Flooding Hits Along the Mississippi River

Kara Capelli: Hello and welcome to USGS CoreCast. I'm your host Kara Capelli. Did you know that floods were the number one natural disaster in terms of lives lost and property damage every year during the 20th century? 2011 was predicted to be a particularly bad year and many areas of the country are currently experiencing flooding. I spoke with USGS National Flood Hazard Coordinator, Bob Holmes, to learn more.

Bob Holmes: It's been an amazingly bad year for flooding. We started out with the floods out in California, with some of the moisture that comes up through there, the atmospheric rivers. Then, we got into the snowmelt flooding that happened up in the upper Midwest northern Plains in North Dakota, South Dakota, Minnesota areas, and then we just progressed right down into this current round of flooding. We're seeing major flooding on the Mississippi and Ohio Rivers.

Kara Capelli: Most of the current flooding is due to heavy rainfall to the Mississippi River.

Bob Holmes: We've had the Red River of the North and the James River up in North and South Dakota and Minnesota had been at flood for the last two or three weeks. So, we've still got that flood going on, but now we've got a large band of flooding from eastern Oklahoma all the way into Oklahoma, parts of West Virginia through, through the lower Midwest, upper Midsouth region, Southern Missouri, Illinois, Southern Indiana, Northern Kentucky, Western Tennessee, Northern Arkansas. So, we're seeing a large band of flooding through there. We've had as much as 10 inches of rain in the last seven days in some of those areas especially along the Missouri-Arkansas border. And, we're starting to see some major flooding on the main stem Ohio and Mississippi Rivers.

Kara Capelli: Bob told me that where the Ohio and Mississippi Rivers met, there are record floods.

Bob Holmes: On the Mississippi itself, we had flooding that had gotten going earlier the spring as a result of snowmelt. And then on top of that, we've had that crest coming down the stream. Couple that with all the rainfall we've had in the last 7 to 10 days in the Ohio River basin - We're having a convergence of two major rivers at Cairo, Illinois and we're having one heck of a flood there. And so, we may set an all-time record there, which that record was set in 1937. So, we got a major flood coming downstream.

Kara Capelli: When floods happen, USGS crews are some of the first to respond.

Bob Holmes: Yeah, we've got numerous field crews out, making streamflow measurements and making sure our stream gauges are operational and repairing those. In some cases, we've had to raise some of those gauges. Other cases, we put in gauges where we didn't have them, in terms of helping the emergency management operations of the Army Corps of Engineers and the National Weather Service. And so, the streamflow measurements and the gauging data we provide them, it's crucial for them to be able to run their forecast models, operate their control structures on the reservoirs, and make decision as to how best to minimize the loss of life and property.

Kara Capelli: I also asked Bob how long he expects these floods to last?

Bob Holmes: We’ve still got flooding up on the Red, that takes a long time for those floods to go away. The rivers are low gradient. They're fairly flat and the flood plains are fairly wide. And so, it takes a long time for that water to move to the system. On the Ohio and the Mississippi Rivers, the drainage areas are so massive and so large. It also takes a long time for that water to be move through. So, the first cresting is projected to come here at the latter part of April, first part of May. And we're not expected to see crest on the Mississippi River down in the Vicksburg area and that area until probably mid May, of course that could be extended out a little bit if we continue to get a little more rain. We're expecting a lot more rain through the middle to end part of this week. And so, it'll just depend on the timing and the magnitude of those rainfall.

Kara Capelli: You can keep yourself updated about water levels for rivers and streams near you by signing up for USGS WaterAlert at water.usgs.gov/wateralert, where you can receive instant customized updates about water conditions at any of the thousands of sites nationwide where USGS collects real-time water information.

When you sign up for WaterAlert, you can customize the alert so that you'll receive notification when water exceeds any preset threshold or goes above the flood stage at your selected stream gauge. You can find detailed information about flood predictions and warnings in your area at the National Weather Service website and don't forget to follow the USGS on Twitter at twitter.com/usgs or visit our other social media channels at usgs.gov/socialmedia. I'm Kara Capelli and CoreCast is a product of the U.S. Geological Survey, Department of the Interior.

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Additional Information:

• Science Feature:  Flooding Spring 2011