Replicate and Expand Ongoing Research on WOTUS Over Time: An Examination of Potential Impacts on Wetlands/Streams Over Different Definitions of Waters of the United States (WOTUS)

Abstract

The purpose of the Clean Water Act’s Section 404 permit program is to regulate, minimize, and mitigate impacts to waters of the United States (WOTUS) to maintain the health of our aquatic resources. The 2023 Supreme Court case Sackett v. EPA narrowed the definition of WOTUS, followed by updated EPA permitting guidance in 2025. Our study examines how these changes may affect wetland permitting in Texas, given that it lacks additional state-level protections. We ask: if the Sackett definition of WOTUS had applied over the past decade, which wetlands would be the most vulnerable to unregulated impacts? Our analysis combines U.S. Army Corps of Engineers, National Wetlands Inventory, and National Hydrography Dataset data to quantify wetland impacts. We also investigate forested wetland conversion rates in the Galveston District using machine learning techniques. Our findings suggest these regulatory changes may both reduce protections and concentrate impacts in high development areas.