F L O O D 

V O L U M E S 

IN THE 

UPPER MISSISSIPPI 

RIVER BASIN 

APRIL I THROUGH SEPTEMBER 30 

9 9 3 

U.S. GEOLOGICAL SURVEY CIRCULAR 1120-H 
Front cover-View of Highway 67, West Alton, Missouri 

(SrencoPhotography, St. Louis, Mo.) 

Back cover-View of Spirit of St . Louis Airport, 

Chesterfield, Mo. (Srenco Photography, 

St . Louis, Mo.) 

Field Hydrologist making streamflow 

measurements (U .S. Geological Survey) 
FLOOD VOLUMES IN THE UPPER MISSISSIPPI RIVER


BASIN, APRIL 1 THROUGH SEPTEMBER 30, 1993


By Rodney Southard 

Floods in the Upper Mississippi River Basin, 1993


U.S . GEOLOGICAL SURVEY CIRCULAR 1120-H

U .S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary 

U.S . GEOLOGICAL SURVEY 

GORDON P. EATON, Director 

Any use of trade, product, or firm names in this 

publication is for descriptive purposes only and does 

not imply endorsement by the U.S . Government 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1995 

Free on application to the€

U.S. Geological Survey€

Information Services€

Box 25286, Federal Center€

Denver, CO 80225€
FOREWORD 

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 traumawas 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 nation 

wide. 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-qual 

ity 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. 

hetl ,1,41ela , A~

Director 

Foreword III 
Contents 

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .III 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Purpose and scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Precipitation, April 1 through September 30, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Flood volumes, April 1 through September 30, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Magnitude and duration of volume of runoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Frequency of volume of runoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Effects of reservoirs on floods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Elevation and contents of selected reservoirs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 

Selected references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 

FIGURES 

l .-2. Maps showing: 

1 . The Mississippi River Basin and general area of flooding, April 1 through September 30, 1993 . . . . . . . . . 2 

2. Areal distribution of total precipitation in the area of flooding in the upper Mississippi River 

Basin, April 1 through September 30, 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

3. Graph showing monthly precipitation for April 1 through September 30, 1993, and 30-year monthly 

normals (April through September 1961-90) at seven weather stations in the upper Mississippi 

River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

4. Map showing location of selected streamflow-gaging stations and reservoirs in the upper Mississippi 

River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

5 .-10. Graphs showing: 

5 . Monthly flow runoff, April 1 through September 30, 1993, and mean monthly runoff volumes at 

selected streamflow-gaging stations in the upper Mississippi River Basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

6. Discharge hydrographs at selected streamflow-gaging stations on the Mississippi River, April 1 

through September 30, 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

7 . Discharge hydrographs at selected streamflow-gaging stations on the Missouri River, April 1 

through September 30, 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

8. Highest n-day mean discharges for indicated number of consecutive days, April 1 through 

September 30, 1993, and 100-year recurrence-interval n-day annual discharges at selected 

streamflow-gaging stations in the upper Mississippi River Basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 

9. Elevation and contents at selected reservoirs in the upper Mississippi River Basin, April 1 

through September 30, 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 

10. Inflow and outflow discharge at selected reservoirs in the upper Mississippi River Basin, April 1 

through September 30, 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 

TABLES 

1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, 

April 1 through September 30, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 

2. Magnitude and frequency of the highest daily mean discharges for 3, 7, and 30 consecutive days at 

selected streamflow-gaging stations in the upper Mississippi River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 

3. Magnitude and frequency of the highest daily mean discharges for 60, 90, and 120 consecutive days at 

selected streamflow-gaging stations in the upper Mississippi River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 

4. Elevation and contents of selected reservoirs in the upper Mississippi River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l l 

Contents V 
CONVERSION FACTORS AND VERTICAL DATUM 

Multiply By To obtain 

inch (in.) 25.4 millimeter 

foot (ft) 0.3048 meter 

mile (mi) 1 .609 kilometer 

square mile (mil) 2.590 square kilometer 

cubic foot per second (ft 3/s) 0.02832 cubic meter per second 

acre-foot (acre-ft) 0.001233 cubic hectometer 

Sea level : In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)-a geodetic datum derived from a 

general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929 . 
Flood Volumes in the Upper Mississippi River Basin, 

April 1 Through September 30, 1993 

By Rodney Southard 

Abstract 

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. 

INTRODUCTION 

A common definition of the word "flood" is 

the temporary overflow from a river onto adjacent 

lands not normally covered by water. In 1993, mil 

lions of acres of land in the upper Mississippi River 

Basin were flooded for weeks and months as persistent heavy rain fell over the Missouri and the Mississippi River Basins . Record or near-record flood discharges were recorded at streamflow-gaging stations 

in North Dakota, South Dakota, Minnesota, Wisconsin, Nebraska, Iowa, Illinois, Kansas, and Missouri 

(fig . 1) . At some streamflow-gaging stations, record 

peak discharges were measured early in the flood 

period only to have that record broken days or 

months later. The intense rainfall caused not only 

peak flood discharges, but sustained large flood volumes that resulted in more than 420 counties in the 

nine-State area being declared a Federal disaster area . 

The sustained high flows transported enormous amounts of sediment and agricultural chemicals 

to the Gulf of Mexico, caused severe river bank ero 

sion and instability, and resulted in scour of river 

channels at bridge crossings from April 1 through 

September 30, 1993. The Missouri and the Mississippi Rivers upstream from St. Louis, Missouri, were 

closed to all barge traffic. Numerous interstates and 

State highways also were closed for weeks until the 

flood waters finally receded. 

Flow volume is an important aspect to be considered in the analysis and description of flooding in 

the upper Mississippi River Basin. At streamflow 

gaging stations throughout the upper Mississippi 

River Basin, record or near-record flow peaks and 

volumes were observed during the April 1 through 

September 30, 1993, flood; record flow peaks at 154 

selected streamflow-gaging stations were described 

by Parrett and others (1993) . Because flow volumes 

may be defined by several different characteristics, 

the flow volume data require more extensive computations that do flow peak data . Only data for the 60 

selected streamflow-gaging stations are presented in 

this report . 

Reservoirs on the Missouri River main stem 

and tributaries to the Missouri and the Mississippi 

Introduction 1 
40-

Figure 1 . The Mississippi River Basin and general area of flooding, April 1 through September 30, 1993. (Map from 

Parrett and others, 1993.) 

Rivers stored millions of acre-feet of water to minimize flood damages downstream of the reservoirs . 

An increase in storage of 3,152,000 acre-feet of water 

in the Harry S. Truman Reservoir at Warsaw, Missouri, from April 1 to August 2, 1993, decreased 

flooding on the main stem of the Missouri River 

downstream. 

Purpose and Scope 

The purpose of this report is to describe quantitatively, for selected locations in the upper Mississippi River Basin, the magnitude and frequency of 

the flood with respect to flow volume from April 1 

through September 30, 1993. A brief summary of the 

excessive rainfall for the 6-month period is presented 

as background information. Flow volumes at selected 

streamflow-gaging stations were computed for the 

entire period of interest and compared with mean 

flow volume for the period ; a comparison also is 

made to the period of record mean annual runoff at 

each station. To further document the magnitude of 

the flooding, selected n-day consecutive periods were 

summarized for 1993 and compared with the previous maximum n-day flood volume. The 1993 n-day 

flow volume recurrence intervals also were computed 

on the basis of the period of record at each station. 

The 1993 flow volumes are compared with the various 100-year flow volumes for n-day consecutive 

periods. The discharge hydrographs for main stem stations on the Mississippi and the Missouri Rivers are 

presented for April through September. Data from 

selected reservoirs are shown graphically to describe 

the magnitude of storage and to present the inflow 

and outflow discharges at these sites. 

Acknowledgments 

The information contained herein is based on 

data collected by the National Weather Service, the 

U.S . Army Corps of Engineers, the U.S . Geological 

Survey, and State and local agencies . Appreciation is 

expressed to the personnel in these offices who put 

forth an extensive effort to provide the data in a 

timely fashion. Also, sincere thanks is extended to all 

who were involved in the field collection of the data 

during often adverse conditions . 

2 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
PRECIPITATION, APRIL 1 THROUGH 

SEPTEMBER 30, 1993 

From April 1 through September 30, 1993, 

record or near-record precipitation was measured in 

the upper Mississippi River Basin. More than 50 

inches of rain fell in parts of Iowa, Missouri, and Kansas (fig . 2) from April to September. The heaviest 

rain fell in eastern Kansas, from southwestern to 

northeastern Missouri, and in the eastern two-thirds 

of Iowa. Rainfall totals of 30 or more inches were 

measured in most places ; a maximum of 52.2 inches 

of rain fell in east-central Missouri. Rainfall during 

this period followed above-normal precipitation that 

had fallen during the winter and early spring . 

An unusual characteristic of the chronological 

distribution of the extreme rainfall is that the heaviest 

rain at any particular location could have fallen in 

any month from April 1 through September 30, 1993. 

