Skip to Content
Questions or Comments:

Cotton Bayou Tidal

This is a project to reduce bacteria and protect recreational safety in Cotton Bayou Tidal. The stakeholders and TCEQ are developing a total maximum daily load (TMDL) and implementation plan (I-Plan), which together will be the road map for improving water quality.

photo of cotton bayou
Cotton Bayou in Mont Belvieu
at Wilburn Ranch Drive

Photo Courtesy of the
Houston-Galveston Area Council
map of the Cotton Bayou watershed

County: Chambers
Parameter: Bacteria
Basin: Trinity River
Segment: 0801C
Assessment Unit (AU): 0801C_01

On this page:

Background and Goals

Since 2010, high concentrations of bacteria, which are found in both human and animal waste, have been observed in Cotton Bayou. The presence of these bacteria may indicate a health risk to people who swim or wade in the bayou, activities referred to as “contact recreation” in the Texas Surface Water Quality Standards.

The goal of this project is to improve water quality in order to protect recreational uses. Toward that goal, TCEQ and stakeholders are developing a TMDL — the maximum pollutant load a water body can receive that allows the water body to meet water quality standards — and an I-Plan, to reduce bacteria in Cotton Bayou.

Watershed Description

Cotton Bayou Tidal, Segment 0801C, has one assessment unit (AU), 0801C_01. Cotton Bayou Tidal is located near the western boundary of Chambers County, near the Texas Coast, and has a watershed area of 16.5 square miles. The headwaters of Cotton Bayou start north of the city of Mont Belvieu. From there, the bayou flows southeast to Cotton Lake, which drains into Trinity Bay. Hackberry Gully is the principal tributary to Cotton Bayou, and enters the bayou from the west.

Though a great portion of the Cotton Bayou Tidal watershed is either undeveloped grassland, forest, shrub, or land cultivated for agriculture, the Mont Belvieu community, as well as expanding areas of urban sprawl, are more developed. Interstate Highway 10 runs through the watershed from east to west.

Get Involved

Staff from the Houston-Galveston Area Council (H-GAC) have been working with communities, interest groups, and local organizations to distribute information about this project and involve stakeholders in developing plans for watershed improvement. All public meetings about this project are open to anyone interested.

The period for public comment on Draft TMDL for Cotton Bayou Tidal ended Nov. 30, 2023. Responses to comments received will be posted in May 2024.


H-GAC staff completed a draft technical report in 2022 that compiled and analyzed all available bacteria data and considered sources of the bacteria and their relative contributions.

Contact the TMDL Program

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

Back to the top of the page Back to top

communities working together taking care of our rivers, lakes, and bays