Williamson County could receive two to four more inches of precipitation than previously thought during major floods, according to a new study.
After about three years of work, the Lower Brushy Creek Water Control and Improvement District has unveiled its Atlas 14 floodplain study, which uses updated National Oceanic and Atmospheric Administration data.
The county will hold a public discussion of results from 5 to 7 p.m. Wednesday, June 5, at the Dicky-Givens Center, 1015 E. MLK Jr.
Blvd., in Taylor.
“The meetings are really to show the results that have been developed to date,” said Cindy Engelhardt, Atlas 14 project lead. “If you have any additional questions or want us to walk you through any of how the study was conducted, as well as the preliminary results, we’re happy to walk you through these things during these public meetings.”
The new information included updating flood plain information throughout the county with the most recent scientific data like NOAA rainfall, modeling streams and waterways that have never been studied, gathering accurate information about topography, drainage structures and bridges and developing mitigation measures.
According to the WCID, preliminary results show the county’s 100-year flood shifted from eight to 10 inches of precipitation to 10-12 inches.
A 100-year flood is defined as an event that has a 1% chance of happening in any given year.
This change means there may be an increased risk of flooding if a 100-year event occurs in the Williamson County area.
Engelhardt said previous studies only used rainfall records that went back to 1994.
“This is a county-wide update of pretty much everything,” Engelhardt said. “It’s helping us better understand this new data and where flood exposure is located based on more current conditions.”
She added that researchers are working to update other aspects of the model, such as changing the county’s land to include growth and changes.
By mapping the land’s structures, like businesses and houses, and measuring information such as elevation, the floodplain studies could be used to predict which buildings would be at risk for exposure to floods, Engelhardt said.
According to Engelhardt, once all of the new data is available, the studies can be used to better prepare for future floods for safety.
“We will be looking at mitigation measures, basically from now through the end of the year,” Engelhardt said.
“These will be very high-level, conceptual mitigation options. Then we’ll have another public meeting likely late this year.”
Connie Odom, county communications director, said residents interested in the survey results should look online at https://www. wilcotx.gov/Atlas-14. A map is available on the page.
“Everything’s on there,” Odom said. “They don’t need to come to the public meeting, the same information is available on the website. It’s just if they want to talk to someone and have somebody walk them through it, that’s what the public meetings are good for.”
The county is hosting a similar open house in Hutto Tuesday, June 4, at the East Williamson County Higher Education Center, 1600 Innovation Blvd.