To illustrate the distribution of precipitation in the 

general area of flooding, the 1993 and normal (1961-

90) monthly precipitation totals of seven selected 

National Weather Service precipitation stations are 

shown in figure 3. At Sioux Falls, South Dakota, the 

largest monthly recorded rainfall was 8.26 inches in 

May. However, near the mouth of the Missouri River 

at St . Louis, Missouri, the largest monthly rainfall 

total (9.16 inches) was in September. The magnitude 

of the monthly rainfall totals also are shown in figure 

3 . The rainfall total for July at Lincoln, Nebraska, 

was 12.50 inches, or 3.9 times the normal rainfall . 

This distribution and magnitude of rainfall in the 

flood area sustained the high stages and discharge volumes of runoff on many streams and rivers, especially on the Missouri and the Mississippi River main 

stems. A general overview of the excessive precipitation during spring and summer 1993 is provided in 

Wahl and others (1993) . 

FLOOD VOLUMES, APRIL 1 THROUGH 

SEPTEMBER 30, 1993 

One of the most significant aspects of the 1993 

floods in the upper Mississippi River Basin is the volume of runoff in area streams and rivers . These flood 

volumes are directly related to total loads of sediment 

and agricultural chemicals that were transported to the 

Gulf of Mexico by the Mississippi River (Goolsby and 

others, 1993) . Thus, the analysis of the displacement of 

these constituents is dependent on quantifying the volume of water in a given time period . Asummary of the 

flood volumes at selected streamflow-gaging stations 

from April 1 through September 30 is presented in this 

report . The magnitude, frequency, and duration of the 

volume of runoff are discussed. 

Magnitude and Duration of Volume of Runoff 

The magnitude and duration of the 1993 flood 

volumes for April through September can be appreciated by comparing them with the mean runoff for the 

same period and to the previous maximum runoff for 

the period of record at each streamflow-gaging station listed in table 1 .' The location of these stations 

in the general flood area is shown in figure 4. For 

informational purposes, the 1993 flows also may be 

compared with the mean annual flows for the period 

at each station. 

To ensure a meaningful comparison or analysis of discharge at a streamflow-gaging station, the 

channel and drainage-basin characteristics for the sta 

tion must be consistent during the period of record 

used in the analyses. For most streamflow-gaging stations in the upper Mississippi River Basin, significant 

effects on the river basin, such as reservoir operation 

and irrigation, do not exist, and the entire streamflow 

record can be used for comparison purposes and statistical analyses . However, at a few of the streamflowgaging stations, such as those on the Kansas and the 

Missouri River main stems, the flow is affected by 

reservoir operation. In these instances, the period of 

record that was used to determine mean flow volumes and recurrence intervals began when the last 

major reservoir was put into operation. 

The runoff volumes from April through September 1993 were in excess of the mean for the 

same period at the 60 stations (table 1 ; fig. 4). In 

fact, of the 60 stations, 53 had flow volumes that 

were greater than twice the mean. The ratio of the 

1993 runoff volume to the mean flow volume at 

each station ranged from 1 .18 for the Flambeau 

River near Bruce, Wisconsin (site number 7), to 

8.75 for the Rock River at Rock Valley, Iowa (site 

number 35) . 

The runoff volume from April through September also was compared with the period of record 

mean annual runoff or the volume of runoff that 

'Tables 1 through 3 appear on pagesl5 through 32. 

Flood Volumes, April 1 Through September 30, 1993 3 
90, 

45° 

40° 

-30- Line of equal total precipitation for 

April 1 through September 30, 

1993-Interval 10 inches 

100 200 MILES 

100 200 KILOMETERS 

Figure 2. Areal distribution of total precipitation in the area of flooding in the upper Mississippi River Basin, April 1 through September 30, 1993. (Precipitation data from David Miscus, National Weather Service, written commun., 1993.) 

4 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
I
 I I


MINNEAPOLIS, MINNESOTA DUBUQUE, IOWA 

I " I " I " I " I " i


I I


LINCOLN, NEBRASKA


Figure 3. Monthly precipitation for April 1 through September 30, 1993, and 30-year monthly normals (April through September 

1961-90) at seven weather stations in the upper Mississippi River Basin. (Map modified from Parrett and others, 1993.) 

Flood Volumes, April 1 Through September 30, 1993 5

90° 

45° 

40° 

EXPLANATION 

Area of flooding streams 

-30 Streamflow-paging station and number 

X64 Reservoir-paging station and number 

100 200 MILES 

100 200 KILOMETERS 

Figure 4. Location of selected streamflow-paging stations and reservoirs in the upper Mississippi River Basin. 

6 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
would normally be expected in a year. Of the 60 stations, only 4 had runoff volumes that were less than 

the mean runoff volume for an entire year, and 9 had 

volumes of flow that were greater than four times the 

mean annual runoff. Graphs of the monthly mean runoff from April through September 1993 and the mean 

monthly runoff for the period of record for seven 

streamflow-gaging stations are shown in figure 5. 

During August, the flows on the James River near 

Scotland, South Dakota (site number 33), were 18 

times the August mean flow. 

Excessive flow volumes also are reflected in 

the number of days the river remained above flood 

stage or the flow at flood stage. Of a possible 183 

days from April 1 through September 30, 1993, 17 

stations were above flood stage for longer than 90 

days, or 3 months . In addition to the flood of 1993, 

the flood of 1973 was a significant event on the main 

stem of the Mississippi River at St. Louis. In a comparison of the floods of 1973 and 1993, the 1973 

event had flows above flood stage for 81 days, and 

the 1993 event had flows above flood stage for 144 

days. A plot of discharge hydrographs for stations on 

the Mississippi River main stem and stations on the 

Missouri River main stem are shown in figures 6 and 

7. These hydrographs depict the long duration of 

flooding with respect to time and multiple peaks during the event. The time sequence as the flood peaks 

travel downstream also is shown on both figures. 

The significance of the 1993 flow volumes 

also may be indicated by determining the period of n 

consecutive days in 1993, which had the highest accu 

mulated flow, and comparing this flow (the 1993 

annual n-day flow) with the previous maximum nday flow for the period of record . This comparison 

for the 1993 flow volume and the previous maximum 

for the period of record for 3-, 7-, and 30-day periods 

is listed in table 2. Comparisons of the 60-, 90-, and 

120-day periods for 1993 flow volumes and previous 

maximums are listed in table 3. In general, the longer 

the n-day period, the more significant the 1993 flow 

was when compared with previous maximums. For 

example, the streamflow-gaging station on the Blue 

Earth River near Rapidan, Minnesota (site number 3), 

had a 3-day flow of slightly less than one-half the previous 3-day maximum, but for the 120-day period, 

the 1993 flow was 1 .69 times the previous maximum. 

Of the 60 stations analyzed in this report, 24 had new 

maximum 3-day flows (table 2) and 47 had new maximum 120-day flows (table 3). 

Frequency of Volume of Runoff 

Recurrence interval or probability of exceedance also can be used to quantify the magnitude of a 

specific flood event (tables 2, 3) . The statistical proce 

dure used here to compute recurrence intervals for 

peak discharges also is applicable to flow analysis for 

any specific highest daily mean discharge for n-day 

consecutive periods. Acomprehensive description of 

the procedures used can be found in Bulletin 17B of 

the Interagency Advisory Committee on Water Data 

(1982) . Recurrence interval is the number of years, 

on the average, between exceedances of the annual nday flow of a specified discharge; for example, the 

100-year flow volume is exceeded, on the average, 

once every 100 years. The probability of exceedance 

is the reciprocal of recurrence interval; for example, 

the 100-year flow volume has a 1 in 100 chance, or 

0.01 probability, of being exceeded in any given year. 

The 100-year recurrence interval was exceeded at 22 

stations for a 3-day duration (table 2) and at 43 stations for a 120-day duration (table 3). Comparison of 

the 1993 n-day flow with respect to the computed 

100-year value for each n-day period is shown in figure 8 for selected stations. In the majority of cases, 

the 1993 flows exceeded the 100-year flows. The 

Missouri River at Kansas City, Missouri (site number 

50), 3-day duration flow and the Iowa River at 

Wapello (site number 19), 120-day duration flow 

were 1.8 times the 100-year flow. 

EFFECTS OF RESERVOIRS ON FLOODS 

The effect of the main-stem reservoirs on the 

Missouri River in reducing flows is apparent when 

comparing the recurrence intervals for the 120-day 

duration at the Nebraska City, Nebraska (site number 

40), streamflow-gaging station with a station farther 

downstream, such as that at St. Joseph, Missouri (site 

number 45). The 120-day flow at Nebraska City had 

a recurrence interval of 16 years in comparison to a 

recurrence interval of 80 years at St . Joseph ; this indicates that the less severe flood at Nebraska City was 

the result of storage of flood waters in upstream reservoirs. However, because of the tremendous amount 

of inflow below the main-stem reservoirs, the shorter 

duration 3-day flow has a 60-year recurrence interval, 

which is significantly higher than the 16-year recurrence interval for the 120-day value at Nebraska City . 

