Lochan Shira, Dam
Dam (20th Century)
Site Name Lochan Shira, Dam
Classification Dam (20th Century)
Alternative Name(s) Sloy Hydroelectric Power Scheme; Lochan Shira Reservoir; River Shira; Glenshira Reservoir; ; Glenshira Dam; Lochan Shira Mor
Canmore ID 277917
Site Number NN12SE 9.01
NGR NN 16375 20190
Datum OSGB36 - NGR
Permalink http://canmore.org.uk/site/277917
- Council Argyll And Bute
- Parish Glenorchy And Inishail (Argyll And Bute)
- Former Region Strathclyde
- Former District Argyll And Bute
- Former County Argyll
NN12SE 9.01 16395 20195
Dam [NAT]
OS 1:10,000 map, 1990.
(Name cited as Lochan Shira Mor, and date as 1959). This round-headed buttress dam was built as part of the Glen Shira [2nd] phase of the Loch Sloy scheme. The contractors were A and M Carmichael Ltd.
J Miller 2002.
This dam has been built across the River Shira, which here forms the boundary between the parishes of Glenorchy and Inishail (to the NW) and Inveraray (to the SE).
The location assigned to this record indicates the centre of the monument. The available map evidence indicates that it extends from NN c. 16136 20397 to NN c. 16643 19953.
Information from RCAHMS (RJCM), 29 December 2005.
Construction (1956)
This dam part of the Glen Shira hydro electric scheme to harness Shira and Fyne rivers and adjacent burns between Loch Fyne and Loch Awe. Completed 1956.
Publication Account (2007)
The Glen Shira Hydro-Electric project was designed to harness the Shira and Fyne and adjacent streams between Loch Fyne and Loch Awe. The Shira Dam is the centrepiece of the scheme and is 133 ft high and 2250 ft long. It is a mass concrete round-head buttress-type dam, the heads of the buttresses being of angular shape rather than truly curved as at Sloy Dam. The project generates 45MW.
The geography of the catchment area led to the construction of a smaller concrete and earth filled dam, 58 ft high, below the main dam to fully utilise the storage potential. This lower reservoir is also used for pumped storage to top up the upper reservoir as required. The high-pressure tunnel to the main dam’s power station is unusual in that it is a partly sloping shaft. It was driven almost entirely from the bottom, because the slope allowed most of the spoil to be removed with very little mechanical assistance.
The original scheme was conceived by James Williamson. The consulting engineers for the works as built were Babtie, Shaw & Morton and the main contractor was A. M. Carmichael of Edinburgh. The scheme was completed in 1956.
R Paxton and Jim Shipway 2007b
Reproduced from 'Civil Engineering heritage: Scotland - Highlands and Islands' with kind permission from Thomas Telford Publishers.
Field Visit (2010)
Shira Dam forms part of the phase II development of the Sloy catchment from 1959 onwards. The dam is a large scale round headed buttress dam with a central control tower and dispersal valve and small fixed spillway. The dam creates storage and flow regulation for Sron Mor power station (see separate item). Water leaves the dam via a tunnel through to the power station. This is a relatively large scale buttress dam set in a remote location in the upper reaches of Glen Shira. It is predominantly functional in design and of relatively standard engineering. P L Payne, 1988, 5; E Wood, 2002, 38; J Miller, 2002.
Note (26 October 2023)
The Shira scheme
Dams were built at Lochan Shira, Lochan Sron Mor and the reservoir supplying Allt na Lairige power station via a tunnel. Sron Mor power station is fed by an aqueduct from Lochan Shira. Aqueducts and a long tunnel supply Clachan underground power station at the top of Loch Fyne at a head of 965 feet. Sron Mor was supplied with pumping facilities in effect to give Clachan the advantage of pumped storage. The installed capacity of the scheme is 51MW. Construction took place between 1951 and 1959.
Information from NRHE item catalogue number WP007424, compiled by George Walker, 2005.
