Commission recommends approval of Westlake Dermatology site plan with waivers

The Planning and Zoning Commission recommended approval of the site and NPS plan for Westlake Dermatology, proposed at 14418 State Highway 71, with associated waiver requests. Consultant John Carlo Batinho of Fritz & Nichols presented the application and described resubmittals and the engineering analysis supporting the waivers.

Batinho said the existing impervious cover on the lot is 47.45% and the proposal raises that to 49.36%, an increase of about 700 square feet from existing conditions. He described drainage modeling for multiple points of analysis and said TxDOT reviewed the applicant's models and "support[ed] that there is no adverse impacts to the ditch capacity within the right of way." The commission opened public comment but received none. Vice Chair Wright moved the recommendation and Commissioner Vickery seconded; the motion passed by voice vote.

Batinho outlined the two waivers: one tied to peak flow increases at an internal point of analysis (he reported existing discharge of 19.35 cubic feet per second rising to 27.72 cfs, an increase of 8.37 cfs at that location) and a second waiver related to treating a downstream portion of the drainage area that cannot be routed into the on-site pond. To address the second waiver, the applicant proposes a slotted trench drain that conveys runoff to a vegetative filter strip and a bioscape/rain-garden vault as a two-stage treatment train. Batinho also noted that utility service will be provided by the West Travis County Public Utility Agency and that required plan sheets (erosion control, grading, landscape and elevations) were included in the submission.

Commissioners asked about long-term maintenance for the vegetative filters during drought and staff said maintenance obligations will be recorded in deed restrictions and the city conducts annual operating-permit inspections for water-quality systems. The recommendation will go to city council for final action.