Mission and Aransas Rivers, Tidal Portions: A Project to Protect Recreational Uses
Photo by Texas AgriLife
Watershed Counties: Aransas, Bee, Goliad, Karnes, Refugio, and San Patricio
Parameter: Bacteria
Basin: San Antonio-Nueces Coastal
Segment: 2001, 2003
- Project Overview
- Background and Goals
- Project History
- Get Involved
- Project Reports
- For More Information
Background and Goals
High concentrations of bacteria are often found in the tidal portions of the Mission and Aransas Rivers. High concentrations of bacteria may indicate a health risk to people who swim or wade in the rivers—activities called “contact recreation” in the state’s standards for water quality.
Bacteria are commonly found in the intestines of warm-blooded organisms such as humans, livestock, cats, and dogs. These bacteria in water may indicate the presence of disease-causing microorganisms.
The goal of the project is to reduce bacteria levels to protect people who swim or wade in the rivers. The Texas Water Resources Institute (TWRI) 
is coordinating development of the TMDLs and I-Plan.
Return to topProject History
The state and its partners collected and analyzed extensive amounts of data about the project watersheds from 2004 through 2010. While the TCEQ, the Texas State Soil and Water Conservation Board (TSSWCB), and stakeholders in the watershed evaluated the most appropriate strategy for reducing bacteria concentrations, agricultural producers voluntarily participated in educational activities aimed at better understanding the water quality issues and various methods for reducing the amount of bacteria that can wash off agricultural property and into waterways.
In 2011, stakeholders and the state agencies decided to develop TMDLs and an implementation plan for the watershed. The goal of a TMDL is to determine the amount (or load) of a pollutant that a body of water can receive and still support its designated uses. The allowable load is then allocated among the categories of sources within the watershed. Stakeholders work with the state to develop an implementation plan (I-Plan) with measures that reduce pollutant loads.
Copano Bay, which is identified as having an impaired oyster waters use, was considered in the assessment stage of this project. Designation of the oyster waters impairment is based on a risk assessment by the Department of State Health Services (DSHS). These risk assessments are not based on concentrations of bacteria in the water; rather, they are based on certain risk factors such as the likelihood of high rainfall and runoff or the influx of sewage from failing or inefficient domestic treatment systems.
Concentrations of bacteria in the waters of the bay are within acceptable levels. Consequently, development of a bacteria TMDL for Copano Bay is not necessary, and would not be effective in reducing the risk assessed by the DSHS.
Get Involved
Project staff are informing the public about this project through a series of public meetings. The meetings are open to everyone.
In all its projects, the TCEQ seeks to gather opinion and information from people who represent government, permitted facilities, agriculture, business, environmental, and community and private interests in the watershed. The TWRI is coordinating public participation in this project.
Educational Resources
See the Texas Water Resources Institute website for the Copano Bay Water Quality Education Project , which provides information about educational programs and demonstrations for land and livestock owners. These programs and demonstrations are designed to increase awareness of water quality issues and best management practices for reducing bacteria in stormwater runoff.
Meeting Summaries and Presentations
Meeting summaries and presentations are in PDF.
- 2012 Meetings on the TWRI project website
- December 2007
- June 2006
- Meeting Summary
- Presentation: Introduction to Microorganisms
- Presentation: Nueces River Authority Proposed Copano Bay TMDL Monitoring
- Presentation: Copano Bay Watershed Historical Data Review
- Presentation: Copano Bay Watershed Historical Data Review Part 2
- Presentation: Overview of the Implementation Plan Process for Copano Bay TMDL
- April 2006
- February 2006
- November 2005
Project Reports
For More Information
Please e-mail us at tmdl@tceq.texas.gov, and mention the Copano Bay project in the title. Or call Roger Miranda at 512-239-6682. Or contact the TWRI project manager, Allen Berthold, at 979-845-2028 or taberthold@ag.tamu.edu.