The main-stem reservoirs on the Missouri River 

Effects of Reservoirs on Floods 7 
300 3,000 2,000 

0 1,500
 z


~w 200 2,000


Ou


=w


~­


zU 1,000


u: LL


0 0


z 100 1,000 Q 

500 

Apr May June July Aug Sept Apr May June July Aug Sept 

3,000 

N

O

Z 

w 2,000 ~w 

04 

x , ;, ~- ¢ 

z 0 

u_ ~ 

0 0 

1,000 

20,000 

0 15,000 z 1993 monthly flow volumes z 

LLI 7W 

0L~ Monthly mean flow volumes 00 w 30,000 

F- uw 2w 

z0 10,000 

u_ ~ 

0 0 

z 

tt 5,000 

Apr May June July Aug Sept Apr May June July Aug Sept 

Figure 5. Monthly flow runoff, April 1 through September 30, 1993, and mean monthly runoff volumes at selected streamflow-gaging stations in the upper Mississippi River Basin. 

8 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
---

-------

2,000 sippi River Basin. Most of reservoirs are on the main 

stem of the Missouri River and in the Kansas River 

Basin, which is a major tributary to the Missouri 

River. Because of storage in the reservoirs in the Kan1,000 

900 sas River Basin, peak flows from below Tuttle Creek 800 

700 Lake downstream to the mouth of the Kansas River 

600 were reduced by 30 percent or more (Perry, 1994). 0 

z 500 0

U 

ti 400 

1,000 w 

a 300 900
 N


w
w


w 800


U


m 200 700
 7
U


O 600


y


0


z 500
 Q


y 100 O 90 H 80 

Z 70 

w 

0 60 

w 300 a 50 a 2

U w U w 0 40 w 

U 

00 

30 U 200 

w 

O 

v) 

20 z 

O 

2

H 

z 

10 (7 100 

APR MAY JUNE JULY AUG SEPT	 s 

¢ 90 

1993 2 

U 80 

EXPLANATION 

Station 05331000, Mississippi River at 

St . Paul, Minnesota 

Station 05420500, Mississippi River at 

Clinton, Iowa 

_ _ Station 05474500, Mississippi River at 

Keokuk, Iowa 

Station 07010000, Mississippi River at 

St. Louis, Missouri 

Station 07022000, Mississippi River at 

Thebes, Illinois 

Figure 6. Discharge hydrographs at selected streamflowgaging stations on the Mississippi River, April 1 through September 30, 1993. 

stored a significant amount of flow from April 

through September, thus reducing the long duration 

of flooding downstream from the reservoirs . However, as a result of the magnitude and intensity of 

storms downstream of the reservoirs, shorter duration 

flow events were still very pronounced and had high 

recurrence intervals . 

An important aspect of the flood of 1993 is the 

role of flood-control reservoirs in the upper Missis70 

60 

50 

40 

30 

EXPLANATION 

Station 06807000, Missouri River at 

Nebraska City, Nebraska 

Station 06818000, Missouri River at 

St . Joseph, Missouri 

------ Station 06893000, Missouri River at 

Kansas City, Missouri 

. . . . . . . . . . Station 06909000, Missouri River at 

Boonville, Missouri 

Station 06934500, Missouri River at 

Hermann, Missouri 

Figure 7. Discharge hydrographs at selected streamflowgaging stations on the Missouri River, April 1 through September 30, 1993. 

Effects of Reservoirs on Floods 9 
w

:

25 100 I I I I I- 75 I 

JAMES RIVER, SCOTLAND, S . DAK. MINNESOTA RIVER, JORDAN, MINN . WISCONSIN RIVER, MUSCODA, WIS. 

v) Z 20 

z0QCp) W ON0 w 15 

t- a 

ZFW 

Ww

W 

U 1D 

=m 

v) U W 

00 

3 7 30 60 

CONSECUTIVE DAYS 

150 

O 0Z 

z0QU 

Z) U) 100 

O a[ xw 

0-

z I­ -w,L w 

a W 

j 50 

yU 0 

00 

3 7 30 60 

CONSECUTIVE DAYS 

600 

OZ

O 

z0 

03 Lu 400 Z) U) 

=w 

~- a 

zF 

- W 

,L	w

w 

¢ U 

200 

00 

3 7 30 60 

CONSECUTIVE DAYS 

80 

60 

40 

20 

90 120 

90 120 

40 hycEXPLANATION 

Highest n-day mean discharges for 

April through September 1993 

nday discharge for 100-year 

recurrence interval 

Area of flooding streams 

Streamflow-gaping station and 

number 

90 120 

50 

25 

CONSECUTIVE DAYS 

O 

pZ 

U) w 800 :) Cn O 

Wa ZFwW 

¢U 

I Fn) 400 

QU 

00 

3 7 30 60 90 120 

CONSECUTIVE DAYS 

Figure 8. Highest n-day mean discharges for indicated number of consecutive days, April 1 through September 30, 1993, and 

100-year recurrence-interval n-day annual discharges at selected streamflow-paging stations in the upper Mississippi River 

Basin. 

1 0 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
;6

N 

N

o

00 00

voirs

ELEVATION AND CONTENTS OF 

SELECTED RESERVOIRS o a M 0 0 

Record or near-record volumes of flood water 

were stored in many reservoirs to reduce outflows 

and to minimize flood damages downstream of reser E D 

00 N 

o 00 

00 

00 

. The Tuttle Creek Lake on the Kansas River E 0 0 

near Manhattan, Kansas (site number 63 ; table 4), is E had a maximum pool elevation of 1,137 .76 feet N

7 above sea level, which was nearly 10 feet higher than .>>
 0

C

the 1986 maximum, and storage of 2,420,000 acrea

d 

o m 

kr~

o

r_: 06 

o


feet, which was 24 percent more flood volume than 

v -, r. ~ r .


the 1986 maximum. The maximum pool elevation


c and contents data for four of the largest reservoirs in .2 0 

v0 N Os ~O ~ r 

not all these reservoirs established new maximum ele-

_m 

W 

03 

vations or contents in 1993, the combined storage of 

the reservoirs and the dates of maximum releases substantially minimized flood damages downstream 

Y 

G 

M 

v v

M 

v

N 00 

from the reservoirs . On the Des Moines River, Lake 

the general flood area are listed in table4. Although a0 N

y

;6 

0 > 

a

l~; ~D N M 

Red Rock (site number 61; table 4) near Pella, Iowa, 0 

w . stored 1,784,000 acre-feet of flood waters from April g o ° c_ o

through September to minimize damages down- .E 

'M C L M N O v)


stream . About 7,661,000 acre-feet was stored in the C 7 ^~ v N


reservoirs listed in table4.Agraphical representation m 

x0 d


of the reservoir elevation and contents from April a`m 

0 0 o r- O


:. aiod ktj

through September 1993 is shown in figure 9. The . 03 W 

dN > OO M M M 

Q 'D N r- rresult of the storage of flood waters with plots of the a W2 

inflow into the reservoirs and outflows from the reservoirs is shown in figure 10. In all cases, it is impor- d M O 00 O o e o M 

tant to note that the maximum outflows were less 

c a) 

M a`> cc n. N

than the maximum inflows during extensive flooding a 

downstream. 

L

W 

3 o

0

SUMMARY z d 'o E a c 

Record high flood flows were observed in a) x 

nine a 

April 1 through September 30, 1993. In the upper a N z .14 

Midwest, sustained high flows caused the halting of U w U 

barge traffic, closing of highways, and flooding of 

States in the upper Mississippi River Basin from U v U v~ o 

a 

farmland, which resulted in billions of dollars in dam- a a H x o 

ages . The high flows were sustained by storms that S 8 8 

lt

produced more than 30 inches of rain in Kansas, Mis- a 8 

0 .0 

c w. wEoa 

00 tn~ 00 N 

souri, and Iowa

; some places received more than 50 0 c 'IT 00 0~ o ~ o 0

inches from April through September. In July, .> 

Lincoln, Nebraska, recorded 12.50 inches of rain, or w . 3 .9 times its normal rainfall for the month. 

C14 Cn am 

The flood runoff or volume that resulted from 

the excessive rainfall can be quantified by comparing 

Summary 11 
> J

1,370 

w 

J 

1,365 

w 

O 

w 1,360 

Z 

z

O 

1,355 

w 

w 

1,350 

1,140 

J

W 

W 

Q 1,120 

w 

O 

m 

a 

1,100 

w

w 

z 

z

O

F 1,080 

J

W 

1,060 

4,200 800 

w w 

uw	 W 

J 

4,000 a w 780 

w m 

O 

m 

0

z m

Q 

3,800 N w 760 

w O w

F Z 

z_ Z 

N O 

3,600 z a 740 

w z 

O W 

U 

3,400 720 

740 

W

> 

J 

O 

m 

a 

720 

w

W 

z 

O


Q 710


J

W 

2,000 

w 

1,500 Q

W 

O 

m 

Z 

1,000 j 

O 

FZ 

500 z 

Z

O

U 

0 

Apr May June July Aug Sept 

EXPLANATION 

Area of flooding streams 

A- Reservoir-gaging station and number 

5,000 

W 

W

U_ 

W 

Q 

4,000 

u. O 

m 

0 

z 

a 3,000 

O 

x 

z 

m 2,000 z 

w 

zZ 

O 

U 

1,000 

Figure 9. Elevation and contents at selected reservoirs in the upper Mississippi River Basin, April 1 through September 30, 1993. 

