Atlas 14

Williamson County kicked off the Atlas 14 Floodplain Mapping Study in spring of 2021 to update rainfall data throughout the county, model streams and waterways, and identify where flood risks are located.

The National Oceanic and Atmospheric Administration (NOAA) has compiled and analyzed historical rainfall records to produce updated precipitation-frequency estimates across the country. This data, commonly known as NOAA Atlas 14 rainfall, was provided to Texas in 2018. In 2019, the state legislature tasked the Texas Water Development Board (TWDB) to identify areas at risk of flooding and potential mitigation measures. Accordingly, in 2021, the TWDB partnered with Williamson County to conduct the Atlas 14 Floodplain Mapping 

Study to: 

  • Update floodplain information throughout the county with the most recent scientific data including NOAA Atlas 14 rainfall. 
  • Model streams and waterways that have never been studied.
  • Gather accurate information about topography, drainage structures and bridges. 
  • Develop mitigation measures that could be implemented to reduce flooding. 

A public meeting was held on March 29 and April 6 to provide the community information about the study and to gather anecdotal information about flooding on private property. The county is asking for anecdotal information and photos/videos about flooding on your property to be included in the data collection process. If you have information about flooding on your property such as photos or videos, please submit via email to Atlas 14  or mail it to:

Public Affairs Office
710 S Main Street
Suite 101
Georgetown, TX 78626. 

You may also fill out this questionnaire. This information will help the technical team corroborate their findings.