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Chocolate Bay Watershed

This is a project to reduce bacteria and protect recreational safety in the Chocolate Bay watershed. The stakeholders and TCEQ developed nine total maximum daily loads for waterbodies within the watershed and a regional implementation plan, which together are the road map for improving water quality.

map of Chocolate Bay Watershed
Chocolate Bay Map (click to enlarge)

County: Brazoria, Fort Bend, and Galveston
Parameter: Bacteria
River Basin: Bays and Estuaries, San Jacinto-Brazos Coastal
Segments: 1107, 1108, 2432A, 2432B, 2432C, 2432D, and 2432E
Assessment Unit(s): 1107_01, 1108_01, 2432A_01, 2432A_02, 2432A_03, 2432B_01, 2432C_01, 2432D_01, and 2432E_01

On this page:

Background and Goal

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

The goal of this project is to reduce bacteria so the public can safely enjoy recreational activities in these waters. To achieve this, TCEQ and stakeholders have developed total maximum daily loads (TMDLs) for bacteria in these watersheds:

Stakeholders have also developed a regional implementation plan (I-Plan) to reduce bacteria in these watersheds, which collectively form the larger Chocolate Bay watershed.

Watershed Description

The Chocolate Bay watershed is approximately 313 square miles, mostly in eastern Brazoria County, with a portion in Fort Bend County. Three main tributaries flow southeast through the region: Chocolate Bayou, Mustang Bayou, and Halls Bayou. The main communities include: Algoa, Alvin, Arcola, Fresno, Hillcrest, Iowa Colony, Liverpool, Manvel, Missouri City, and Pearland. Some lie entirely within the watershed while others include only portions of their boundaries.

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 watershed improvement activities. All public meetings about this project are open to anyone interested. Watch for meeting announcements here. See meeting records in the "Get Involved" section of the H-GAC's webpage San Jacinto-Brazos Coastal Basin Bacteria Reduction Project .

Chocolate Bay stakeholder meeting

The watershed stakeholder group will discuss any work done in relation to the Chocolate Bay I-Plan. During this meeting, we will discuss measures the community is taking to reduce fecal sources of bacteria to help the Chocolate Bay watershed meet water quality standards.
  • Chocolate Bay stakeholder meeting
  • 2026-08-26T16:30:00-05:00
  • 2026-08-26T18:30:00-05:00
  • The watershed stakeholder group will discuss any work done in relation to the Chocolate Bay Implementation Plan. During this meeting, we will discuss measures the community is taking to reduce fecal sources of bacteria to help Chocolate Bay meet water quality standards.

Wednesday, Aug. 26, 2026
4:30 – 06:30 p.m.

Approved I-Plan

Community stakeholders worked together to create the I-Plan. The Commission approved the stakeholders' plan on August 12, 2026.

Adopted TMDLs

The US Environmental Protection Agency (EPA) has approved all TMDLs, at which point they became an update to the state’s Water Quality Management Plan.

Reports

H-GAC staff completed technical reports for each watershed that compiled and analyzed all available bacteria data and considered sources of the bacteria and their relative contributions.

Contact Us

Please e-mail tmdl@tceq.texas.gov and reference the Chocolate Bay TMDL in the subject line. Or call us at 512-239-6682.

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