Constructing the mine

The design and construction of the Diavik mine is a success on a grand scale in the most forbidding of places. Open-pit mining could only safely operate if the waters of Lac de Gras could be held at bay with certainty, so a unique 3.9km rockfill dike had to be built into the lake. Not only did the extremely harsh climatic conditions present significant construction challenges, but nothing was allowed to blemish the pristine waters of the lake during its building. International searches were mounted to determine the best methods to be used and, eventually, new engineering technologies were developed to achieve the task. So unusual was the approach, both in Canada and across the world, that a dike review board - consisting of five distinguished independent dam engineers - was appointed to oversee its development.

Some highlights:

• The dike design, engineering and construction played a key role in allowing Diavik to safely open pit mine world class rough diamonds and as a result Diavik has grown to generate approximately 25 per cent of the Northwest Territories' Gross Domestic Product, and be one of the North's largest employers with a workforce of approximately 750 people many of whom live in the North (69 per cent). Half the Northern workforce is Aboriginal. In terms of business, Diavik's northern spending total is $1.7 billion, of which $1 billion is with northern Aboriginal businesses.
• The dike received Canada's highest award for engineering excellence - from the Canadian Council of Professional Engineers - and the engineering model is now widely applicable across the Tundra.
• The construction project engaged the Soviet military's machine's most powerful computer to solve the problem of predicting the drift of fine sediment in wind-generated currents, one of engineering mathematics most intractable problems.
• In another feat of ingenuity, a brief, seasonal ice highway - operating eight to ten weeks per year and bridging frozen lakes and ponds and portages - links the mine to permanent roads. This winter road was needed to transport thousands of tonnes of construction materials to Diavik. Each year, Diavik, and other resource companies use the ice road for mine resupply. This includes millions of litres of fuel and other operations' supplies.
• Development of a water management system: 12 on-land engineered dams locked to permafrost and lined with geosynthetic material, successfully heat-welded under the coldest temperatures ever attempted. These state-of-the-art dams, are unusual in that they use their permafrost setting to their advantage. These on-land dams exist to ensure that no pollutants will ever enter Lac de Gras.