Flood Risk

Flooding Is a Real Risk in Williamson County

Flash flooding regularly affects homes and roads in Williamson County, and FEMA flood maps were last updated in 2019.

The San Gabriel River and Brushy Creek watershed are the main flood threats in Williamson County. A major disaster was declared after devastating floods in July 2025, with an estimated $25 million in damage to public property alone. Flash floods can happen quickly across the county.

FEMA revised flood maps for the county in 2019 using studies by the Texas Water Development Board and the Upper Brushy Creek WCID. If you build or improve property in or near a 100-year floodplain in unincorporated areas, you need a Floodplain Development Permit. Structures must be elevated at least one foot above base flood elevation. Check current maps at msc.fema.gov or the county's GIS page. Call the County Engineer at 512-943-3330 with questions.

Source to confirm: Williamson County — Floodplain Management

More Williamson County notes

Property Tax Basics

Two Offices Handle Your Property Tax in Williamson County

The appraisal district sets your property's value; the tax office collects the money — and they are separate offices.

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Homestead Exemption

Texas Homestead Exemption Cuts Your School Tax Bill

Williamson County homeowners who live in their home can apply for a $140,000 reduction off the value used to figure school taxes.

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Age 65 / Disability Exemption

Extra Property Tax Breaks for Seniors and Disabled Homeowners

Homeowners who are 65 or older, or who have a qualifying disability, can get an additional property tax exemption and a school tax freeze.

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Disabled Veteran Exemption

Veterans with Service Disabilities Get a Property Tax Break

Texas veterans with a service-connected disability rating of 10% or more qualify for a property tax exemption in Williamson County.

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