Re-Engineering a Home for Salamanders through Aquatic Ecosystem Restoration

For the first time in nearly a century, endangered Barton Springs salamanders have a surface stream at Eliza Spring that allows aquifer flow to revitalized habitat. The complex geotechnical and structural design provides a stable site for in-stream habitat enhancement, native riparian landscaping, and improved water quality with hydraulic control. This project uses a sophisticated engineering design to support natural and beneficial ecological functions. 

Barton Springs has been an oasis for visitors for thousands of years. Today, it is a gathering place for more than 1 million annual visitors and is referred to as the crown jewel of Austin. By the time Andrew Zilker deeded the land to Austin in 1918, construction had changed the character of the site and, eventually, the spring-fed stream was enclosed within a buried concrete pipe. 

This proved consequential for the habitat of the highest known density of endangered Barton Springs salamanders that call the Eliza Spring home. Once propagating the spring, the concrete pipe severed the natural connection to Barton Creek, resulting in loss and fragmentation of surface habitat by eliminating hydraulic surface connections and degradation of aquatic habitat quality. 

Working with HDR, the City of Austin removed the pipe, restored the stream, and reduced the anthropogenic flow regime and habitat modifications of the past. Public forums, meetings and signage both during and after construction informed residents about the endangered salamanders, the history of the site, natural resource protection, historical and current construction methods, and the salamanders’ status as an indicator species for water quality in the Edwards Aquifer, the drinking source for over 1.5 million Texans.

Completed in March 2018, the revitalized Eliza Spring supports long-term species recovery and offers the community a highly visible place to view and learn about Austin’s unique environment and two of its iconic endangered species. By daylighting the historic spring, this aquatic ecosystem restoration project changed the perception of engineering solutions through the incorporation of multiple objectives and environmental sustainability.