Highland Bayou and Marchand Bayou Special Study

In 2002, the TCEQ determined that both Highland and Marchand bayous didn't meet designated water quality standards for DO and bacteria and were placed on the 303 (d) List of Impaired Waters in the State of Texas. Currently, both water bodies are cited in the Integrated Report as being impaired for both parameters. In 2006, H-GAC teamed up with the U.S. Geological Survey (USGS) and the TCEQ to conduct systematic data collection on Highland and Marchand Bayous. Data describing physical, chemical, and biological characteristics was collected to determine if a DO problem existed in the bayous and, if so, how often the DO problem occured. Another project goal was to identify the distribution and frequency of the bacterial contamination in these bayous. The goal of this study was to generate a set of chemical and biological water-quality data, not to change the water quality standards. Water quality data was compared to State screening levels for selected parameters. Data collection began in the summer of 2006 and was completed in August 2007. The final report was released in 2008.

The Highland Bayou watershed is located in southeast Galveston County and has a drainage area of 34.8 square miles. With headwaters located near the town of Santa Fe, TX, Highland Bayou extends approximately 12.6 miles to the southeast and drains into Jones Bay which empties into West Bay (Segment 2424). The watershed contains rural areas as well as highly-developed subdivisions and municipalities. Currently, the cities of La Marque and Hitchcock are the major urbanized communities in the watershed; however, urban density is increasing. Marchand Bayou is a smaller water body that drains into Highland Bayou near the middle of its course and shares similar land use characteristics with Highland Bayou.

The 24-hr DO measurements collected during the study confirmed DO problems occurred at all locations. Bacteria results commonly exceeded the State standard for contact recreation but the frequency and distribution revealed no discernible pattern to identify the cause. The habitat, macrobenthic community, and fish community data was found to be similar to other tidal streams and was submitted to TCEQ to help develop assessment methodologies for coastal waters and estuaries.

While several intolerant species were collected throughout the bayous, one tolerant species also was caught in the lower reaches where the water quality was better.

See the full study here.  (PDF 1.70MB)

Report Contents