As Category 4 Hurricane Laura approaches the Gulf Coast – bringing with it heavy rains, wind and storm surge – anyone interested in tracking water level data for rivers and streams can access more than 10,000 real-time U.S. Geological Survey streamgages across the nation on the USGS Flood Event Viewer, which includes more than 250 in Louisiana and almost 670 in Texas.

USGS streamgages provide real-time data on water levels for rivers and streams, with many also tracking streamflow. The National Weather Service, U.S. Army Corps of Engineers, and local emergency managers use the streamgage data to develop flood forecasts, make flood control decisions, track flooding, identify the best evacuation routes and plan emergency response, ultimately working to save lives and property. The public can track changing water levels at locations of interest by following changes in readings at the nearest USGS streamgage in the flood event viewer.

“The real-time information these streamgages provide is invaluable in providing timely, critical information to decision makers as they address public safety,” said Marie Peppler, USGS emergency management coordinator. “It’s also very useful for the public as they track local conditions, but everyone should always follow the evacuation and safety guidance of their local emergency officials.”

The flood event viewer also shows where instruments called storm tide sensors were deployed before the storm, although the data from those instruments aren’t shown in the viewer in real time. Storm tides are increases in ocean water levels caused by extreme storms. They include the storm generated surge plus changes to water levels from local tide cycles. Storm tides are among the most dangerous natural hazards unleashed by hurricanes. They can destroy homes and businesses, wipe out roads, bridges, water and sewer systems, and profoundly alter coastal landscapes.

Scientists at the USGS and elsewhere are working to better understand storm surges, and to help in this effort the USGS has developed a network of storm tide monitoring sites along the coast. At these sites, and other locations when needed, storm tide sensors are installed to record water levels to document the timing and magnitude of storm surge and waves as they make landfall. The sensors are housed in steel pipes a few inches wide and about a foot long. Field crews install them on bridges, piers and other structures that have a good chance of surviving a hurricane’s storm surge. 

Forecasters use the storm tide sensor data to model and predict surge-related flooding. This helps them produce more accurate forecasts. City planners and engineers can also use the storm tide sensor data to design better storm resistant structures for more resilient coastal communities.

USGS crews were in the field August 23, installing 28 storm tide sensors along the Gulf coast from Texas to Alabama to measure and record Hurricane Laura’s coastal impacts. Eight scientists from the Lower Mississippi-Gulf Water Science Center installed 11 storm tide sensors along the Louisiana coast, three sensors in Alabama and three in Mississippi. In Southeast Texas, six scientists from the Oklahoma-Texas Water Science Center installed storm tide sensors at 11 locations near the Louisiana border.

When the sensors were installed over the weekend, USGS scientists used the forecasted paths and intensity of both Laura and Tropical Storm Marco to deploy the sensors at coastal locations within the expected landfall area for both storms. Typically, these sensors are collected a few days after a storm passes. However, due to Marco and Laura’s unusually close timing, USGS experts decided it would be best to keep the sensors in the field and record both storms back to back. Once the storm has passed, USGS scientists will retrieve the sensors, collect their readings and make the results available in the flood event viewer.

As the USGS continues to take all appropriate preparedness actions in response to Hurricane Laura, those ­­­in the storm’s projected path can visit www.ready.gov or www.listo.gov for tips on creating emergency plans and putting together an emergency supply kit.