Houston Metropolitan Area

About the TMDL Project

The TMDL document for the Greens Bayou Watershed was adopted by the TCEQ on June 2, 2010, and approved by the EPA on August 12, 2010. The TMDL documents for the Brays Bayou Watershed, Sims Bayou Watershed, Halls Bayou Watershed, and Eastern Houston Watersheds were adopted by the TCEQ on September 15, 2010, and approved by the EPA on September 27, 2010.

The Texas Commission on Environmental Quality had determined that several watersheds within the Houston Metropolitan Area sometimes have bacteria levels that are higher than state standards for contact recreation. The State of Texas requires that water quality in the Lake Houston watershed be suitable for swimming, wading, fishing, and aquatic life. Swimming and wading is called contact recreation in the state’s standards for water quality, referring to all recreation in which people come in direct contact with the water. People who swim or wade in the bayous may be at risk because of high level of bacteria. Bacteria from human and animal waste often indicate the presence of disease-causing microorganisms, which pose a threat to public health.

In response to the elevated bacteria levels in the bayous, the TCEQ initiated a total maximum daily load (TMDL) project to determine the measures necessary to support recreational uses in these water bodies. 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 load is then allocated among all the potential sources of pollution within the watershed, and measures to reduce pollutant loads are developed as necessary.