The Lochaber hydroelectric scheme was a hydroelectric power generation project constructed in the Lochaber

Lochaber

District of Lochaber 1975 to 1996Highland council area shown as one of the council areas of ScotlandLochaber is one of the 16 ward management areas of the Highland Council of Scotland and one of eight former local government districts of the two-tier Highland region...

 area of the western Scottish Highlands

Scottish Highlands

The Highlands is an historic region of Scotland. The area is sometimes referred to as the "Scottish Highlands". It was culturally distinguishable from the Lowlands from the later Middle Ages into the modern period, when Lowland Scots replaced Scottish Gaelic throughout most of the Lowlands...

 after the First World War

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. Like its predecessor at Kinlochleven

Kinlochleven

Kinlochleven is a village in Lochaber, in the Scottish Highlands and lies at the eastern end of Loch Leven, a sea loch cutting into the western Scottish Highlands. To the north lie the Mamores ridge; to the south lie the mountains flanking Glen Coe...

, it was intended to provide electricity for aluminium

Aluminium

Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 production, this time at Fort William, a little further north. The scheme was initially designed by engineer

Engineer

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

 Charles Meik

Charles Meik

Charles Meik was an English engineer and part of a minor engineering dynasty. His father Thomas Meik was also an engineer, as was Charles' brother Patrick Meik; collectively, they established a company which is now one of the UK's major engineering consultancies.Both boys were born in Crow Tree...

 but after his death in 1923, the scheme’s realisation was left to William Halcrow

William Halcrow

Sir William Halcrow was one of the most notable English civil engineers of the 20th century, particularly renowned for his expertise in the design of tunnels and for projects during the Second World War.-Early years:...

, by then a partner in the firm originally founded by Meik’s father Thomas Meik

Thomas Meik

Thomas Meik was a British engineer, born in Duddingston, Midlothian. He was particularly associated with ports and railways in Scotland and northern England, and fathered two prominent engineering sons: Patrick Meik and Charles Meik...

.

The project was finally sanctioned by Parliament in 1921, but construction did not start until 1924; the aluminium smelter was established in 1929 and took about 95% of the of power generated.

The scheme harnessed the headwaters of the Rivers Treig and Spean and the floodwaters of the River Spey

River Spey

The River Spey is a river in the northeast of Scotland, the second longest and the fastest-flowing river in Scotland...

 (plus a further eleven burn

Burn (stream)

In Scotland, North East England and some parts of Ireland and New Zealand, burn is a name for watercourses from large streams to small rivers. The term is also used in lands settled by the Scots and Northern English in other countries, notably in Otago, New Zealand, where much of the naming was...

s along the way). The Laggan Dam

Laggan Dam

Laggan Dam is a dam located on the River Spean south west of Loch Laggan in the Scottish Highlands. The dam is 700 feet long and rises 170 feet above its foundations, and is part of the Lochaber hydro-electric scheme...

 ( long and high) contained the flow of the Spean in a reservoir (Loch Laggan

Loch Laggan

Loch Laggan is a freshwater loch situated east of Fort William, in Lochaber, Highland, Scotland. The A86 road from Spean Bridge to Kingussie follows along its north bank...

). A tunnel

Tunnel

A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...

 then linked this body of water with another reservoir (Loch Treig

Loch Treig

Loch Treig is a 9 km freshwater loch situated in a steep-sided glen 20 km east of Fort William, in Lochaber, Highland, Scotland...

) contained by the Treig dam. From here, the main tunnel, until 1970 the longest water-carrying tunnel in the world, an enormous long and in diameter, was driven around the Ben Nevis

Ben Nevis

Ben Nevis is the highest mountain in the British Isles. It is located at the western end of the Grampian Mountains in the Lochaber area of the Scottish Highlands, close to the town of Fort William....

 massif. From the western mountainside, down five massive steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 pipes, the water rushed towards the turbine

Turbine

A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...

s in the power house at the smelting

Smelting

Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...

 plant.

The hydro-electric scheme and smelter are now operated by Rio Tinto Alcan.