Austin Council Mandates Green Stormwater Infrastructure in Updated Development Code

On March 27, 2025, the Austin City Council approved an ordinance to strengthen erosion protections on the Colorado River downstream of Longhorn Dam. The measure also requires Green Stormwater Infrastructure, such as rain gardens and biofiltration, as the primary water quality protection method for most developments.

Austin’s Land Development Code (LDC 25-8) sets two core environmental goals of water quality protection and natural character preservation. It imposes strict limits on impervious cover ranging from 15% to 90% depending on watershed classification. Development near creeks with 64 or more acres of drainage is restricted within Critical Water Quality Zones that carry setbacks of 50 to 700 feet. Construction is further limited near bluffs, caves, sinkholes and wetlands under LDC sections 25-8-281 and 282.

Effects on local infrastructure and services

These requirements directly influence how stormwater infrastructure is designed and built in Austin. Projects must incorporate green methods instead of conventional systems, which affects the scope of work for local engineering and construction services. The Austin-Round Rock area must also meet updated EPA standards that tighten the limit for fine particulate matter from 12 to 9 micrograms per cubic meter, requiring local reductions to achieve compliance.

The city aims for net-zero communitywide emissions by 2040 and a 40% reduction in embodied carbon of locally used building materials by 2030. New 2024 Technical Building Codes, amended locally, take effect July 10, 2025, to enforce efficiency measures and EV readiness in development projects.

Next steps for compliance

City departments will continue to apply the updated standards to permit reviews and infrastructure planning. Residents and businesses involved in development will encounter these rules through site planning, material selection and stormwater design requirements documented in the Land Development Code and related ordinances.