E F F E C T S 

OF 

R E S E R V O I R S 

ON 

FLOOD 

D I S C H A R G E S 

IN THE 

K A N S A S 

AND 

M I S S O U R I 

RIVER BASINS 

9 9 3 

U.S . GEOLOGICAL SURVEY CIRCULAR 1120-E 

Click here to return to USGS publications 
Front cover-ibttle Creek Lake, dam, and spillway 

(Paul Maginness, Photographic Services, 

Kansas State University, Manhattan, 

Kansas) 

Back cover-'IUttle Creek Lake spillway power right) and 

uncontrolled flow over spillway at Milford 

Lake (upper left) 
EFFECTS OF RESERVOIRS ON FLOOD€

DISCHARGES IN THE KANSAS AND THE MISSOURI€

RIVER BASINS, 1993€

By Charles A. Perry 

Floods in the Upper Mississippi River Basin, 1993€

U.S. GEOLOGICAL SURVEY CIRCULAR 1120-E 
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary 

U .S . GEOLOGICAL SURVEY 

ROBERT M. HIRSCH, Acting Director 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1994€

Free on application to the€

USGS Map Distribution€

Box 25286, MS 306€

Denver 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. 

Acting Director 

January 26, 1994 

Foreword III 
Contents 

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

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

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

Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Flood-control reservoirs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Climatic conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Flood storage in and effects of reservoirs on flood discharges, Missouri River Basin . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 5 

Missouri River main stem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

Platte River in Missouri. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

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

Chariton River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Osage River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Combined effect of flood-control reservoirs on Missouri River discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Record reservoir levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Kansas River flood discharge analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

Kansas River tributaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Kansas River main stem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Reservoir level maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Comparison of 1951 and 1993 floods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 

FIGURES 

1 . Map showing locations of flood-control reservoirs and selected streamflow-gaging stations in 

the Missouri, the Kansas, and the upper Mississippi River Basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

2. Schematic diagram showing hypothetical hydrographs of an uncontrolled stream and reservoirregulated outflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

3. Diagrammatic cross section of a typical reservoir showing locations of surcharge, flood-control, and 

multipurpose-pool levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

4.-5. Map showing: 

4. Persistent weather pattern responsible for the floods of 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

5. Areal distribution of rainfall during July 1993 and locations of reservoirs in the Kansas 

River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

6. Schematic diagram showing flood-control storage in the Kansas River Basin reservoir system, 

maximum storage for July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

7.-15 . Hydrographs showing observed and simulated uncontrolled discharges in the: 

7. Saline River at Tescott, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

8. Solomon River at Niles, Kansas, July 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

9. Smoky Hill River at Mentor, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

10 . Smoky Hill River at Enterprise, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

11 . Republican River below Milford Dam, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

12 . Big Blue River near Manhattan, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

13 . Kansas River at Wamego, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

14 . Kansas River at Topeka, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

15 . Kansas River at DeSoto, Kansas, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

16 . Hydrographs showing water-level elevations of selected reservoirs in the Kansas River Basin, 

1993 water year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

17.-18 . Map showing total precipitation in the Kansas River Basin: 

17 . April 1 to July 31, 1951 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

18 . April 1 to July 31, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

19. Hydrographs showing floods in the Kansas River at DeSoto, Kansas, 1951 and 1993. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 

Contents V 
TABLES 

1 . Summary of flood-control and storage characteristics for selected reservoirs in the Missouri 

River Basin, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

2. Flood discharge in selected streams in the Kansas and the Missouri River Basins, July 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

CONVERSION FACTORS AND VERTICAL DATUM 

Multiply 

inch (in.)


foot (ft)


mile (mi)


square mile (mil)


cubic foot per second (ft3/s)


acre-foot (acre-ft)


By 

25 .4 

0.3048 

1 .609 

2.590 

0.02832 

0.001233 

To obtain 

millimeter


meter


kilometer


square kilometer


cubic meter per second


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. 
Effects of Reservoirs on Flood Discharges in the Kansas and the


Missouri River Basins, 1993 

By Charles A. Perry 

Abstract 

The floods of 1993 were of historic magnitude as water in the Missouri and the Mississippi 

Rivers reached levels that exceeded many of the 

previous observed maximums . Although large 

parts of the flood plains of both rivers upstream 

from St. Louis, Missouri, were inundated, water 

levels would have been even higher had it not 

been for the large volume of runoff retained in 

flood-control reservoirs . Most of the total floodcontrol storage available upstream from St. 

Louis is located along the main stem and tributaries of the Missouri River; the largest concentration of reservoirs is located within the Kansas 

River Basin. The Kansas River Basin accounts 

for about 10 percent (60,000 square miles) of the 

drainage area of the Missouri River Basin, and 

reservoirs control streamflow from 85 percent 

(50,840 square miles) of the drainage area of the 

Kansas River Basin. Analyses of flood discharges in the Kansas River indicate that reservoirs reduced flooding along the Kansas and the 

lower Missouri Rivers . Results of analyses of 

the 1993 flooding, which include total basin rainfall, peak discharge, and total flood volume on 

the Kansas River, are compared with analyses of 

the 1951 flood, which had a similar total volume 

but a substantially larger peak discharge. 

INTRODUCTION 

Wetclimatic conditions prevailed from the 

Pacific Northwest, through the northern one-half of the 

Central Plains, to the Upper Midwestern States during 

1993 . A multiyear drought in the western one-half of 

this large region was broken by average and above-average 1992-93 winter precipitation. Average to aboveaverage precipitation in the upper Midwest during 1992 

continued into spring and summer 1993 and reached 

accumulations during the 1993 water year (October 1, 

1992-September 30, 1993) that were more than twice 

the normal (October-September 1961-90) precipitation 

(National Weather Service, 1993). As a result, flooding 

was severe in many rivers in the upper Mississippi River 

Basin (fig. 1) . Flood discharges from the Mississippi 

and the Missouri Rivers combined for a historic peak of 

1,080,000 cubic feet per second (ft3/s) on the Mississippi River at St. Louis, Missouri, on August 1, 1993. 

Historic streamflow records show that this discharge 

was the largest since 1861 and has been exceeded only 

by an estimated discharge of 1,300,000 ft3/s for the 

flood of 1844. Discharge for the flood of 1903, which 

has been estimated to be 1,019,000 ft3/s, was slightly 

less than that of 1993. However, changes in the upper 

Mississippi River Basin, such as the construction of 

many flood-control reservoirs, that have been made in 

the last 50 years reduced the magnitude of the maximum 

discharge ofthe 1993 flood at St. Louis. 

Flood-control reservoirs throughout the upper Mississippi 

River Basin helped reduce flooding during 1993. 

Introduction 1 
--

EXPLANATION 

95° .- Boundary of the upper 

Mississippi River Basin 

7 .- Boundary of drainage basin 

~Xe 

MO NTANA 

Boundary of drainage 

subbasin 

N RTH,DAKG 31 Reservoir and reference 

number used in table I 

A E Selected stream gaging 

station and reference 

letter used in table 2 

45- 90^ 

Lak, 

Ouh 

Mlnneapolis~' Paul Wise,) 

HjDAKOTA rre 

3 < 

WY OMING 

MISSISPPI 

M6L 

5= 111son it 

UPPER ~sm MISSISSIPPI i1\0 ER . BA- I N 

W I IOWA RIVER 

`~dar Rapids ',,

BASIN Sov~~re~~le 

1NEBRASKA A Lake _ 

Loke Comlulll Mtvenpo 

Ohey Im Red Rock R-1101 

BASIN Peori 

40- iLLINOI IN 

m CHAR ON 

-

\112 9 -1h1-,,' 14 \\ . _RIVER BASIN_ AS 

DENVER 7 K/ANSA$wzo`~e RIVEIR ~ BASINzz, 

,30 qL 

glie 

r 

wam Fs

./\ 

4rada SprinOs \ - iB_ 21 D -0 15~ 

c 

Ie PASt 

Pas City A .- . R AD0 

20. . !a 1 `. .33_ ,~,it~rson 

C­ S	 RIV P. 

