From The Estes Park Trail (John Cordsen):
“…the only option available to the park is to repair the dam, ” said park superintendent Vaughn Baker during his May report to the Estes Park board of trustees.
The work was required after the U.S. Bureau of Reclamation rated the Lily Lake Dam, located in Rocky Mountain National Park, as a high-hazard dam. This study was released in 2010. Failure of the dam was not imminent, which gave park staff time to evaluate long-term solutions, which ultimately became one option because of the legal requirements to maintain the water rights.
The Lily Lake Dam is situated at the headwaters of Fish Creek, which flows into Lake Estes in Estes Park. Fish Creek is about 5 miles in length and the elevation difference between Lily Lake and Lake Estes is about 1,500 feet. If the dam were to fail, the ensuing floodwaters could result in the loss of life and property along Fish Creek…
Repair to the Lily Lake Dam will be done in a manner to retain the lake and its features in a manner similar to what currently exists. The repair work may last through the end of November. During the repair work, a roughly 500-foot area of the Lily Lake Trail across the dam will be closed…
The repairs will involve the removal of surface vegetation on the downstream face of the dam, stripping and salvage of topsoil, regrading the downstream face of the dam and the area around the toe of the dam, placement of filter fabric (geotextile), filter gravel and another layer of filter fabric and installation of articulated concrete blocks (ACB).