Real-time Monitoring

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

Comal Springs Sites

  • Comal Spring Run 3
  • Comal Spring 7
  • Comal River below Dry Comal Creek

San Marcos Springs

  • San Marcos River at University Drive
  • San Marcos River at Rio Vista Park
  • San Marcos River at TPWD Fish Hatchery

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 (HDO)
  4. pH
  5. Turbidity

These data are transmitted via telemetry to a web-based water quality data service, called “EnviroNet” which is a product of Netronix. The EAA can provide user access to the continuous water quality data through the EnviroNet service to the public by assigning a user account to interested individuals. For data access, please contact Dr. Marcus Gary at the EAA (, and a user account invitation will be provided. Dr. Gary can also answer user questions as requested.

Comal HCP Final Sample Locations 2014

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San Marcos HCP Final Sample Locations 2016

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