U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2008-3103

January 2009

Prepared in cooperation with the U.S. Army Corps of Engineers, Little Rock and Memphis Districts

Floods of Selected Streams in Arkansas, Spring 2008

Printed on recycled paper

Floods can cause loss of life and extensive destruction to 

property. Monitoring floods and understanding the reasons for 

their occurrence are the responsibility of many Federal agencies. The National Weather Service, the U.S. Army Corps of 

Engineers, and the U.S. Geological Survey are among the most 

visible of these agencies. Together, these three agencies collect 

and analyze floodflow information to better understand the 

variety of mechanisms that cause floods, and how the characteristics and frequencies of floods vary with time and location. 

The U.S. Geological Survey (USGS) has monitored and 

assessed the quantity of streamflow in our Nation’s streams 

since the agency’s inception in 1879. Because of ongoing collection and assessment of streamflow data, the USGS can provide information about a range of surface-water issues including 

the suitability of water for public supply and irrigation and the 

effects of agriculture and urbanization on streamflow. As part 

of its streamflow-data collection activities, the USGS measured 

streamflow in multiple streams during extreme flood events 

in Arkansas in the spring of 2008. The analysis of streamflow 

information collected during flood events such as these provides 

a scientific basis for decision making related to resource management and restoration. Additionally, this information can be 

used by water-resource managers to better define flood-hazard 

areas and to design bridges, culverts, dams, levees, and other 

structures.

Water levels (stage) and streamflow (discharge) currently 

are being monitored in near real-time at approximately 150 

locations in Arkansas. The streamflow-gaging stations measure 

and record hydrologic data at 15-minute or hourly intervals; the 

data then are transmitted through satellites to the USGS database and displayed on the internet every 1 to 4 hours. Streamflow-gaging stations in Arkansas are part of a network of over 

7,500 active streamflow-gaging stations operated by the USGS 

throughout the United States in cooperation with other Federal, 

State, and local government agencies. In Arkansas, the major 

supporters of the streamflow-gaging network are the U.S. Army 

Corps of Engineers, Arkansas Natural Resources Commission, 

Arkansas Department of Environmental Quality, and Arkansas 

Geological Survey. Many other Federal, State, and local government entities provide additional support for streamflow-gaging 

stations. It is the combined support of the USGS and all funding 

partners that make it possible to maintain an adequate streamflow-gaging network in Arkansas. Data collected over the years 

at streamflow-gaging stations can be used to characterize the 

relative magnitude of flood events and their statistical frequency 

of occurrence. These analyses provide water-resource managFigure 1. Location of selected U.S. Geological Survey continuous record streamflow-gaging stations and statewide precipitation amounts for 

March 18-19 and April 10, 2008 (modified from National Weather Service, 2008).
ers with accurate and reliable hydrologic information based on 

present and historical flow conditions. Continued collection 

of streamflow data, with consideration of changes in land use, 

agricultural practices, and climate change, will help scientists to 

more accurately characterize the magnitude of extreme floods in 

the future.

Spring 2008 Flood Event

Heavy precipitation fell in northern and western Arkansas during March and April of 2008 (fig. 1). This precipitation 

caused widespread flooding in the State comparable to the 

December 1982 flooding in northern Arkansas. Data collected 

at USGS streamflow-gaging stations show that flooding on 

several rivers and streams in Arkansas reached magnitudes that 

have not occurred since the December 1982 floods (table 1). 

For example, USGS streamflow-gaging station 07060500 White 

River at Calico Rock reached a stage of 40.27 feet (202,000 

cubic feet per second), and 07056000 Buffalo River near St. Joe 

reached a stage of 49.41 feet (134,000 cubic feet per second). 

Most of the rivers with drainage areas less than 1,000 square 

miles experienced rises in stage ranging from 20 feet in less 

Table 1. Continuous record streamflow-gaging stations in Arkansas that experienced flooding in spring 2008 and in December 1982.

