When 3.2 inches of rain fell on Mueller in under two hours last Thursday evening, the neighborhood's network of bioswales — vegetated drainage channels designed to capture and filter stormwater — performed largely as designed, preventing the kind of street flooding that affected nearby neighborhoods. But several residents on the south side of the development reported standing water in their yards for over 12 hours, raising questions about whether the system is adequate for the neighborhood's increasing density.
Mueller's stormwater management system, designed as part of the original 2004 master plan, relies on a network of bioswales, rain gardens, and a 30-acre detention lake rather than conventional concrete storm drains. The system was engineered for a 100-year rain event based on historical rainfall data from the former airport site.
Thursday's storm, while intense, was well below the 100-year threshold. But the bioswales along the southern edge of the development — near the newer townhome construction on Tower Street — showed signs of saturation, according to Austin Watershed Protection Department spokesperson Maria Santos.
"The system is performing within design parameters," Santos said in an email Friday. "But we're aware that localized drainage issues exist in areas where recent construction has added impervious cover. We're scheduling a site inspection."
Mueller's drainage infrastructure was designed for the neighborhood's original density. As the development adds taller, denser buildings — including the seven-story projects now permitted on Barbara Jordan Boulevard — the ratio of impervious surface to green drainage increases. The Austin Watershed Protection Department has not updated Mueller's stormwater capacity analysis since 2018.
Residents concerned about drainage on their property can request a free site assessment from Austin Watershed Protection at 512-974-2000 or austintexas.gov/watershed. During flood events, call Austin 311 (512-974-2000) to report standing water or drainage blockages. Sign up for Austin's Warn Central Texas alerts at warncentraltexas.org for real-time weather notifications.