National Wetlands Inventory

The National Wetlands Inventory (NWI) provides users with scientifically-based information on wetlands and deepwater habitats to promote the understanding and conservation of the Nation’s wetland resources through research, education, resource management and policy development.

The NWI Wetlands Data Layer provides users with scientifically-based information on wetlands and deepwater habitats to promote the understanding and conservation of the Nation’s wetland resources.

Recognizing the importance of America’s wetlands, Congress enacted the Emergency Wetlands Resources Act (Public Law 99-645) of 1986. It requires the U.S. Fish and Wildlife Service (Service) to map wetlands in the United States, as well as conduct national status and trends studies and report to...

The Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al. 1979) was developed to support a detailed inventory and periodic monitoring of the Nation’s wet habitats using remote sensing. It became a National Standard in 1996 (FGDC-STD-004), but has been the de...

This document provides the wetlands and deepwater classification hierarchy table. For assistance, please call 703-358-2171.