The amphitheater was built by Andrew Zilker in the early 1900s. Since then the stream flowing from Eliza Spring was buried in a pipe underground and a concrete floor was poured in the Spring. These activities reduced salamander habitat.
The City of Austin is working towards restoring salamander habitat and flow at Eliza Spring. This includes reconstructing the buried stream flowing from Eliza Spring, known as daylighting, and removal of the amphitheater concrete floor.
During this process, trees and vegetation are allowed to grow within the amphitheater because they provide most of the nutrients (carbon and nitrogen) into Eliza Spring/ These nutrients are the basis of the food web that the endangered salamanders rely on.
New trees outside the amphitheater will be planted with the daylighting project to provide nutrients and canopy cover. Once trees are established outside the amphitheater and those trees are providing leaves to the Spring, the City of Austin can start to remove vegetation growing within the amphitheater.
More information can be found at the "Splash! Into The Aquifer" exhibit at the Sheffield Education Center next to Barton Springs.