U.S. Department of the Interior

U.S. Geological Survey

 U.S. GEOLOGICAL SURVEY REAL-TIME RIVER DATA APPLICATIONS

Figure 1. Sketch of a U.S. Geological Survey streamflowgaging station.

The U.S. Geological Survey (USGS) is a primary

source of real-time data for flood warnings and

forecasts. River flood warnings and forecasts are

key elements in protecting lives and property.

In the United States, flooding has

•caused the deaths of more than 10,000 persons

since 1900,

•produced damages averaging $3.1 billion

annually in the last 10 years, and

•been a major factor in 9 out of 10 presidential

disaster declarations.

Indiana is not immune to the effects of flooding.

Some examples of damaging floods that have occurred

in Indiana include

•1982 flooding in Fort Wayne that caused

$50 million in damages,

•1991 flooding in much of Indiana that caused

more than $100 million in damages, and

•flooding along the Ohio River in 1997 that

resulted in more than $7.5 million in damages.

STREAMFLOW-GAGING STATIONS

Real-time river data provided by the USGS originate

from streamflow-gaging stations. The USGS operates and

maintains a network of more than 7,000 such stations

across the nation (Mason and Wieger, 1995). These gaging

stations, used to produce records of stage and streamflow

data, are operated in cooperation with local, state, and other

federal agencies. The USGS office in Indianapolis operates

a statewide network of more than 170 gaging stations.

The instrumentation at USGS gaging stations monitors

and records river information, primarily river stage (fig. 1).

As technological advances are made, many USGS gaging

stations are being retrofitted with electronic instrumentation

to monitor and record river data. Electronic instrumentation

facilitates transmission of real-time or near real-time river data

for use by government agencies in such flood-related tasks as

operating flood-control structures and ordering evacuations.

DATA TELEMETRY

The primary communication system used by the USGS

for data transmission is earth-satellite telemetry. More

than 4,000 USGS gaging stations across the nation have

satellite-telemetry capability (Mason and Wieger, 1995).

All 48 of the USGS satellite telemetry-equipped gaging

stations in Indiana transmit data on a regular 4-hour interval.

The data travel through several satellites and ground stations

to USGS offices. Indiana has begun to configure gagingstation instruments that will, in addition to transmitting on

fixed intervals, transmit if a pre-set river stage or changein-stage threshold is exceeded.

The USGS also uses land-line telephone telemetry. In Indiana,

about 50 gaging stations are equipped to transmit data by landline telephone. Currently, the USGS office in Indianapolis calls

these gaging stations once daily and downloads data onto a

computer. Land-line telephone gaging-station instrumentation

can be programmed to call and transmit data to USGS offices

or to cooperating agencies whenever a pre-set river stage or

change-in-stage threshold is exceeded.

Cellular-telephone telemetry is a third method of river-data

telemetry employed by the USGS. In 1995, the USGS Indiana

District established a real-time data network to monitor rainfall

and river stage in the Little Calumet River Basin in northwestern Indiana. The network is operated in cooperation with

the U.S. Army Corps of Engineers as part of a flood-protection

project for the Little Calumet River Basin. This network transmits

stream-level and rainfall data from 11 USGS gaging stations.

Gage house

Recorder

Satellite antenna

Stilling well

Float

Intakes

River stage
ACCESS TO AND USE OF

REAL-TIME RIVER DATA

Most of the data transmitted by satellite telemetry are

received by the National Weather Service river-forecast

centers where personnel use the data to prepare flood forecasts and warnings. The forecasts and warnings then are

distributed to local forecasting offices that distribute the information to the public. The forecasts and warnings allow federal,

state, and local officials to take early actions, such as evacuations and road closures.

To further facilitate use of real-time river data by the

general public, the USGS began providing real-time river data

through the World Wide Web (fig. 2). The Indiana District’s

web page began offering real-time river data in June 1996. Since

then, the Indiana District web page has served thousands of

real-time river hydrographs. Real-time data give emergencymanagement officials the ability to make decisions during floods

and allow citizens to make decisions regarding their lives and

property.

Gaging stations in the Little Calumet River cellulartelephone network transmit data directly to computers at

local emergency-management offices where personnel

can make rapid decisions concerning evacuations and road

closures. Data also are transmitted to the Indiana USGS office

in Indianapolis where the operational status of the gaging

stations is monitored.

BENEFITS

Across the nation, benefits from the availability of realtime data for flood warnings are becoming more apparent.

Examples include

•the 1995-96 winter floods in Oregon, when realtime data provided by the USGS was used by

federal, state, and local agencies to manage the

storage and release of flood waters upstream

from Portland, thereby reducing potential property

losses by $2.7 billion (U.S. Geological Survey, 1996);

•the extensive 1993 Midwest floods, during

which the National Weather Service relied on

USGS real-time data to issue more than 135 flood

warnings and more than 2,500 river flood statements (Mason and Wieger, 1995).

Benefits from real-time data availability also have been

realized in Indiana, such as

•the decision by Lake County emergency managers to cancel a major road closure based on

data provided by the Little Calumet River Basin

network, which saved personnel hours and costs

that would have been incurred by the closure of

an important thoroughfare;

•flood warnings and forecasts provided by the

National Weather Service during the 1997 flooding

along the Ohio River that allowed local officials to

take early action in issuing evacuation notices.

FUTURE OPPORTUNITIES

The demand for real-time data is likely to increase. In addition

to flood warnings and forecasts, many other uses for real-time

data exist—such as reservoir management, water-withdrawal

operations, waste-disposal management, and recreational activities.

New technologies in data collection, telemetry, and presentation

continue to emerge. Many of these technologies undoubtedly will

be used by the USGS to meet the growing need for real-time data.

—Scott E. Morlock

SELECTED REFERENCES

Mason, R.R. and Wieger, B.A., 1995, Stream gaging and

flood forecasting—A partnership of the U.S. Geological Survey

and the National Weather Service: U.S. Geological Survey

Fact Sheet FS-209-95, 4 p.

U.S. Army Corps of Engineers, 1995, Annual flood damage

report to Congress for Fiscal Year 1995, table 1.

U.S. Federal Emergency Management Agency, 1991, Interagency hazard mitigation report for Indiana, disaster

declaration FEMA-885-DR-IN: Chicago, Ill., 36 p.

U.S. Federal Emergency Management Agency World Wide

Web site, http://www.fema.gov

U.S. Geological Survey, 1996, The U.S. Geological Survey—

Recent program highlights: U.S. Geological Survey Fact

Sheet FS-113-96, 2 p.

March 1998 Fact Sheet FS-029-98

Figure 2. Example of real-time hydrograph from U.S. Geological

Survey World Wide Web page.

For more information, contact

District Chief

U.S. Geological Survey

5957 Lakeside Boulevard

Indianapolis, IN 46278

http://www-dinind.er.usgs.gov

Additional earth science information

can be found by accessing

the USGS Home Page

on the World Wide Web

at

http://www.usgs.gov