The NWI+ Web Mapper is an online mapping tool that allows users to view special project data prepared by the NWI not available through the Fish and Wildlife Service’s “Wetlands Mapper.”  The data were prepared for special projects and are not a standard NWI product.  In addition to viewing NWI types for these areas, a number of other data layers are available.  These layers may show wetlands classified by hydrogeomorphic properties (landscape position, landform, and water flow path = LLWW descriptors), areas that may support wetlands based on soil mapping (hydric soils lacking a recognizable wetland photo-signature), wetlands that have been predicted to be important for providing numerous functions, and potential wetland restoration sites.

Attention: All data layers posted on the mapper are not available for all project areas.  See the available layers for each project by clicking here.

Viewing NWI+ and Other Data Using ESRI ArcGIS Online

This web application is not completely intuitive, so we’ll walk you through the process. When you open the web mapper, data will be loaded and in a few moments, you’ll see a map of the United States with red boxes indicating where NWI+ data are available. Click on one of the outlined area and then zoom in to your area of interest. The default data that will be viewed should be wetlands classified by landscape position (NWI+ Landscape). Click on the “Map Contents” icon on the tool bar to view the available data layers. The tool bar contains a number of icons.  The “Intro to the Mapper” provides a summary of what these icons represent and a general description of the available data layers. When the contents are opened, to activate any layer simply click on the applicable box, then click on the name of the layer (e.g., NWI+ Landscape).  Since most data layers should be viewed individually be sure to click off other data layers as the mapper will show the uppermost layer. To view the legend use the “Show Legend Tool” and a list of all the legends will appear; open the one of interest by clicking on the symbol preceding the layer name.  This process will take a little getting used to but after a couple of uses, you should have the procedure mastered.

Once you have opened the mapper, you’ll see icons on the tool bar above the map plus a list of five topics: “Intro to the Mapper” (a must-read description of mapper contents and operation), “Wetlands One-Stop” (takes you to the page where other sources of wetland information can be accessed), “NWI” (takes you to the NWI website), “Northeast NWI” (takes you to the home page of the Northeast Region’s NWI Program), NWI Legend (opens an NWI classification legend), NWI+ Codes (opens the LLWW classification document that contains map codes), NWI+ Reports (takes you to a list of available reports), and “CMI” (takes you to the home page of Virginia Tech’s Conservation Management Institute).

It is important to recognize that the NWI+ data posted are preliminary and have not been verified through field investigations.  All project areas have had at least some desktop review of their LLWW classification, yet only three areas have had the results for functions similarly reviewed: Delaware, Long Island (NY), and Connecticut.  The predicted functions for other areas were based on the correlations used in Connecticut and should be considered a first approximation.  Their functions may be reviewed on-screen at a later date if time permits.  In the meantime, if questions arise regarding these findings, please contact Ralph Tiner (FWS-retired) at .