Flooding Leading Cause of Natural Disaster
Flooding remains the leading cause of natural-disaster loss across the United States. The Hill Country and Central Texas have a greater risk of flash flooding than most regions of the United States. This area is called Flash FloodAlley because of the area’s steep terrain, shallow soil and unusually high rainfall rates. Heavy rains can quickly transform into walls of fast-moving water with great destructive potential.
Flooding, particularly flash flooding, is also one of the hardest for weather forecasters to predict. The National Weather Service (NWS), in conjunction with Federal Emergency Management Agency (FEMA), U.S. Army Corps of Engineers and U.S. Geological Survey (USGS) currently has approximately 3,600 river forecast points across the country. Using the National Water Model, NWS can now provide hydrologic forecasts to over 2 million people, as well as provide flood inundation maps based on the model.
The NWS Austin/San Antonio office hosted a seminar on Sept. 12 in Gonzales to present the model and to get feedback from area emergency management coordinators, GIS administrators and floodplain administrators. Fayette County’s GIS Administrator Dawn Moore, Floodplain Administrator Amber Hielscher and Emergency Management Coordinator Angela Hahn attended the seminar.
“Flood maps can help visualize flood forecasts and their impacts, improve the ability to target areas and preposition resources and increase confidence to improved response time. It allows us to plan ahead for potential response activities such as planned evacuation routes, identification of vulnerable areas requiring road closure, and resource planning in advance of flood events,” said Hahn.
“Flood inundation maps are computer-generated imagery of the potential flooding for a given geospatial area – its water on a map. We can add these layers to our county GIS system to help better understand what areas might be impacted,” Moore added.
“It’s a great tool to have although the NWS did stress that because of the nature of flooding the official river forecasts still provide the most useful information on what to expect,” Hielscher said.
NWS officials at the seminar asked for local input on the maps presented, saying that it was important to focus on local impacts and critical infrastructure.
“Flood extent maps are a great guidance tool for more detailed flood impacts, however, there are still some limitations. Not all levees and flood reduction projects are captured, so use your local knowledge. And share it with us. While floods are impossible to prevent completely, and there is no way to guarantee protection of property, loss of life can be greatly reduced when communities have access to good data, practice sound land use, floodplain management and development practices and incorporate warning systems. Local communities can partner with us to provide solutions to reduce their communities flood risk,” said Paul Yura, the warning coordination meteorologist for National Weather Service Austin-San Antonio.