For the past 50 years, the National Wetlands Inventory Program (NWI) has shaped the understanding and conservation of wetlands, while supporting the vitality of America鈥檚 communities and economy.
Wetlands contribute to the health, safety, and prosperity of communities by supplying clean water, protecting people and infrastructure from floods and storms, and providing opportunities for recreation including birding, hunting, fishing, and boating. Wetlands have long been central to the mission of the U.S. Fish and Wildlife Service because they are critical to the well-being of a wide range species 鈥� from fisheries that put food on American tables to migratory birds that people look forward to welcoming home each year.
The NWI Program was created in 1974 to inventory wetland area, location, type, and trends 鈥� the foundational information needed to better manage wetlands and their many benefits. Similar to the way that scientists must consider the path of water and migratory birds over thousands of miles, wetland managers must zoom out to the landscape scale to understand how wetlands are intertwined with the landscape to best conserve them and their benefits. NWI maps (geospatial data) and Wetlands Status and Trends reports provide this comprehensive, landscape scale information so that decision-makers can best support American interests.
Over the past five decades, NWI and its partners built the knowledge and structures necessary to collect this vital information. It started with the development of a comprehensive, hierarchical classification system 鈥� the 鈥淐lassification of Wetlands and Deepwater Habitats.鈥� Scientists spent years collaboratively developing this system 鈥� which would become the national Wetland Classification Standard. The process included gathering feedback from hundreds of wetland managers and testing at pilot sites across the United States. The resulting classification system is so precise that it can pinpoint the habitat of thousands of fish and wildlife species, yet flexible enough to support a wide range of mapping objectives.
Mapping in the 1970s and '80s, was very different than it is today. That was the era of mainframe computers that occupied entire rooms but had less computing power than today鈥檚 smart phone. At that time, wetlands were drawn by hand on mylar overlays and stereoscopes were used to find low-lying areas where wetlands often form. The public could request NWI maps by calling 1-800-USA Maps.
Technology changed rapidly since that time, and the NWI Program has been at the forefront of these advancements. The Program leverages the best available mapping approaches while meeting the high standards for accuracy and detail called for by the national Wetlands Mapping Standard. NWI does this by adaptively managing all components of the mapping process to leverage the best of different datasets and techniques 鈥� including automated approaches that rely on satellite imagery and artificial intelligence.
This leveraging is made possible by partnerships with companies, nonprofits, universities, other government agencies, and more. By working directly with partners on data production 鈥� NWI benefits from research being conducted by these groups. Partners benefit from funding for mapping projects 鈥� and create jobs across the United States. Taxpayers benefit from improved data 鈥� as well as the cost efficiencies that come from partnerships. This includes coordination between NWI and the U.S. Geological Survey 3D Hydrography Program that aims to produce more cost-effective and interoperable wetland and stream data.
NWI data enables environmental managers and policymakers to make more efficient, strategic decisions regarding the future of America鈥檚 wetlands. NWI maps are used to help streamline planning and regulatory decision-making that supports effective infrastructure and energy development. A wide array of organizations, ranging from Tribes to companies, use NWI data in this way 鈥� savings tens of millions of dollars every year.
Partners, like Ducks Unlimited, rely on NWI data to target wetland restoration to areas where waterfowl and sports enthusiasts benefit the most. Tribes depend on NWI data to help support enduring traditions, like subsistence hunting and fishing and the harvest of culturally important plants. Within the Service, NWI maps and reports are used to guide billions of dollars鈥� worth of wetland conservation, supporting wildlife while generating clean water and other benefits for communities.
The most widespread application, and perhaps the most impactful, is the use of NWI maps by individuals to guide land acquisition and development. This conserves countless wetlands and their benefits through passive avoidance 鈥� or the voluntary decision not to impact a wetland.
NWI data can be used in many different ways and these applications have and will continue to shift along with the needs of data users. However, one fact will remain unchanged. The use of NWI data helps people across the country 鈥� from farmers that depend on a consistent supply of water to small business owners that rely on abundant fish and shellfish.
Widespread reliance of stakeholders on NWI data is evidenced by its extensive use. NWI鈥檚 Wetlands Mapper is viewed over half a million times each year and its web map services receive several tens of millions of requests for information annually. In 2024, NWI maps were downloaded more than 286,000 times and nearly 300,000 maps were printed.
The need for NWI data is further demonstrated by increased partner investment in data production. Last year was one of the largest updates ever to the NWI Wetlands Mapper, and 2025 is on track to match or exceed that record!
As the NWI Program celebrates its 50th anniversary we recognize not only the achievements of the past 鈥� but the promise of the future. Over the past decades, NWI has provided the foundational geospatial data necessary to guide strategic wetland decision-making by harnessing technological advancements to produce consistent, high-quality national wetlands data. The Program will continue to lead the development and distribution of this vital information by not only providing training, shared standards, quality control, database management, and national distribution but also working with partners to identify, develop, and implement even better ways to produce and share high-quality wetlands data.
As workflows evolve along with technology, the Program will incorporate these advancements into the national Wetlands Mapping Standard which ensures that user needs are met consistently across America. The Program will also continue to work with other geospatial data producers to ensure interoperability and production efficiency. These actions and others uphold the principles of FAIR 鈥� findable, accessible, interoperable, and reusable 鈥� data in keeping with statutory authorities like the Geospatial Data Act of 2018.
Producing the data needed to support the conservation of wetland benefits while supporting efficient infrastructure and energy development requires strong and sustained partnerships. The NWI Program stands ready to work with partners to provide consistent, high-quality wetlands data to the public. Doing so is especially important today given the growing importance of wetland benefits in meeting the needs of America鈥檚 communities and economy.
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