Wetlands and Riparian Areas
- Category: Water
- Data Type: GIS Data Layer
- Steward(s): Utah Geological Survey, Utah Department of Natural Resources; U.S. Fish and Wildlife Service
- Abstract: Wetland and riparian location and classification polygon map data from the U.S. Fish and Wildlife Service’s National Wetlands Inventory (NWI) and additional project-specific information.
Wetlands and Riparian Data
The U.S. Fish and Wildlife Service’s (USFWS) National Wetlands Inventory (NWI) program maintains a dataset depicting wetland and waterbody features across the United States. All features in the NWI dataset are described according to the Cowardin Classification System which uses coded values to describe vegetation communities, water, and disturbances present at each feature; codes can be interpreted online. Much of the original NWI dataset in Utah was mapped using imagery from the 1980s and may no longer accurately reflect current wetland locations. Several organizations, including the Utah Geological Survey, are actively conducting new mapping projects that update the NWI dataset for parts of the state.
Newer mapping projects also map riparian areas, which are non-wetland areas along streams, rivers, and lakes that have distinct or distinctly more vigorous vegetation compared to adjacent upland areas. Riparian features are mapped alongside wetland features following the USFWS’s A System For Mapping Riparian Areas in the United States.
Metadata are a description of individual wetland and riparian mapping projects, including the scale at which mapping was conducted and the imagery year used for the mapping. Most mapping projects include a supplemental report describing who completed the project, mapping methods, and types of features captured. Unlike wetlands mapping, which is available statewide, riparian mapping is only available for certain projects that are depicted by the riparian metadata polygons.
Wetlands and riparian features are mapped using a combination of aerial imagery examination and on-the-ground assessment. NWI mapping may serve as an initial screen of likely wetland locations, but is not suited or intended to replace field-based wetland delineations necessary for the permitting process.
Downloads and Web Services
- USFWS typically update the NWI data twice per year. The location of recent and ongoing mapping projects can be found in the NWI Projects Mapper.