When the National Weather Service updated its rainfall maps from 1994 to 2017, it redefined the flood maps for Central Texas. Before the study, there was a 1 percent chance of 10.2 inches of rain falling in 24 hours in Austin – this was the accepted definition of what people call a 100-year storm. The new maps show a 100-year storm will be closer to 13 inches of rain in some parts of Austin, which is more in line with the current 500-year storm definition. To recalibrate watershed maps for the city, Watershed Protection Department staffers are working on a three-year effort to update 90 percent of the floodplain maps in Travis County. “Without their efforts, we would be in the position of waiting years for FEMA to update the floodplain maps,” said Shawn Snyder, a floodplain project manager with Travis County. To assist in Austin’s remapping efforts, the Travis County Commissioners Court unanimously voted to write a letter of support for the city’s application to request funding from the state’s Flood Infrastructure Fund. Austin is also collaborating with Bastrop County and the city of Pflugerville to expand the continuity of the floodplain map updates for the Central Texas region.
County helps city’s watershed remapping efforts
