The 2011 Mississippi River Floods have been the most damaging along the river since 1993 and may rival the Great Mississippi Flood of 1927. This natural disaster illustrates the importance of emergency planning and preparedness for areas that are more susceptible to severe weather. The Census Bureau has provided a number of reference maps that highlight the impact the floods will have on the population living along the Mississippi River and its tributaries, specifically in areas where the National Weather Service has described the outlook of flooding as either occurring or imminent. Numerous counties in several states have already been declared federal disaster areas.
The Mississippi River floods in April and May 2011 were among the largest and most damaging recorded along the U.S. waterway in the past century, comparable in extent to the major floods of 1927 and 1993.
In April 2011, two major storm systems deposited record levels of rainfall on the Mississippi River watershed. When that additional water combined with the springtime snowmelt, the river and many of its tributaries began to swell to record levels by the beginning of May.
Areas along the Mississippi itself experiencing flooding included Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.