The Attoyac Bayou is a sub-watershed within the Upper Neches River Watershed extending approximately 82 miles through Rusk, Nacogdoches, San Augustine, and Shelby Counties before emptying into Sam Rayburn Reservoir. Several rural communities can be found throughout the area, with the majority of the lands in the watershed being used for cattle and poultry operations, forestry or recreational/wildlife uses.
The Attoyac Bayou is one of many rural watersheds listed as an impaired water body on the Texas Water Quality Inventory and 303(D) List due to high levels of E. coli bacteria. Three monitoring stations managed by the Angelina-Neches River Authority (ANRA), the US Geological Survey (USGS), and Texas Commission on Environmental Quality (TCEQ) have been providing water quality data on the bayou for a number of years. E. coli data were first collected beginning in 2000 and has consistently resulted in elevated E. coli levels that exceed the applicable Texas Water Quality Standards.
Studies done on the Sam Rayburn Reservoir watershed and nearby forest operations in order to understand bacteria and nutrient loading in the area seem to justify the Attoyac's impairment listing, but the limited flow data on file make it difficult to calculate loading rates and identify sources of contamination for E. coli. Collecting additional water quality and streamflow data will help to develop a better understanding of E. coli loadings in the waterbody and input from local stakeholders will further facilitate the accurate identification of E. coli sources in the watershed and enable the development of an effective watershed protection plan.