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. An automatic sampler is stationed at Barton Springs to collect data on pH, temperature, turbidity, specific conductivity, dissolved oxygen, and depth. Watershed Protection groundwater monitoring staff test for suspended solids and nutrients every two weeks. Additionally, twice weekly, and following rainfall over one inch, the Parks and Recreation and/or County Health Departments test for bacteria levels.
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 Barton Springs Salamander is primarily found.
- 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.
- Old Mill Spring (Sunken Garden), also known as 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.
- Upper Barton Springs is located upstream of Barton Springs Pool.