Continuous Water Quality Monitoring - Edwards Aquifer Authority

Continuous Water Quality Monitoring

The EAA operates six continuous water quality sondes in the Comal and San Marcos spring systems as part of the Edwards Aquifer Habitat Conservation Plan (EAHCP) program. Maps presented here show the locations of the three active sites at Comal Springs, and three active sites at San Marcos Springs. The names of the sites are:

Comal Springs

  • Comal Spring Run 3
  • Comal Spring 7
  • Comal River at Old Channel
  • Landa Lake (Discontinued)
  • Comal River at New Channel (Discontinued)

San Marcos Springs

  • Sessom Creek
  • San Marcos River at Aquarena Springs Drive
  • San Marcos River at A. E. Wood Fish Hatchery
  • San Marcos River at Rio Vista Park (Discontinued)

At each of these six monitoring sites, water quality instruments are installed that measure and record the following parameters in 15-minute intervals:

  1. Water Temperature
  2. Specific Conductivity
  3. Dissolved Oxygen
  4. pH
  5. Turbidity*

*only at Sessom site

These data are transmitted via telemetry to EAA servers daily. To request these data, please contact EAA Data Management at

The EAA Board Meeting will take place on June 11, 2024 at 1pm.
Please click here for more information.