The BASINS Watershed Analysis System — Evolving to Embrace New Data and Techniques

EPA's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed for use by regional, state, and local agencies performing watershed and water quality-based studies. This system makes it possible to quickly assess large amounts of data in a format that is easy to use and understand. BASINS allows the user to assess water quality at selected stream sites or throughout an entire watershed. This invaluable tool integrates environmental data, analytical tools, and modeling programs to support development of cost-effective approaches to watershed management and environmental protection. All versions of BASINS to date contain a suite of GIS-based tools and operate in a GIS environment, using the GIS interface as the front end of the user interface. With each new version of BASINS additional data types have been added to the system. In addition, the analytical tools and techniques in BASINS themselves are continually evolving. The design of the watershed analysis system must support the addition of new data and new techniques for analyzing that data. BASINS is designed around an extensible architecture that allows for the addition of new data types and new tools. This design has proven effective during the development of versions 3.1 and 4.0. The National Elevation Dataset (NED) and National Hydrography Dataset (NHD) are examples of data types recently added for version 3.1. Currently additional data are being added from the U.S. Census of Population and the U.S. Census of Agriculture. New analytical tools have also been added, such as USDA-ARS's Automated Geospatial Watershed Assessment (AGWA). The core BASINS software does not have to be enhanced to support any of these new data types or tools. This flexibility enables BASINS to continue evolving to meet the changing needs of the watershed management community.