Information Resources and Technology Management


You are invited to read the definitions of terms used in this data standard.

Classification of Wetlands and Deepwater Habitats of the United States

The Service's definition and classification system provides standardization of concepts and terms used to describe the biological limit of wetland types found in the United States, and is used nationwide by many Federal, State, and local agencies as part of the management of their wetland resources.

The FGDC Steering Committee endorsed the revision of the Wetlands Classification Standard in summer 2013. The revised FGDC Wetlands Classification Standard has been formatted to be consistent with more recently endorsed FGDC Standards. The text has been edited, refined, clarified, and rewritten as necessary. Some portions were rewritten because the scientific foundation upon which the original classification (Cowardin et al. 1979) was developed has advanced. Changes were thoroughly vetted in the wetlands community.   The most recent Wetlands Classification Standard is available here - 

The previous Wetlands Classification Standard is available here -

NOTE: The FGDC endorsed the Wetlands Mapping Standard in July 2009. The purpose of this standard is to support accurate mapping and classification of wetlands, while ensuring mechanisms for their revisions and update as directed under OMB Circular A-16, Revised. It is designed to direct the current and future digital mapping of wetlands. This mapping standard will be used for all wetland mapping nationally including Federal Agencies, States, Tribes, especially if that mapping data will be uploaded into NWI/The National Map as a data layer. Specifically, if Federal funding is involved, then use of the proposed Standard is required. For all other efforts, use of the standard is strongly encouraged. More information about the Wetlands Mapping Standard is available here - FGDC Wetland Mapping Standard.

Historical Data For information on past versions of this standard, contact the Chief Data Officer

Part 270, FW 6, Data Management and Standards, has been superceded by Part 274, FW 2, Establishing Service Data Standards.

Part 660, FW 2, Wetlands Classification System.

Federal Geographic Data Committee Formally Adopts Wetlands Classification Standard, December 17, 1996.

Adoption of the Federal Standard for Wetlands Classification, August 4, 1997.

Use Instructions
Service personnel will use the Service's wetlands definition and classification system to describe wetland resources.
FWS Created & Adopted
Approval Date
September 15, 1980
Validation Date
September 4, 2015
Data Steward
Mitch Bergeson, Division of Ecological Services, Branch of Geospatial Mapping and Technical Support


Last updated: May 9, 2019