Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system that is designed to help regional, state, and local agencies perform watershed- and water quality-based studies.  It was developed by the US Environmental Protection Agency to assist in watershed management and Total Maximum Daily Load (TMDL) development by integrating environmental data, analysis tools, and watershed and water quality models.  Because many states and local agencies are moving toward a watershed-based approach, the BASINS system is configured to support environmental and ecological studies in a watershed context. The system is designed to be flexible and can support analysis at a variety of scales by using tools that range from simple to sophisticated.

BASINS comprises a suite of interrelated components for performing the various aspects of environmental analysis. The components include (1) nationally derived databases with tools to build projects, (2) watershed characterization reports that address large- and small-scale characterization needs, (3) utilities to facilitate organizing and evaluating data, (4) tools for watershed delineation, and (5) watershed loading and transport models including Hydrological Simulation Program-Fortran (HSPF).

AQUA TERRA Consultants (a division of RESPEC) has been EPA’s prime contractor for BASINS development since 1998. Find out more  at the official EPA BASINS website:


Clients use BASINS to:

  • Facilitate examining environmental information.
  • Provide an integrated watershed modeling framework.
  • Support the analysis of point- and nonpoint-source management alternatives.
  • Support the development of TMDLs.


Want to Learn BASINS?

Click here to learn more about BASINS/HSPF training workshops

Morrisville, North Carolina
April 16 – April 20, 2018