National Wetlands Inventory
Ecological Services
USFWS Madison Wetland Management District, South Dakota

Credit: USFWS Madison Wetland Management District, South Dakota

Horicon National Wildlife Refuge.
Horicon National Wildlife Refuge. Credit: USFWS


Wetlands provide a multitude of ecological, economic and social benefits. They provide habitat for fish, wildlife and plants - many of which have a commercial or recreational value - recharge groundwater, reduce flooding, provide clean drinking water, regulate our climate, offer food and fiber, and support cultural and recreational activities. Unfortunately, over half of America’s wetlands have been lost since 1780, and wetland losses continue today. This highlights the urgent need for geospatial information on wetland extent, type, and change.

The National Wetlands Inventory

The US Fish and Wildlife Service (FWS) is the principal US Federal agency tasked with providing information to the public on the status and trends of our Nation's wetlands. The US FWS National Wetlands Inventory (NWI) is a publically available resource that provides detailed information on the abundance, characteristics, and distribution of US wetlands. NWI data are used by natural resource managers, within the US FWS and throughout the Nation, to promote the understanding, conservation and restoration of wetlands.

Wetlands Mapper

Wetlands Mapper iconThe Wetlands Mapper delivers an easy-to-use map-like view of America’s wetland resources. It spatially integrates NWI data with additional natural resource information and political boundaries to produce a robust decision support tool.

Status and Trends

Status and Trends report cover page iconStatus and Trends reports provide estimates of US wetland extent, type, and change specific to different time periods, ranging from the 1700’s to 2009. Reports are currently being produced on a decadal basis. The reports educate policy-makers and the public on the status of the Nation's wetlands and potential causes of wetland change.

Latest News and Reports (Archive News)

Wetlands Mapper with new data icon New Data added to the Wetlands Mapper - May 1, 2017

New data have been added to the Wetlands Mapper for over 9 million acres of the U.S. These updates include various areas within the lower 48 states and Alaska. To view these updates, please visit our Wetlands Mapper webpage.
SWI Process image icon New: National Wetlands Inventory Version 2.0 – May 2016

Version 2.0 of the National Wetlands Inventory provides more inclusive geospatial data of all wetlands and surface water features. This national geospatial data product will contribute substantially to improved modeling of flow and water movement in surface water basins, channels, and wetlands. For more information visit the Wetlands Product Summary web page.
Mobile Mapper image icon Wetlands Mapper now accessible on Mobile Devices - November 2015

A new version of the Wetlands Mapper has been developed to run on mobile devices. When accessing the Wetlands Mapper from a mobile device, the user will now be automatically directed to this new mobile friendly version. Use your mobile device to access the new version of our Wetlands Mapper.
Water Restrictions Code table image Updated Data Collection Procedures

The Data Collection Requirements and Procedures document has been updated to include digital mapping conventions related to Cowardin 2.0 (adopted by the FGDC in 2013), instructions on the NWI QA/QC Tool for Arc 10.x, the NWI Map Code Diagram and the NWI Water Regime Restriction Table sorted by sub-class. To download the updated document click here.
Watersheds map icon Watershed Downloads Now Available

'Download by Watershed' capability is now implemented in the Wetlands Mapper. By using the Tools menu, users can interactively select HUC8 Watersheds to download wetlands and wetlands related layers for that area. For more information visit our data download page at:
Last updated: May 10, 2017