Flood discharges in the upper Mississippi River basin, 1993

Abstract

During spring and summer 1993, record flooding inundated much of the upper Mississippi River Basin. The magnitude of the damages-in terms of property, disrupted business, and personal trauma-was unmatched by any other flood disaster in United States history. Property dam age alone is expected to exceed $10 billion. Damaged highways and submerged roads disrupted overland transportation throughout the flooded region. The Mississippi and the Missouri Rivers were closed to navigation before and after the flooding. Millions of acres of productive farmland remained under water for weeks during the growing season. Rills and gullies in many tilled fields are the result of the severe erosion that occurred throughout the Midwestern United States farmbelt. The hydrologic effects of extended rainfall throughout the upper Midwestern United States were severe and widespread. The banks and channels of many rivers were severely eroded, and sediment was deposited over large areas of the basin's flood plain. Record flows submerged many areas that had not been affected by previous floods. Industrial and agricultural areas were inundated, which caused concern about the transport and fate of industrial chemicals, sewage effluent, and agricultural chemicals in the floodwaters. The extent and duration of the flooding caused numerous levees to fail. One failed levee on the Raccoon River in Des Moines, Iowa, led to flooding of the city's water treatment plant. As a result, the city was without drinking water for 19 days. As the Nation's principal water-science agency, the U.S. Geological Survey (USGS) is in a unique position to provide an immediate assessment of some of the hydrological effects of the 1993 flood. The USGS maintains a hydrologic data network and conducts extensive water resources investigations nationwide. Long-term data from this network and information on local and regional hydrology provide the basis for identifying and documenting the effects of the flooding. During the flood, the USGS provided continuous streamflow and related information to the National Weather Service (NWS), the U.S. Army Corps of Engineers, the Federal Emergency Management Agency (FEMA), and many State and local agencies as part of its role to provide basic information on the Nation's surface-and groundwater resources at thousands of locations across the United States. The NWS has used the data in forecasting floods and issuing flood warnings. The data have been used by the Corps of Engineers to operate water diversions, dams, locks, and levees. The FEMA and many State and local emergency management agencies have used USGS hydrologic data and NWS forecasts as part of the basis of their local flood-response activities. In addition, USGS hydrologists are conducting a series of investigations to document the effects of the flooding and to improve understanding of the related processes. The major initial findings from these studies will be reported in this Circular series as results become available. U.S. Geological Survey Circular 1120, Floods in the...

Floodplain sedimentation and sensitivity: summer 1993 flood, Upper Mississippi River Valley

“…These climatic conditions were similar to those that prefaced the spring 1973 flood (Chin et al, 1975;Wahl et al, 1993;Parrett et al, 1993). Numerous gauging stations in the upper Mississippi River basin recorded record peak discharges during the summer of 1993, including gauges on the Mississippi River throughout the 300 km long reach between Keokuk, Iowa, and St Louis, Missouri, where the recurrence interval of the flood was >100 years (Parrett et al, 1993). Our survey of the geomorphological effects of the 1993 flood focused on the 70 km long reach between Keokuk, Iowa, and Hannibal, Missouri (Figure 1 ) peak discharges.…”

“…The storms arose from the highly anomalous circulation evident throughout much of the northern hemisphere that locally allowed the easterly flowing jet stream and its associated surface front, which spawned the recurrent thunderstorm systems, to establish a quasi-stationary position over the northern portion of the Mississippi River basin (Dowgiallo, 1994). These climatic conditions were similar to those that prefaced the spring 1973 flood (Chin et al, 1975;Wahl et al, 1993;Parrett et al, 1993). Numerous gauging stations in the upper Mississippi River basin recorded record peak discharges during the summer of 1993, including gauges on the Mississippi River throughout the 300 km long reach between Keokuk, Iowa, and St Louis, Missouri, where the recurrence interval of the flood was >100 years (Parrett et al, 1993).…”

“…Fisk, 1944;Chrzastowski et al, 1994;Jacobson and Oberg, in press). Record stages were recorded as far downriver as Thebes, Illinois, and the flood was equally protracted, although downriver from St Louis the recurrence interval of the 1993 flood was substantially less than 100 years (Parrett et al, 1993;Bhowmik, 1994). Low flows in the Ohio River and an increase in channel capacity were responsible for the additional reduction in the magnitude of the summer 1993 flood that was experienced downriver from Cairo, Illinois (Dowgiallo, 1994).…”

Restoring ecological integrity of great rivers: historical hydrographs aid in defining reference conditions for the Missouri River

“…However, sources of hydrologic alteration differed somewhat among the channelized-river stations and between them and 3336FB (Table 5). Notably, post-regulation magnitude and duration of annual maximum flows were higher at 317BV and 158HM than at other channelized sites because 317BV and 158HM were more affected by climatically driven flooding in 1993(Parrett et al, 1993Galat et al, 1998).…”

Flooded flatheads: evidence of increased growth in Mississippi River Pylodictis olivaris (Pisces: Ictaluridae) following the Great Midwest Flood of 1993

“…This event has become known to many as ''The Great Midwest Flood of 1993'' (Galat et al, 1996(Galat et al, :55, 1998. The biological consequences of this 1-in-100+ year event (Parrett et al, 1993;Kunkel et al, 1994;Malamud et al, 1996) were numerous, including:…”