BiA~tt~t 

�_ 

Wi llit Y 31_ 

ARKAf1 AS I =RIVER \, ,- ~ -:^ ~~~ [[pp\ryfrald \ __ ~ =: BASIN IdiSSOURi 

Base from U .S . Geological Survey 

1 :10,000,000,1975 100 200 MILES 

i I I 

100 200 KILOMETERS 

Figure 1 . Locations of flood-control reservoirs and selected streamflow-gaging stations in the Missouri, the Kansas, and the 

upper Mississippi River Basins. 

Purpose and Scope 

As the principal Federal agency responsible 

for the collection of water-resources data, the U.S. 

Geological Survey (USGS) operates a network of 

about 7,300 continuous-record streamflow- and lakelevel-gaging stations throughout the Nation. The 

records from selected stations on the Kansas and the 

Missouri Rivers form the basis for the discussion of 

the effects of flood-control reservoirs on the 1993 

flood discharges in the upper Mississippi River 

Basin. Because most of the flood-control reservoirs 

are in the Missouri River Basin, this report focuses 

on this part of the upper Mississippi River Basin, 

with special emphasis on the Kansas River Basin. 

2 Effects of Reservoirs on Flood Discharges in the Kansas 

An analysis of total flood storage in the Missouri 

River Basin from April 1 to August 1 and during July 

1993 is provided to assess the effects of reservoirs on 

flood discharges downstream. A detailed analysis of 

the effects of reservoirs on peak discharge is provided for the Kansas River, including a comparison 

of the controlled flood discharges of 1993 with the 

uncontrolled flood discharges of 1951 . 

Flood-Control Reservoirs 

The function of flood-control reservoirs is to 

store temporarily a part of the flood discharge for 

later release so that the flood peak downstream will 

be reduced. In an uncontrolled stream, the flood disand the Missouri River Basins, 1993 
charges of the tributary streams are added to the discharge in the main stem. As a result, the total flood 

volume increases in the downstream direction, as 

does the peak discharge (fig . 2A). In the case of the 

controlled stream, all or part of the flood discharge is 

stored in a reservoir for later release at a reduced 

flow rate (fig . 2B). Downstream from the reservoir, 

additional flood discharges in the tributaries enter the 

main stem, which add uncontrolled flood discharges 

to the controlled discharge. In the actual operation of 

a flood-control reservoir, the uncontrolled flood discharges from the drainage area downstream from a 

reservoir need to be considered before reservoir 

releases are made . If uncontrolled flood discharge 

from areas below the reservoir produces a flood on 

the main stem, then reservoir releases can be reduced 

to near zero discharge to minimize additional flooding downstream. 

Most flood-control reservoirs in the Kansas 

and the Missouri River Basins are of the multipurpose type, which are used to store water for irrigation, navigation, public-water supply, and recreation. 

The flood-control, or flood-storage capacity, pool of 

a reservoir is always above the multipurpose-pool 

level (fig . 3). All reservoirs with provision for flood 

control are operated so that a minimum amount of 

water in the flood-control pool is maintained prior to 

flooding to maximize flood protection. The flood 

reduction potential of a reservoir is compromised if 

additional flood water must be stored before the previously stored water can be released. 

Flood-control reservoirs are constructed with 

an emergency spillway to protect the dam from being 

overtopped, which can cause severe damage to or fail 

ure of the dam. Flow through the spillway can be 

uncontrolled or can be controlled by gates that reguUPSTREAM DISCHARGE DOWNSTREAM DISCHARGE 

HYDROGRAPH HYDROGRAPH 

w w 

(7 (7 s s Q Q S S U U y U 

TIME ]110 TIME 00 

late the releases up to a certain elevation in the reservoir. Once the water level in the reservoir rises to the 

top of the closed spillway gates or the sill of an 

uncontrolled spillway, water stored above this elevation in the reservoir is in the surcharge pool. Outflow 

of surcharge in the reservoir is determined by the 

depth of water and the geometry of the spillway or 

the spillway gate opening. 

Surcharge 

pool / \ Spillway 

elevation 

Figure 3. Typical reservoir showing locations 

of surcharge, flood-control, and multipurpose-pool levels . 

CLIMATIC CONDITIONS 

Precipitation during the 1992-93 winter, 

spring, and summer months (January-August) in 

much of the upper Mississippi River Basin generally 

was more than 100 to 200 percent of normal (January-August 1961-90) (National Weather Service, 

1993). Some precipitation stations recorded singlemonth (July) accumulations of more than 600 percent 

of normal (July 1961-90) (Wahl and others, 1993). 

Persistent wet soil conditions in 1993 throughout this 

large region, coupled with many intense rainstorms, 

led to widespread flooding in the upper Mississippi 

River Basin. 

UPSTREAM INFLOW DOWNSTREAM OUTFLOW 

HYDROGRAPH HYDROGRAPH 

w w


C7 C7
 S


Q Q
 S S
 U U
 N (/1


D


TIME 10 TIME 10 

Figure 2. Hypothetical hydrographs of (A) an uncontrolled stream and (B) reservoir-regulated outflow. 

Climatic Conditions 3 
As a result of average to above-average precipitation during late summer and fall 1992 in many 

Midwestern States, stream, ground-water, and lake 

levels were near normal at the beginning of 1993. 

During winter 1992-93, average to above-average 

snowpack was produced throughout much of the 

Northern Rocky Mountains as storms from the North 

Pacific Ocean drove inland; this precipitation ended a 

severe 6-year drought. The plentiful precipitation 

continued into spring and summer 1993 and spread 

eastward into Wisconsin and Illinois as a storm-steering jet stream anchored itself to an upper-atmospheric 

low-pressure trough over the Northwestern States and 

a strong high-pressure ridge over the Eastern States 

(fig . 4). West of the trough, the jet stream directed 

cool air from the Gulf of Alaska southeastward, while 

east of the trough, the jet stream pulled warm, moist 

air northward from the Gulf of Mexico. Under the 

eastern high-pressure ridge, severe drought conditions developed by midsummer. 

40-

EXPLANATION 

Convergence zone ; area of 

intense rainfall 

TROUGH Stationary upper atmospheric

low-pressure area 

RIDGE Stationary upper atmospheric 

high-pressure area 

H Stationary surface high-pressure 

L Transient low-pressure 

storm system 

Flash flooding was common throughout the 

Missouri River Basin. 

Tuttle Creek Lake rose over 60 feet above 

multipurpose level into its surcharge pool . 

Figure 4. Persistent weather pattern responsible for the floods of 1993 (modified from Wahl and others, 1993). 

4 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 
As a result of the persistent position of the jet 

stream, very cool conditions prevailed in the northwestern part of the United States through the spring 

and summer months, while the southeastern part of 

the country was very warm. Weather on the eastern 

side of the trough was very active as the contrasting 

air masses clashed within the convergence zone. 

Thunderstorms that extended to heights of 60,000 

feet (ft) above land surface released torrential rains 

somewhere in the North-Central States nearly every 

day during spring and summer. Individual storm rainfall totals, which sometimes exceeded 5 inches (in .), 

fell on already saturated soils ; this commonly produced local flash floods in small streams and persistent riverine floods in much of the upper Mississippi 

River Basin. 

The initial influx of large volumes of runoff 

into the small streams caused local flooding. 

Because many of the small streams flooded simulta 

neously, the larger streams also exceeded flood 

stages . Flood-control reservoirs on the larger streams 

easily contained the initial onslaught of flooding . 

