Minnesota Regions Prone to Surface Karst Feature Development

Maps created using this product can be used as standalone products or can be used in conjunction with the Minnesota Karst Features Database for planning purposes (see Section 5 Detailed Citation). When combined with the Minnesota Karst Features Database this GIS coverage can be used to document the occurrence and distribution of sinkholes and other surface karst features for planning, environmental and risk management, hazard mitigation, scientific, and other purposes. The coverage outlines areas where karst features may form on the land surface and where karst conditions are likely present in the subsurface. Karst processes provide a direct, very rapid exchange between surface and ground waters and significantly increase groundwater contamination risk from surface pollutants. A field-verified sinkhole is direct evidence that karst processes are active both on the surface and subsurface. The absence of sinkholes on the land surface does not imply that karst conditions are absent in the subsurface. Subsurface karst conditions also occur in carbonate rock in areas where there is more than 50 feet of unconsolidated material over bedrock but those conditions rarely lead to karst surface feature development in Minnesota.