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2024 Hennepin County All -Jurisdiction Hazard Mitigation Plan <br />Volume 2 — Hazard Inventory <br />Inspections and maintenance of lines in vulnerable locations should be a priority to <br />reduce risk. Water and sewer lines are also vulnerable to damage and destruction by <br />landslide events. <br />4.1.1.3.1.4. Energy pipelines: Gas lines and other energy pipelines that pass -through <br />landslide susceptible areas may become weakened or severed by slide action. Damages <br />may be caused by direct physical impacts or by indirect transmission of stresses through <br />soil to the pipeline causing weaknesses or deformation of the lines. <br />4.1.1.3.1.5. Telecommunications: Telecommunications cables that pass -through <br />landslide susceptible areas may become weakened or severed by slide action. Damages <br />may be caused by direct physical impacts or by indirect transmission of stresses through <br />soil to the cable causing weaknesses or deformation of the lines. Fiber optic lines are <br />particularly susceptible to deformation which can cause erratic signals or total signal loss. <br />4.1.1.3.1.6. Structural damage: Landslides impacts to structures ranges from rapid <br />catastrophic destruction resulting from a landslide impact to gradual degradation of <br />structures from slow earth movements. Complex load factors act on structures that are <br />subject to landslide forces. Engineering assessment of compromised structures is vital to <br />both response and recovery phases of a landslide incident. Landslide impacts to <br />structures is both a life -safety hazard and can also be an occasion for costly property <br />damage. <br />4.1.1.3.1.7. Recreational impacts: Parks and trails are frequently placed in areas subject <br />to landslides. Often parks or trails are in scenic areas in ravines or valleys associated with <br />rivers with natural slopes being a main feature. They may also be part of former railroad <br />rights -of -way that have been abandoned. Human -modified slopes or other historic <br />disruptions of natural soils and terrain can elevate landslide susceptibility in parklands. <br />Slides in parks and trails is a risk to lives and safety, as well as a costly disruption to <br />recreation activities. <br />4.1.1.3.2. SECONDARY CONSEQUENCES: <br />4.1.1.3.2.1. Hazardous material spill or release: If cut by a landslide, pipelines may <br />release hazardous liquids or gasses, or polluting materials that can threaten lives, impact <br />property or harm the environment as a secondary hazard after the landslide. <br />4.1.1.3.2.2. Fire or explosion: In certain instances, landslides may trigger fires or <br />explosions at the site of buildings or other impacted structures, or where pipelines or <br />service lines carrying gas or other flammable material. <br />4.1.1.4. Potential for Cascading Effects <br />4.1.1.4.1. Life -Safety: Landslides can result in deaths and have done so in Hennepin County (1955) <br />and adjacent metro counties (2013). Injuries have resulted in numerous other instances, as well <br />as close calls. The landslide at Fairview -Riverside hospital in Minneapolis (2014) narrowly missed <br />pushing passing motorists on West River Road into the Mississippi River, for instance. <br />14 <br />