Travis County Master Flood Plan

The Flood Plan will provide updated floodplain mapping and mitigation alternatives for portions of Travis County.

About the Plan

Travis County, in collaboration with the Texas Water Development Board (TWDB), is developing a Master Flood Plan for the County that includes:

• Evaluating flood mitigation alternatives for areas of southeast Travis County
• Updating floodplain maps for Western Travis County based on updated Atlas 14 rainfall data provided by the National Oceanic and Atmospheric Administration (NOAA)
• Gathering information about existing drainage structures and bridges
• Developing a database of low-water crossings

The Plan builds off previous efforts initiated by the County and the City of Austin and is broken up into three tasks that once completed, will provide updated floodplain mapping and mitigation alternatives for portions of the County.

Virtual Open House

Phase 1 Flood Mitigation Alternatives Open House – Oct. 16 – Nov. 8, 2024

Travis County is hosting an online open house to share information and seek feedback from community members on flood mitigation options in several flood-prone areas of the county. Two options are available to participate in the open house:

The virtual open house is self-guided and includes a recorded presentation and materials for download. Materials will be available in English and Spanish.

Live Online Meeting

Wednesday, Oct. 16, 2024, 5:30 – 6:30 p.m.

RSVP here https://forms.gle/NfdxDgNoxpAwEViz5 to receive the online meeting link.

The online meeting will be hosted live via Microsoft Teams and include a presentation and opportunities to ask questions. Please RSVP using the link above to participate. The online meeting will be conducted in English. Si necesita materiales en español, por favor llame al 512-900-4330 o envíe un correo electrónico a [email protected].

Study Background

The National Oceanic and Atmospheric Administration (NOAA) completed a historical rainfall study for the United States in 2018, called Atlas 14, to create a more accurate picture of rainfall estimates. The study included rainfall estimates from past major events including the Tropical Storm Hermine in 2010, Blanco River Memorial Day Flood in 2015, Hurricane Harvey in 2017, and many other local flooding events that impacted Texas between 1994 and 2017.

Rainfall data is used to define flood risk and to analyze and design stormwater infrastructure such as bridges, culverts, channels, storm drainage systems, and detention facilities. The Atlas 14 rainfall data for the County shows approximately 3 – 3.5 inches of increase in the 24-hour 1% annual chance event. The 1% annual chance flood event has a 1 in 100 probability of occurring in any given year.

To address the growth in flood risk, Travis County has partnered with the Texas Water Development Board (TWDB) for a Flood Infrastructure Fund (FIF) Category 1 grant to develop the Master Flood Plan for the County.

For more details, please reference the FAQ Sheet.

Study Timeline