Austin will begin evaluating the removal of an old wastewater pipe that runs along Barton Creek in response to worries about possible contamination from the line, and to clear the way for more redevelopment around Southwest Austin and nearby cities.

What's happening

Council member Paige Ellis, who represents Southwest Austin, drafted a resolution this spring that kick-starts planning for the pipe's removal from the Barton Creek Critical Water Quality Zone. The measure, approved May 30, calls for city staff to come up with a report on its possible relocation by November.

Ellis said she's seeking to address concerns about city sewage running in close proximity to Barton Creek as well as the longtime roadblock for modern development and other infrastructure improvements in Southwest Austin.

“This is really a generational project for me, and a way for these 1970s, 1980s builds to be able to come into the modern times and be ready for the future," Ellis said in an interview. "We know the impacts that people and infrastructure have on the environment, and this is not the best practice. ... There’s no excuse to leave aging infrastructure in place and pretend that there’s not a problem.”

The overview

The Barton Creek Wastewater Interceptor runs for more than 2 miles through the Barton Hills and Zilker Park area with stretches buried in or near Barton Creek.

The line is a central piece of a wastewater system covering several square miles that also serves the jurisdictions of West Lake Hills and Rollingwood.

The line is decades old and predates the 1992 passage of the Save Our Springs Ordinance that established new environmental protections around Barton Springs. Since then, city code has generally prohibited new development, including utility lines, in critical water quality zones such as Barton Creek.

The wastewater interceptor that runs through the creek has been studied and updated, most recently in 2005, but remains situated on the waterway. Its capacity is also outdated, a factor that has reportedly limited some local development plans for years.

Zooming in

Given its pathway along Barton Creek, Ellis said she's "absolutely concerned" that the old pipes may already be contaminating the waterway with Southwest Austin's sewage.

She pointed to reports of higher E. coli levels and lower water chemistry ratings in Barton Creek as examples of possible signs of pollution from the wastewater line.

"Sometimes you don’t know where a leak is until someone has gone in to specifically identify it and try to repair it," Ellis said. "It seems like the odds are pretty good that something’s leaking in a pipe that’s 25 to 30 years old. I would not bet that it is completely sound and tight at this point of its construction, and it is a wastewater pipe."
The wastewater line runs along the Barton Creek Greenbelt. (Ben Thompson/Community Impact)
The Barton Creek Wastewater Interceptor runs along the Barton Creek Greenbelt. (Ben Thompson/Community Impact)
According to Austin Water, wastewater mains near Barton Springs are meant to be inspected on five- and 10-year cycles, and haven't shown signs of disrepair.

Utility spokesperson Amy Petri said Austin Water has established processes for wastewater pipeline reviews, and that inspections in 2009, 2010, 2021, 2022, 2023 and 2024 revealed "no noted structural defects or evidence of pipe leaking."

"We use a risk-based approach to prioritize defects for repair and replacement through capital projects," she said in an email. "Austin Water has established relationships with the Watershed Protection Department to coordinate on areas they have noted as having high E. coli levels that are potentially from a wastewater source. We work with Watershed to either discover the E. coli source or show that wastewater was not the source."

A closer look

Aside from the environmental impact, upgrading the outdated wastewater infrastructure around Barton Creek could open the door for new development across the city's southwest side.

Ellis said multiple projects in her district—including some with affordable housing—have stalled out over the years thanks to the wastewater system hitting its capacity. Her resolution asks for input from representatives of proposed redevelopments to help guide next steps.

One of those projects could be Barton Creek Square, according to a representative of the national shopping mall and real estate company Simon Property Group.

Simon's Stephen Shea said the company has been trying to redevelop the expansive mall property off MoPac and Capital of Texas Highway for about a decade. However, plans have been rejected due to low wastewater capacity there.

With new infrastructure in place, he said redevelopment under current regulations could move ahead.

“Clearly the site’s potential is unrealized and stuck in amber due to constraints beyond our control," Shea said May 30. "We envision a vibrant redevelopment that would provide much-needed housing and improved environmental standards that have come into effect since the mall was built in 1981. I’ve heard nonprofit organizations have considered portions of the existing parking lot for affordable housing. However, any affordable housing project faces the same roadblocks as ours, specifically a lack of wastewater capacity."

Austin property owners are not the only ones who'd stand to benefit from a new sewage system in the area. Officials with the neighboring cities of West Lake Hills and Rollingwood asked City Council to pass Ellis' resolution given their contracted usage of Austin's wastewater lines.

Their municipal agreements control the amount, location and quality of wastewater that can be sent into Austin's pipelines. While septic use is prevalent in both cities, the Barton Creek interceptor's status was noted as a key factor for their future planning, especially on Bee Caves Road.

"Our City Council is nearing the completion of a rewrite of the city’s commercial code that is aimed at encouraging redevelopment of the commercial corridor, and increasing opportunities for retail and restaurants to locate in Rollingwood," Mayor Gavin Massingill wrote in a letter to Austin leaders. "However, this future redevelopment could be impeded by the limitations on the amount of wastewater that Rollingwood can send to the city of Austin’s wastewater system based on the current wastewater contract."

West Lake Hills solely relies on Austin for wastewater treatment. City Administrator Trey Fletcher said it'd be a challenge to shift to a different system, even in the face of existing constraints, leaving the outlook for growth or new construction uncertain. He also noted that leaders hope to review their civic master plan, including a new look at the Bee Caves corridor and its water system needs.

"I think redevelopment—whether it’s opportunities in Austin or Rollingwood or West Lake Hills or unincorporated areas that may benefit from this—it’s kind of the tide that raises all boats," Fletcher said in an interview.

What's next

In addition to housing and economic activity, Ellis said any new development would benefit the area by building under stricter environmental regulations than many of the structures built decades ago in Southwest Austin.

"The practices from the 1980s are not what we practice today, for a good reason. We need to make sure that we have modern standards, new innovation, trying to make sure people can live on smaller footprints in places that won’t flood," she said. "That’s a conversation that’s happening in any of these footprints that were developed in the 1980s. We know better now, and we have a chance to do better for the next 30, 40 years with our infrastructure."

Before the city report on the pipe replacement is completed this fall, Austin Water staff will be analyzing the Southwest Austin-area wastewater system and capacity needs. Petri said the utility still has to identify which redevelopments or other stakeholders will be involved in this year's process.