1 2 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
Z 

z

----

40 

U O 

Z O 30 

U 

y W

U 

O Er = W 

r a 

? w 20 

LL! W C7 U

Q rD 2 L)

N U 

- W 10 O O 

EXPLANATION 

L . . . J Area of flooding streams 

Inflow discharge into reservoir 

Outflow discharge of reservoir 

,63 Reservoir-gaging station and number 

100 200 

0 80 U O 

z O 150 

zz o QU yw r/) W 7U ::) U 60 O cc OQ 2 W 

xw ~- a ~- a 100 z~ 

-w iu w 

LL! w O

it W(D W 40 U

U 2IL 2 rD 7QQ() U = 00 U U 50

0 20 

0 0 

Apr May June July Aug Sept 

Figure 10. Inflow and outflow discharge at selected reservoirs in the upper Mississippi River Basin, April 1 through September 30, 1993. 

Summary 1 3 
the 1993 flood volumes at selected streamflow-gaging stations with the mean runoff for the period of 

record of each station. Comparisons also may be 

made by determining the highest mean discharges or 

accumulated flows for periods of n consecutive days 

(n-day values) and by comparing these values to previous maximums or determining recurrence intervals 

for the 1993 n-day values from station records . For 

the 60 stations included in this report, 53 recorded 

flow volumes that were greater than twice the mean 

for the April to September period. In fact, 9 of the 60 

stations had flow volumes that were four times the 

mean annual flow. At 47 of the 60 stations, the magnitude of the 1993 flood volumes was significantly 

greater than the previously recorded maximums for 

120-day volumes. Frequency analysis of the historic 

or period of record flows also indicated that the 100-

year flood volume for the 120-day period was 

exceeded at 43 of the 60 stations in 1993 . At the 

Iowa River streamflow-gaging station at Wapello, 

Iowa, the 1993 flood volume was 1.8 times the 100-

year flood volume. 

The storage of large volumes of water in reservoirs significantly decreased the peak flow and flood 

damages downstream from the dams. Lake Red Rock 

near Pella, Iowa, stored 1,784,000 acre-feet to minimize flooding downstream from April through September 1993 . The storage of millions of additional 

acre-feet of water in reservoirs on the main stem of 

the Missouri River and in the Kansas River Basin 

eased the flooding on the Missouri and the Mississippi Rivers. 

SELECTED REFERENCES 

Anderson, D.B., and Burmeister, I.L., 1970, Floods of 

March-May 1965 in the upper Mississippi River 

basin: U.S . Geological Survey Water-Supply Paper 

1850-A, 448 p. 

Chin, E.H., Skelton, John, and Guy, H.P., 1975, The 1973 

Mississippi River basin flood-compilation and analyses of meteorologic, streamflow, and sediment data: 

U.S . Geological Survey Professional Paper 937, 

137 p. 

Goolsby, D.A., Battaglin, W.A., and Thurman, E.M., 

1993, Occurrence and transport of agricultural chemicals in the Mississippi River Basin, July through 

August 1993 : U.S . Geological Survey Circular 1120-

C, 22 p. 

Interagency Advisory Committee on Water Data, 1982, 

Guidelines for determining flood flow frequency : 

U.S . Geological Survey Hydrology Subcommittee 

Bulletin 17B, 183 p. 

Parrett, Charles, Melcher, N.B ., and James, R.W., Jr ., 

1993, Flood discharges in the upper Mississippi 

River Basin: U.S . Geological Survey Circular 1120-

A, 14 p. 

Perry, Charles A., 1994, Effects of reservoirs on flood discharges in the Kansas and Missouri River Basins : 

U.S . Geological Survey Circular 1120-E, 20 p. 

Wahl, K.L., Vining, K.C., and Wiche, G.J ., 1993, Precipitation in the upper Mississippi River Basin, January 1 

through July 31, 1993: U.S . Geological Survey Circular 1120-B, 13 p. 

1 4 Flood Volumes in the Upper Mississippi River Basin, April 1 Through September 30, 1993 
-- --

Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993 

[miz , square mile ; acre-ft, acre-feet; --, data unavailable] 

April-September 1993 Period of record 

Site April-September 

num- Station Drainage Num­

(fig. 4) (mi l) of 

days 

(acre-ft) Years ber of 

years 

Mean 

runoff 

(acre-ft) 

maximum 

Runoff Year (acre-ft) 

runoff 

(acre-ft) 

1 05311000 Minnesota River 6,180 4/6-13,15-22 73 1,830,000 1910-17 71 401,000 1986 1,761,000 543,000 

at Montevideo, 6/24-8/19 1930-92 

Minn. 

2 05317000 Cottonwood 1,280 4/1-3 29 1,113,000 1912-13 58 148,000 1986 588,000 233,000 

River near 5/9-14 1936-37 

New Ulm, 6/18-28 1939-92 

Minn. 7/4-12 

3 05320000 Blue Earth River 2,430 6/19-22 4 2,720,000 1940-45 49 486,000 1991 1,315,000 682,000 

near Rapidan, 1950-92 

Minn. 

4 05325000 Minnesota River 14,900 4/1-12,14-25 73 9,320,000 1905 71 1,606,000 1986 4,940,000 2,221,000 

at Mankato, 5/11-18 1911-17 

Minn. 6/18-7/22 1930-92 

8/17-22 

5 05330000 Minnesota River 16,200 4/1-5/30 159 10,672,000 1935-92 58 2,075,000 1986 5,766,000 2,779,000 

near Jordan, 6/3-9/9 

Minn. 

6 05331000 Mississippi River 36,800 6/23-7/19 27 17,569,000 1895, 94 5,520,000 1986 15,470,000 7,977,000 

at St. Paul, 1897 

Minn. 1901-92 

ber number Station name area 

Date(s) ber Runoff 

Num- Previous Annual 

7 05360500 Flambeau River 1,860 931,000 1952-92 41 790,000 1968 1,226,000 1,314,000 

near Bruce, 

Wis. 

8 05369500 Chippewa River 9,010 6/20-25 6 4,596,000 1929-92 64 3,236,000 1943 5,633,000 5,537,000 

at Durand, Wis. 
-- --

-- --

Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued 

April-September 1993 Period of record m o 

c Site °o.
 April-September


c num- Station Drainage Num- Num­
 c bar number Station name area ber Runoff ber Previous Annual


B


w (fig-4) 

( M12) Date(s) of (acre-ft) Years of Mean maximum runoff


runoff days years (acre-ft) Runoff (acre-ft) 

A Year (acre)
 c


v


9 05382000 Black River near 2,080 4/1-3 12 1,950,000 1932-92 66 771,000 1938 51,468,000 1,268,000 

N Galesville,Wis . 6/11, 12, 19-25 

N


N 10 05398000 Wisconsin River 4,020 2,309,000 1945-92 48 1,451,000 1968 2,282,000 2,560,000


at Rothschild, 

Wis. 

v 

m 11 05407000 Wisconsin River 10,400 6/24-28 5 6,742,000 1914-92 79 3,571,000 1973 5,832,000 6,285,000 

m at Muscoda, 

Wis. 

12 05418500 Maquoketa River 1,553 7/5-14 13 1,439,000 1914-92 79 394,000 1947 921,000 742,000 

near Maquoketa, 7/18-20 

Iowa . 

0 

z at Clinton, Iowa. 6/19-7/31 

v 

3 14 05422000 Wapsipinicon 2,330 4/1-5/18 146 3,010,000 1935-92 58 651,000 1947 1,410,000 1,129,000 

Dewitt, Iowa. 8/9-9/9 

13 05420500 Mississippi River 85,600 4/6-5/18 86 50,350,000 1874-92 119 22,200,000 1888 39,482,000 34,770,000 

River near 6/8-8/5 

-° 9/14-15, 25-29 i 

w 15 05429500 Yahara River near 1,564 171,000 1930-92 63 54,900 1933 108,200 112,000 

McFarland, Wis. 

