Potential environmental hazard due to tailings dam failure in Minnesota iron range and safety concern of the Dams in the US

Clara Lee, Fei Liu

An ongoing debate centered around mining operations and tailings dam usage near the Minnesota mining range led to an investigation of potential environmental hazards near the cities of Hoyt Lakes and Embarrass. Topographic data from Satellite observations made available by USGS and HEC-RAS developed by US Engineer Corp are used to simulate the extent of mud flow from a hypothetical tailings dam break at the proposed mining site. Simulation results indicate significant flooding and pollution in the city of Embarrass, the lakes near The Legend at Giants Ridge, and the Embarrass River flowing southwest. Parts of the mud flow can also reach the area northwest of Lost Lake. Recent dam breaks in Michigan prompted a survey of the dams across the entire US in connection with annual average precipitation and number of Earthquake statistics per State. The States with high precipitation and Earthquake events are especially vulnerable for dam breaches since precipitation and seismic activities are major causes of dam breach events. In conclusion, Dam breaches is a serious threat to the US water system, especially as the dams are aging and lack appropriate levels of maintenance. Finally we discuss additional work using different modes of failure and dam breach parameters that may affect the downstream flooding patterns simulated.