Site updates

This page will provide regular updates about the ongoing exploratory works at Coire Glas.

We welcome feedback on the information we provide and as a result of this the format of our updates may change as the works move forward.

Please email coireglas@sse.com with any comments or suggestions about this update service.

Ground investigation and tree felling works in Glengarry Forest

To further develop the design of the Upper Works access to Coire Glas, further ground investigations (GI) will soon be carried out in the Glengarry Forest. These works will include:

  • Creation of a new access junction on the A87 (with associated traffic management)

  • 3 hectares of tree felling

  • Creation of a temporary compound and laydown areas

  • Boreholes

  • Trial pits

The works will begin on 24 February 2025 and are estimated to take approximately 16 weeks, with 6-8 weeks for forestry activities and 8-10 weeks for GI works, which will not run concurrently.

Traffic management on the A87 will be required to facilitate the safe formation of the access junction and felling of roadside trees. This will involve a single lane closure for approximately 5 weeks from 27 February 2025, managed by traffic lights.

A map showing the site and tree felling locations can be viewed by clicking the link below.

White Bridge Car Park and access to active travel routes within the forest will be largely unaffected and will remain open. Some areas will be managed by signage, banksmen and temporary barriers.

However, there will be a requirement to temporarily close part of the Core Path LO11.01 and the Ciste Dubh Trail to enable trial pitting/drilling to take place for a short duration of up to two weeks. Further details will be communicated at least one month in advance of this closure.

There will be further tree felling and GI works required in the Glengarry Forest required later in 2025 and we will ensure further updates will be posted here once the information is available.

Updated February 2025

Exploratory works

The exploratory works at Coire Glas are complete.

Their purpose was to determine the ground conditions necessary to inform the design of the underground works. This involved the creation of a tunnel approximately four metres wide and 1.2km long, which was cut into the hillside towards the proposed location of the underground powerhouse complex.

Samples of the materials extracted from within the hill will be analysed and survey and assessment work will be carried out to give a detailed understanding of the geological conditions.

The information will then be used in detailed design of underground structures.

Updated January 2025

Wider site ground investigation (WSGI) works

These works have now been completed. The works involved several boreholes located within the Coire, on the ridge and close to the exploratory tunnel area.

The WSGI works were undertaken to investigate and characterise the soils, rocks and groundwater conditions likely to be encountered across the entire site.

These activities are a major milestone for the project and are a key stage in the process of deciding whether the proposed scheme will go ahead.

The site has several work areas which are shown on the site overview map.

Updated January 2025

Site overview map

Site Overview Progress

  • 03/02/23

    Foundations for site offices at Clunes Compound

  • 03/02/23

    Spoil storage area adjacent to the Clunes Compound

  • 03/02/23

    Groundworks at the Exploratory Works Adit (Tunnel) area

  • 03/02/23

    Exploratory Works Slipway and Compound areas

  • 12/06/23

    Compound areas at the Lower Works

  • 12/06/23

    Ready to commence drilling and blasting at the Exploratory Works Adit (Tunnel) area

  • New List Item

    Description goes here

Exploratory Adit Progress

  • 03/02/23

    Groundworks at the Exploratory Works Adit (Tunnel) Area

  • 15/03/23

    First blast complete

  • 16/03/23

    Creating a ramp using material from first blast

  • 24/03/23

    Grouting the spiles

  • 28/04/23

    All portal rock excavation, rock bolting and netting installation complete

  • 09/05/23

    Initial tunnel excavation commences

  • 12/05/23

    Tunnelling Commences!

  • w.c 15/05/23

    Underground Blasting commences

  • 29/05/23

    Adit at approx. 34m

WSGI Progress

  • 15/06/23

    Track under construction from Glengarry Forest to the Upper Works

  • 01/06/23

    Coire Class Crescent!

    Accommodation for Wider Site Ground Investigations at Upper Works

  • 01/06/23

    Accommodation for Wider Site Ground Investigations at Upper Works

  • 01/06/23

    Site of rig at the Upper Works. 24hr working is in place to drill a borehole to a depth of up to 750m.

  • A final decision will be made after the Exploratory Works are completed and all necessary information has been gathered. This is likely to be during 2026.

  • To access Coire Glas planning documents go to coireglas.com/planning-documents

General Project

Exploratory Works

  • Experienced tunnelling and engineering firm Strabag UK have been contracted to carry out the Exploratory Works, supported by Highland-based civil engineering firm RJ McLeod.

  • The first phase of this work will focus on establishing appropriate road access for vehicles, creating storage capacity for equipment, and installing temporary on-site welfare facilities for the workers.

    Once the site is ready, the next phase of the exploratory work will see the creation of a tunnel 5m high, 4.5m wide and up to one kilometre long, which will cut into the hillside towards the proposed location of the underground powerhouse complex.

    Samples of the ground encountered during the tunnelling operations will be analysed, and survey and assessment work will be carried out to give a detailed understanding of the geological conditions.

  • Works are now complete, however working hours were as follows:

    The mobilisation phase of the Exploratory Works and all surface works will be carried out during the hours 7am - 7pm Monday to Friday and 8am-2pm on Saturdays.

    The tunnelling and exploratory drilling phases of the Exploratory Works will follow a continuous 24-hour working pattern, with workers on a rotating 3 shift pattern. 24-hour working is required to ensure safe tunnel construction (without leaving the working face unattended for any period of time), with the additional benefit that this part of the Exploratory Works is completed as quickly as possible.

    These working hours have been agreed with The Highland Council.

  • Works were completed in December 2024.

  • Yes, Kilfinnan Road will be open to all users as usual.

Wider Site Ground Investigation (WSGI) Works

  • These works were undertaken by leading Geo-data specialist called Fugro. Their focus was on collecting and analysing comprehensive information about the Earth and the structures built upon it.

  • Works to investigate and characterise the soils, rocks and groundwater conditions likely to be encountered across the entire site. Our contractor worked on several boreholes located within the Coire, on the ridge and close to the exploratory tunnel area.

  • Works are now complete, however working hours were as follows:

    Lower Works (areas alongside Loch Lochy via Kilfinnan Road): from 0800 to 1800 hours weekdays and 0800 to 1400 on Saturday

    Upper Works (dam and reservoir area via Glengarry Forest): 0800 to 2000 hours weekdays, and 0800 to 1800 Saturdays and Sundays

    There will be 24/7 working within the Coire itself once satellite compound areas have been established. Continuous operation is required to maintain the integrity of this borehole at depth.

    These working hours have been agreed with The Highland Council.

  • Works were completed in December 2023

  • Given the remote location, high elevation and challenging weather conditions, the use specialised all-terrain vehicles and helicopters to access the site and transport equipment was essential.

Frequently Asked Questions

Contact and Enquiries

  • We are compiling a database of local service providers. To be added to this database, please email your details to coireglas@sse.com

  • If you have any questions about the Exploratory works, or about the wider Coire Glas project, please email coireglas@sse.com.

  • Any queries relating to FLS operations or planned works should be directed to David Robertson, Area Visitor Services Manager at FLS: David.J.Robertson@forestryandland.gov.scot