16 05451500 Iowa River at 1,564 4/1-5/21 163 2,076,000 1957-92 79 372,000 1983 952,000 602,000 

Marshalltown, 6/2-9/16 

Iowa. 9/20-21, 25-27 

17 05453100 Iowa River at 2,794 4/1-5/20 157 4,205,000 1957-92 36 817,000 1983 1,773,000 1,333,000 

Marengo, Iowa. 6/9-9/12 

9/14-18,25-30 

18 05465000 Cedar River near 7,785 4/1-5/19 144 11,082,000 1940-92 53 2,140,000 1969 4,553,000 3,487,000 

Conesville, 6/8-9/8 

Iowa. 9/26-27 
Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued 

April-September 1993 Period of record 

April-September Site 

num- Station Drainage Num- Num- area Previous Annual ber number Station name 

(mi l) Date(s) ber Runoff Years ber Mean maximum runoff (fig

days years (acre-ft) Year Runoff 

(acre-ft) 

19 05465500 Iowa River at 12,499 4/1-5/21 164 17,707,000 1915-92 78 3,150,000 1969 7,160,000 6,257,000 

Wapello, Iowa . 6/8-9/22 

9/25-30 

20 05471500 South Skunk 1,635 4/1-10,19-23 131 2,289,000 1946-92 47 444,000 1990 1,034,000 708,000 

River near 5/2-16 

Oskaloosa, 6/4-5,9-11 

Iowa. 6/14-27 

. 4) of (acre-ft) of runoff (acre-ft) 

6/30-8/8 

8/10-9/10 

9/13-16,25-30 

21 05474000 Skunk River at 4,303 4/21-24 60 5,570,000 1915-92 78 1,050,000 1973 2,903,000 1,782,000 

Augusta, Iowa . 5/4-8 

6/8-11,2-27 

7/1-2,6-30 

8/11-25, 9/6 

22 05474500 Mississippi River 119,000 4/5-5/20 125 87,903,000 1879-92 114 29,000,000 1986 47,289,000 46,740,000 

at Keokuk, 6/10-15 

Iowa. 6/20-8/5 

8/12-9/6 

23 05474500 Des Moines River 2,256 4/1-5/29 139 2,567,000 1965-92 28 471,000 1984 1,324,000 671,000 

at Humboldt, 5/31-8/7 

Iowa. 8/16-21 

8/31-9/4 

- 24 05481300 Des Moines River 5,452 4/1-5/24 138 6,381,000 1921-92 72 1,010,000 1984 3,359,000 1,470,000 

c near Stratford, 6/2-8/4 

Iowa. 8/15-26 

i

V 

8/29-9/5 
J 

Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued 

M April-September 1993 Period of record
 0
0
a


o Site April-September 

3 num- Station Drainage Num- NumH bar number Station name area 

(fig . 4) (mi z) Date(s) bar Runoff bar Previous Annual 

of (acre-ft) Years of Mean maximum runoff 

runoff days years (acre-ft) Year Runoff (acre-ft) 

(acre-ft) 

25 05482500 North Raccoon 1,619 4/1-11, 20-27 79 1,485,000 1941-92 52 368,000 1984 1,073,000 550,000 

aw Jefferson, Iowa. 6/9, 14-23, 26 

6/30-7/6 

. 7/8-28 

8/17-22 

W

m

N

3 26 05484000 South Raccoon 994 

8/30

7/8-14 11 875,000 1941-92 52 220,000 1973 598,000 342,000 

.o = 

i 

River at 

Redfield, Iowa. 

8/12,29-31 

w River near 5/7-16 

27 05484500 Raccoon River at 3,441 5/10-16 39 3,172,000 1916-92 77 691,000 1973 2,056,000 1,054,000 

0 c Van Meter, 6/19-21

Iowa. 7/1, 4-6, 8-23 

7/25 

8/11-12 

8/18-19 

8/29-9/1

w

0

" 28 05485500 Des Moines River 9,879 4/1-5/25 147 11,324,000 1978-92 15 3,000,000 1984 6,494,000 4,392,000 

w below the 6/14-9/11 

Raccoon River 9/25-26 

at Des Moines, 

Iowa. 

29 05490500 Des Moines River 14,038 7/5-8/3 30 15,463,000 1970-92 23 3,750,000 1973 7,607,000 5,730,000 

at Keosauqua, 

Iowa. 

30 05570000 Spoon River at 1,636 4/16-19 12 1914-92 79 421,000 1978 1,152,000 761,000 

Seville, Ill . 7/24-31 

31 05586100 Illinois River at 26,742 4/1-5/22 155 19,900,000 1939-92 54 8,760,000 1954 15,581,000 16,000,000 

Valley City, Ill . 6/20-9/30 
-- --

Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued 

April-September 1993 Period of record 

April-September Site 

num- Station Drainage Num- Num- Station name area Previous Annual bar number ber Runoff ber 

(fig. 4) (mi l) Date(s) of (acre-ft) Years of Mean maximum runoff 

runoff (acre-ft) days years (acre-ft) Runoff Year (acre-ft) 

32 06468170 James River near 1,060 7/27-30 4 84,900 1969-92 24 14,800 1969 51,000 19,500 

Grace City, 

N. Dak. 

33 06478500 James River near 20,653 5/9-18 76 1,302,000 1929-92 64 239,000 1962 1,405,000 300,000 

Scotland, 6/23-8/27 

S. Dak. 

34 06481000 Big Sioux River 4,483 4/1-4 30 1,086,000 1949-92 44 171,000 1986 915,000 232,000 

near Dell 5/13 

Rapids, S. Dak. 6/21-7/14 

7/18 

35 06483500 Rock River near 1,592 4/1-3,9 63 1,567,000 1949-92 44 179,000 1984 897,000 273,000 

Rock Valley, 5/8-12 

Iowa. 5/30-6/5 

6/7-10,17-27 

6/30-7/21 

7/25-29 

8/15-17, 30-31 

36 06606600 Little Sioux River 2,500 4/1-3 34 2,554,000 1919-92 74 392,000 1983 1,535,000 584,000 

at Correction- 6/9-10,14-25 

ville, Iowa . 7/2-7, 13-23 

37 06800500 Elkhorn River at 6,900 1,863,000 1929-92 64 537,000 1984 2,031,000 903,000 

Waterloo, Nebr. 

38 06803500 Salt Creek at 684 7/24-25 2 378,000 1950-92 43 105,000 1984 356,000 164,000 

Lincoln, Nebr. m 

39 06805500 Platte River at 85,800 7/23-26 4 6,654,000 1954-92 39 2,512,000 1984 7,704,000 4,731,000 

Louisville, 

Nebr. 
(gc Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued


T April-September 1993 Period of record


O
a


< Site April-September


o num- Station Drainae
 -


3	 ber number Station name area Num- Num- Previous Annual 

(fig- 4)) (mi z) Date(s) bar Runoff 

of (acre-ff) Years	 bar Mean maximum runoff of runoff ' days years (acre-ft) Runoff 

(acre-ft) 

year (acre-ft) V

v 

40 06807000 Missouri River at 410,000 7/9-31 23 23,474,000 1967-92 26 15,600,000 1984 28,908,000 27,850,000 

N 

w 

Nebraska City, 

Nebr. 

e 

"a 41 06808500 West Nishnabotna 1,326 7/1,9-11 12 1,075,000 1949-92 44 268,000 1973 693,000 430,000 

~o River at 7/13-14 

Randolph, 7/22-25 

0o 

d Iowa. 8/30-31

w


v River above 5/8-19,23-25 

=' i Hamburg, Iowa. 6/6-8, 14-16

0 

6/18-22

6/24-8/21 

N 

8/29-9/10

9/22-29 

43 06815000 BigNemahaRiver 1,340 4/1 19 1,565,000 1945-92 48 286,000 1951 1,281,000 430,000 

Q at Falls City, 5/8-9,11 

D 

42 06810000 Nishnabotna 2,806 4/1-2 108 2,794,000 1923-92 70 517,000 1947 1,517,000 822,000


Nebr. 6/30 w 

7/1-2,5-10 

7/18,22-25 m

w 

44 06817000 Nodaway River at 762 6/30-7/1 21 869,000 1921-92 72 165,000 1982 440,000 259,000 

Clarinda, Iowa. 7/8-11, 13-14 

7/20-26 

8/29-31 

9/22,25-26 

45 06818000 Missouri River at 420,300 4/1-5 38 34,474,000 1921-92 64 19,916,000 1984 17,445,000 29,770,000 

St. Joseph, Mo. 5/9-18 

6/15,19-21 

6/25-8/7 

8/31-9/3 

9/23,24 
Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued 

April-September 1993 Period of record 

April-September

Site 

num- Station Station name 

Drainage Num- Num- area Previous Annual

ber number (mi l) Date(s) ber Runoff Years ber Mean maximum runoff (fig . 4) of (acre-ft) of runoff (acre-ft) days years (acre-ft) Year	 Runoff 

(acre-ft) 

46 06820500 Platte River near 1,760 4/1-4 43 2,011,000 1933-92 60 425,000 1982 618,000 672,000 

Agency, Mo. 5/8-12 

6/7, 8, 15-16 

7/2-17,22-29 

9/22-27 

47 06853020 Republican River 22,090 7/18-28 11 277,000 1951-92 42 142,000 1951 940,000 215,000 

at Guide Rock, 

Nebr . 

48 06879100 Kansas River at 44,870 7/18-30 13 7,174,000 1964-92 29 977,000 1987 3,103,000 1,764,000 

Fort Riley, 

Kans. 

49 06891000 Kansas River at 58,460 7/18-8/7 21 16,538,000 1937-92 56 3,383,000 1951 17,527,000 5,028,000 

LeCompton, 

Kans. 

