By mid- to late August, hikers will be asking rangers with the Indian Peaks Wilderness Alliance, “What's happened to the lake?” They'll be asking about Lake Isabelle, more than 30 acres of sparkling mountain beauty that are reduced to dull mudflats every summer. Lake Isabelle is drained by the Left Hand Ditch Company, which has owned the water rights at Isabelle since 1936, decades before passage of the 1964 Wilderness Act and congressional designation of the Indian Peaks Wilderness in 1978. The history of the Left Hand Ditch Company dates back even further, to 1866, when it was incorporated. Because Lake Isabelle is used to store water for irrigation, it is actually a reservoir, although a dam was never built to raise its level. Located near the middle of the lake is a drain that empties into a vertical shaft connected to a horizontal tunnel, which diverts the water eastward to where, I don't know.
Efforts to reach the Left Hand Ditch Company by email and telephone have been unsuccessful. As of Aug. 19, the lake had not been drained, according to the Boulder Ranger Station, which didn't know when the diversion would take place. So, if a hiker asks you, “What's happened to the lake?” you can give them a brief history of Lake Isabelle and her water rights.
– David Hatcher is a 6th-year IPWA Volunteer
Photos of Lake Isabelle Drained (Forest Service, Aug. 2015)
Special thanks to historian Sue Struthers with the Forest Service. For more information about water rights in Colorado, check out the books: "A Land Made from Water: Appropriation and the Evolution of Colorado's Landscape, Ditches, and Water Institutions" (Robert R. Crifasi, 2015), and "Water: Basis for Success, Left Hand Ditch Company History, the First 130 Years" (S. Alice Ochs, 1996).