EPA's basins model: Good science or serendipitous modeling?

Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) i s a geographic-based watershed assessment tool developed by EPA's Office of Water to help states more efficiently target and evaluate water-bodies tha t are not meeting water quality standards. BASINS (EPA, 1996a, 1998) brings together data on water quality and quantity, land uses, point source loadi ngs, and other related spatial data with supporting nonpoint and water qual ity models at a quicker and more effective pace. EPA developed BASINS, to b etter integrate point and nonpoint source water quality assessments for the Nation's 2100+ watersheds. In its zeal to achieve this endpoint, EPA has i nitiated a simplistic approach that was expected to grow through scientific enhancements as TMDL developers become more familiar with modeling require ments. BASINS builds upon federal databases of water quality conditions and point source loadings for numerous parameters where quality assurance is s uspect in some cases. Its design allows comprehensive assessments and model ing in typical Total Maximum Daily Load (TMDL) computations. While the TMDL utility is the primary reason BASINS was developed, other longer-range wat er quality assessments will become possible as the Agency expands the suite of assessment models and databases in future releases. The simplistic appr oach to modeling and user-friendly tools gives rise, however, to technical and philosophical concerns related to default data usage. Seamless generati on of model input files and the failure of some utilities to work properly suggest to NCASI that serious problems may still exist and prompts the need for a more rigorous peer-review. Furthermore, sustainable training becomes paramount, as some older modelers will be unfamiliar with Geographic Infor mation System (GIS) technology and associated computer skills. Overall, how ever, BASINS was judged to be an excellent beginning tool to meet the compl ex environmental modeling needs in the 21st Century.