Diamond Mining in Canada!

That is an incredible feat of engineering! The dikes (or rock dams) built at the Diavik Diamond Mine are widely considered masterpieces of modern civil engineering, especially given the harsh subarctic conditions of Canada's Northwest Territories. To safely mine the diamond-bearing kimberlite pipes (named A154 North, A154 South, A418, and A21) located directly beneath the waters of Lac de Gras, engineers couldn't simply dig. They had to hold back the lake. Here is how they accomplished this massive undertaking: • Water-Tight Barriers: They constructed miles of crushing rockfill dikes directly through the lake water. To prevent water from seeping through the porous rock, they injected a specialized plastic concrete cutoff wall down into the lakebed sediment and bedrock. • Dewatering: Once a section of the lake was fully enclosed by the dike, millions of gallons of water were pumped out, exposing the lake floor. • Freezing the Ground: Because the mine is in a permafrost region, they utilized "thermosyphons"—tubes that draw heat out of the ground—to keep the foundation of the dams frozen and structurally stable year-round. This approach allowed them to successfully conduct open-pit mining (and later, underground mining) right in the middle of a frozen lake, turning Diavik into one of the world's premier producers of high-quality gemstones.