NOAA Office for Coastal Management


This open-source version of the Nonpoint Source Pollution and Erosion Comparison Tool is used to investigate potential water quality impacts from climate change and development to other land uses. The downloadable tool is designed to be broadly applicable for coastal and noncoastal areas alike. Tool functions simulate erosion, pollution, and the accumulation from overland flow.

Requires MapWindow GIS v.4.8.8 (open source software)

Previous Versions: N-SPECT for ArcGIS 9.3, 9.2, 9.0 and 9.1


  • Obtain estimates and maps of surface water runoff volumes, pollutant loads, pollutant concentrations, and total sediment loads
  • Identify areas that might benefit from changes to proposed development strategies
  • Process digital elevation data quickly and easily
  • Analyze land use change scenarios

Additional Information

Tool Screenshots

Tell us how you use this resource.

Help us build better tools and services by sharing your story with us.