50 06893000 Missouri River at 485,200 5/10-13 37 54,674,000 1898-92 95 24,076,000 1951 26,193,000 36,235,000 

Kansas City, 7/3 

Mo. 7/6-8/6 

51 06897500 Grand River near 2,250 4/1-2,8-10 49 1,502,000 1922-92 71 524,000 1947 899,000 844,000 

Gallatin, Mo. 5/7-13 

6/6-9,14-15 

7/1-17,21-28 

9/22-27 

52 06898000 Thompson River 701 7/1,5-8 12 790,000 1921-92 58 171,000 1947 470,000 278,000 

at Davis City, 7/10-11,22 

Iowa. 7/24-26, 8/21 

53 06899500 Thompson River 1,670 7/5-8,11-12 9 1,933,000 1922-23 66 429,000 1947 713,000 710,000 

at Trenton, Mo. 7/23-25 1929-92 
N

N Table 1 . Summary of flow volumes at selected streamflow-gaging stations in the upper Mississippi River Basin, April 1 through September 30, 1993-Continued


-i! April-September 1993 Period of record
 0
0
a


o Site April-September 

B num- Station 

area ber number Station name 

Drainage Num- Num- Previous Annual y (fig.4) (m1 2) Dates ber Runoff years ber Mean maximum runoff () of (acre-ft) of runoff (acre-ft) days years (acre-ft) Runoff year (acre-ft) 

54 06902000 Grand River near 6,880 4/1-3,8-11 84 9,589,000 1924-92 69 1,683,000 1947 2,979,000 2,836,000 w

N Sumner, Mo. 4/13-18, 20-21 

y 5/3-14


.0 6/6-11, 14-16
 v


7p 

9/14-16,20-30 

55 06904500 Chariton River at 1,370 7/8-13 10 1,468,000 1931-52 60 355,000 1973 529,000 611,000 

Novinger, Mo. 7/22-25 1955-92 

s 

56 06905500 Chariton River 1,870 7/1-2,7-15 22 2,077,000 1929-92 64 511,000 1973 846,000 867,000 

near Prairie Hill, 7/23-28 

7/1-8/3


Mo. 8/13 

9/15,23,26

m 

57 06909000 Missouri River at 501,700 4/1-7,14-18 101 74,060,000 1926-92 67 28,530,000 1951 31,358,000 43,554,000

Booneville, Mo. 5/4-5,8-18 

3 6/6-11 

m 7/1-8/19 -, 

c 8/23,24 

9/3-5,14-17 

w 9/20-30 

58 06934500 Missouri River at 524,200 4/2-8, 14-23 116 90,700,000 1897-92 96 35,706,000 1951 40,656,000 55,587,000 

Hermann, Mo. 5/5-21 

6/6-12, 25-26 

7/1-8/25 

9/14-30 

59 07010000 Mississippi River 697,000 4/5,7-8 144 216,807,000 1862-92 131 79,173,000 1951 74,411,000 131,692,000 

at St . Louis, Mo. 4/11-5/24 

6/26-9/30 

60 07022000 Mississippi River 713,200 4/1-5/27 152 220,307,000 1933-92 60 81,001,000 1951 77,296,000 143,348,000 

at Thebes,111 . 6/2-9/30 
Table 2. Magnitude and frequency of the highest daily mean discharges from 3, 7, and 30 consecutive days at selected streamflow-gaging stations in the upper 

Mississippi River Basin 

[ft3/s, cubic feet per second; recurrence interval, rounded to nearest 5 years for 20- to 50-year recurrence intervals and to nearest 10 years for 55- to 100-year recurrence intervals; >, greater than] 

3-day values 7-day values 30-day values 

Site Station 

Recur- Previous Recur- Previous Recur- Previous 

number Station name rence maximum rence maximum 1993 rence maximum 

(fig. 4) number 1993 interval for period 1993 interval for period (ft3/s) interval for period (ft3/s)	 for 1993 of record (ft3/s) for 1993 of record for 1993 of record 

(years) (ft3/s) (years) (ft3/s) (years) (ft 3/s) 

1 05311000 Minnesota River at 10,900 10 33,000 10,200 10 27,900 8,520 15 14,000 

Montevideo, Minn. 

2 05317000 Cottonwood River near 19,700 60 24,400 15,100 70 18,400 7,450 >100 7,110 

New Ulm, Minn. 

3 05320000 Blue Earth River near 18,800 16 40,300 17,000 17 37,800 12,300 40 13,600 

Rapidan, Minn. 

4 05325000 Minnesota River at 72,100 35 92,200 67,300 30 86,100 46,800 60 45,000 

Mankato, Minn. 

5 05330000 Minnesota River near 89,300 80 111,000 83,600 80 100,000 56,100 >100 48,700 

Jordan, Minn. 

6 05331000 Mississippi River at 103,000 30 169,000 98,800 25 162,000 85,000 50 101,000 

St . Paul, Minn. 

7 05360500 Flambeau River near 13,300 13 15,700 10,000 7 13,700 4,870 3 8,290 

Bruce, Wis. 

8 05369500 Chippewa River at 74,700 20 104,000 54,400 14 78,600 24,600 5 38,300 

Durand, Wis. 

9 05382000 Black River near 44,400 >100 51,000 29,800 80 34,800 12,000 80 12,200 

Galesville, Wis. 

10 05398000 Wisconsin River at 36,400 18 42,500 25,900 13 31,200 12,000 7 15,300 

Rothschild, Wis. 

11 05407000 Wisconsin River at 57,800 16 75,300 50,000 16 64,500 30,500 15 38,100 

Muscoda, Wis. 

61 12 05418500 Maquoketa River near 20,400 15 22,900 17,600 >100 14,800 9,200 >100 6,810 

c 

to

N 

13 05420500 

Maquoketa, Iowa. 

Mississippi River at 235,000 25 304,000 233,000 30 296,000 208,000 65 224,000 

N Clinton, Iowa. 

w 
CD

N

A 

m 

0 

c. 

0 

c

3 

w 

s(o 

c 

v 

m 

tow

rAN 

.d 

m 

m

N 

7

3 

1 

0

C

tCZ 

N

m 

v 

3 

c

0 

w

0 

i 

w 

Table 2. Magnitude and frequency of the highest daily mean discharges from 3, 7, and 30 consecutive days at selected streamflow-gaging stations in the upper 

Mississippi River Basin-Continued 

3-day values 7-day values 30-day values 

Site Recur- Previous Recur- Previous Recur- Previous 

number Station Station name rence maximum rence maximum rence maximum 1993 (fig . 4) number 1993 interval for period 1993 interval for period (ft3/s) interval for period (ft3/s) for 1993 of record (ft3/s) for 1993 of record for 1993 of record 

14 05422000 Wapsipinicon River near 

DeWitt, Iowa. 

15 05429500 Yahara River near 

McFarland, Wis. 

16 05451500 Iowa River at 

Marshalltown, Iowa. 

17 05453100 Iowa River at 

Marengo, Iowa. 

18 05465500 Cedar River near 

Conesville, Iowa. 

19 05465500 Iowa River at 

Wapello, Iowa. 

20 05471500 South Skunk River near 

Oskaloosa, Iowa. 

21 05474000 Skunk River at 

Augusta, Iowa. 

22 05474500 Mississippi River at 

Keokuk, Iowa. 

23 05474500 Des Moines River at 

Humboldt, Iowa. 

24 054813000 Des Moines River near 

Stratford, Iowa. 

25 05482500 North Raccoon River near 

Jefferson, Iowa. 

26 05484000 South Raccoon River at 

Redfield, Iowa. 

(years) (ft3/s) (years) (ft3/s) (years) (ft3/s) 

20,000 25 21,500 19,600 70 17,200 14,600 >100 11,000 

670 30 842 648 25 825 588 45 

16,000 20 33,100 13,700 100 21,900 8,970 >100 8,280 

32,600 >100 23,000 28,300 >100 19,500 20,200 >100 11,600 

63,900 40 63,700 52,400 50 54,700 43,300 >100 34,100 

99,800 >100 80,700 93,600 >100 64,300 80,800 >100 49,000 

19,200 >100 16,400 17,100 >100 13,400 11,900 >100 9,300 

43,800 >100 57,300 36,900 >100 39,900 27,200 >100 21,000 

425,000 >100 341,000 419,000 >100 323,000 388,000 >100 266,000 

16,200 60 17,300 15,200 55 15,600 12,400 >100 8,620 

38,200 25 51,700 35,900 40 43,600 28,400 >100 21,900 

14,700 13 17,900 12,900 20 13,500 7,760 45 8,020 

23,400 >100 15,100 15,400 >100 10,000 5,740 >100 5,030 

719
Table 2. Magnitude and frequency of the highest daily mean discharges from 3, 7, and 30 consecutive days at selected streamflow-gaging stations in the upper 

Mississippi River Basin-Continued 

Site Station number number Station name 

(fig . 4) 

27 05484500 Raccoon River at 

Van Meter, Iowa. 

28 05485500 Des Moines River below 

Raccoon River at 

Des Moines, Iowa. 

29 05490500 Des Moines River at 

Keosauqua, Iowa. 

30 05570000 Spoon River at 

Seville, Ill. 

31 05586100 Illinois River at 

Valley City, Ill . 

32 06468170 James River near 

Grace City, N. Dak. 

33 06478500 James River near 

Scotland, S. Dak. 

34 06481000 Big Sioux River near 

Dell Rapids, S. Dak. 

35 06483500 Rock River near 

Rock Valley, Iowa. 

36 06606600 Little Sioux River at 

Correctionville, Iowa. 

37 06800500 Elkhorn River at 

Waterloo, Nebr. 

38 06803500 Salt Creek at 

Lincoln, Nebr. 

