Technical Bulletin No. 0744: An Overview of EPA's Watershed Model BASINS and Related Federal Spatial Data Products

The watershed is quickly replacing rivers or estuaries as the focus of EPA and state water quality assessment and permitting. This activity is impacted by the need to develop Total Maximum Daily Loads (TMDLs) for water bodies not meeting water quality standards after the imposition of technology-based effluent limitations. The BASINS model is offered by EPA to assist states in the modeling and assessment of point and nonpoint source impacts on water quality.