Mid Cibolo Creek: A TMDL Project for Dissolved Oxygen
Counties: Comal, Guadalupe, Bexar
Parameters: Dissolved oxygen
Basin: San Antonio River
- Project Overview (PDF)
- Background and Goals
- Public Participation
- Draft TMDL and Project Status
- Project Documents
- For More Information
In Mid Cibolo Creek in south central Texas, water quality testing found low concentrations of dissolved oxygen. The program’s South Central Texas Streams project verified that the impairment was severe enough to warrant development of a TMDL for the creek.
Oxygen, which dissolves in water, is essential for the survival of aquatic life. While the amount of dissolved oxygen in water fluctuates naturally, various human activities can cause unusually or chronically low levels of dissolved oxygen, which may harm fish and other aquatic organisms.
Project staff informed the public about this project through public meetings, which were open to everyone.
After completion of the draft TMDL, the TCEQ determined that since a single regulated discharger was believed to be the primary source of the impairment, it was not necessary to complete and submit a TMDL to the EPA.
The TCEQ expects that upgrades completed to the discharging facility in 2007 will ameliorate the low dissolved oxygen conditions in the creek. The state will continue to monitor the stream to ensure that the facility upgrades are sufficient to restore conditions that support a healthy aquatic community.
Subsequently, in 2008, the dissolved oxygen impairment in Mid Cibolo Creek was removed from the state’s 303(d) list and reclassified in the state’s Water Quality Inventory and List. The dissolved oxygen impairment is assigned to Category 4b, which is the classification for water bodies in which a standard is not met, but for which a TMDL is not required because other control requirements are reasonably expected to result in the attainment of the standards.
- Draft One Total Maximum Daily Load for Dissolved Oxygen in Mid Cibolo Creek, Segment 1913 (PDF)
- Response to Public Comment (PDF)
Final reports from the assessment to determine the extent and severity of the impairment in the stream. (PDF.)
For additional information regarding this project, please call Dania Grundmann at 512-239-6682. Or e-mail us at firstname.lastname@example.org, and reference the Mid Cibolo Creek TMDL in the subject line.