Relationship of Turquoise Lake Levels to Mine Tunnel Flow in the Sugarloaf Mining District 2003-2005
Relationship of Turquoise Lake Levels to Mine Tunnel Flow inthe Sugarloaf Mining District 2003-2005
Study Area: Statewide
This study assesses the existence of a hydrologic connection between Turquoise Lake (near Leadville, Colorado) and downgradient, draining mine tunnels in the Sugarloaf mining district. Air photos that show increased wetland area downgradient of some mine tunnels after the raising of the Turquoise Lake dam in 1968 provide anecdotal evidence that raising the lake elevation increased the elevation of the local water table and increased discharge from the mine tunnels. Acid mine drainage from the tunnels degrades water quality in Lake Fork, a tributary to the Arkansas River. If there is a hydrologic connection between Turquoise Lake and the draining mine tunnels, any increase in lake elevation may promote increased flow from the tunnels, and increased water-quality degradation in the Lake Fork. The U.S. Bureau of Reclamation has a need to assess the existence of a hydrologic connection in order to plan appropriate remedial activities, if necessary, concurrent with dam enlargement.