However, as the rains continued to fall over a very 

large area and uncontrolled streams continued to 

flood, the capacity of reservoirs to store additional 

storm runoff was diminished. Because of little opportunity to lower the water-surface elevations of these 

reservoirs to their multipurpose-pool levels, waterlevel elevations in many reservoirs reached record 

highs. 

FLOOD STORAGE IN AND EFFECTS OF 

RESERVOIRS ON FLOOD DISCHARGES, 

MISSOURI RIVER BASIN 

Missouri River Main Stem 

The six-reservoir system on the main stem of 

the upper Missouri River from Montana through 

North Dakota and South Dakota is used for power 

generation, storage for navigation and public-water 

supply, and flood control . When the 1993 water year 

began, the total storage content in the reservoir system was about 43,900,000 acre-feet (acre-ft) . By 

April 1, 1993, the total system content had increased 

to 45,468,000 acre-ft (U.S. Army Corps of Engineers, 

written commun., 1993). The additional 1,568,000 

acre-ft resulted from runoff produced by melting 

snowpack in the mountains during winter and early 

spring. The total increase in storage contents of the 

six-reservoir system from April 1 to August I was 

10,293,000 acre-ft (table 1), which was the result of 

increased rainfall during this period. During July 

1993 alone, reservoirs in the main-stem Missouri 

River stored nearly 5,369,000 acre-ft of floodwater. 

If this water had been released at a constant rate, then 

the daily average discharge of the Missouri River 

downstream during July would have been about 

87,000 ft 3/s larger than the observed average discharge of 291,000 ft3/s on the Missouri River at 

Kansas City, Missouri. 

Flood storage in the Missouri River Basin reservoirs, such 

as the Harry STruman Lake, reduced the average daily 

flow near St . Louis for July 1993 by over 211,000 ft3/s . 

(U .S . Army Corps of Engineers.) 

Platte River in Missouri 

The Platte River in Missouri is a small tributary of the Missouri River just upstream of its confluence with the Kansas River and is controlled by the 

Lake Smithville reservoir . During July 1993, this reservoir stored 55,200 acre-ft of floodwater. The water 

level in the reservoir reached a record elevation of 

874.3 ft above sea level on July 28. 

Kansas River Basin 

The Kansas River Basin is about 60,000 square 

miles (mi) in area, of which streamflow from 85 percent, or 50,840 miz, of the basin is controlled by reser 

voirs. Except for the main-stem Missouri River 

reservoir system, the Kansas River Basin is the largest 

basin under flood control in the Mississippi River 

Basin. Eighteen reservoirs (table 1), which have a total 

flood-control capacity of 7,390,000 acre-ft, provide 

flood protection within the basin and along the Missouri 

Flood Storage In and Effects of Reservoirs on Flood Discharges, Missouri River Basin 5 
10

m 

e 

N 

° Table 1 . Summary of flood-control and storage characteristics for selected reservoirs in the Missouri River Basin, 1993 . 

m [Basins: Mu, upper Missouri River (above Sioux City, Iowa); P, Platte River in Missouri ; K, Kansas River; O, Osage River; C, Chariton River; miZ, square miles; acre-ft, acre-feet; ft, w feet; --, data unavailable; data from U.S . Corps of Engineers, Bureau of Reclamation, and U.S . Geological Survey] 

0 

1 

y 

O


3 Reservoir Previous record 1993 Maximum


m reservoir elevation reservoir elevation Change in storage


0 Drainage Year Multi- Flood- Surchare Spillway


O


a Map Gaging Name area storage purpose control elevation


pool pool pool (ft above Ft above Ft above April 1 to July 1 to v no . station (basin) (miZ) began (acre-ft) (acre-ft) (acre-ft) sea level) sea level Date sea level w Date August 1 August 1

n (fig . 1) no . (acre-ft) (acre-ft) m 

m 

y Montana 

7 

7 

so 1 06131500 Fort Peck (Mu). . . . . . . . . . . . . . 57,500 1937 15,773,000 2,657,000 980,000 2,250.0 2,251 .6 7/15/75 2,228 .4 9/30 2,085,000 1,169,000 

d 

w

d North Dakota N 

N 

7 

d 2 06338000 Garrison (Mu). . . . . . . . . . . . . . . . 181,400 1953 18,750,000 4,250,000 1,854 1,854.6 7/5/75 1,837 .4 9/25 4,453,000 2,000,000 

m 

CC South Dakota N 

O 

C 

3 06439980 Oahe (Mu) . . . . . . . . . . . . . . . . . . . . 243,500 1958 20,140,000 2,390,000 1,100,000 1,620.0 1617 .9 8/22/75 1,611 .6 9/12 3,426,000 1,869,000 

m 4 06442700 Sharpe (Mu) . . . . . . . . . . . . . . . . . . 249,300 1963 1,465,000 260,000 175,000 1,423.0 1,421 .9 4/22/71 1,421 .2 6/13 9,000 22,000 

W

d 

5 06452500 Francis Case (Mu) . . . . . . . . . . 263,500 1952 1,336,000 3,498,000 982,000 1,375.0 1,364.2 6/ 2/62 1,361 .0 7/28 333,000 294,000

6 06467000 Lewis and Clark (Mu). . . . . . 279,500 1955 156,000 321,000 64,000 1,210.0 1,210.7 4/ 1/60 1,208.9 7/15 -13,000 15,000 

N 

i 

Colorado w 

7 06826000 Bonny (K). . . . . . . . . . . . . . . . . . . . . 1,820 1950 41,400 128,800 3,710.0 3,678.10 5/17/57 3,671 .92 6/ 6 -940 -1,000 

Nebraska 

8 06829000 Swanson (K). . . . . . . . . . . . . . . . . . 8,620 1953 116,100 137,900 107,600 2,773.0 2,757 .42 8/ 2/62 2,752 .29 6/14 2,160 -11,500 

9 06832000 Enders (K). . . . . . . . . . . . . . . . . . . . 950 1950 36,010 38,510 6,210 3,127.0 3,118 .20 3/25/60 3,101 .62 6/24 -1,230 -3,890 

10 06837390 Hugh Butler (K). . . . . . . . . . . . . 730 1961 31,470 54,890 76,240 2,604.9 2,584 .14 9/ 8/78 2,580 .63 7/30 4,210 2,520 

11 06842000 Harry Strunk (K). . . . . . . . . . . . 880 1949 32,230 57,080 106,690 2,386.2 2,374 .10 3/23/60 2,371.40 7/28 10,220 5,220 

12 06849000 Harlan Co. (K). . . . . . . . . . . . . . . 20,750 1952 319,800 509,000 46,800 1,973.5 1,955 .67 4/ 6/60 1,953.62 9/8 126,300 82,800 
- -

- -

--

Kansas 

13 06847950 Keith Sebelius (K) . . . . . . . . . . 683 1964 35,930 98,800 58,280 2,331 .4 2,304.59 6/27/67 2,297.10 9/29 2,620 2,180 

14 06853900 Lovewell (K) . . . . . . . . . . . . . . . . 345 1957 41,690 50,460 94,140 1,595.3 1,595.01 10/13/73 '1,595 .37 7/22 24,400 17,500 

15 06857050 Milford (K). . . . . . . . . . . . . . . . . . 24,880 1967 415,400 673,600 291,000 1,176 .2 1,170.03 10/17/73 -1,181 .94 7/25 805,000 735,000 

16 06861500 Cedar Bluff (K) . . . . . . . . . . . . . 5,530 1950 185,060 191,900 493,400 2,166.0 2,154.90 7/ 2/51 2,119.79 9/29 46,000 39,600 

17 06865000 Kanopolis (K) . . . . . . . . . . . . . . . 7,857 1948 55,200 356,700 69,000 1,507 .0 1,506.98 7/14/51 1,505.85 7/25 246,000 233,000 