3-day values 7-day values 30-day values 

Recur- Previous Recur- Previous Recur- Previous 

1993 

(ft3/s) interval 

for 1993 

for period

of record (ft3/s) interval for 1993 

for period 

of record (ft3/s) interval 

for 1993 

for period

of record 

(years) (ft3/s) (years) (ft3/s) (years) (ft 3/s) 

47,800 >100 32,400 35,100 >100 28,600 17,700 >100 14,000 

101,000 >100 55,400 87,800 >100 54,300 56,900 >100 37,300 

107,000 >100 50,300 105,000 >100 40,700 89,600 >100 36,400 

27,600 60 27,600 21,400 90 19,500 9,230 90 8,740 

86,900 5 122,000 84,800 5 121,000 73,000 6 98,800 

2,950 35 2,770 2,320 25 2,300 971 18 

15,900 45 25,600 13,100 30 19,800 8,780 30 9,330 

12,900 14 30,900 10,500 17 20,600 7,080 40 6,940 

17,400 15 30,000 13,800 20 21,500 10,200 >100 6,510 

18,900 25 25,600 17,000 25 21,300 12,400 >100 9,810 

23,600 9 69,600 18,200 11 38,000 11,800 30 12,000 

17,300 60 11,600 10,200 80 6,230 3,500 40 3,100 

rence maximum 1993 rence maximum 1993 rence maximum 

802 
i

Table 2. Magnitude and frequency of the highest daily mean discharges from 3, 7, and 30 consecutive days at selected streamflow-gaging stations in the upper

Mississippi River Basin-Continued 

m 

0° 3-day values 7-day values 30-day values a 

o Site Recur- Previous Recur- Previous Recur- Previous 

3 number Station Station name 1993 rence maximum 1993 rence maximum rence maximum 

w (fig. 4) number (tt3

/s) interval for period (n3/5 interval for period 1993 interval for period

for 1993 of record ) for 1993 of record ( /s) for 1993 of record 

(years) (ft3/s) (years) (ft 3/s) (years) (ft3/s) 

vc 

. 

g 

39 06805500 Platte River at 

Louisville, Nebr. 

111,000 50 102,000 81,200 35 82,700 43,600 40 42,000

w 40 06807000 Missouri River at 

Nebraska City, Nebr. 

182,000 60 170,000 155,000 45 168,000 118,000 60 123,000

v, 

~o 

41 06808500 West Nishnabotna River 

at Randolph, Iowa. 

12,700 10 16,500 9,060 40 9,490 6,640 >100 4,820 

A 

W 

w 

42 06810000 Nishnabotna River above 

Hamburg, Iowa. 

35,000 >100 38,100 28,200 >100 24,700 18,000 >100 16,500 

43 06815000 Big Nemaha River at 

Falls City, Nebr. 

38,800 80 39,800 27,800 >100 19,700 16,300 >100 7,880

Cc 

44 06817000 Nodaway River at 

Clarinda, Iowa. 

16,200 >100 19,000 12,400 >100 10,700 6,960 >100 4,960 

m 

to(o

v 

45 06818000 Missouri River at 

St . Joseph, Mo. 

311,000 >100 193,000 273,000 >100 191,000 198,000 >100 159,000

3 

w 

46 06820500 Platte River near 

Agency, Mo. 

48,500 >100 39,500 34,600 >100 30,700 21,900 >100 14,100

0 

47 06853020 Republican River at 7,160 20 14,300 5,200 25 8,810 2,400 13 4,750 R o Guide Rock, Nebr. w 

48 06879100 Kansas River at 

Fort Riley, Kans . 

80,900 >100 49,500 72,600 >100 41,700 43,200 >100 26,600

50 06893000 Missouri River at 

Kansas City, Mo. 

511,000 >100 285,000 448,000 >100 240,000 309,000 >100 193,000

51 06897500 Grand River near 

Gallatin, Mo. 

79,000 >100 60,500 59,100 >100 42,400 35,000 >100 23,100

52 06898000 Thompson River at 

Davis City, Iowa. 

21,000 50 35,800 13,800 70 20,600 7,540 >100 5,180
Table 2. Magnitude and frequency of the highest daily mean discharges from 3, 7, and 30 consecutive days at selected streamflow-gaging stations in the upper 

Mississippi River Basin-Continued 

3-day values 7-day values 30-day values 

Recur- Previous Recur- Previous Recur- Previous Site Station rence maximum 1993 rence maximum 1993 rence maximum number number Station name 1993 interval for period (ft3/s) interval for period (ft3/s) interval for period (fig . 4) (ft3/s)€ for 1993 of record for 1993 of record for 1993 of record 

(years) (ft3/s) (years) (ft3/s) (years) (ft3/s) 

53 06899500 Thompson River at 46,300 80 53,200 37,700 >100 30,800 19,400 >100 16,900 

Trenton, Mo. 

54 06902000 Grand River near 157,000 >100 147,000 145,000 >100 98,200 89,900 >100 68,800 

Sumner, Mo. 

55 06904500 Chariton River at 19,400 35 19,400 17,600 50 16,200 10,100 100 9,800 

Novinger, Mo. 

56 06905500 Chariton River near 29,200 100 27,800 27,000 >100 19,800 16,400 >100 15,000 

Prairie Hill, Mo. 

57 06909000 Missouri River at 696,000 >100 321,000 609,000 >100 299,000 415,000 >100 229,000 

Booneville, Mo. 

58 06934500 Missouri River at 703,000 >100 498,000 622,000 >100 443,000 434,000 >100 341,000 

Hermann, Mo. 

59 07010000 Mississippi River at 1,033,000 >100 843,000 1,001,000 >100 820,000 904,000 >100 698,000 

St. Louis, Mo. 

60 07022000 Mississippi River at 969,000 >100 868,000 948,000 >100 847,000 888,000 >100 743,000 

Thebes,111 . 
Table 3. Magnitude and frequency of the highest daily mean discharges for 60, 90, and 120 consecutive days at selected streamflow-gaging stations in the upper

Mississippi River Basin 

C [ft 3/s, cubic feet per second; recurrence interval, rounded to nearest 5 years for 20- to 50-year recurrence intervals and to nearest 10 years for 55- to 100-year recurrence intervals; >, greater than] 0 

60-day values 90-day values 120-day values 

3 Site Station Recur- Previous Recur- Previous Recur- Previous 

y number number Station name 1993 rence maximum 

1993 rence maximum 1993 rence maximum 

3 (fig. 4) interval for period interval for period 

(

ft3/s) 

interval for period (ft%) for 1993 of record (ft3/s) for 1993 of record for 1993 of record 

(years) (ft3/S) (years) (ft3/S) (years) (ft 3/s a 

1 05311000 Minnesota River at 7,910 25 9,790 6,430 30 7,610 5,730 50 6,240 

Montevideo, Minn. 

rA 

La. 

,-v0. 2 05317000 Cottonwood River near 5,160 >100 4,030 4,430 >100 2,910 3,990 >100 2,450 

New Ulm, Minn. 

3 05320000 Blue Earth River near 10,200 >100 8,540 9,160 >100 6,550 9,110 >100 5,390 

Rapidan, Minn. 

W

d 

w 4 05325000 Minnesota River at 35,300 >100 30,000 30,600 >100 22,900 30,000 >100 19,900 

D Mankato, Minn. 

v 

= 

J 5 05330000 Minnesota River near 41,300 >100 32,600 35,800 >100 24,800 34,200 >100 21,500 

Jordan, Minn. 

6 05331000 Mississippi River at 65,400 45 72,600 58,300 60 60,100 55,900 90 51,700 

N

0 

St . Paul, Minn. 

9 

3 

7 05360500 Flambeau River near 

Bruce, Wis. 

3,920 4 6,040 3,720 5 5,220 3,270 5 4,290

c 8 05369500 Chippewa River at 19,200 6 25,700 18,200 11 23,300 16,100 14 20,600 

Durand, Wis. m 

m 

9 05382000 Black River near 8,020 >100 7,360 8,170 >100 5,750 6,960 >100 4,700 

Galesville, Wis. 

10 05398000 Wisconsin River at 9,910 12 11,600 9,380 40 9,260 7,930 40 7,570 

Rothschild, Wis. 

11 05407000 Wisconsin River at 25,000 40 30,700 25,400 >100 25,700 23,300 >100 21,100 

Muscoda, Wis. 

12 05418500 MaquoketaRiver near 6,480 >100 4,810 5,300 >100 4,090 4,720 >100 3,770 

Maquoketa, Iowa. 

13 05420500 Mississippi River at 173,000 80 191,000 161,000 >100 164,000 159,000 >100 142,000 

Clinton, Iowa. 
Table 3. Magnitude and frequency of the highest daily mean discharges for 60, 90, and 120 consecutive days at selected streamflow-gaging stations in the upper Mississippi River Basin-Continued 

site Station number Station name number (fig. 4) 

14 05422000 Wapsipinicon River near 

DeWitt, Iowa. 

15 05429500 Yahara River near 

McFarland, Wis. 

16 05451500 Iowa River at 

Marshalltown, Iowa. 

17 05453100 Iowa River at 

18 05465500 

19 05465500 

20 05471500 

21 05474000 

22 05474500 

23 05474500 

Marengo, Iowa. 

