Williamson County adopts amended subdivision regulations adding turn-lane, water and floodplain provisions

On March 4, 2025, the Williamson County Commissioners Court voted unanimously to adopt amended county subdivision regulations, effective March 4, 2025, adding requirements for turn lanes and traffic‑impact analyses on larger developments, written commitments from water providers for proposed subdivisions, and use of the county Atlas 14 flood‑plain data once that study is final.

The changes, presented by Williamson County Engineer Adam Boatwright, are intended to address public health and safety amid rapid growth in the county. Boatwright told the court staff began drafting redline amendments last November, solicited public comment, and held 16 meetings attended by about 70 people to refine the rules.

"We're in a booming area and development is very rapid. For public health and safety, we really need to include a turn lane and TIA requirement as part of our subdivision regulations," Boatwright said. He added that not every development will trigger the requirements and that the rules include flexibility so some projects can opt to build specific improvements in lieu of completing a full TIA.

David Glenn, senior director of government relations for the Home Builders Association, told the court the association engaged closely with staff and that the final draft reflected compromises reached during repeated meetings. "It was great to see a team of collaboration," Glenn said, and he thanked county staff for working through concerns.

A resident, Bill Kerberloff (identified in remarks as a long‑time Williamson County resident), argued during the public comment period that some definitions in the draft were too broad and could be applied to private property transactions. He urged the court to narrow language to avoid unintended enforcement against private landowners.

The adopted amendments include: required deceleration/turn lanes and traffic‑impact analyses for developments that meet the county’s size thresholds; a requirement that larger subdivisions provide firm, written commitments from water and wastewater providers or ensure off‑site infrastructure is constructed or bonded before final plat approval; allowance for small subdivisions to use the county Atlas 14 floodplain data once finalized rather than commissioning an independent flood study; documentation of a corridor agreement with TxDOT for studied transportation corridors; and clarification of county positions on new municipal utility districts (MUDs) and maintenance of subdivision roads within MUDs. The county recommended that necessary permits for water or wastewater systems be in place prior to final plat approval.

County officials noted two clerical corrections before final implementation: a correction on page 28 clarifying that county plat recording fees "shall be paid at the recording office pursuant to the Williams County Clerk's fee schedule," and a spelling correction on page 39 (the word "shoulder"). The judge moved to implement the subdivision rules and regulations with those corrections and with an effective date of 03/04/2025; Commissioner Covey moved the approval, Commissioner Cook seconded, and the motion passed unanimously.

During discussion several commissioners emphasized the balance between public safety and enabling viable development. The judge said the outreach process — more than 200 hours of staff and stakeholder meetings — likely reduced legal risk and helped clarify language that had prompted concern.

No amendments to the adopted provisions were recorded during the vote. The court also noted the Atlas 14 study was not yet final but close to completion; once finalized, smaller projects may rely on county data in lieu of paying for individual flood studies.

The court recessed to executive session later in the morning and reconvened without taking further public action on real estate or economic development items; the subdivision regulations implementation was the principal land‑use decision taken in public session.