New development along the Colorado River on Austin's east side is now subject to stricter erosion-related reviews intended to stabilize the vulnerable riverbank and scores of properties in the area.
“This ordinance furthers City of Austin goals to become more resilient in the face of ever worsening climate disasters,” Watershed Protection Department Director Jorge Morales said in a statement. “Prevention is always preferable to rebuilding after a disaster.”
What's happening
A few years ago, City Council asked to improve protections along the river downstream of the Longhorn Dam. The changes were meant to help reinforce the sandy riverbank that's particularly to susceptible to erosion, and the waterway Morales labeled as a "crucial resource" for Central Texas.
Council voted to expand the city's Erosion Hazard Zone, or EHZ, along the Colorado on March 27. The change roughly doubles the zone on the river's eastern stretch to 200 feet wide, where formal erosion risk analysis can be required before new construction takes place. The rest of the Colorado and Austin's creek's still have the standard 100-foot EHZ in place.
“It’s strictly preventative. It doesn’t make anybody do anything new that’s already there," he said in February. "It basically declares an area of concern that you need to look at, and then you get to choose whether or not you want to move forward with something in that area based on the facts or whether you want to push your thing further out."
Marian Sanchez, representing the east side environmental justice group PODER, told council the changes will help residents directly impacted by erosion along the banks as current regulations proved to be ineffective.
"The protections outlined by the ordinance will not only keep current and future surrounding communities safe and prevent any further property loss, but additionally save the city millions of dollars in erosion," she said March 27.
The approach
The new regulations apply to some non-residential and infrastructure construction along the river within Austin city limits and extraterritorial jurisdiction, or ETJ. Council passed the new ordinance with an exemption for smaller single-family projects and mobile homes.
More information on the update including an interactive map of the city's new erosion buffer zone is available online.
“I know no one likes being told they can’t do something, but I feel like they’d like their house falling into the river even less," council member Ryan Alter said in February.
About 200 parcels along the river would be covered by the expanded EHZ, according to the Watershed Protection Department, although staff estimate less than 40 would likely be impacted if property owners pursue new construction on their land.
"Some community members have also expressed a desire to ensure that the Colorado River and its banks and riparian corridors are adequately protected from future development. Fortunately, the city of Austin already has in place a Critical Water Quality Zone that staff feel is adequate to protect the riparian corridor of the river," she said.
Travis County also has its own erosion zones covering its unincorporated land outside Austin's ETJ, although those regulations apply for water quality and wastewater infrastructure and parks rather than buildings or roadways, according to the watershed department.
Property owners now have the ability to remove themselves from city ETJ into the county. And so far, Travis County staff haven't seen any uptick in erosion or water quality concerns near properties like Tesla's Gigafactory that have exited Austin's oversight.
"Based on our current monitoring and available data, there have been no notable changes or emerging trends in these areas," county spokesperson Hector Nieto said.
Zooming in
Morales previously said the update responds to high erosion risks and public safety concerns in the area, and the high costs associated with erosion-related repairs. For example:
- Floodwater damage and erosion along Falwell Lane prompted $900,000 in emergency repairs in the 2010s, and future stabilization projects could cost tens of millions more.
- Stormwater pipe repairs on the river off Tillery Street cost $1.9 million in the early 2000s.
- Utility repairs near the river in the Holly neighborhood in 2019 cost $88,000.
- Stabilization work in Roy G. Guerrero Colorado River Metro Park will cost an estimated $25 million—although the Watershed Protection Department noted the new erosion zone likely wouldn't have impacted those park projects.
