A Guide to Understanding National Wetlands Inventory Mapping Codes

In 1979, the U.S. Fish and Wildlife Service adopted "Classification of Wetlands and Deepwater Habitats of the United States." by Cowardin et al. as the agency's official wetland classification system. The National Wetlands Inventory (NWI) is congressionally mandated to map wetlands of the United States and uses the Cowardin system to meet this mandate.

Program
Large pool of water surrounded by low tundra grasses under cloud covered sky.
The U.S. Fish and Wildlife Service is the principal federal agency tasked with providing information to the public on the extent and status of the nation’s wetland and deepwater habitats, as well as changes to these habitats over time.
Ecosystem
Subject tags
Wetlands