For the Water, For the People, For the Future. Barton Springs, the Barton Creek Greenbelt, and our surrounding neighborhoods and wild spaces are under threat from the proposed MoPac South expansion from Slaughter Creek to Enfield Road. The Central Texas Regional Mobility Authority (CTRMA) plans to add four new toll lanes (and additional auxiliary lanes) along this corridor, widening bridges, disrupting wildlife habitats, and increasing traffic and pollution. Even worse, this 8.77-mile stretch sits atop the Edwards Aquifer Recharge zone, putting our water at risk from increased pollution runoff and years of construction. Despite these risks, CTRMA is pushing forward without a full Environmental Impact Statement and it is ignoring smarter, more sustainable alternatives such as metered lanes, HOV lanes, fixing the bottlenecks, and investing in public transit.
Save Our Springs Alliance and other community leaders have been pushing back against this short-sighted and damaging project since 2012. In 2015, we shut the MoPac South expansion down with a groundswell of opposition made up of unified experts and community leaders that understood and stood up for what was at stake. A renewed effort came together when this proposal reared its ugly head (again). This work is now being done by the Better MoPac Coalition, which is advocating for more environmentally sensitive alternatives.
Central Texas Regional Mobility Authority (CTRMA) has released the draft Environmental Assessment for the proposed MoPac South expansion. The official public hearing comment period begins Monday, March 9th through Sunday, May 3rd.
A Threat to Water and Wildlife Expanding a highway here means over 110 acres of additional pavement, more polluted runoff, and 5-7 years of disruptive construction in one of the most environmentally sensitive regions in Central Texas. This proposal would widen an 8.77-mile stretch of highway through the Edwards Aquifer recharge zone that feeds Barton Springs. This is not the place to expand a highway. The recharge zone is very fragile and lacks natural filtration. Rainfall moves quickly through caves, sinkholes, and fractures into the aquifer. More pavement means more runoff, more sediment, and greater risk of contamination. In a region already facing prolonged drought and extreme aquifer stress, protecting recharge is an imperative.
The Draft EA confirms the project will likely harm endangered species, including the Barton Springs and Austin Blind salamanders as well as federally protected cave invertebrates. When impacts threaten species with such limited habitat, that is a clear red flag. Federal law requires a full Environmental Impact Statement for projects with potentially significant effects, and the draft EA’s own findings make the case for a deeper, more rigorous review. Now it’s up to us to make sure it happens.
We also know from decades of transportation research that widening highways does not solve congestion in the long term. Added lanes induce more traffic. Toll lanes benefit those who can afford them. Meanwhile, this proposal would bring years of overlapping construction alongside the I-35 overhaul and deliver marginal time savings for a subset of drivers while allowing permanent damage to water, wildlife, neighborhoods, and the people that work, live, and play nearby (i.e. the Hike-and Bike trail, the Barton Creek Greenbelt, Barton Springs, Austin High School students and faculty).
We’re urging CTRMA to consider a “low-build” alternative that:
Your Voice Matters Take a few minutes to submit a personalized comment to CTRMA—and make it your own. Share why Austin’s water, endangered wildlife, beloved Greenbelt trails, and community health matter to you. Show your passion. If you live, work, or go to school nearby the impacted area, let them know! The more specific and unique your comment, the more likely it will be read and considered, rather than just counted. Tell your friends. Every comment makes a difference.
