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Gilleland Creek

This is a current project to keep recreation safe in Gilleland Creek by reducing bacteria levels. The adopted total maximum daily load (TMDL) and the approved implementation plan (I-Plan) are the road map to improving water quality in the creek.
photo of a volunteer collecting data in the Gilleland Creek watershed
A volunteer collecting data in the Gilleland Creek watershed

Watershed County: Travis
Parameter: Bacteria
River Basin: Colorado
Segment: 1428C

On this page:

Overview and Goal

Water quality testing found that bacteria concentrations are elevated in Gilleland Creek, located in northeastern Travis County. High bacteria concentrations might pose a risk to people who swim or wade in the creek - activities referred to as “contact recreation” in the state’s water quality standards.

In response, TCEQ developed a TMDL to determine the amount—or load—of a pollutant that a body of water can receive and still sup-port its designated uses. The allowable load was then allocated among categories of sources within the watershed. Stakeholders also developed an I-Plan with measures that aim to reduce pollutant loads. In 2016, stakeholders revised the I-Plan with adjustments needed to continue water quality improvements in the watershed.

The goal of this project is to reduce bacteria concentrations to within acceptable risk levels for contact recreation.

Watershed description

Gilleland Creek is located in central Texas, where its watershed flows through about 76 square miles flowing through Travis County. Land use in the watershed is transitioning from agricultural to urban. The results of urbanization are most evident during dry weather, when the water in Gilleland Creek is dominated by wastewater effluent from the municipal wastewater treatment facilities (WWTFs) in the watershed. The watershed includes the City of Pflugerville, a small portion of the City of Round Rock, and portions of the cities of Manor and Austin. Gilleland Creek has four assessment units (AUs), numbered from one through four, from the most upstream to the most downstream portions.

Watershed Photos

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Get Involved

The TCEQ worked with a stakeholder group coordinated by the Lower Colorado River Authority to develop the TMDL and original I-Plan. In 2017, stakeholders revised the I-Plan, with facilitation from the Center for Public Policy Dispute at the University of Texas School of Law. Find out more about what it means to participate in TMDL projects


The organizations listed below are partners in improving the water quality in Gilleland Creek.
All of the links in this section exit the TCEQ website.

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Status and Activities

The TCEQ coordinates regular meetings with stakeholders to assess their progress implementing their I-Plan and discuss changes in the watershed. If water quality goals have not been met by the time a plan is completed, stakeholders may choose to form a new committee to develop a revised plan covering another five-year term. The stakeholders' welcome comments on the current I-Plan at any time; email comments to with "Gilleland Creek" in the subject line.


In 2013, the Austin City Council passed a comprehensive overhaul of the city's Watershed Protection Ordinance . At the core of the ordinance were three interrelated changes: better stream buffers, improved floodplain protections, and new erosion hazard provisions. The ordinance extended creek buffers—setbacks to ensure that development is not built too close to waterways—for over 400 miles of smaller “headwaters” streams.

On August 14, 2012, the Travis County Commissioners’ Court approved requirements to establish stream setbacks applicable to development in all unincorporated areas of the watershed.

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Approved I-Plans

TMDL I-Plans are developed by watershed stakeholders, usually for five-year terms. Stakeholders meet regularly throughout implementation of the plan to review their progress. 

Revised I-Plan, 2017

Stakeholders developed a revised I-Plan for activities for 2018 through 2022 and submitted it to TCEQ on November 16, 2017.

Original I-Plan 2011

The Commission approved the original I-Plan on February 9, 2011.

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Adopted TMDL

The Commission adopted this TMDL on August 8, 2007. EPA approved it on April 21, 2009, at which time it became part of the state’s Water Quality Management Plan.

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Updates to TMDLs

From time to time, it is necessary to revise TMDLs to account for changing conditions in the watershed, such as new or amended permits, or urban growth, or to correct oversights in the original TMDL report. Revisions to the load allocations in TMDLs are made via the state’s WQMP, which is updated quarterly.

The WQMP provides projected effluent limits for use in planning and permitting activities under the Texas Pollutant Discharge Elimination System (TPDES). The TCEQ reviews all applications for new and amended permits for conformance with applicable portions of the WQMP, including adopted TMDLs.

Learn more about WQMP updates and about opportunities to comment on revisions to them.


  • July 2019, Appendix II, pages 15-16
  • July 2011, Appendix II, page 13
  • October 2009, Appendix I, page 13
  • April 2009, Appendix II, pages 16-17
  • January 2008, pages 12-13

WQMP updates may be viewed in person at the TCEQ Library, Building A, 12100 Park 35 Circle, Austin, Texas. Electronic versions of updates published from 2014 through the present are available on the Texas State Library and Archives Commission website .

For WQMP updates prior to 2014, use the TRAIL Search  engine as outlined below. The main search box on the page will only conduct a simple search with no exclusionary parameters and should not be used.

  1. First, limit your search to TCEQ only. Do this via the advanced search feature on the left of the page. To limit a search to TCEQ content, enter "" or "" into the “From the Host” search box.
  2. Refine your search to narrow down results. The other search boxes on the left of the page allow for search terms to be included, excluded, or used in an exact phrase search. Date ranges can be used as well.

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Contact the TMDL Program

Please email, and mention the Gilleland Creek bacteria project in the subject line. Or call us at 512-239-6682.

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Communities Working Together