Buying Land in Williamson County, Texas

No groundwater district, and a documented fight to create one

Williamson County has no groundwater conservation district covering it, which puts wells here under the statewide rule of capture with no local board setting spacing, permitting, or production limits. What makes this genuinely distinctive is how actively contested that gap has been in just the last few years. In March 2023, Williamson County Commissioner Terry Cook published a public case for why the county needed a groundwater district, describing the county as "operating on zero data, except, 'my well is going dry.'" A local landowner group, the Aquifer Conservation Alliance, moved to formalize that concern by petitioning for annexation of western Williamson County into the neighboring Clearwater Underground Water Conservation District (which already manages the Trinity and Edwards BFZ Aquifers in Burnet County). That effort stalled on two fronts in late 2023 and early 2024: the Williamson County Commissioners Court declined to formally support the petition, and Clearwater UWCD's own board ultimately voted not to approve the annexation, citing the cost of running the required elections -- roughly $75,000 in Bell County and $380,000 in Williamson County.

Rather than drop the issue, Williamson County allocated $1 million of its own budget to commission an independent groundwater study of the Trinity Aquifer, selecting LRE Water, LLC to lead the work in partnership with the Bureau of Economic Geology and Baylor University. Earlier LRE Water analysis of Trinity Aquifer drawdown in the region found many well owners already pumping from near the bottom of their wells, with western Williamson County specifically flagged for drying creeks, springs, wetlands, and residential wells during dry periods. For a land buyer, the practical takeaway is that this is a real, currently unresolved regulatory gap on a genuinely stressed aquifer, not a hypothetical one -- see our standalone well-water page on Williamson County for what the drawdown data means well-by-well and how to check on a specific parcel before counting on a well.

The Edwards Aquifer Recharge Zone and a fast-changing subdivision rulebook

Separately from the Trinity Aquifer situation, a portion of Williamson County has been added to the officially mapped Recharge Zone of the Edwards (Balcones Fault Zone) Aquifer under TCEQ's Chapter 213 water-quality rules -- the same aquifer that supplies much of the San Antonio and Austin areas' drinking water. Development in the recharge zone can trigger Edwards Aquifer Protection Program permitting requirements aimed at protecting water quality; TCEQ directs Hays, Travis, and Williamson County questions on this program to its Austin regional office. This affects only part of the county's geography, so confirm a specific parcel's recharge-zone status directly rather than assuming it either does or doesn't apply based on general location.

On the subdivision side, Williamson County's growth pressure produced a substantial rewrite of its Subdivision Regulations, effective for new applications received on or after March 4, 2025. The updated rules require a traffic-impact and turn-lane analysis for larger developments -- those generating more than 2,000 vehicle trips per day -- and require builders to secure a water-service commitment from a utility or supplier before a final plat can be approved, both aimed at forcing infrastructure planning to keep pace with growth. The regulations continue to classify subdivisions as either urban or rural and define a "minor plat" narrowly: four or fewer lots, no new road construction, no FEMA-mapped floodplain anywhere in the plat, and no watercourse with an upstream drainage basin larger than 64 acres within or adjacent to the plat. A plat that misses any of those thresholds needs the full subdivision review process rather than the streamlined minor-plat path -- worth checking early with the county's Development Services & Drainage office, since the rules and required checklists changed materially in 2025 compared to the prior 2013 regulations.

Flood control and the San Gabriel River

Lake Georgetown, a US Army Corps of Engineers reservoir on the North Fork San Gabriel River about three miles west of Georgetown, was completed in 1979 specifically to provide flood control for the Georgetown area, and today also supplies drinking water to both Georgetown and Round Rock. Williamson County's own County Engineer's Office serves as the county's designated floodplain administrator, and a 2019 FEMA map update (the "San Gabriel Watershed Phase 2" revision) updated Zone A floodplain boundaries scattered across the rest of the San Gabriel River watershed outside the Corps' own detailed studies -- worth checking directly for any parcel near a San Gabriel River tributary, since Zone A designations can shift with map updates in ways a buyer might not expect from an older flood map.