18 06868100 Wilson (K) . . . . . . . . . . . . . . . . . . . 1,917 1964 242,500 1,245,000 179,500 1,582 .0 1,528 .06 4/26/87 '1,548 .27 8/6 388,000 388,000 

19 06871700 Kirwin (K) . . . . . . . . . . . . . . . . . . . 1,367 1955 99,700 214,900 198,400 1,757 .3 1,732 .15 6/10/61 '1,733 .47 9/29 54,000 42,200 

20 06873100 Webster (K). . . . . . . . . . . . . . . . . . 1,150 1956 76,430 184,300 140,900 1,923 .7 1,899.66 6/10/61 `1,903 .9 9/29 63,700 50,500 

21 06874200 Waconda (K) . . . . . . . . . . . . . . . . 5,076 1969 241,400 722,300 165,000 1,488 .3 1,471 .32 4/27/87 '1,487 .02 7/29 566,000 600,000 

22 06886900 Tuttle Creek (K) . . . . . . . . . . . . 9,628 1962 388,600 1,937,000 860,100 1,136.0 1,127 .90 10/18/73 '1,137 .76 7/22 1,615,000 1,317,000 

23 06890898 Perry (K) . . . . . . . . . . . . . . . . . . . . . 1,117 1969 225,000 517,500 36,160 922 .0 917 .07 10/19/73 '920 .94 7/25 443,000 437,000 

24 06891478 Clinton (K) . . . . . . . . . . . . . . . . . . . 367 1977 129,200 268,400 285,800 903 .4 886.72 6/ 4/82 '887 .57 7/31 84,400 88,600 

0 25 06910997 Melvern (O) . . . . . . . . . . . . . . . . . 349 1972 154,400 258,600 507,600 1,057 .0 1,049.07 6/ 2/82 1,048.31 7/29 107,000 103,000

to 

26 06912490 Pomona (O) . . . . . . . . . . . . . . . . . . 322 1963 66,640 176,500 255,400 1,003 .0 990.24 6/ 2/82 '992 .67 7/31 91,000 90,300 

27 06914995 Hillsdale (O) . . . . . . . . . . . . . . . . . 144 1981 76,270 83,570 155,800 931 .0 928 .49 10/20/86 826.70 7/28 55,000 55,800 m 

a 

m Iowa 

m 

0 28 06903880 Rathbun (C) . . . . . . . . . . . . . . . . . . 549 1969 199,800 345,800 926.0 924.46 7/22/82 '927 .20 7/28 295,000 269,000 

m 

Missouri 

0 

0 29 

30 

06821140 Smithville (P). . . . . . . . . . . . . . . . 

06906190 Long Branch (C). . . . . . . . . . . . 

213 

109 

1981 

1978 

144,600 

34,640 

101,800 

30,600 

182,200 

98,590 

876.2 

801 .0 

873.17 

799.56 

11/16/85 

7/28/81 

'874 .3 

799.0 

7/28 

7/26 

72,600 

9,000 

55,200 

9,000 

0 31 06918990 Stockton (O). . . . . . . . . . . . . . . . . 1,160 1969 887,100 779,600 892.0 885.94 4/28/73 884.5 9/29 74,000 42,000 

e. 32 06921325 Pomme de Terre (O). . . . . . . 611 1960 241,500 407,200 - - 874.0 862.35 4/30/73 '864 .6 9/27 21,000 29,000 

33 06922440 Harry S Truman (O). . . . . . . 11,500 1977 1,203,000 4,006,000 2,911,000 739.6 738.69 10/11/86 735.2 8/3 3,078,000 3,046,000 

m 34 06925500 Lake of the Ozarks (0). . . 14,000 1931 1,927,000 400,000 660.0 665.45 5/22/43 659 .92 6/17 122,000 -78,000 

m

N 

'New record elevation. 

Sl 

00 

c 

so 

W 

m 

y

7 
River downstream. From April 1 to August 1, 1993, the 

reservoir system in the Kansas River Basin stored 

4,500,000 acre-ft. Of this amount, 4,027,000 acre-ft 

was stored during July alone. Ifthis water had been 

released at a constant rate, then the average discharge of 

the Kansas River downstream during July would have 

been about 65,500 ft3/s larger than the observed average 

discharge of 76,800 ft3/s on the Kansas River at DeSoto, 

Kansas. About one-half of the July total of 4,027,000 

acre-ft was stored in Milford and Tuttle Creek Lakes. 

Both lakes filled their flood-control pools and were 

required to store floodwater in their surcharge pools. 

Tuttle Creek Lake stored 97,000 acre-ft in its surcharge 

pool, while Milford Lake stored 207,000 acre-ft in its 

surcharge pool. 

Chariton River Basin 

The Chariton River is a tributary of the Missouri River and flows from Iowa through northern 

Missouri. Lake Rathbun in Iowa and Lake Long 

branch in Missouri are flood-control reservoirs in the 

Chariton River Basin and stored 269,000 and 9,000 

acre-ft, respectively, during July 1993. The water 

level in Lake Rathbun reached a record elevation of 

927.2 ft above sea level on July 28, thus requiring the 

storage of 27,000 acre-ft in its surcharge pool. 

Osage River Basin 

Streamflow from the nearly 15,000-mil Osage 

River Basin is almost completely controlled by Lakes 

Melvern, Pomona, and Hillsdale in Kansas and Lakes 

Stockton, Pomme de Terre, and Harry S Truman and 

Lake ofthe Ozarks at Bagnal Dam in Missouri . The reservoir system in this basin stored 3,547,000 acre-ft 

between April 1 and August 1, 1993; of this total, 

3,289,000 acre-ft was stored during July. The effect of 

Lake Harry S Truman on discharge in the Osage River 

was significant because it stored more than 3,000,000 

acre-ft during July. The storage in Lake Harry S Truman and that of the other reservoirs in the Osage River 

Basin system reduced the average discharge ofthe 

Osage River at its confluence with the Missouri River 

for the month of July by 53,500 ft3/s . 

Combined Effect of Flood-Control Reservoirs 

on Missouri River Discharge 

As severe as the flooding was in 1993, stream 

and river levels could have been even higher had a 

system of flood-control reservoirs not been in place 

throughout the Missouri River Basin. About 

10,300,000 acre-ft of additional water was stored in 

the upper Missouri River main-stem reservoirs in 

Montana, North Dakota, and South Dakota from 

April 1 to August 1, 1993 . In the lower sections of 

the Missouri River Basin, the quantity of water stored 

from April 1 to August 1 in reservoirs on the Kansas 

River was 4,500,000 acre-ft, while reservoirs in the 

Platte, the Chariton, and the Osage River Basins 

stored 3,900,000 acre-ft. If the total 18,700,000 acreft stored in the system had been allowed to flow to St. 

Louis, then the average discharge of the Missouri 

River would have been 77,300 ft3/s greater for this 4-

month period. During July alone, the combined storage of about 13,000,000 acre-ft in the Missouri River 

Basin-5,400,000 acre-ft in the Missouri River main 

stem reservoirs, about 4,000,000 acre-ft in the Kansas 

River Basin reservoirs, and about 3,600,000 acre-ft in 

the reservoirs of the Platte, the Chariton, and the 

Osage River Basins-reduced the average discharge 

of the Missouri River at Hermann, Missouri, from 

about 587,000 ft3 /s to 376,000 ft 3 /s, which is a difference of 211,000 ft3/s. 

Record Reservoir Levels 

The 34 major reservoirs in the Missouri River 

Basin drain an area that is greater than 100 mil. Of 

these reservoirs, water levels in 13 reached historic 

elevations, 3 came within I ft of their records, and 4 

exceeded their spillway elevations (table 1) . Water 

levels in reservoirs on tributaries of the Mississippi 

River upstream of its confluence with the Missouri 

River, including Lakes Saylorville, Coralville, and Red 

Rock, all in Iowa, also reached record elevations. 

