Columbia Lake is a fresh water lake located along Highway 93 and 95, between the centres of Canal Flats and Fairmont Hot Springs in British Columbia, Canada. Its average July temperature of 18°C makes it the largest warm water lake in the East Kootenay. It has a typical depth of 15 feet with excellent water clarity as it enjoys a much smaller volume of boat traffic than its northern neighbour, Windermere Lake. 
The Kootenay River, a major tributary of the Columbia, passes within a few thousand feet of the south end of the lake. In freshets the Kootenay, here already a large stream, sometimes overflows into Columbia Lake, and historically the Baillie-Grohman Canal connected the two bodies of water to facilitate the navigation of steamboats (although only three trips were ever made through it).