Austin staff to compare indirect potable reuse and Lake Walter E. Long as near‑term supply options

Austin Water staff said the department is expanding consultant work to compare three near‑term water‑supply options: indirect potable reuse (IPR) discharging treated reclaimed water into Lady Bird Lake, using Lake Walter E. Long (often called Decker Lake) as a municipal supply reservoir, and direct potable reuse. The work will feed a feasibility report planned for early fall 2025.

“Indirect potable reuse was characterized as a drought emergency strategy that we would only implement when combined storage at the Highland Lakes reached 400,000 acre‑feet,” Marissa (Austin Water staff) told the task force, citing the Water Forward 2024 planning assumptions. She said the IPR footprint in the Water Forward plan targets about 22,400 acre‑feet per year of yield and that the project was preliminarily targeted for substantial completion in 2028, though costs and timing are still being refined.

Marissa summarized how the two main options under discussion would work operationally. For IPR through Lady Bird Lake, staff said the plan is to treat wastewater effluent from the South Austin Regional (SAR) wastewater treatment plant to reclaimed‑water quality, perform additional treatment under a TCEQ permit and discharge to Lady Bird Lake near…