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Water Woes: USGS Continues to Monitor Flooding Along Isaac’s Path and Drought Conditions Elsewhere

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The worst of the storm may be over, but Isaacs’s impacts on the Gulf coastline and the potential for inland flooding continue. While precipitation continues to affect states in the storm track, drought conditions persist in many other parts of the country.

Over the next few days, USGS will send crews into the field to assess flooding, gather high water marks, and begin to collect and analyze data from storm surge sensors deployed prior to Hurricane Isaac’s landfall. USGS will also conduct aerial surveys along the Gulf’s coastline to photograph coastal change from the storm’s waves and currents.

USGS Flood Monitoring Network:

USGS boat launched during 2011 flood waters in Louisiana.

USGS boat launched during 2011 flood waters in Louisiana.

For more than 125 years, the USGS has monitored flow in selected streams and rivers across the U.S. through an extensive streamgaging network. More than 7500 streamgages throughout the U.S. provide real-time information of river and stream flow which is routinely used for water supply and management, monitoring floods and droughts, bridge and road design, determination of flood risk, and for many recreational activities.

Rising Floodwaters from Isaac:

Several southern states have experienced significant flooding as a result of rains from Hurricane Isaac.

Multiple USGS field crews from several states are recording high-water marks, collecting discharge measurements and obtaining water quality data in coastal and inland Alabama, Mississippi and Louisiana. This information is important because it is used by the National Weather Service to issue flood warnings, and the data is also used by emergency responders and planners to mitigate current and future flood hazards. These crews are being augmented by USGS staff from the Georgia Water Science Center. As the storm continues to move, crews from Illinois, Indiana, Kentucky, Missouri and Arkansas remain ready to address flooding along the storm’s track.

USGS field crews have also begun retrieving the 170 storm surge sensors and 17 temporary real-time gages that were deployed in response to Hurricane Isaac in locations where the storm has passed. Data from these sensors networks will be uploaded to the USGS Hurricane Storm Tide Sensor Map.  The sensors provide critical data for more accurate modeling and prediction capabilities and allows for improved structure designs and response for public safety.

Three dimensional (3D) topographic and bathymetric model of Yellowleaf Creek, AL.

Three dimensional (3D) topographic and bathymetric model of Yellowleaf Creek, AL.

New 3-D Mapping Technology to Measure Isaac’s Flooding

A new technology is being used by the USGS to map flooding in certain urban areas caused by the hurricane. Called terrestrial lidar, or T-lidar, this new capability is being deployed by scientists from the USGS to collect highly-detailed information in select population areas where the storm had the greatest impact in Louisiana, Alabama and Mississippi. The USGS has not previously used T-lidar for flood work.

Drought Persists in other parts of the U.S.

Although Isaac has brought significant precipitation in its wake, much of the country continues to be plagued by severe drought conditions. The U.S. Drought Monitor has provided the latest drought impacts for the states listed below. Real-time updates on the Nation’s drought conditions are available on the USGS drought homepage:

Dry, cracked streambed as a result of drought.

Dry, cracked streambed as a result of drought.

All of Wyoming is experiencing moderate drought, with 37 percent of the state comprising parts of the Cheyenne, North Platte, and Green River basins in extreme drought conditions.  More than 74 percent of Arkansas continues to be in extreme or exceptional drought conditions.  Colorado, Nebraska and Missouri all have 100 percent of the state in severe drought. Indiana is experiencing 97 percent of the state in severe drought. Moderate to below normal drought conditions cover the vast majority of the state of Georgia. Only the upper Tennessee basins and the Suwannee, Alapaha, and Ochlockonee River basins are in the normal range. In Kansas there are 56 USGS streamgages measuring zero water flow and in Oklahoma there are 22 gages currently measuring zero flow.

Access current flood and drought conditions across the country by visiting the USGS WaterWatch website.

Receive instant, customized updates about water conditions in your area via text message or email by signing up for USGS WaterAlert.