Cedar River near 

Conesville, Iowa. 

Iowa River at 

Wapello, Iowa. 

South Skunk River near 

Oskaloosa, Iowa. 

Skunk River at 

Augusta, Iowa. 

Mississippi River at 

Keokuk, Iowa. 

Des Moines River at 

Humboldt, Iowa. 

24 054813000 Des Moines River near 

Stratford, Iowa. 

25 05482500 North Raccoon River near 

Q Jefferson, Iowa. 

w 26 05484000 South Raccoon River at 

N Redfield, Iowa. 

60-day values 90-day values 120-day values 

Recur- Previous Recur- Previous Recur- Previous 

1993 

(ft3/s) interval 

for 1993 

for period 

of record 

1993 

(ft3/s) interval 

for 1993 

for period 

of record 

1993 

(ft 3/s) interval 

for 1993 

for period 

of record 

(years) (ft3/s) (years) (ft 3/s) (years) (ft 3/s) 

11,700 >100 7,460 10,400 >100 6,660 8,900 >100 6,030 

526 80 501 474 >100 459 483 >100 

8,050 >100 5,820 7,540 >100 5,130 6,480 >100 4,400 

17,900 >100 9,900 15,600 >100 8,800 13,200 >100 7,670 

38,700 >100 23,200 36,100 >100 20,300 32,400 >100 17,800 

71,100 >100 33,800 61,900 >100 31,000 54,000 >100 27,900 

9,920 >100 6,380 8,720 >100 4,970 7,500 >100 4,190 

23,000 >100 16,100 20,000 >100 14,200 17,500 >100 12,100 

313,000 >100 240,000 280,000 >100 223,000 269,000 >100 200,000 

10,400 >100 5,810 9,090 >100 6,100 8,800 >100 5,400 

24,600 >100 17,000 21,000 >100 16,000 21,200 >100 14,000 

5,630 50 5,960 5,030 60 5,460 5,010 >100 4,680 

4,180 >100 3,010 3,470 >100 2,390 3,020 >100 2,300 

rence maximum rence maximum rence maximum 

401 
ro

W 

O Table 3. Magnitude and frequency of the highest daily mean discharges for 60, 90, and 120 consecutive days at selected streamflow-gaging stations in the upper Mississippi River Basin-Continued 

21


0 60-day values 90-day values 120-day values
 a


o 

3 

ID 

Site 

number 

(fig . 4) 

Station Station name number 1993 

( /s) 

Recurrence 

interval 

for 1993 

(years) 

Previous 

maximum 

for period 

of record 

(ft 3/S) 

1993 

(

ft3/s ) 

Recurrence 

interval 

for 1993 

(years) 

Previous 

maximum 

for period 

of record 

(ft3/S) 

1993 

( /s) 

Recurrence 

interval 

for 1993 

(years) 

Previous 

maximum 

for period 

of record 

(ft 3/S ) 

c 27 05484500 Raccoon River at 12,600 >100 10,700 11,100 >100 9,840 10,200 >100 8,340 

m Van Meter, Iowa. 

3 

28 05485500 Des Moines River below the 43,300 60 30,300 37,500 35 29,000 35,100 40 26,100 

rri Raccoon River at N 

Des Moines, Iowa . v 

29 05490500 Des Moines River at 67,700 >100 31,000 57,200 >100 27,600 50,400 >100 26,300 

Keosauqua, Iowa. W 

30 05570000 Spoon River at 6,460 >100 5,780 5,420 >100 4,940 4,600 >100 4,460 

n Seville, Ill . 

v 

=' J 31 05586100 Illinois River at 66,300 8 90,700 58,300 8 77,300 57,300 14 65,900

Valley City, Ill . 

c 32 06468170 James River near 565 17 416 394 16 282 299 15 213 

Grace City, N. Dak. N 

<D 

33 06478500 James River near 6,630 35 7,740 5,300 30 6,420 4,500 30 5,430 

a Scotland, S. Dak. 

er 

c 34 06481000 Big Sioux River near 4,690 40 4,770 3,900 45 3,920 3,760 60 3,270 

"i Dell Rapids, S. Dak. 

35 06483500 Rock River near 8,070 >100 4,600 6,550 >100 4,600 5,620 >100 4,030 

Rock Valley, Iowa. 

36 06606600 Little Sioux River at 11,000 >100 8,090 9,020 >100 6,830 8,630 >100 6,480 

Correctionville, Iowa. 

37 06800500 Elkhorn River at 8,130 35 9,960 6,680 25 10,200 6,200 30 8,690 

Waterloo, Nebr. 

38 06803500 Salt Creek at 2,170 45 2,000 1,610 40 1,720 1,360 40 1,470 

Lincoln, Nebr. 
Table 3. Magnitude and frequency of the highest daily mean discharges for 60, 90, and 120 consecutive days at selected streamflow-gaging stations in the upper Mississippi River Basin-Continued 

Site Station numbe Station name number (fig . 4) 

39 06805500 Platte River at 

Louisville, Nebr. 

40 06807000 Missouri River at 

Nebraska City, Nebr. 

41 06808500 West Nishnabotna River at 

42 06810000 

43 06815000 

44 06817000 

45 06818000 

Randolph, Iowa. 

Nishnabotna River above 

Hamburg, Iowa. 

Big Nemaha River at 

Falls City, Nebr. 

Nodaway River at 

Clarinda, Iowa. 

Missouri River at 

St. Joseph, Mo. 

46 06820500 Platte River near 

Agency, Mo. 

47 06853020 Republican River at 

Guide Rock, Nebr. 

48 06879100 Kansas River at 

Fort Riley, Kans. 

49 06891000 Kansas River at 

LeCompton, Kans. 

50 06893000 Missouri River at 

LT Kansas City, Mo. 

w 51 06897500 Grand River near 

w Gallatin, Mo. 

60-day values 90-day values 120-day values 

Recur- Previous Recur- Previous Recur- Previous 

rence maximum 1993 rence maximum 1993 rence maximum 1993 interval for period (ft3/s) interval for period (ft 3/s) interval for period (ft3/s)	 for 1993 of record for 1993 of record for 1993 of record 

(years) (ft3/s) (years) (ft3/s) (years) (ft3/s) 

28,800 30 39,100 23,600 20 37,000 21,600 25 32,600 

92,800 45 101,000 80,800 20 100,000 73,400 16 92,700 

4,760 >100 3,500 4,020 >100 3,010 3,650 >100 2,710 

12,800 >100 9,860 11,000 >100 7,350 9,670 >100 6,050 

8,950 >100 6,330 7,260 >100 5,380 6,080 >100 4,440 

4,140 >100 2,700 3,480 >100 2,140 2,990 >100 2,060 

145,000 >100 126,000 123,000 90 124,000 109,000 80 115,000 

12,700 >100 7,470 9,660 >100 6,070 8,080 >100 5,760 

1,610 9 4,140 1,360 9 3,540 1,050 8 3,540 

33,400 >100 21,800 27,800 >100 17,900 23,700 >100 15,100 

75,100 >100 101,000 62,100 >100 76,000 53,300 >100 65,200 

224,000 >100 157,000 187,000 >100 157,000 170,000 >100 149,000 

19,800 >100 12,300 14,600 >100 9,730 12,200 >100 7,680 
Table 3. Magnitude and frequency of the highest daily mean discharges for 60, 90, and 120 consecutive days at selected streamflow-gaging stations in the upper Mississippi River Basin-Continued 

60-day values 90-day values 120-day values 

Site Station Recur- Previous Recur- Previous Recur- Previous 

number 

(fig . 4) number Station name 1993 rence maximum 1993 rence maximum 1993 rence maximum 

interval for period interval for period interval for period (ft3/s) for 1993 of record (ft3/s) for 1993 of record (ft3/s) for 1993 of record 

(years) (ft3/s) (years) (ft3/s) (years) (ft3/s) 

52 06898000 Thompson River at 4,340 >100 2,800 3,290 >100 2,530 2,760 >100 2,110 

Davis City, Iowa. 

53 06899500 Thompson River at 

Trenton, Mo. 

11,100 >100 8,970 8,580 >100 7,630 7,210 >100 6,200

54 06902000 Grand River near 

Sumner, Mo. 

52,600 >100 38,800 39,500 >100 31,800 33,500 >100 25,900

55 06904500 Chariton River at 

Novinger, Mo. 

6,470 50 5,820 5,380 60 5,250 4,660 >100 4,440

56 06905500 Chariton River near 

Prairie Hill, Mo. 

9,940 80 9,390 8,330 80 8,110 6,820 80 6,900

57 06909000 Missouri River at 

Booneville, Mo. 

305,000 >100 203,000 256,000 >100 182,000 227,000 >100 176,000

58 06934500 Missouri River at 349,000 >100 309,000 312,000 >100 268,000 279,000 >100 237,000

Hermann, Mo. 

59 07010000 Mississippi River at 766,000 >100 671,000 687,000 >100 615,000 630,000 >100 548,000

St . Louis, Mo. 

60 07022000 Mississippi River at 776,000 >100 717,000 697,000 >100 664,000 639,000 >100 595,000

Thebes, Ill.