Many reservoirs in the midwest rose to record levels in 1993. 

8 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 
Several reservoirs, which are located in the Arkansas 

River Basin just south of the Kansas River Basin, had 

record and near-record water-level elevations. The number of reservoirs with record water-level elevations is an 

indication of the magnitude and wide extent of the 

floods of 1993. 

KANSAS RIVER FLOOD DISCHARGE 

ANALYSIS 

The Kansas River Basin is unique within the 

Mississippi River Basin because streamflow from all 

major tributaries is controlled by reservoirs. Many of 

these tributaries flooded during spring and summer 

1993, as well as other rivers in much of the upper 

Mississippi River Basin. If the reservoirs had not stored 

104` 102' 100° 

40' 

38° 

EXPLANATION 

a large volume of floodwaters, then discharges on the 

Kansas, the Missouri, and the Mississippi Rivers would 

have been greater than they were. An analysis of the 

storage of flood volumes in the Kansas River Basin 

from April 1 to September 1, and specifically during 

July, enables a comparison of discharges at various 

points along the river with and without the protection of 

the reservoirs. 

The Kansas River Basin is located in northern 

Kansas, southern Nebraska, and eastern Colorado. 

Major tributaries of the Kansas River Basin include the 

Big Blue, the Republican, the Saline, the Solomon, and 

the Smoky Hill Rivers. The Kansas River begins at the 

confluence ofthe Republican and the Smoky Hill Rivers 

(figs . 5, 6) . Total drainage areas and drainage areas of 

subbasins where discharge is uncontrolled in the Kansas 

Range of precipitation, in inches -. . -Boundary of Kansas River Basin 

0 to 4.99 15- Reservoir and reference number 

used in figure 6 

5.0 to 9.99 

10 to 14 .99 

15 to 19 .99 

20 to 27 

Figure 5. Areal distribution of rainfall during July 1993 and locations of reservoirs in the Kansas River Basin. 

Kansas River Flood Discharge Analysis 9 
EXPIANATION 

9 10 

Enders Hugh Butler 

Little Blue River 

Big Blue River 

01 20 Ca U7 Webster dI 

e 

Republican ..J : 18 River below O IX Wilson Milford Dam 

U^ 

C 

Smoky Hill 

River at F G 

Cedar

18

Bluffs Mentor Smoky Hill River Kansas River at Enterprise at R . Riley 

17 

Kanopolis 

18 

Wilson Reservoir name and reference number used in 

figure 1-Size of rectangle is relative to actual 

flood-control pool . See table 1 for actual data 

Surcharge storage, July 1993-Only applies 

when flood storage for July 1993 exceeded floodcontrol pool 

Flood-control pool 

Flood storage, July 1993 

I Streamflow-gaging station name and reference 

Kansas River Z letter used in figure 1-Size of circle is relative to at Wamego actual drainage area . See table 2 for actual data 

-Outside circle represents area of basin upstream 

from streamflowyaging station 

Inside circle represents area of basin where 

\ st -eamflow is uncontrolled 

Area of basin where streamflow is controlled 

- -00 Dally mean discharge-Line thickness represents

relative quantity of discharge 

1 J L N

Kansas River Kansas River Kansas River Kansas River atwamego atTopeka at Lecompton at DeSoto 

M cn 0 Wakarusa River U3 

near Lawrence ,~ 4 

Figure 6. Flood-control storage in the Kansas River Basin reservoir system, maximum storage for July 1993. 

River Basin are listed in table 2. Many streams and rivers flooded in the Kansas River Basin as significant precipitation fell during July (fig . 5) throughout the basin 

(National Weather Service, 1993). 

The reservoirs in the Kansas River Basin were 

operated as part of the total Mississippi River Basin 

system during July 1993. The total flood-storage sys 

tem in the Kansas River Basin is shown in figure 6. 

Most reservoirs west of the area that had 10 in. or 

greater precipitation (fig . 5) were able to store most of 

the flood discharges in their multipurpose pools. Lakes 

Kanopolis, Wilson, Waconda, Milford, Tuttle Creek, 

and Perry contained most of the pool volume. [Note: the 

flood-control pool and the portion filled during July 

1993 for each reservoir shown in figure 6 is scaled in 

relation to the size of the rectangle representing a reservoir. Drainage areas (total and subareas where streamflow is uncontrolled) for selected streamflow-gaging 

stations are scaled to the size of the circles . The geographic location of each reservoir is shown in fig . 5.] 

Kansas River Tributaries 

The discharges for streams in the Kansas River 

Basin during July 1993 were analyzed under the 

condition that the reservoir system was not in place. 

Floodwater that was stored in a particular reservoir was 

routed down the river valley under high-discharge conditions and added to the observed discharge downstream. 

This simulation process was iterative because several 

streams had additional reservoirs upstream. Routing 

times were determined from observed high discharges 

before reservoir construction. The Muskingum routing 

method (Viessman and others, 1972) was used to allow 

for flood discharge storage along the river valley as the 

flood discharges moved downstream. Daily mean discharges were estimated for selected gaging stations in 

10 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 

0 
Table 2 Flood discharge in selected streams in the Kansas and the Missouri River Basins, July 1993 

[mil, square miles ; ft'/s, cubic feet per second; <, less than; --, data unavailable] 

Percent- Area Percent- observed Uncontrolled Simulated 

Map 

Gaging Total age of where age of instantaneous instantaneous uncontrolled ref- basin peak peak maximum 

ence station Stream name and location drainage total discharge where discharge, discharge' daily average area Kansas is uncon- letter number discharge July 1993 discharge' (mi') River trolled (fig. 1) is uncon­ Basin (mi') trolled ft'/s Date ft'/s Date ft'/s Date 

Kansas 

A 06856000 Republican River at 23,560 39 2,517 11 38,500 7/23 42,400 7/23 33,800 7/23 

Concordia . 

B 06857100 Republican River below 24,890 42 10 0 33,700 7/26 - - - - 67,300 7/9 

Milford Dam. 

C 06866500 Smoky Hill River at 8,358 14 501 6 10,700 7/22 30,300 7/25 29,5007/24 

Mentor. 

D 03269500 Saline River at Tescott. . . . . 2,820 5 903 32 10,700 7/25 52,900 7/25 45,600 7/22 

E 06876900 Solomon River at Niles . . . . 6,770 11 1,694 25 17,900 7/22 74,000 7/24 62,700 7/23 

F 06877600 Smoky Hill River at 19,260 32 4,410 23 45,600 7/22 155,000 7/24 122,000 7/23 

Enterprise . 

G 06879100 Kansas River at Ft. Riley . . 44,870 75 5,130 11 87,600 7/25 200,000 7/24 189,000 7/24 

H 06887000 Big Blue River near 9,640 16 12 0 60,000 7/26 - - - - 107,0007/5 

Manhattan . 

1 06887500 Kansas River at Wamego . . 55,280 92 5,912 11 171,000 7/26 258,000 7/25 240,000 7/25 

J 06889000 Kansas River at Topeka. . . . 56,720 95 7,352 13 166,000 7/26 261,000 7/26 245,000 7/25 

K 06890900 Delaware River below 1,117 2 0 0 5,000 7/26 - - - - 28,500 7/6 

Perry Dam. 

L 06891000 Kansas River at 58,460 98 7,975 14 175,000 7/27 265,000 7/26 240,000 7/25 

Lecompton. 

M 06891500 Wakarusa River near 425 < 1 58 14 260 7/27 - - - - 8,100 7/23 

Lawrence . 

N 06892350 Kansas River at DeSoto. . . . 59,756 100 8,904 15 172,000 7/27 266,000 7/27 252,000 7/10 

Missouri 

0 06818000 Missouri River at 420,300 700 140,500 34 335,000 7/26 461,000 7/26 

St . Joseph . 

