The New York City Department of Environmental Protection uses NWI maps and trends data to protect wetlands important for maintaining high water quality for New York City's 8.3 million residents and 40+ million visitors. Data are used to develop research studies evaluating water quality and the impacts of local development on this resource and in reporting to EPA on the status of wetlands. By protecting wetlands and their role in water quality renovation, NYCDEP is able to avoid the costs of filtration of reservoir waters in the Catskill/Delaware water supply, saving the City billions of dollars.

For nearly two decades, Vermont has used NWI maps to produce state maps showing wetlands of significance that received increased protection through the Vermont Wetland Rules. A Conditional Use Determination can only be issued if it is determined that the use will have no undue adverse impact on protected functions, unless such impacts are mitigated.

Unless replaced by more current wetland data from state or local agencies, NWI maps and data serve as the main guide for local governments across the region. Maine Department of Environmental Protection staff use the NWI maps regularly to identify and characterize sites for biological monitoring, to provide information for license and permit reviews, and for enforcement issues.

The Service's New Jersey Field Office used NWI data and expertise to develop a conservation strategy for protecting and restoring the Hackensack Meadowlands – the largest estuarine wetland complex in northern New Jersey. NWI helped identify wetlands and potential restoration sites, provided a landscape-level analysis of wetland functions, and offered information on historic and recent wetland trends.

NWI is considered a fundamental layer used for many aspects of refuge planning and management program. Canaan Valley National Wildlife Refuge uses NWI data on a regular basis: 1) to evaluate habitat management projects and identify areas where public access can and can't be permitted, 2) to produce informal reports to realty staff working on acquisitions to show relative wetland/upland acres to support acquisition packages, and 3) to distribute survey and inventory points for sampling wetland wildlife and/or specific plant communities.

The New York Natural Heritage Program uses NWI data and state wetland data to target the full range of habitats potentially used by wetland-dependent species of concern. Known occurrences of these species (determined by ground surveys and radio-telemetry) are combined with wetlands and uplands within the known range of the species using conservative estimates to determine areas that should be conserved.

NWI data have been used by numerous researchers to identify wetlands for studying wetland wildlife and for environmental analysis. One such study investigated salt marsh bird diversity in New England and Long Island, New York (Shriver et al. 2004). NWI data were used to identify potential estuarine emergent wetland sites for this regional study of bird breeding in salt marshes.