The Walnut Creek Wastewater Treatment Plant is one of two regional facilities treating about 50 percent of Austin's wastewater. It receives flow from Austin Water's sanitary sewer collection system and returns the cleaned and treated wastewater to the Colorado River.
This year, Austin Water is starting construction on a $1 billion expansion and modernization project for the facility, adding 25 million gallons of daily treatment capacity to prepare this critical infrastructure for the needs of the future and maintain reliable wastewater service for more than 1 million people across the Austin metropolitan area.
The existing plant, which first came online in 1977, is currently permitted to treat 75 million gallons per day. Flows into the plant exceeded 75 percent of total treatment capacity in 2015 and surpassed 90 percent of treatment capacity for three months in 2024, triggering state requirements to expand the facility.
Project Overview
This project will provide significant operational enhancements and technical modernizations to the plant alongside the required expansion, replacing aging components and improving the treatment process to protect the environmental health of the Colorado River downstream of Austin.
These upgrades will replace the facility's current chemical disinfection system with an ultraviolet (UV) light disinfection process, which will eliminate the use of chlorine for disinfection and will make the plant inherently safer for workers and the community. To improve the resiliency of the plant against future weather events, a wall will be built around the site to protect it from floodwaters.
Timeline
Austin Water estimates a construction timeline of six years, with the expansion coming online in 2031.
Communications
Thank you to our neighbors who attended the June 2025 Public Meeting. It was a good opportunity to share information about the upcoming construction project. Review the information shared during the meeting:
Walnut Creek June 2025 Public Meeting Presentation (Adobe PDF)
Walnut Creek June 2025 Public Meeting Presentation - Spanish (Adobe PDF)
Community Outreach Contact
Emlea Chanslor
Public Information Office, Austin Water
512-972-0145
Email
- Past Community Meetings
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- August 24, 2023 Community Meeting
- May 24, 2022 Community Meeting
- June 29, 2021 Community Meeting
- Dec. 9, 2020 Community Meeting
Watch the recording
View the presentation
- Liquid Waste Information
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The City’s approved receiving station for hauled liquid wastes is also located at the Walnut Creek Wastewater Treatment Plant. For more information, including receiving station hours, please visit the Liquid Waste Hauler Program webpage.