P 06893000 Missouri River at Kansas 485,200 808 154,900 32 541,000 7/28 713,000 7/27 

City . 

Q 06934500 Missouri River at 524,200 873 179,400 34 750,000 7/31 852,000 7/31 

Hermann. 

'Data supplied by the U.S . Army Corps of Engineers, Kansas City District . Values computed by use of the BENEFITS computer program . 

'Values computed by the Muskingum routing method described in Viessman and others (1972) . 

the Kansas River Basin by using daily reservoir storage 

and observed stream discharges. The computer program 

BENEFrIS (U.S. Army Corps of Engineers, written commun., 1993) was used to estimate the uncontrolled 

instantaneous peak discharge at selected gaging stations 

on the Kansas and the Missouri Rivers. The uncontrolled instantaneous peak discharges are compared with 

the observed instantaneous peak discharges and the simulated uncontrolled maximum daily mean discharges 

(table 2). The locations of these stations in relation to 

the reservoirs are shown in figures 1 and 6. 

Examples of observed controlled and simulated 

uncontrolled daily mean discharges are shown in figures 

7 to 15. Figures 7 to 9 show the streamflow contribution of each of the three major tributaries upstream of 

the Smoky Hill River at Enterprise, Kansas; these 

tributaries are the Saline, the Solomon, and the Smoky 

Hill Rivers. From July 22 to 25, all three tributaries had 

Kansas River Flood Discharge Analysis 
the largest simulated uncontrolled discharges, which 

were two to three times greater than the observed reservoir-controlled discharges. The greatest instantaneous 

peak discharge for each river as determined by BENEFITS also is shown in figures 7 to 10 and 13 to 15. 

The combined flood discharge from the three 

tributaries of the Smoky Hill River at Enterprise is 

shown in figure 10. The addition of the simulated 

uncontrolled discharges would have resulted in a simulated uncontrolled maximum discharge of 122,000 

ft 3/s at that location . However large, this discharge is 

much less than the 233,000 ft3/s recorded during the 

1951 flood (U.S . Geological Survey, 1992). Effects 

of multiple upstream reservoirs, controlled reservoir 

outflow, and uncontrolled spillway releases for the 

Republican River below Milford Dam are shown in 

figure 11 . Flood storage in Lake Milford prevented 

a simulated uncontrolled daily average discharge of 

67,300 ft3/s in the Republican River below Milford 

Dam on July 9, 1993 . 

60,000 

Saline River at Tescott, Kansas 

Z o 50,000 

ui Z

O 

Q w 40,000 

x En

U

U w 

p 1 30,000 z w 

w w u_ 

20,000 

. m7 

O U 

10,000 

Kansas River Main Stem 

In Kansas, the Republican and the Smoky Hill 

Rivers converge at Junction City to form the Kansas 

River. At the streamflow gage at Fort Riley, which is 

located 1 .6 miles (mi) downstream from the juncture, an 

instantaneous peak discharge of 87,600 ft3/s was 

recorded on July 25, 1993 . Without the reservoirs in 

place, an uncontrolled instantaneous peak of about 

200,000 ft3/s would have occurred, and a simulated 

uncontrolled maximum daily average discharge would 

have been about 189,000 ft3 /s on July 24 (table 2). 

About 20 mi downstream from the Fort Riley 

gage, the Kansas River receives discharge from the 

Big Blue River. At this confluence, the normal dis 

charge of each river is nearly equal. The Big Blue 

River drains much of southeastern Nebraska and 

northeastern Kansas, which also was the area of greatest rainfall recorded in July (fig . 5). The storage of 

floodwaters in Tuttle Creek Lake reduced a potentially devastating flood of more than 107,000 ft3 /s on 

July 5 on the Big Blue River near Manhattan, Kansas, 

Uncontrolled instantaneous peak 

discharge computed by the 

BENEFITS computer program 

Figure 7. Observed and simulated uncontrolled discharges in the Saline River at Tescott, Kansas, July 1993. 

60,000 

70,000 Solomon River at Niles, Kansas 

z o Uncontrolled instantaneous peak


O 60,000 discharge computed by the
 Ld Z


C7 U Simulated BENEFITS computer program


Q w 50,000 uncontrolled
 x
U o:


w


o a 40,000 Z w 

w w u. U 30,000 w Observed 

J m controlled 

U 20,000 y 

10,000 

I 

1 

16 21 

JULY 1993 

Figure 8. Observed and simulated uncontrolled discharges in the Solomon River at Niles, Kansas, July 1993. 

12 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 

31 
Without the storage of Tuttle Creek Lake, the flood of 1993 

on the Big Blue River near Manhattan, Kansas, would have 

exceeded the record flood of 1951 by more than 13,000 .f3/s

to a much less destructive flood of 60,000 ft3/s on 

July 25 (fig . 12) . At this location, the historic flood 

of 1951 was 93,400 ft3 /s . Without the reservoir storage, the Big Blue River near Manhattan would have 

35,000 

Smoky Hill River at Mentor, Kansas 

30,000 

ui z 

0 O

U 25,000 

Q W 

U W 20,000 

w 15,000 W W 

U 

J m 10,000 Q U 

5,000 

0 

overtopped the Federal levee, and flooding downstream along the Kansas River would have been 

much more severe. 

After joining with the Big Blue River, the 

Kansas River meanders eastward along its broad 

fertile flood plain toward Kansas City, Kansas. 

Because only low levees have been built along the 

river between Manhattan and Topeka, Kansas, the 

protection of thousands of acres of prime agricultural 

land is provided by the upstream reservoirs. Tuttle 

Creek and Milford Lakes and other reservoirs 

upstream reduced the Kansas River discharges, as 

shown in the observed and simulated uncontrolled 

discharges of the Kansas River at Wamego, Kansas 

(fig . 13), to levels that could be contained by the low 

levees. Controlled floods on the Big Blue River on 

July 5, the Republican River on July 9, and the upper 

tributaries on July 22-23 caused the Kansas River to 

inundate only the lowest lying farmlands during 

1993. The discharges in the Kansas River at Topeka 

(fig . 14) were contained by its levee system. 

. 

1 Uncontrolled instantaneous 

/ peak discharge computed Simulated -/ by the BENEFITS computer uncontrolled i program 

/	 Observed 

controlled 1 

16 21 26 

JULY 1993 

Figure 9. Observed and simulated uncontrolled discharges in the Smoky Hill River at Mentor, Kansas, July 1993. 

160,000 

Smoky Hill River at Enterprise, Kansas Uncontrolled instantaneous peak 

140,000 discharge computed by the 

z o BENEFITS computer program 

O O ui z 120,000 Simulated / \ U 

a W 

100,000 

uncontrolled i x 

U W
 V_)


O 60,000
 Z W 

w LL 60,000 U

J m 

U 40,000 

Observed 

20,000 controlled 

16 21 26 31 

JULY 1993 

Figure 10. Observed and simulated uncontrolled discharges in the Smoky Hill River at Enterprise, Kansas, July 1993. 

Kansas River Flood Discharge Analysis 1 3 

x 

31 
The streamflows from only two other tributaries to the Kansas River are controlled downstream 

from Wamego. Perry and Clinton Lakes control the 

Delaware and the Wakarusa Rivers, respectively . 

The water level in Perry Lake, which filled its floodcontrol pool on July 25, surpassed its previous high 

elevation in 1973 by almost 4 ft (table 1). Although 

60,000 z o 

0 50,000 ¢ w ¢ <n U w 40,000 

O a 

z w 30,000 

w w 

U J m 20,000 

O U 

10,000 

the water level in Clinton Lake was at an all-time 

high elevation on July 31, the lake still had reserve 

flood storage available . 

