Font Size

100% 150% 200%

Background Colour

Default Contrast
Close Reset

In recognition of the essential restrictions and measures imposed by the Scottish and UK Governments, we have closed all sites, depots and offices, including the HES Archives and Library, with immediate effect. Read our latest statement on Coronavirus (COVID-19).

Blackwater Reservoir, Dam

Dam (Period Unassigned)

Site Name Blackwater Reservoir, Dam

Classification Dam (Period Unassigned)

Alternative Name(s) Kinlochleven Hydroelectric Power Scheme; River Leven; Black Water; Blackwater Dam

Canmore ID 76813

Site Number NN26SW 3

NGR NN 24790 60371

Datum OSGB36 - NGR


Ordnance Survey licence number 100057073. All rights reserved.
Canmore Disclaimer. © Copyright and database right 2020.

Toggle Aerial | View on large map

Digital Images

Administrative Areas

  • Council Highland
  • Parish Lismore And Appin (Lochaber)
  • Former Region Highland
  • Former District Lochaber
  • Former County Argyll

Recording Your Heritage Online

Kinlochleven Pioneering hydroelectricity plant and (now demolished) aluminium smelter, with good survival of early company housing, dwarfed by the Mamore hills at the head of Loch Leven. Opened in 1909, it is now obsolete to its original function, but an ambitious programme of phased regeneration has established part of the site as an outdoor tourism and small business centre. There was an inn here in the 18th century (where Pennant breakfasted on minced stag), and, by about 1900, two lodges - Kinlochmore and Kinlochbeg. In 1904 an Act of Parliament established the Loch Leven Water and Electric Power Co, which merged with the North British Aluminium Co Ltd. (set up in 1894) and built the Aluminium Works, 1905-9. Operated by the largest British hydroelectric power station of its day, works consisted of a large factory block containing rows of 76 smelters (closed in 2000 and now demolished), a warehouse, carbon works and laboratory. The power house, with a dramatic long perspective of 10 pelton wheel turbines by Escherwyss of Zurich and an 11 th of similar design, is still in situ and, as such, almost unique. The water supply was fed by the Blackwater Reservoir four miles away, its mass concrete dam by engineers Thomas Meik & Sons, 1904-9, 1 km wide - the largest in Europe at that time. The carbon silos/bunkers, vast arcaded rubble blocks incorporating structures of early reinforced concrete by T. Meik & Sons and A. H. Roberts, were converted in 2002 by Bruce & Neil Architects for the Kinlochleven Land Development Trust as an outdoor activity/interpretation centre and micro brewery. Most of the rest of the carbon factory was demolished in 1989.

[The North British Aluminium Company was set up in 1894 with Lord Kelvin as technical adviser.]

Taken from "Western Seaboard: An Illustrated Architectural Guide", by Mary Miers, 2008. Published by the Rutland Press

Archaeology Notes

NN26SW 3.00 24790 60371

Dam [NAT] (at NN 247 603)

OS 1:10,560 map, 1968.

NN26SW 3.01 NN 24731 60260 to NN 20214 60445 Aqueduct

NN26SW 3.02 [NN 202 604 to NN 247 602] Possible construction railway

NN26SW 3.03 NN 20188 60458 Lower Penstock Valve House

For (associated) Blackwater Reservoir (NN 30500 60200), see NN36SW 2.

For associated burial-ground (navvies' or construction graveyard) at NN 24213 60253, see NN26SW 4.

For (relevant) field survey area (AOC, 1997), see NN26SW 27.

Location formerly cited as NN 247 603.

Extends across parts of map sheet and Kilmallie parish.

This dam was constructed to impound the Blackwater Reservoir (NN36SW 2), which formerly supplied water for hydro-electric power generation at Kinlochleven Aluminium Works (NN16SE 3.00).

The location assigned to this record indicates the apparent midpoint of the structure. The available map evidence suggests that it extends from NN c. 24944 60770 to NN c. 24612 59900; the norrthern parts extends into Kilmallie parish.

Information from RCAHMS (RJCM), 9 June 2006.


Publication Account (2007)

Kinlochleven Hydro-Electric Works and Blackwater Dam

(Institute Civil Engineers Historic Engineering Works no. HEW 0611/0611)

The Loch Leven Water Power Acts of 1901 and 1904 authorised the generation of electricity for the production of aluminium in the West Highlands. Work on what was the first major hydro-electric project in Britain began in 1905 by harnessing the water power available from the

western section of the Blackwater chain of lochs stretching from Rannoch Moor to Kinlochleven and was completed in 1909 at a cost of about £600 000.

The Blackwater was dammed to create an 8-mile long reservoir drawing on a catchment area of about 55 square miles. Water from the dam was led to a generating station at the head of Loch Leven which supplied electricity to the aluminium smelters and associated works. The Pelton

wheel turbines produced an aggregate power of 30 660 hp with an generator output of 21 088 kW.

The main feature of the hydro scheme was a mass concrete gravity dam 3112 ft long and 86 ft high. It was necessary to amend the cross-section of the dam when it was found that the unit weight of concrete made with

locally obtained aggregate was less than that used previously in calculations. The dam profile was amended to give a heavier section with a base 62 ft wide and a factor of safety against overturning of 2.28.

The dam, with a storage capacity for 24 billion gallons, was connected to the 25MW generating station through a closed concrete conduit 3 1/2

miles long and six steel pipes each 39 in. diameter and 935 ft long.

The transport of materials to site from the wharf at Loch Leven was by means of a cableway 6 1/2 miles long with trestles from 10 ft–130 ft high and spans from 100 ft–1000 ft driven by a 250 hp Pelton wheel. A railway between the same termini followed the general contour of the valley

except for two rope inclines of 200 ft and 600 ft rise. This and the derricks at the dam were electrically driven, the power being obtained from a temporary hydro-electric plant provided by the contractor.

The works were designed by Thomas Meik and Sons with Sir A. R. Binnie consulting and the resident engineer A. H. Roberts. The main contractor was Sir John Jackson Ltd, and during construction between two and three thousand navvies laboured in rain-soaked conditions. During one period of 24 hours 5.59 in. of rain fell at Kinlochleven drowning the inner shell dam by 15 ft but it stood perfectly. Robert McAlpine & Sons constructed the jetty and laid the water mains throughout the village.

R Paxton and J Shipway, 2007.

Reproduced from 'Civil Engineering heritage: Scotland - Highlands and Islands' with kind permission from Thomas Telford Publishers.

Field Visit (2010)

The Blackwater dam created the Blackwater Reservoir to provide water for hydro generation at the Kinlochleven smelter (see separate record above). The dam was a massive undertaking at the time, built as a gravity dam over 86 feet high and 62 feet thick at its base with a length of over half a mile.The dam is of a large scale for its date, and was constructed in rugged and difficult terrain. Although lacking in any significant degree of technical innovation as seen at later dams, such as Laggan, the scale of the dam provided the most significant technical challenge. It was reputed to be the longest dam in the world at the time of its completion and is also an early use of mass concrete in dam construction of this type with Sir Robert MacAlpine as principal contractor. Architectural detail is limited to the central valve house which echoes the functional classicism of the powerhouse. The landscape presence of the dam is significant with the battered downstream face visible from the West Highland Way. A Scott, The British Aluminium Company’s Works in Constructional & Engineering IV, 1909, p 587; Alcan, n.d., The Lochaber Water Scheme; Concrete and Constructional Engineering, 1909; P L Payne, 1988; E Wood, 2002.


MyCanmore Image Contributions

Contribute an Image

MyCanmore Text Contributions