Barton Springs has been called "the soul of Austin" with a history of human activity that dates back at least 10,000 years. It is the main discharge point for water that enters the Barton Spring segment of the Edwards Aquifer.
Monitoring water quality at Barton Springs is essential for assessing the cumulative impact of development on the entire Barton Springs Edwards Aquifer as well as for endangered species protection and preservation of the unique swimming site. Barton Springs is actually comprised of four separate but related spring outlets. Main Barton Springs, also known as Parthenia, discharges from the aquifer directly into the pool from numerous fractures and openings upstream of the diving board area. This is also where the endangered salamander is primarily found in the pool.
Eliza Spring discharges into a concrete amphitheater on the north side of the pool near the concession stand. Water is visible welling up from holes drilled into the artificial concrete floor and flows out through a drainage pipe at the east end of the amphitheater. Old Mill Spring, also know as Sunken Garden or Zenobia Spring, discharges into a stone-walled pool on the south side of the creek downstream of Barton Springs pool and flows through a short tributary to Barton Creek.