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April 14, 2026

Austin Water and City Leaders Break Ground on Expansion of Walnut Creek Wastewater Treatment Plant

City of Austin

For Immediate Release

Release Date:

April 14, 2026

Contact:

Austin Water Media Line
512-972-0499

AUSTIN – Austin Water and City leaders broke ground today on the $1.5 billion expansion of the Walnut Creek Wastewater Treatment Plant (WWTP), marking the beginning of key upgrades to critical infrastructure that will improve the treatment processes and protect the health of the Colorado River downstream of Austin. All improvements will be made while the plant remains fully operational, without interruptions.

“This generational investment to expand and modernize the Walnut Creek Wastewater Treatment Plant is about taking care of Austin,” said Austin Mayor Kirk Watson. “We’re making improvements to keep these essential services strong and building a future we can count on.”

Walnut Creek WWTP continues to stand among the nation’s top-performing plants, earning the National Association of Clean Water Agencies’ Platinum Peak Performance Award. Built in 1977, when Austin’s population was just over 320,000, the plant expanded over time to meet the needs of our growing city which is more than one million people. Today, it serves more than 50% of Austin and operates at a treatment capacity of 75 million gallons per day (MGD). Through this expansion, that capacity will increase to 100 MGD – helping meet future demand and state-mandated requirements set by the Texas Commission on Environmental Quality (TCEQ), for Austin’s projected growth of 1.5 million by 2040.

“Today’s groundbreaking marks an important milestone in securing vital City Services, while energizing economic development and creating jobs,” said Mike Rogers, Assistant City Manager. “These are the types of jobs envisioned and created by the Austin Infrastructure Academy, a local coalition of partners in government, education and business who are growing Austin’s workforce and providing opportunities for advancement, training and competitive compensation for workers who are building, operating and maintaining our critical infrastructure.”

In addition to increased treatment capacity, other significant improvements include:

  • Advanced treatment technology to reduce the nutrients that contribute to algae growth and blooms, benefiting the health of the Colorado River
  • Replacing chlorine gas with a modern ultraviolet (UV) disinfection system, for the safety of workers and the surrounding community
  • Advanced odor control technologies which include biofilters and activated carbon filters
  • Construction of a flood wall to protect vital infrastructure during extreme weather
  • Modernization to rebuild or replace aging parts of the existing plant and incorporate improved operational and environmental features

Located on FM 969, Walnut Creek WWTP is one of two regional wastewater treatment plants in Austin, treating more than 50% of the city’s wastewater. A portion of the treated effluent is reused for irrigation on site, and other non-drinking uses through the city’s reclaimed (purple pipe) system, while the rest is safely returned to the Colorado River.

“The health of the Colorado River is tied to the work we do at Walnut Creek, and this expansion project strengthens that connection,” said Austin Water Director Shay Ralls Roalson. “We’re making smart, cost-effective improvements to help protect our environment and provide the reliable services our community depends on every day.”
 
This expansion project will be funded through a combination of federal and state low-interest loans, including up to $1 billion from the U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Finance and Innovation Act (WIFIA) program and $59 million from the Texas Water Development Board Clean Water State Revolving Fund program, along with Austin Water’s funding.

Partners of this expansion include:

  • MWH Constructors – CMAR (Construction Manager at Risk)
  • AECOM – Design Engineering


About Austin Water

Austin Water provides safe, reliable, high quality, sustainable and affordable water services that have met the community’s needs for over 100 years. Austin Water serves over 1 million people in the Austin metropolitan area across more than 538 square miles. As Austin continues to evolve, our mission remains the same: To provide water for people and care for the environment. For more information visit austinwater.org.