Austin Water to invest $1B in Walnut Creek Wastewater Treatment Plant

AUSTIN (KXAN) — Austin Water will be investing one billion dollars in the Walnut Creek Wastewater Treatment Plant (WWTP) to better support Austin's clean water supply.

Currently, WWTP can filter 75 million gallons per day, but due to population growth, that's not enough.

"In 2024 several times, we actually exceeded 90% of the capacity of the plant," said Charles Celauro, Austin Water's assistant director of engineering. "When that happens, it does trigger state, federal, state regulatory requirements to expand the plant."

The "capacity" has to do with the biochemical oxygen demand, which indicates how much oxygen is required to remove waste organic matter. Austin's population growth has contributed to the increasing levels of the pollutants entering water systems leading to a high biochemical oxygen demand.

"This investment is certainly critical as it supports the growth that Austin has and is experiencing," said Randi Jenkins, Austin Water's assistant director of customer experience.

WWTP was created in 1977, when Austin's population was 322,900 according to the U.S Census Bureau. In 2023, Austin population grew to 979,882, which is more than a 200% increase from 1977.

Parts of the facility that are set to be improved include the water basins, the facility's disinfecting process, machine parts in the headworks and building a new flood wall.

"Ultimately, this will protect the health of the public health the environment and as well as the health of the Colorado River," Celauro said.

Construction for the investment will begin in the summer, and the upgrades will be installed over the next six years. The upgrades will result in an additional 25 million gallons of water treated.