The total effect of the Kansas River Basin 

reservoirs can be seen in the analysis of the flood discharges on the Kansas River at DeSoto, Kansas 

(fig 15) . The simulation of uncontrolled disharges 

16 21 26 

JULY 1993 

Figure 11 . Observed and simulated uncontrolled discharges in the Republican River below Milford Dam, Kansas, July 1993. 

120,000 

Big Blue River near Manhattan, Kansas 

'1 

Z O 100,000 

W Z 

O (5

¢ 

x 

U 

w 

`° 

W 

80,000 

' ` y1\ 

Observed 

/controlled 

O 

¢ 

a 

w 

60,000 

Y 

\

\ 

Simulated 

uncontrolled \ / \ i\\ 

w w 

U 40,000 

U

J m 

U \ 

20,000 

I I 

6 11 16 21 26 31 

JULY 1993 

Figure 12. Observed and simulated uncontrolled discharges in the Big Blue River near Manhattan, Kansas, July 1993. 

300,000 - I 

Kansas River at Wamego, Kansas Uncontrolled instantaneous peak discharge 

computed by the BENEFITS 

z o 250,000 computer program 

w Z 

C7 O 

W 200,000

= rn Simulated \\

U w uncontrolled _ _ f \ 

O a 150,000 _ /\ \ % \ z w 

w LL 

_U 100,000 J m 

U \Observed 50,000 controlled 

16 21 26 31 

JULY 1993 

Figure 13. Observed and simulated uncontrolled discharges in the Kansas River at Wamego, Kansas, July 1993. 

14 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 

31 
300,000 

Kansas River at Topeka, Kansas 

250,000 z o 

w z 

0 0 

200,000 

¢

x rn 

U w 

E5 It 150,000 

z w 

w \/ \\/ U 100,000 J m 

U V 

50,000 

6 

, I 

Uncontrolled instantaneous peak 

discharge computed by the BENEFITS 

computer program /\ 

Simulated 

uncontrolled ---, / 

31 

JULY 1993 

Figure 14. Observed and simulated uncontrolled discharges in the Kansas River at Topeka, Kansas, July 1993. 

z o 

ui z

o ¢ w 

x

U x

w 

a 

r z w ¢ w w 1L 

U_

Cl1 

-J 7 

¢ U 

Uncontrolled instantaneous peak 

discharge computed by the BENEFITS -0 

computer program 

11 

I 

16 21 26 

JULY 1993 

Figure 15. Observed and simulated uncontrolled discharges in the Kansas River at DeSoto, Kansas, July 1993. 

resulted in the highest daily mean discharge of 

252,000 ft 3/s on July 10. A secondary simulated 

uncontrolled discharge of 233,000 ft3/s would have 

occurred on July 26. An observed instantaneous peak 

discharge of 172,000 ft3 /s occurred on July 27 . Many 

other cities and hundreds of thousands of acres of 

farmland along the tributaries and main stem of the 

Kansas River benefited from the flood-control 

reservoirs as flood discharges were reduced by 30 to 

70 percent . 

All simulated uncontrolled discharges on the 

Kansas River would have been contained by the 

Federal levee system, except in Kansas City where 

backwater from the flooding Missouri River on July 

27 might have caused the river stage to overtop the 

levee system there . However, without the control of 

reservoirs in the main-stem Missouri River, the combined uncontrolled discharges of the Kansas and the 

Missouri Rivers would have overtopped the Kansas 

City levees (Flood Insurance Administration, 198 1) . 

Reservoir Level Maintenance 

To maintain storage capacity in flood-control 

reservoirs, stored floodwater is released as soon as 

the river downstream can accept it without additional 

flooding, as indicated by figure 16, which shows 

water-level fluctuations during the 1993 water year at 

selected reservoirs in the Kansas River Basin. The 

water levels in many of the reservoirs in the Kansas 

River Basin at the beginning of the 1993 water year 

were above multipurpose-pool elevation, but all were 

lowered during the 1992-93 winter. However, the 

snowmelt and precipitation of February through May 

1993 resulted in fluctuations and steadily increasing 

discharge in streams in the Kansas River Basin as 

summer approached. An example is Tuttle Creek 

Lake, where, beginning in February, monthly 

increases in storage were followed by controlled 

releases to lower the lake level back to multipurposepool elevation . At the same time, other reservoirs in 

the Kansas River Basin were releasing stored water, 

and many uncontrolled streams were flooding. This 

Kansas River Flood Discharge Analysis 1 5 

1 

31 
-------------

1,560 I I I 

1,550 

1,540 

J 

W 1,530 w 

J 

a Wilson Lake elevation plus 5 feet
 w 1,520


w


O 1,510 - Waconda Lake elevation plus 50 feet


m 

a 1,500 W 

w 

u_ 1,490 z 

z 

O 1,480 

1,470 w 

J 

W 

1,460 w 

W 

1,450 

w 

1,440 

1,430 

1,420 

1,410 

, 

,_" , 

-' 

Kanopolis Lake elevation plus 

25 feet 

Milford Lake elevation plus 327 feet 

Tuttle Creek Lake elevation plus 360 feet 

Perry Lake elevation plus 535 feet 

I I 

Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. 

1992 1993 

Figure 16. Water-level elevations of selected reservoirs in the Kansas River Basin, 1993 water year. 

combination resulted in many streams being at bankfull capacities for extended periods of time. 

This cycle of precipitation, flooding, and 

resulting releases of water from reservoirs was interrupted in July when intense rains fell somewhere in 

the basin nearly every day of the month. With most 

uncontrolled streams at or above flood stage and the 

lower Missouri and Mississippi Rivers flooding, the 

flood-storage capacity of the Kansas River Basin reservoir system was tested . Some floodwater was 

released as water levels in Tuttle Creek and Milford 

Lakes reached surcharge storage elevations, but the 

reservoir system contained most of the flooding. 

Comparison of 1951 and 1993 Floods 

The flood of 1951 on the Kansas River at 

DeSoto, which had a peak discharge of 510,000 ft'/s, 

is considered to be the largest flood in the Kansas 

River Basin during the 20th century ; all floods in the 

basin are compared to it . The flood of 1903 ranks 

second to the 1951 flood with an estimated peak discharge of 337,000 ft3/s. Even without the reservoirs 

in place, the 1993 flood is estimated to be about 

266,000 ft3 /s (about 50 percent of the 1951 flood), 

thus ranking it third. Peak discharge, however, is 

only one way of ranking floods; another way is to 

compare flood volumes . This type of ranking is usually more consistent with the longer term, widespread 

climatic patterns that are responsible for the flooding . Instantaneous peaks are greatly dependent on 

storm intensities, timing, and direction of movement, 

On July 13, 1951, peak flow of 510,000 fts/s from the 

Kansas River flooded Kansas City, Kansas and Missouri . 

(Warner Studio, Kansas City, Missouri.) 

16 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 
EXPLANATION 

April 1 to July 31, 1951 precipitation, 

in Inches -. . -Boundary of Kansas River Basin 

0 to 14 .99 

15 to 24.99 

25 to 34.99 

35 to 45 50 100 KILOMETERS 

Figure 17. Total precipitation in the Kansas River Basin, April 1 to July 31, 1951 . 

which are critical in the development of large floods . 

However, total rainfall during the flooding period correlates closely with total flood volumes. 

The total volumes of the floods of 1951 and 

1993 are comparable because they occurred at nearly 

identical times of the year and the precipitation 

patterns also were quite similar. Figures 17 and 18 

show the total rainfall for the period from April 1 to 

July 31, 1951 and 1993, respectively . The greatest 

rainfall in 1951 was in northeastern Kansas and 

extended southward toward east-central Kansas . The 

area of greatest rainfall in 1993 was farther north and 

extended from central Kansas into southeastern 

Nebraska. 

