Atascosa River: Evaluating the Aquatic Life and Recreational Uses
Counties: Atascosa, Bexar, Frio, Karnes, Live Oak, McMullen, Medina, Wilson
Parameters: Bacteria and Dissolved Oxygen
Basin: Nueces River
In the Atascosa River in south central Texas, water quality testing found elevated levels of bacteria and low concentrations of dissolved oxygen. The TCEQ is working with the Nueces River Authority and other stakeholders to develop a plan to address these conditions.
High concentrations of bacteria may indicate a health risk to people who swim or wade in the rivers—activities referred as “contact recreation” in the state’s Standards for surface water quality. Dissolved oxygen is essential for the survival of aquatic life, and so is used to indicate whether conditions support the “aquatic life use” in the Standards
In 2009, proposed revisions to the state’s recreational use standard prompted the TCEQ to re-evaluate development of a TMDL, which had been underway since fall 2004. The agency decided to evaluate the aquatic life and contact recreation uses at the same time to gain a fuller understanding of the biological and flow conditions for the entire stream.
Using protocols developed by the TCEQ’s Water Quality Standards Group, the TMDL Team managed a study to support both an aquatic life use attainability analysis (ALUAA) and a recreational use attainability analysis (RUAA) on the entire length of the Atascosa River. UAAs are comprehensive examinations of the physical, chemical, and biological factors that determine whether a particular use is attainable in a specific area of a water body.
Depending on the results of these UAAs, the recreational and aquatic life use standards may be modified. Contact the TCEQ Standards Team to inquire about the status of these analyses.
The TCEQ informed stakeholders about this project at public meetings and in print and electronic media. Meetings about the project were open to
Reports are provided in PDF unless otherwise noted. The TCEQ Standards Team will use these reports to analyze use attainability and decide whether to recommend revisions to the standards.
ALUAA Report for the Atascosa River
Final reports from the 2004 assessment to determine the extent and severity of impairments to the recreational and aquatic life uses of the river.
- Final Report, Volume 1: Physical and Chemical Components
- Final Report, Volume 2: Biological and Habitat Components