Geology topics

Research about upper Mississippi River basin

Source-linked reports with geographic coverage including upper Mississippi River basin.

8 recordsLinked to original sources

USGS2022

Recommendations regarding water level management to achieve ecological goals in the Upper Mississippi River System

The Water Level Management Regional Coordinating Committee tasked an ad hoc group to employ structured decision making (SDM) practices to reach partnership agreement around a set of basic recommendations as to when, where, and why WLM should be used as an ecosystem restoration tool in the UMRS. Between April 2021 and August 2021, the Upper Mississippi River Basin Association (UMRBA; www.umrba.org) hosted a series of six virtual meetings for the ad hoc group to evaluate the issues, explore agency perspectives, and develop shared recommendations for WLM implementation. This report describes the process and outcomes of the SDM exercise.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2000

Water quality in the upper Mississippi River basin, Minnesota, Wisconsin, South Dakota, Iowa, and North Dakota, 1995-98

The report summarizes major findings about water quality in part of the upper Mississippi River basin that emerged from an assessment conducted from 1995 to 1998 by the NAWQA Program. Water quality is discussed in terms of local and regional issues and compared to conditions in the other 36 NAWQA study units assessed to date. Findings are also explained in the context of selected national benchmarks, such as those for drinking-water quality and the protection of aquatic organisms. Finally, this report includes information about the status of aquatic communities and the condition of instream habitat. Many topics covered in the report reflect concerns of officials of State and Federal agencies, water-resource managers, and members of stakeholders groups who provided advice and input during the assessment.

Iowa, Minnesota, North Dakota, South Dakota, Wisco↗

USGS1998

Delineation of flooding within the upper Mississippi River basin: Flood of August 1-3, 1993, in St. Louis and vicinity, Missouri

A five-sheet hydrologic investigations atlas provides flood-peak elevation data and delineates the areal extent of flooding of the Missouri, the Mississippi, and the Meramec Rivers and the River des Peres in St. Louis and vicinity from August 1 through 3, 1993. The August 1993 flood is compared with the Federal Emergency Management Agency's (FEMA) 100- and 500-year flood profiles. This atlas is one of a series of USGS reports that documents the 1993 flooding in the upper Mississippi River Basin. The information presented here will improve the technical base on which flood-plain management decisions can be made.

Missouri↗

USGS1995

Propagation and composition of the flood wave on the upper Mississippi River, 1993

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 damage 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, during, 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 ground-water 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 Upper Mississippi River Basin, 1993, consists of individually published chapters that will document the effects of the 1993 flooding. The series includes data and findings on the magnitude and frequency of peak discharges; precipitation; water-quality characteristics, including nutrients and man-made contaminants; transport of sediment; assessment of sediment deposited on flood plains; effects of inundation on ground-water quality; flood-discharge volume; effects of reservoir storage on flood peaks; stream-channel scour at selected bridges; extent of floodplain inundation; and documentation of geomorphologic changes.

upper Mississippi River basin↗

USGS1995

Postflood occurrence of selected agricultural chemicals and volatile organic compounds in near-surface unconsolidated aquifers in the upper Mississippi River basin, 1993