[n/a, gage was not in operation during this event]

Identifier 

number

(figure 1)

Station

number Station name Date of peak

Spring 2008

 peak stage

(feet)

Spring 2008 

peak flow

(cubic feet

per second)

December

1982 peak 

stage

(feet)

December 1982

peak flow

(cubic feet

per second)

1 07050500 Kings River near Berryville March 18, 2008 35.29 50,100 30.20 39,400

2 07056000 Buffalo River near St. Joe March 19, 2008 49.41 134,000 53.75 158,000

3 07060500 White River at Calico Rock April 11, 2008 40.27 202,000 41.14 201,000

4 07061000 White River at Batesville March 20, 2008 26.96 208,000 29.27 312,000

5 07064000 Black River at Corning March 22, 2008 15.92 27,100 14.82 23,400

6 07069000 Black River at Pocahontas March 22, 2008 26.56 72,200 25.22 66,300

7 07069305 Spring River at Town Branch Bridge at Hardy March 19, 2008 22.29 80,700 n/a n/a

8 07069500 Spring River at Imboden March 19, 2008 29.15 97,300 38.12 244,000

9 07072000 Eleven Point River near Ravenden Springs March 19, 2008 23.81 69,700 29.06 162,000

10 07072500 Black River at Black Rock March 20, 2008 29.74 135,000 31.51 190,000

11 07074420 Black River near Elgin Ferry March 21, 2008 32.571 127,000 27.702 n/a

12 07074500 White River at Newport March 21, 2008 33.87 266,000 34.00 330,000

13 07074850 White River near Augusta March 22, 2008 38.41 252,000 38.313 255,0003

14 07076750 White River near Georgetown March 24, 2008 30.18 175,000 28.87 179,000

15 07077000 White River at DeValls Bluff April 17, 2008 31.41 189,000 30.004 n/a

16 07195000 Osage Creek near Elm Springs March 18, 2008 15.55 15,800 n/a n/a

17 07257006 Big Piney at Highway 164 near Dover March 18, 2008 21.76 73,700 33.875 111,0005

18 07257500 Illinois Bayou near Scottsville April 10, 2008 23.46 77,600 27.49 130,000

19 07261500 Fourche LaFave River near Gravelly March 19, 2008 30.91 81,500 32.45 162,000

1

 Peak stage was caused by backwater from the White River. Backwater adjustments were made to the discharge.

2

 Obtained from surveyed floodmarks.

3

 From the U.S. Army Corps of Engineers, Little Rock District, Post Flood Report for the December 1982 Event.

4

 Estimated value obtained from the U.S. Army Corps of Engineers, Memphis District.

5

 Prior to 1993 water year, gage was located at a different location and datum.

than 24 hours to 47 feet in 30 hours. Rivers with drainage 

areas greater than 1,000 square miles experienced rises in stage 

greater than 20 feet over a period of several days to one week.

Flood-frequency analysis provides statistical information 

about the magnitude and frequency of flood discharge. Floodfrequency statistics describe the chance of a given discharge 

being exceeded once in any given year (probability) or recurrence interval (reciprocal of probability) of the discharge in 

years. For example, a flood discharge having a 2-percent chance 

of being exceeded in any given year has a recurrence interval 

of 50 years. Flood-frequency analysis commonly is performed 

on a series of annual peak discharges collected at a streamflowgaging station over a period of time. 

Bulletin 17B of the Hydrology Subcommittee of the Interagency Advisory Committee on Water Data (1982) identifies 

recommended procedures for consistent determination of flood 

frequency from peak-discharge records. These procedures were 

used to compute recurrence intervals for floods that occurred 

at 19 streamflow-gaging stations in Arkansas during the period 

between March 18 and April 17, 2008 (table 2).
Table 2. Recurrence intervals for select streamflow-gaging 

stations in Arkansas.

Identifier 

number

(figure 1)

Station 

number Station name

Spring 2008

peak flow

(cubic feet

per second)

Recurrence

interval

(years)