Hydrographs of observed discharge during the 

two flood periods for the Kansas River at OeSoto 

shown in figure 19 are similar in some ways. Both 

hydrographs show a discharge increase in early May, 

the major flooding in July, and another increase in 

September. However, the observed discharges for 

1993 are lower in June 1993 than those in June 1951 

because water was being stored in the flood-control 

reservoirs . Observed discharges in August and early 

September 1993 are much higher than those during 

the same time in 1951 because stored floodwater was 

being released . Even though the discharges shown in 

figure 19 end on September 30, flows during fall 

1993 remained high because of the release of about 

900,000 acre-ft that had been retained in flood-control reservoirs as of October 1, 1993. The total flood 

volume from April 1 to September 30, 1951, was 

19,500,000 acre-ft compared with 15,500,000 acre-ft 

for the same period in 1993 (includes the amount in 

flood-control pools on October 1, 1993). 

Kansas River Flood Discharge Analysis 17 
104° 102° 100° 

40° 

38° 

EXPLANATION 

April 1 to July 31, 1993 precipitation,

in inches -. . -Boundary of Kansas River Basin 

0 to 14 .99 

15 to 24 .99 

U 25 to 34 .99 

35 to 45 

Figure 18. Total precipitation in the Kansas River Basin, April 

Daily streamflow records for the Kansas River 

at DeSoto extend back to 1917. When the entire 

water year (October 1-September 30) is considered, 

the Kansas River flood volume for 1993 exceeded the 

previous maximum of 21,300,000 acre-ft recorded 

during the 1951 water year by slightly more than 

1,000,000 acre-ft. 

SUMMARY 

The floods of 1993 were of historic magnitude 

as water in the Missouri and the Mississippi Rivers 

reached levels that exceeded many of the previous 

observed maximums. The floods were generated by 

large-scale climatic patterns that resulted in greaterthan-normal rainfall from the Rocky Mountains to the 

50 100 MILES 

I I _j 

50 100 KILOMETERS 

1 to July 31, 1993. 

Great Lakes. Runoff from the intense spring and 

summer rainfall converged on the Mississippi River 

at St. Louis to produce a historic peak discharge of 

1,080,000 ft 3 /s on August 1, 1993 . During spring 

and summer, record or near-record discharges in 

many other streams resulted in substantial flood damage throughout the Midwest. 

As severe as the flooding was in 1993, stream 

and river levels could have been even higher had a 

system of flood-control reservoirs not been in place 

throughout the Missouri River Basin. More than 

10,000,000 acre-ft of additional water was stored in 

the upper Missouri River main-stem reservoirs in 

Montana, North Dakota, and South Dakota from 

April 1 to August 1, 1993 . In the lower sections of 

the Missouri River Basin, the 4-month storage held in 

reservoirs on the Kansas River was 4,500,000 acre-ft, 

18 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993 
500,000 

450,000 

O


Z
O 400,000
 U


w


a 350,000 

F -


w


w


U 300,000


[O


U


Z 250,000


0


200,000 

U 

V7 

O 

150,000 

w 

50,000 

0 

Figure 19. 

- Kansas River at Desoto, Kansas 

1951 observed 

_V 

. . . . . . . . . 4 . . . . . . . . 

APRIL MAY JUNE JULY AUGUST SEPTEMBER 

Floods in the Kansas River at DeSoto, Kansas, 1951 and 1993. 

while the other Missouri River tributaries held back 

3,900,000 acre-ft. If the total 18,700,000 acre-ft 

stored in the system had been allowed to flow to 

St. Louis, then the average discharge of the Missouri 

River would have been 77,300 ft3/s greater for this 

4-month period. During July alone, flood storage of 

13,000,000 acre-ft in flood-control reservoirs in the 

Missouri River Basin reduced the average discharge 

for the month at its confluence with the Mississippi 

River by 211,000 ft3/s. 

An analysis of flood discharges in the Kansas 

River Basin demonstrated the storage capacity of its 

reservoirs and how peak discharges were reduced 

substantially . The greatest effect was observed on 

the Big Blue River near Manhattan where Tuttle 

Creek Lake withheld a daily mean flow of 107,000 

ft 3 /s on July 5 . The instantaneous peak for this day 

would have been higher, which would have caused 

much greater damage than the 60,000-ft3/s release 

later in the month. Many other cities and hundreds of 

thousands of acres of farmland along the tributaries 

and main stem of the Kansas River benefited from 

the flood-control reservoirs as flood discharges were 

reduced by 30 to 70 percent . 

The flood-control reservoirs and the Federal 

levee system working in concert protected Junction 

City, Manhattan, Topeka, Lawrence, and Kansas 

City. Without the levees, these cities would have 

been flooded. Without the reservoirs, Manhattan and 

Kansas City would have had their levees overtopped. 

Flooding in the Kansas River Basin is always 

compared with the great flood of 1951 when 510,000 ft3/s 

flowed past DeSoto on July 13, 1951 . Precipitation totals 

and patterns were similar for 1951 and 1993 . The total 

volume of floodwater in the Kansas River from April 1 

to September 30 was 19,500,000 acre-ft in 1951 and 

18,500,000 acre-ft in 1993. The total flood volumes 

were similar, but the timing of the flood discharges from 

the tributaries was different, thus producing an estimated 

uncontrolled flood discharge in 1993 that was about 50 

percent of that of 1951 . The total flow volume for the 

Kansas River at DeSoto for the entire 1993 water year 

was the greatest of any water year since daily records 

began in 1917 . 

Reservoirs throughout the Missouri River 

Basin and also those in the rest of the upper Mississippi River Basin reduced peak discharges down 

stream during 1993 . As many levee systems reached 

capacity conveyance, the reduction of the flood discharges by those reservoirs prevented additional 

destruction of agricultural lands, urban environment, 

and, most importantly, human lives. 

REFERENCES 

Flood Insurance Administration, 1981, Flood insurance 

study, City of Kansas City, Kansas: U.S . DepartReferences 1 9 
ment of Housing and Urban Development, February 

1981, 31 p. 

Matthai, H.F ., 1968, Missouri River Basin below Sioux City, 

Iowa, pt . 6-B of Magnitude and frequency of floods in 

the United States : U.S . Geological Survey Water-Supply Paper 1680, 491 p. 

National Weather Service, 1993, Update on Midwestern 

floods-Heat and drought in the East, special 

climate summary: Ashville, N.C ., v. 93, no. 2, 8 p. 

Parrett, Charles, Melcher, N.B ., and James, R.W., Jr ., 1993, 

Flood discharges in the upper Mississippi River Basin, 

1993, in Floods in the upper Mississippi River Basin, 

1993: U.S . Geological Survey Circular 1120-A, 14 p. 

U.S . Army Corps of Engineers, 1965, Flood plain information-Kansas River, Kansas, Junction City to the 

mouth: U.S . Army Corps of Engineers, Kansas City 

District, April 1965, 13 p. 

U.S . Geological Survey, 1992, Water resources data for Kansas, Missouri, Nebraska, Iowa, Nebraska, South 

Dakota, North Dakota, Montana and Colorado, Water 

Year 1992: U.S . Geological Survey Water-Data 

Reports KS-92-1, MO-92-1, NE-92-1, IA-92-1, SD92-1, ND-92-1, MT-92-1, and CO-92-1. 

Viessman, Warren, Jr., Harbaugh, T.E ., and Knapp, J.W., 

1972, Introduction to hydrology: New York, Intext 

Educational Publications, p. 173-221 . 

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

through July 31, 1993, in Floods in the upper Missis 

sippi River Basin, 1993 : U.S . Geological Survey 

Circular 1120-B, 13 p. 

20 Effects of Reservoirs on Flood Discharges in the Kansas and the Missouri River Basins, 1993