The draft 2008 TCEQ 303(d) List (March 19, 2008) identified several assessment units in the Lower Leon Creek as being impaired based on the state’s contact recreation (bacteria) and high aquatic life (dissolved oxygen) use criterion. In response to these conditions, the TCEQ Total Maximum Daily Load Program in partnership with the San Antonio River Authority (SARA)initiated a project to verify depressed dissolved oxygen and develop information necessary to support a bacterial (E. coli) Total Maximum Daily Load (TMDL) in the Lower Leon Creek, Segment 1906. The specific objectives of the Leon Creek Segment 1906 TMDL for Dissolved Oxygen and Bacteria Impairments, TCEQ contract number 582-8-80193 were to: (1) Collect targeted 24 hour dissolved oxygen data in order to verify the water quality impairment and overall organic loading; (2) Collect targeted bacterial data in order to establish source of impairment and over loading; (3) Conduct modeling and assessment activities required to allocate loading; (4) Provide technical assistance to the TCEQ in the evaluation of actions necessary to achieve the recommended loading allocations, and; (5) Document, compile, and summarize technical analyses in reports to the TCEQ. There were two phases to this project; Phase I addressed dissolved oxygen deficiencies in Leon Creek, Phase II addressed excessive bacteria concentrations.
Mission Reach Area Maintenance
Mission Reach Area Maintenance
*MARCH 2026 UPDATE*
Ongoing stem-density maintenance is currently taking place in this area. Crews will be working Monday through Friday during daytime hours. We appreciate your patience as we complete this important work to maintain and enhance the park for everyone to enjoy.
When: Beginning October 20, 2025 through Spring 2026
What: Crews will be performing stem-density removal and related vegetation maintenance along sections of the Mission Reach to help manage flood risk and protect surrounding infrastructure. Some trails or segments may be closed temporarily while work is underway.
Why: Removing excess stems that naturally establish along the river helps maintain stormwater conveyance, reduces flood risk, and protects public infrastructure while allowing grassland and native vegetation to recover and thrive.
What to expect:
- Limited trail closures and intermittent work zones.
- Crews and equipment working near the riverbanks during daytime hours.
- Parking areas remain open, but visitors may see signage and temporary barriers.
Questions? Call the San Antonio River Authority at (210) 227-1373 or visit https://www.sariverauthority.org/services/river-health/ecosystems/.
Thank you for your patience while we keep the Mission Reach safe, clean, and enjoyable.