1 07050500 Kings River near Berryville 50,100 10-25

2 07056000 Buffalo River near St. Joe 134,000 25–50 

3 07060500 White River at Calico Rock 202,000 25–50 

4 07061000 White River at Batesville 208,000 25–50 

5 07064000 Black River at Corning 27,100 10–25 

6 07069000 Black River at Pocahontas 72,200 25–50 

7 07069305 Spring River at Town Branch 

Bridge at Hardy 80,700 25–50 

8 07069500 Spring River at Imboden 97,300 25–50 

9 07072000 Eleven Point River near

Ravenden Springs 69,700 100–200 

10 07072500 Black River at Black Rock 135,000 25–50 

11 07074420 Black River near Elgin Ferry 127,000 50–100 

12 07074500 White River at Newport 266,000 25–50 

13 07074850 White River near Augusta 252,000 25–50 

14 07076750 White River near Georgetown 175,000 25–50 

15 07077000 White River at DeValls Bluff 189,000 25–50 

16 07195000 Osage Creek near Elm Springs 15,800 10–25 

17 07257006 Big Piney at Highway 164

near Dover 73,700 10–25 

18 07257500 Illinois Bayou near Scottsville 77,600 50–100 

19 07261500 Fourche LaFave River near 

Gravelly 81,500 50–100 

Most of the floods that occurred in Arkansas during the 

spring of 2008 had recurrence intervals ranging from 25 to 50 

years. The largest recorded flood peak occurred in March at 

streamflow-gaging station 07072000, Eleven Point River near 

Ravenden Springs; frequency analysis determined that this 

flood peak had a recurrence interval of 100 to 200 years (table 

2). Smaller magnitude floods with recurrence intervals ranging 

from 10 to 25 years occurred on streams in the upper reaches of 

the White River and Arkansas River Basins (table 2).

It is important to emphasize that a 100-year (or other 

T-year) flood does not mean there will be only one occurrence in a 100-year (or other T-year) period. According to the 

statistical definition, a 100-year flood has a 1-percent chance 

(probability) of being exceeded in any given year. This concept is illustrated by historical flooding of the Kings River at 

Berryville. The computed 5-year flood at the Kings River near 

Berryville streamflow-gaging station (29,500 cubic feet per 

second) has a 20-percent chance of being exceeded in any given 

year; in fact, the 5-year flood discharge has been exceeded three 

times in the 7-year period from 2002 – 2008 (table 3). Flood-insurance studies use these statistics in a slightly different context. 

For example, a home located in a 100-year flood plain will have 

a 25-percent chance of experiencing a 100-year flood during a 

typical 30-year home-mortgage period. 

Bankfull discharge, defined as the amount of water flowing 

in a stream that completely fills the channel to the top of one 

or both banks, can be expected to occur for most streams, on 

average, approximately once every 1.5 years (Leopold, 1994). 

Out-of-bank flooding, when the water breaches the stream’s 

banks and flows into the flood plain, is inferred from flood-frequency analyses to occur, on average, approximately once every 

2.3 years; this equates to a 43-percent chance of occurring in 

any given year (U.S. Geological Survey, 2008). Larger floods, 

such as those that occurred in Arkansas during the spring of 

2008, increase the risk of flood-related damages to property and 

infrastructure when development occurs in flood-prone areas 

(such as in flood plains). 

Collecting streamflow information during extreme flooding events is an important mission for the USGS. Streamflow 

measurements made during flood conditions (fig. 2) are critical 

Figure 2. A, U.S. Geological Survey hydrographer Kane Martin, 

making a discharge measurement on March 18, 2008, at the Buffalo 

River Highway 65 bridge crossing near St. Joe, Arkansas. Photograph 

by William Baldwin, U.S. Geological Survey. B, U.S. Geological Survey 

hydrographers William Baldwin and Jaysson Funkhouser, making a 

discharge measurement on March 25, 2008, at the White River U.S. 

Highway 64 bridge crossing near Augusta, Arkansas. Photograph by 

Reed Green, U.S. Geological Survey.

A

B

Figure 2. A, U.S. Geological Survey hydrographer making a discharge 

measurement on March 18, 2008, at the Buffalo River Highway 65 bridge 

crossing near St. Joe, Arkansas. Photograph by William Baldwin, U.S. 

Geological Survey. B, U.S. Geological Survey hydrographers making 

a discharge measurement on March 25, 2008, at the White River U.S. 

Highway 64 bridge crossing near Augusta, Arkansas. Photograph by 

Reed Green, U.S. Geological Survey.

Table 3. Peak streamflow data collected at the Kings River near 

Berryville streamflow-gaging station (07050500).

