The Copano Bay watershed covers approximately 1.4 million acres encompassing portions of Karnes, Bee, Goliad, Refugio, San Patricio and Aransas counties. Copano Bay and its main tributaries, the Mission and Aransas rivers, were placed on the Texas Commission on Environmental Quality (TCEQ) 303(d) list in 1998 due to levels of bacteria that exceed water quality standards established to protect oyster waters use. A Total Maximum Daily Load (TMDL) program was initiated in September 2003 to identify and assess sources of these bacteria. The Center for Research in Water Resources at the University of Texas at Austin (UT CRWR) was funded by TCEQ to conduct computer-based modeling to determine the bacterial loading and reductions necessary to attain water quality standards. Subsequently Texas A&M University-Corpus Christi (TAMU-CC) conducted bacterial source tracking (BST) with funding from Texas General Land Office (TGLO) and the Coastal Bend Bays and Estuaries Program (CBBEP) to determine actual sources of bacteria.