Saturday, May 7, 2011

USGS Monitoring Historic Flooding Along the Mississippi and Ohio Rivers

Crews are measuring the amount of water spilling into the New Madrid floodway after the intentional breaching of the Birds Point Levee in Missouri. In Arkansas, scientists are monitoring extremely high floodwaters that caused a major interstate to close. The USGS is busy providing flood data to emergency managers so they can keep families and communities safe.

Current flood conditions

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2011 was predicted to be a particularly bad year for flooding in the northern Plains and upper Midwest. Areas along the Red River in North Dakota and Minnesota and the James Rivers in the Dakotas are still experiencing flooding from snowmelt.

Now extreme rainfall is causing severe flooding along the Mississippi and Ohio Rivers. Record floods are possible in some areas.

When flooding happens, USGS field crews are among the first to respond. During and after storms and floods, USGS field crews measure the streamflow and height of rivers and ensure the accuracy and reliable operation of stream gages. Field crews continue to work as waters recede, gathering high water marks for post flood analysis. All this data and information is crucial for such activities as the issuance of flood warnings and characterization of flood hazards to mitigate future damages.

You can keep yourself updated about water levels for the rivers and streams near you by signing up for USGS WaterAlert at, where you can receive instant customized updates about water conditions at any of the thousands of sites nationwide where the USGS collects real-time water information. When you sign up for WaterAlert, you can customize the alert so that you receive notification when water exceeds any preset threshold or goes above the flood stage at your selected stream gage. You can find detailed information about flood predictions and warnings in your area on the National Weather Service website.

What will happen if other levees are breached downstream? Will contaminants inundate farmland? Will changes in the river’s velocity impact shipping? 

USGS scientists are measuring the amount of water spilling into the New Madrid floodway as a result of the recent intentional breaching of the Birds Point Levee in Missouri. The measurements are critical for estimating how much water downstream levees will need to hold back and for predicting flood crest heights, as the remaining flood waters pass through the Mississippi River. 

“In order to protect lives and property during flooding the federal government, states, emergency managers and communities need to have the best information possible to understand how the water will react when a levee breaks,” said Bob Holmes, USGS National Flood Hazard Coordinator. “While flood measurements are never routine, the recent breaching of the levee at Birds Point and the rush of the Mississippi River into the New Madrid floodway calls for highly unusual flow measurements – information that is a key part of management actions to alleviate upstream flooding in the vicinity of Cairo, Ill. and other areas along the Mississippi River.” 

Up to date information about USGS data collection at the Birds Point-New Madrid floodway is available online

In preparation for the breeching USGS field crews installed 38 storm surge sensors, originally developed after Hurricanes Katrina and Rita to measure storm surges. These temporary sensors will measure water flowing into the Birds Point-New Madrid floodway. The USGS is also sampling the floodwater for various chemical contaminants in newly inundated fields and farms. 

While the levee breach is helping to reduce flooding of communities along the Mississippi, Missouri, and Ohio Rivers, it may also create unusual flow conditions that could impact barge traffic near the breach, as outward flowing water alters river currents. These new, complex river currents are being mapped daily by USGS. The maps will enable the barge traffic to avoid the fastest currents and adjust ship routes to account for the new currents.
Real-time data on river flows and depths are continually needed to forecast incoming flows and flooding threats. The USGS is the nation’s primary collector of river flow information that feeds flood forecasts and decisions related to flood-fighting taking place along the Mississippi River and elsewhere. 

“While the USGS routinely monitors and documents flooding and provides the stream flow information needed to inform developmental plans and land use decisions, this documentation effort below the levee is extraordinary for its scope, intensity and innovative use of new technologies,” said Holmes. “USGS has a unique opportunity to collect data that increases our understanding of the hydraulics of the Ohio and Mississippi Rivers. This data will be critical in future flood forecasts.” 

The work is being conducted in close cooperation with the U.S. Army Corps of Engineers, the National Ocean and Atmospheric Administration, the U.S. Coast Guard, and many state and local agencies.  The National Weather Service refines river forecasts, the Corps of Engineers adjusts flood-control reservoir releases, the Coast Guard issues shipping directives and advisories, and local communities prepare for floods based on USGS river measurements. 

The USGS collects river data through its network of about 7,700 stream gages around the Nation. You can receive instant, customized updates about water conditions, including flooding, by subscribing to USGS WaterAlert.

USGS Local Flood Resources

·         Illinois Flooding Resources

USGS National Flood Resources
Additional Flood Resources

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