we advise the applicant seeks to secure additional areas to bring the total area of peatland restoration to 1250ha, in line with the 1:10 loss:restoration ratio in our guidance.
In addition, there is no clarity in the application on what is proposed as peatland habitat enhancement. We would expect enhancement to be in the region of an additional 10% of the baseline assessment of the extent of priority peatland habitat on the development site.
- Other comments
We provide our detailed comments and assessment for these and other protected areas in Annex A, and advice on priority peatland habitat in Annex B. Our protected species advice is in Annex C.
The proposal will not affect any designated landscape or Wild land Area. Therefore, we do not intend to provide comment on this part of the application.
If you require any further information on this letter please contact Corrina.mertens@nature.scot
The advice in this letter is provided by NatureScot, the operating name of Scottish Natural
Heritage
Annex A, B & C can be provided on request or found on the ECU website.
References
1 https://op.europa.eu/en/publication-detail/-/publication/11e4ee91-2a8a-11e9-8d04-01aa75ed71a1