IL

Storm restoration across Monroe County

Monroe County sits along the Mississippi River bluffs in southwestern Illinois within the St. Louis metro area, making it a recurring target for the full spectrum of Midwest severe weather. Tornadoes are a documented and ongoing threat, with 26 recorded events from 1805 through 2011 including EF2 strikes near Waterloo in 2010 and 2011; the county has also sustained F3 tornado damage as recently as the late 19th century. Large hail and straight-line winds accompany the same supercell and squall-line systems that move northeast out of Missouri, while derechos tracking along the Missouri-Illinois corridor regularly produce widespread wind damage across both the river bluffs and interior farmland. The western lowlands along the American Bottom floodplain carry severe flood risk from Mississippi River overflows and levee failures, most catastrophically during the 1993 Great Flood, which inundated roughly 70,000 acres of Monroe County cropland and forced the entire town of Valmeyer to relocate to higher ground; flash flooding from heavy rain events adds an additional, independent flood hazard across the county's karst terrain.