Description

William Halcrow supervising engineer; Balfour Beatty general engineers, 1921-26; some later additions. Rectangular-section rock fill gravity dam with coursed random rubble upstream face (S) and concrete panel fascia to downstream face (N). Continuous spillway to top of dam with small cantilevered concrete walkway to valve controls. Swept up concrete wave walls to either side on downstream face (with later additions to increase height) with additional buttressed walls running diagonally across downstream face.

Statement of Interest

This dam represents a significant technological achievement as the first rock fill embankment dam in Scotland, receiving international attention upon its completion. The dam also forms part of the Lochaber water power scheme and aluminium smelter, one of the most significant civil engineering schemes of the 20th century in Britain. The dam provides a significant contribution to the surrounding landscape and is directly adjacent to the West Highland Rail Line, which its completion caused to be re-routed. The dam provides storage capacity for the powerhouse at Lochaber (see separate listing), with water conveyed through a pressure tunnel driven through the bedrock under Ben Nevis.

The sweeping lines of the dam and wave walls are appropriate to its landscape setting amidst a bowl of hills. The use of concrete panels to the downstream face of the dam clearly demonstrates the idea of modernity and progress which characterised the development of hydroelectricity in this period.

The Lochaber powerhouse and smelter form part of one of the most significant British engineering achievements of the 20th century. The creation of a pressure tunnel bored through solid bedrock under the flanks of Ben Nevis to connect the powerhouse with the Laggan and Treig reservoirs was a major technological achievement. The scheme was designed to a very high degree of detail, capturing every available

water supply available and was highly efficient.

The development of the Lochaber scheme predates the 1943 Hydroelectric (Scotland) Act which formalised the development of Hydroelectricity in Scotland and led to the founding of the North of Scotland Hydroelectric Board. Those developments which predated the 1943 act were developed by individual companies as a response to particular market and topographic conditions. The completion of a number of schemes (including Galloway, Grampian and those associated with Alcan - see separate listings) without a national strategic policy framework is exceptional as is the consistency of high quality aesthetic and engineering design across all of the schemes.

Sir William Halcrow was one of the foremost engineers of the 20th century, and was highly experienced in the development of hydroelectricity having served his apprenticeship with Thomas Meik and Sons who were responsible for both Kinlochleven and Lochaber water power schemes on behalf of the British Aluminium Company (see separate listings). His work on the Grampian scheme came in between the Kinlochleven and Lochaber developments, and his experience in developing the Kinlochleven scheme can clearly be seen in the highly efficient pioneering nature of the Tummel Garry development. Halcrow's association with hydropower and water engineering was longstanding and after 1943 he went on to work on a number of projects for the North of Scotland Hydro-Electric Board including the Glen Affric and Glen Morriston schemes. The company also completed work elsewhere in the UK and overseas.

Later alterations have been made to the wave walls, increasing their height and strength following inspections carried out under the 1975 Reservoirs Act.

(Reviewed as part of Hydroelectric Power Thematic Survey, 2010)

External Links

• Historic Environment Scotland Listing
• Wikidata Q17826037

External links are from the relevant listing authority and, where applicable, Wikidata. Wikidata IDs may be related buildings as well as this specific building. If you want to add or update a link, you will need to do so by editing the Wikidata entry.

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