Austin, TX Environmental Rules: Stormwater Management (2026)

City Code Sec. 25-7-151 makes the owner or developer of property responsible for conveying all stormwater flowing through the property, including water directed there by other developed property or that flows naturally because of topography. If a drainage facility is required along a shared property line, the developing owner is responsible for the facility on both sides of that line. An owner who develops only part of a tract must still provide a drainage facility for that portion, and must fund the full cost of off-site drainage improvements needed to accommodate the development's full effects, including acquiring necessary property interests after certifying by affidavit that a good-faith attempt to get them failed.

Sec. 25-7-152 requires the property owner to dedicate to the public an easement or right-of-way, open or enclosed, for a drainage facility and stormwater flow up to the 100-year floodplain limit, wide enough for continuous maintenance access; the Watershed Protection director may grant a variance in the full-purpose city limits under specific conditions such as non-conforming use status or park improvements.

Sec. 25-7-153 shifts to upkeep: the record owner of a commercial development must maintain its detention basin ("commercial basin") to Drainage Criteria Manual standards even if the basin sits on another parcel, and must prove a legal right of access to it. Where several commercial developments share one basin, all record owners are jointly and severally liable for maintenance. The City inspects every above-ground commercial basin at least once every three years and may charge a re-inspection fee if a basin fails; subsurface commercial basins instead require an annual engineer's report. Residential basins remain the owner's responsibility until the City formally accepts them for maintenance.