The Mississippi River is the primary river, and second-longest river, of the largest drainage basin in the United States. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 miles (3,766 km) to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km2), of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
The Des Moines River is a tributary of the Mississippi River in the upper Midwestern United States that is approximately 525 miles (845 km) long from its farther headwaters. The largest river flowing across the state of Iowa, it rises in southern Minnesota and flows across Iowa from northwest to southeast, passing from the glaciated plains into the unglaciated hills near the capital city of Des Moines, named after the river, in the center of the state. The river continues to flow in a southeastern direction away from Des Moines, later flowing directly into the Mississippi River.
Illinois is in the midwestern United States. Surrounding states are Wisconsin to the north, Iowa and Missouri to the west, Kentucky to the east and south, and Indiana to the east. Illinois also borders Michigan, but only via a northeastern water boundary in Lake Michigan. Nearly the entire western boundary of Illinois is the Mississippi River, except for a few areas where the river has changed course. Illinois' southeastern and southern boundary is along the Wabash River and the Ohio River, whereas its northern boundary and much of its eastern boundary are straight survey lines. Illinois has a maximum north–south distance of 390 miles (630 km) and 210 miles (340 km) east-west. Its total area is 57,918 square miles (150,010 km2).
In mid-July 1951, heavy rains led to a great rise of water in the Kansas River, Missouri River, and other surrounding areas of the Central United States. Flooding occurred in the Kansas, Neosho, Marais Des Cygnes, and Verdigris river basins. The damage in June and July 1951 across eastern Kansas and Missouri exceeded $935 million. The flooding killed 17 people and displaced 518,000.
St. Louis is located at 38°38′53″N90°12′44″W.
Floods in the United States are generally caused by excessive rainfall, excessive snowmelt, and dam failure. Below is a list of flood events that were of significant impact to the country during the 20th century, from 1900 through 1999, inclusive.
The Great Flood of 1844 is the biggest flood ever recorded on the Missouri River and Upper Mississippi River in North America in terms of discharge. The adjusted economic impact was not as great as subsequent floods because of the small population in the region at the time. The flood devastation was particularly widespread since the region had few levees at the time, so the waters were able to spread far from the normal banks. Among the hardest hit in terms of mortality were the Wyandot Indians, who lost 100 people in the diseases that occurred after the flood in the vicinity of today's Kansas City, Kansas.
The Ohio River flood of 1937 took place in late January and February 1937. With damage stretching from Pittsburgh, Pennsylvania, to Cairo, Illinois, 385 people died, one million people were left homeless and property losses reached $500 million. Federal and state resources were strained to aid recovery as the disaster occurred during the depths of the Great Depression and a few years after the beginning of the Dust Bowl.
Floods in the United States (2000–present) is a list of flood events which were of significant impact to the country during the 21st century, since 2000. Floods are generally caused by excessive rainfall, excessive snowmelt, storm surge from hurricanes, and dam failure.
The Missouri River Valley outlines the journey of the Missouri River from its headwaters where the Madison, Jefferson and Gallatin Rivers flow together in Montana to its confluence with the Mississippi River in the State of Missouri. At 2,300 miles (3,700 km) long the valley drains one-sixth of the United States, and is the longest river valley on the North American continent. The valley in the Missouri River basin includes river bottoms and floodplains.
The June 2008 Midwestern United States floods were flooding events which affected portions of the Midwestern United States. After months of heavy precipitation, a number of rivers overflowed their banks for several weeks at a time and broke through levees at numerous locations. Flooding continued into July. States affected by the flooding included Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri and Wisconsin. The American Red Cross assisted the victims of flooding and tornadoes across seven states and the National Guard was mobilized to assist in disaster relief and evacuation.
The Iowa flood of 2008 was a hydrological event involving most of the rivers in eastern Iowa which began June 8 and continued until July 1. Flooding continued on the Upper Mississippi River in the southeastern area of the state for many more days. The phrase "Iowa's Katrina" was often heard.
Major floods along the Mississippi River 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 Great Mississippi Flood of 1927 and Great Flood of 1993. In April 2011, two large storm systems deposited record levels of rainfall on the Mississippi River drainage basin. 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. Flooding occurred in Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
The Mississippi flood of 1973 occurred between March and May 1973 on the lower Mississippi River. The flooding was the third most severe along the U.S.'s Mississippi River during the 20th century.
