What Is the National Wetlands Inventory?

In 1974, the U.S. Fish and Wildlife Service (USFWS) established a nationwide inventory of wetlands (National Wetlands Inventory [NWI]) with the intention to provide information on the distribution and type of wetlands that can be found in the U.S. This inventory of wetlands can be used by federal, state and local governments, private industry, and non-profit organizations as baseline information for wetland regulation and management decisions, land use and conservation planning, environmental impact assessments, and natural resource inventories. Along with the NWI providing insight for decision-making, this data is also available to the public and can be accessed nation-wide through the National Map.

New Mexico NWI

GSS has completed approximately 18.6 million acres of wetland and riparian area mapping throughout New Mexico. In collaboration with the New Mexico Environment Department, wetlands have been delineated and classified using the NWI (Cowardin et al. 1979) and Landscape Position, Landform, Water Flow Path, Waterbody Type (LLWW) (Tiner 2011) classification systems. Together, these two data sets (NWI and LLWW) create a database called NWIPlus that could be used to inform New Mexico resource experts and the public on New Mexico’s wetland ecosytems.

Minnesota NWI

Because the most recent wetland mapping for Minnesota was from the early to mid-1980s, the Minnesota DNR took the lead in coordinating an update throughout the state. GSS was one of the partners that collaborated with the Minnesota DNR in creating, classifying, and ultimately updating the Minnesota NWI.

From 2012 to 2015, Saint Mary's University of Minnesota completed wetland updates in the Southern Minnesota region. In September 2016, the University was selected to undertake updating the 19-county Northwest Minnesota region. This two-year project not only utilized the technical and problem-solving skills of our full-time staff, but also fostered practical work experience for the SMUMN students involved in the project, as they created much of the new wetland data.

 Bureau of Land Management (BLM) -Western States & Alaska NWI

West-wide Wetland and Riparian Area Mapping

GSS has been collaborating with The Bureau of Land Management (BLM) for the past 5 years to create a comprehensive wetland and riparian inventory that captures the extent and status of these ecosystems across BLM-administered lands and more in the Western U.S.

This inventory will provide a basis for understanding the health of wetland and riparian ecosystems. In addition, this effort will inform the investigation of wetland status, condition, and trends across much of the U.S.

Current work is in eight western states and Alaska. GSS mapping in the west spans areas of significant BLM lands as well as all other lands in a given project area. Work in Alaska exceeds 27 million acres for the BLM (GSS has additional projects in AK, not listed here).

In addition to NWI and riparian mapping in these projects, GSS is applying LLWW for Inland Wetlands and Western United States codes (ver. 4) as well as HGM and deriving wetlands functions for all mapping.

Selawik, Alaska NWI

The NWI Program has identified the completion of wetland mapping for Alaska Refuge lands as a priority focus area.  In particular, coastal wildlife refuges that are susceptible to landscape change and habitat degradation due to the effects of increased storm surges, thermokarst activity and sea level rise represent important baseline wetland inventory opportunities. The Selawik National Wildlife Refuge, which straddles the Arctic Circle and several distinct ecoregions and constitutes 3.2 million acres of northwestern Alaska, represents a prime opportunity for the testing, refinement and implementation of new fine-scale wetland inventory mapping protocols developed through previous cooperative agreements between the USFWS and GSS. Refuge land managers also need up to date hydrography data to make informed decisions about the changing landscapes so the updating of the National Hydrography Dataset will be conducted at the same time as the wetland updates.   

Baseline wetland and hydrographic data will provide required information in support of landscape change assessment and wetland habitat modeling activities. The completed wetland and hydrography datasets will be used in collaboration to investigate wetland functions across the Selawik Refuge.  In response to Environmental Protection Agency guidance on the Application of Elements of a State Water Monitoring and Assessment Program for Wetlands (EPA, 2006), Saint Mary’s University of Minnesota and various partners have been working on developing and refining applied science techniques for landscape-level wetland functional assessment.