Laserfiche WebLink
<br />Ramsey County | Multi-Jurisdiction Hazard Mitigation Plan 41 <br />• Long-term economic challenges due to the cost of rebuilding and the potential for reduced <br />investment and tourism. <br />• Potential loss of jobs and income. <br />Impact on Public Confidence in the Jurisdiction's Governance <br />• Erosion of public trust if the flooding is perceived as preventable or if the response is <br />inadequate. <br />• Increased scrutiny of floodplain management, land-use planning, and emergency preparedness <br />policies. <br />3.8 Geologic Hazards <br />3.8.1 PROFILE <br />A geologic hazard is an adverse geological condition causing damage or loss of property or life. These <br />hazards only become hazards when they impact life or property and are very much a normal part of <br />environmental processes. Ramsey County is at risk of a variety of geologic hazards, the most common of <br />which are: <br />• Landslide: The downward movement of a mass of rock, soil, and debris along a slope or cliff <br />face. This movement can range from gradual, slow displacement to rapid, catastrophic events. <br />Landslides are typically triggered by factors such as heavy rainfall, earthquakes, volcanic activity, <br />or human activities that destabilize slopes. Examples of landslides include rock falls and debris <br />flows. According to the United States Geological Survey, the most common type of landslides in <br />Minnesota are shallow slope failures that occur during heavy rain. <br />• Land subsidence: The gradual sinking or settling of the earth's surface, often due to the <br />compaction of underground layers of soil, sediment, or rock. This phenomenon can occur <br />naturally or be exacerbated by human activities such as groundwater extraction, oil and gas <br />extraction, mining, or the drainage of organic soils. Examples of land subsidence include <br />sinkholes and soil compaction. According to the USGS, more than 80% of the identified <br />subsidence in the United States is a consequence of human impact on subsurface water and is <br />an often-overlooked environmental consequence of land and water-use practices. Increasing <br />development can exacerbate subsidence problems and initiate new ones. <br />3.8.2 LOCATION <br />Parts of Ramsey County sit on a thick layer of limestone rock that is riddled with small holes and caves, <br />known as karst topography. Its large rivers and hills also create many slopes and cliffs. Heavy surface <br />rains may cause karst landscapes to fail causing landslides or sinkholes. Figure 10 shows karst <br />distribution throughout Minnesota.