Ecological Services
Northeast Region
National Wetlands Inventory

About the National Wetlands Inventory Program

The National Wetlands Inventory Program was established in 1974 to develop a nationwide inventory of wetlands to provide Service biologists and others with information on the distribution of wetlands to aid in conservation efforts. Many partners, from agencies to tribes and nonprofit organizations, have helped NWI by providing funding, conducting surveys, or reviewing or distributing data.

The Service uses a wetland classification system and specific techniques for mapping and recording the inventory findings. Trained photo interpreters (image analysts) interpret wetlands and deepwater habitats from habitats from aerial photography or digital aerial imagery. These federal standards are applied to all federal grants involving wetland mapping, so mapping by states and others can be added to the NWI's wetlands master geospatial database.

NWI produces two main products:

  1. wetlands master geospatial database that can be used to generate maps and statistics about the status of the Nation’s wetlands, and
  2. the national wetlands status and trends reports derived from data collected from four-square mile plots.

In addition to these products, regions may produce wetland status and special reports based on regional NWI activities.

Data are available through the Wetlands Mapper tool, on Google Earth or USGS National Map Viewer. GIS users can also connect their application to real-time data directly through an online wetland mapping service or download NWI data for their own maps, data analyses and reports. Reports can be found on the NWI website through the search engine and at the Service’s Conservation Library. Regional reports for the Northeast can be found at the website you are viewing.

To meet the needs of our partners, NWI has developed a few other products. These products include riparian habitat classification and mapping, enhanced NWI mapping, landscape-level wetland functional assessments, potential wetland restoration site inventories, and natural habitat integrity indices for use in watershed condition assessments.

For an in-depth overview of the program, download this PDF.

Back to the NWI Homepage.

Last updated: July 20, 2015