The historic stream flooding and intense rainfall across the upper Mississippi River Basin during summer 1993 had an immediate effect on near-surface unconsolidated aquifers by raising the water levels closer to the land surface . The objective of this study was to determine if this flooding also had immediate effects on groundwater quality . Water samples were collected during September and October 1993 from 110 wells completed in near-surface unconsolidated aquifers and were analyzed for herbicides, herbicide metabolites, inorganic nutrients, and volatile organic compounds. The results of these samples were compared with those obtained during summer 1991 or 1992. The difference was not statistically significant in the frequency of herbicide detection, total herbicide concentration, nitrate concentration, or the frequency of volatile organic compound detection between water samples collected in 1991 and 1992 and those collected in 1993 when all 110 wells were considered collectively . However, water samples from the Missouri River alluvial aquifer had a fourfold increase in the frequency of herbicide detection . There also appears to be a relation between increases in total herbicide concentration and the occurrence of stream flooding near a well. Water samples from wells that had at least a 20-percent increase in dissolved-oxygen concentration had the greatest frequency of substantial changes in total herbicide concentration and substantial increases in nitrate concentration . Increased dissolved-oxygen concentration could indicate areas where recharge has increased as a result of extensive stream flooding and intense rainfall . An inverse relation was determined between well depth and changes (increase or decrease) in total herbicide concentration . Water in shallow wells more quickly reflect changes in water quality in response to changes in recharge. Significantly more urban residential and industrial land use was within a 30-meter radius of the well for wells in which volatile organic compounds were detected. Because water moves more slowly along ground-water flow paths compared with surface-water runoff, additional information is required to determine long-term effects of the 1993 flood on ground-water quality.

upper Mississippi River basin↗

USGS1995

Flood volumes in the upper Mississippi River basin, April 1 through September 30, 1993

Previous maximum flows on many streams and rivers were exceeded during the flood of 1993 in the upper Mississippi River Basin. Not only were peak discharges exceeded at many streamflow-gaging stations, but flood volumes were significantly higher than previous maximums. Rainfall amounts that were greater than 50 inches were recorded in parts of Kansas, Missouri, and Iowa from April 1 through September 30, 1993 . As a result of the excess rainfall, 53 of the 60 stations discussed in this report had flow volumes that were greater than twice the mean flow volume for April through September. The Mississippi River at St. Louis, Missouri, remained above flood stage for 144 days from April 1 to September 30, 1993, compared with 81 days during the 1973 flood. Of the 60 stations, 24 recorded new maximum 3-day flood volumes, and 47 recorded new maximum 120- day flood volumes. This indicates that the flooding of 1993 is significant with respect to its long duration and magnitude of flow . The same aspect is indicated in the frequency analysis of the 1993 flood. During the 1993 flood, the 100- year 3-day flows were exceeded at 22 stations, and the 120-day flows were exceeded at 43 stations.

upper Mississippi River basin↗

USGS1993

Flood discharges in the upper Mississippi River basin, 1993

From mid-June through early August 1993, flooding was severe in the upper Mississippi River Basin following a wet-weather pattern that persisted over the area for at least 6 months before the flood. The magnitude and timing of several intense rainstorms in late June and July, combined with wet antecedent climatic conditions, were the principal causes of the flooding. Flood-peak discharges that equaled or exceeded the 10-year recurrence interval were recorded at 154 streamflow-gaging stations in the upper Mississippi River Basin. At 41 streamflowgaging stations, the peak discharge was greater than the previous maximumknown discharge. At 15 additional gaging stations, peak discharges exceeded the previous maximum regulated peak discharge. At 45 gaging stations, peak discharges exceeded 100-year recurrence intervals.

upper Mississippi River basin↗

USGS1993

Precipitation in the upper Mississippi River basin, January 1 through July 31, 1993

Excessive precipitation produced severe flooding in a nine-State area in the upper Mississippi River Basin during spring and summer 1993. Following a spring that was wetter than average, weather patterns that persisted from early June through July caused the upper Midwest to be deluged with an unusually large amount of rainfall. Monthly precipitation data were examined at 10 weather-station locations in the flood-affected region to illustrate precipitation patterns and amounts in the flood-affected area. In 1993, all 10 of the selected locations received greater than the normal rainfall for January through June 1961-90, 8 of the 10 locations received more than 200 percent of the normal rainfall for July 1961-90, and 3 received more than 400 percent of the normal rainfall for July. (The average rainfall for any given 30-year period is termed the 'normal' rainfall for the given period.) May through July 1993 was the wettest or nearly the wettest such period on record at many locations in the flooded area. Of the 10 locations, 6 received more rainfall in the first 7 months of 1993 than generally is received in a year.

upper Mississippi River basin↗