The 2011 flooding event on the Missouri River in the United States was triggered by record snowfall in Rocky Mountains of Montana and Wyoming along with near-record spring rainfall in central and eastern Montana. All six major dams along the Missouri River released record amounts of water to prevent overflow which led to flooding threatening several towns and cities along the river from Montana to Missouri; in particular Bismarck, North Dakota; Pierre, South Dakota; Dakota Dunes, South Dakota; South Sioux City, Nebraska, Sioux City, Iowa; Omaha, Nebraska; Council Bluffs, Iowa; Saint Joseph, Missouri; Kansas City, Missouri; Jefferson City, Missouri, and St. Louis, Missouri. Many smaller towns were also at risk, suffering the same fate as the larger cities if not worse. According to the National Weather Service, in the second half of the month of May 2011, almost a year's worth of rain fell over the upper Missouri River basin. Extremely heavy rainfall in conjunction with an estimated 212 percent of normal snowpack in the Rocky Mountains contributed to this flooding event.
The Great Flood of 1913 occurred between March 23 and March 26, after major rivers in the central and eastern United States flooded from runoff and several days of heavy rain. Related deaths and damage in the United States were widespread and extensive. While the exact number is not certain, flood-related deaths in Ohio, Indiana, and eleven other states are estimated at approximately 650. The official death toll range for Ohio falls between 422 and 470. Flood-related death estimates in Indiana range from 100 to 200. More than a quarter million people were left homeless. The death toll from the flood of 1913 places it second to the Johnstown Flood of 1889 as one of the deadliest floods in the United States. The flood remains Ohio's largest weather disaster. In the Midwestern United States, damage estimates exceeded a third of a billion dollars. Damage from the Great Dayton Flood at Dayton, Ohio, exceeded $73 million. Indiana's damages were estimated at $25 million. Further south, along the Mississippi River, damages exceeded $200 million. Devastation from the flood of 1913 and later floods along the Mississippi River eventually changed the country's management of its waterways and increased federal support for comprehensive flood prevention and funding for flood control projects. The Ohio Conservancy Act, which was signed by the governor of Ohio in 1914, became a model for other states to follow. The act allowed for the establishment of conservancy districts with the authority to implement flood control projects.
The Midwestern United States experienced major floods in the spring of 2019, primarily along the Missouri River and its tributaries in Nebraska, Missouri, South Dakota, Iowa, and Kansas. The Mississippi River also saw flooding, although starting later and ending earlier. The 2019 January-to-May period was the wettest on record for the U.S., with multiple severe weather outbreaks through May in the Midwest, High Plains, and South exacerbating the flooding and causing additional damage. Throughout late May and early June, rain in Iowa, Illinois, and Missouri caused every site on the Mississippi River to record a top-five crest. At least three people in Iowa and Nebraska died.
Flooding in the Mississippi River Basin during the winter, spring, and summer of 2019 caused at least 12 deaths and economic losses in 19 states totaling in excess of $20 billion. Estimated damages in the Midwestern United States alone had reached $12.5 billion by April 2019. Flood damages totaling $6.2 billion were reported in the 11 states bordering the Mississippi River. In addition to property and crop losses and infrastructure damages, commercial navigation on the Mississippi River was interrupted repeatedly by high currents, low bridge clearances, and closed locks. This delayed shipments of agricultural commodities, adding to the economic stress of crop losses caused by flooding. As of late April 2019, shipments of corn to export terminals in Louisiana were 31% lower than in same period in 2018.
In April 2013, persistent heavy rains caused widespread flooding, primarily impacting the Midwestern and Great Lakes regions. In a span of two days on April 17 and 18, heavy rainfall associated with a slow-moving storm system caused widespread flooding across rivers and areas, where rainfall amounts over 8 inches (200 mm) caused rivers to swell and crest, including the Mississippi River and the Red River, with the latter river dealing with melting ice caps. The Grand River crested to a record level, prompting water rescues and evacuations in Grand Rapids, Michigan. A local state of emergency was declared for the city of Des Plaines, Illinois after the Des Plaines river swelled to 10.92 feet (3,330 mm). The governors of Illinois and Missouri declared state of emergencies, and the Federal Emergency Management Agency declared a federal emergency and a disaster declaration for 46 counties in Illinois. Five fatalities occurred: two each in Illinois and Indiana, with a fifth in Missouri. Three others were injured, all in Illinois.
