The Snowy Mountains scheme was one of the world’s largest ever civil engineering projects. The aim of the scheme was to generate electricity and to provide irrigation to areas of NSW, Victoria and the ACT. The waters of the Snowy River and several smaller rivers were redirected through tunnels under the mountains of the Great Dividing Range and through dams. As the water falls past the various power stations, it generates electricity. The longest tunnel, which connects the Snowy River to Lake Eucumbene, is 24.3km long and 6.7m in diameter. Many of the people who worked on the scheme were recent migrants to Australia who brought specialist skills and knowledge to the project. Overall the work was done quickly and efficiently, and when the entire scheme was completed in 1974 it was ten years ahead of schedule and had cost a total of $800 million.