[Red numbers indicate a flow greater than or equal to the 5-year flood event]

Water year Yearly peak streamflow

(cubic feet per second)

2002 32,300

2003 11,300

2004 39,000

2005 8,370

2006 8,290

2007 17,000

2008 50,100
to the documentation of peak flows. These measurements also 

are needed to define or verify the high flow of the stage-discharge relation maintained by the USGS at most streamflowgaging stations so that recorded stream stage data can be converted to streamflow in near real-time. During the spring 2008 

floods, the USGS made over 60 discharge measurements at 

nearly two dozen streamflow-gaging stations in Arkansas. These 

measurements were made using Acoustic Doppler Current 

Profilers (fig. 3) to measure discharge by using sound waves 

transmitted through the water to determine the velocity, and the 

depth and the width of the water that is flowing in the stream to 

determine the area. At most sites, high-water marks (leaf litter, 

trash, other floating debris) left behind on the banks after the 

flooding were marked with flagging, and altitudes were determined by standard surveying methods at a later date. Altitudes 

of the surveyed high-water marks were used to verify the peaks 

recorded by equipment in the streamflow-gaging stations. 

Figure 3. An Acoustic Doppler Current Profiler and a global 

positioning system mounted to a tethered boat used for measuring 

the discharge of a stream. Photograph by Reed Green, U.S. 

Geological Survey.

Important Uses for Continuous-Streamflow Data

There are many important uses for continuous-streamflow 

data. Water-level forecasts for streams in Arkansas are produced 

by the National Weather Service and the U.S. Army Corps of 

Engineers (USACE). Used in conjunction with accurate and 

timely weather data, weather forecasts, and precipitation data, 

continuous-streamflow data form the foundation for reliable 

water-level forecast models that help the USACE make important decisions. The USACE uses water-level forecasts to help 

determine which reservoir to release water from and how much 

water to release. 

USACE reservoir releases (fig. 4) during and after the 

spring 2008 floods along the White River were made in an 

effort to help lower the pool elevation of each reservoir. During 

the spring 2008 floods, the levels of all five of the U.S. Army 

Corps of Engineers’ reservoirs in the White River Basin experienced record pool elevations (Kevin Fagot, U.S. Army Corps of 

Engineers, oral commun., 2008). Without accurate continuousstreamflow information at the streamflow-gaging stations on the 

major inflow streams, reservoir pool elevation prediction and 

subsequent decisions about reservoir releases would have been 

difficult to make, and the effects of these releases would have 

been difficult to predict.

Figure 4. Spillway releases from Table Rock Dam, April 2008. 

Photograph from the U.S. Army Corps of Engineers, Little Rock 

District.

USGS Monitoring is for Assessment Only

The USGS has no regulatory responsibilities within its 

mission scope and focuses strictly on scientific evaluation of the 

water resource, whether it is being used as a source of drinking 

water or for industry, irrigation, or recreation. USGS waterquantity data complement water-resource management activities 

of State and other Federal agencies such as the USACE, which 

is responsible for investigating, developing, and maintaining the 

Nation’s water and related environmental resources.

Visit http://ar.water.usgs.gov for access to online data 

(real-time and historical) and reports, including current streamflow, rainfall, and water-quality data for the State of Arkansas. 

Links from the website also provide access to the National 

Water Information System for real-time and historical water 

data and online reports for other States.

References

Leopold, L.B., 1994, A view of the river: Cambridge, Mass., 

Harvard University Press, p. 135. 

Hydrology Subcommittee of the Interagency Advisory Committee on Water Data, 1982, Guidelines for determining flood 

frequency: U.S. Geological Survey Bulletin 17B, Office of 

Water Data Collection, Reston, Virginia, variously paginated.

National Weather Service, 2008, Precipitation analysis, accessed 

on December 12, 2008, at: http://www.srh.noaa.gov/rfcshare/

precip_analysis_new.php

U.S. Geological Survey, 2008, Flood chronology of the Carson River Basin, California and Nevada—What is a flood 

frequency?, accessed August 11, 2008 at:

http://nevada.usgs.gov/crfld/floodfreq_desc.htm

—Jaysson E. Funkhouser and Ken Eng

 For additional information, please contact the Director of 

the USGS Arkansas Water Science Center at (501) 228-3600 or 

by email at dc_ar@usgs.gov