In honor of World Water Day, the Natural Resources Defense Council (NRDC) has published a groundbreaking report, Mapping Destruction: Using GIS Modeling to Show the Disastrous Impacts of Sackett v. EPA on America’s Wetlands, on how federal wetlands protection under the Clean Water Act has changed after the Supreme Court’s decision in Sackett v. EPA.
In 2023, the Supreme Court issued the decision in Sackett v. EPA, which narrowed the scope of wetlands protected by the Clean Water Act. Prior to the decision, consistent with the Supreme Court’s prior case law, the EPA interpreted the Waters of the United States to include wetlands that had a “significant nexus” to navigable waters. This meant that nearly all wetlands and non-perennial streams were eligible for protection. Sackett v. EPA narrowed this definition to include only wetlands that have a continuous surface connection to Waters of the United States.
What Changed in Wetlands Protection
Blue Raster worked with NRDC to identify which wetlands were potentially protected under the previous interpretation of the Clean Water Act but are now at risk of not being protected. Using the National Wetlands Inventory (NWI) data, our team first created a dataset of wetlands likely to meet the regulatory definition of “wetlands” in federal Clean Water Act rules, based on the presence of water, hydric soils, and hydrophilic soils. We then used the National Hydrography Dataset (NHD) to identify jurisdictional wetlands under three scenarios interpreting Sackett v. EPA in comparison to jurisdictional wetlands under the previous interpretation.
- Includes streams that the NHD identifies as “relatively permanent” and human-made features, such as ditches and canals, as having perennial or intermittent flows, which likely overstates the number of streams and wetlands remaining protected
- Excludes human-made features and only includes streams NHD classifies as perennial.
- Excludes wetlands except those that are likely to have surface water for a very substantial part of the year, in order to approximate the effect of an interpretation requiring that wetlands must be “indistinguishable” from other Waters of the United States.
Wetlands Eligible for protection prior to Sackett v. EPA (green) as compared to three separate interpretations. Scenario 1: yellow; Scenario 2; Pink; Scenario 4: Purple
NRDC used these datasets to estimate the area and number of wetlands in each state, and by county, that have lost federal protection and is advocating for state and local government protections to fill the gap left by Sackett v. EPA. These datasets can also be explored in a companion viewer application that Blue Raster helped create.
Want to understand how GIS can support policy, advocacy, and environmental protection? Contact Blue Raster to explore what’s possible with spatial analysis.
- Posted in
- ArcGIS Experience Builder
- ArcGIS Online
- ArcGIS Pro
- Conservation
- Environment
- Esri
- Nonprofit/NGO
- Water
Related Posts
- Blue Raster Pioneering Imagery Management Technology and Delivery Workflows with ArcGIS
- Conducting Research and Data Analysis for The Nature Conservancy’s Coastal Restoration Opportunities Project
- Bringing Transparency to Transboundary Water Policy in the Mekong River Basin
- Mekong Infrastructure Tracker
- National Audubon Society’s Bird Migration Explorer