Planning commission approves text amendment to bar non‑traditional wastewater systems for new residential development inside UGBs

County staff presented a text amendment to Articles 11 and 23 of the zoning ordinance to address non‑traditional wastewater treatment and disposal systems located inside urban growth boundaries (UGBs).

Staff said the change implements Strategy 1A of the Williamson County growth plan (adopted November 2024) and reflects consultations with municipal staffs, who generally objected to allowing non‑traditional systems inside UGBs because retrofitting those systems to municipal sewer later is difficult and costly. Staff explained the proposed text would prohibit such systems on properties zoned RD5 and RP5 when those properties are inside a UGB and when they are proposed for new residential development; the text would continue to allow non‑traditional systems when serving individual uses such as a school or church, as is current practice.

When commissioners asked about homeowner impact, staff said many property owners within a UGB pursue annexation and city sewer connection when they choose to develop. Staff also clarified that the Board of Zoning Appeals cannot grant a use variance for this change and that removing the prohibition would require an ordinance amendment. A commissioner asked whether the change conflicts with the septic task force’s work; staff said it does not have a direct bearing on the task force recommendations.

A motion to approve the staff recommendation passed by voice vote. Staff told the commission the attached resolution and text amendment would be forwarded to the county commission with a recommendation for adoption.