New York’s freshwater wetlands regulations changed significantly in 2025 following implementation of revised regulations under 6 NYCRR Part 664. The revised regulations expanded NYSDEC jurisdiction over freshwater wetlands by removing the requirement that wetlands be officially mapped in order to be regulated and broadening jurisdiction over wetlands statewide. The regulations also established a future reduction in the minimum regulated wetland size threshold from 12.4 acres to 7.4 acres beginning in 2028.
See our previous post here: Navigating New York’s Wetland Delineation and JD Process (2025 Update)
The revised regulations became effective on January 1, 2025, but were challenged in court shortly thereafter. On April 8, 2026, the Albany County Supreme Court annulled the revised Part 664 regulations, finding that NYSDEC failed to adequately comply with SEQRA during promulgation of the rules.
Despite the court decision, NYSDEC has stated that the Freshwater Wetlands Act remains in effect and that the Department continues regulating wetlands that remain jurisdictional under existing State law. Currently, NYSDEC continues to regulate:
- Previously mapped freshwater wetlands
- Wetlands 12.4 acres or greater in size
- Wetlands of unusual local importance mapped prior to January 1, 2025
- Associated 100-foot adjacent areas
As a result, wetlands delineations, jurisdictional determinations, and permitting evaluations remain important components of project planning throughout New York State.
At the federal level, wetlands jurisdiction continues to evolve following the United States Supreme Court’s 2023 Sackett v. EPA decision, which narrowed the federal definition of “Waters of the United States” (WOTUS). Under Sackett, federally jurisdictional wetlands generally must have a continuous surface connection to relatively permanent waters in order to fall under Clean Water Act jurisdiction. This significantly reduced the scope of federally regulated wetlands compared to prior interpretations using the broader “significant nexus” standard.
As of 2026, both New York State and federal wetlands jurisdiction remain in a period of regulatory transition. Because wetlands jurisdiction can vary based on site-specific conditions and evolving agency interpretation, early environmental review and wetlands evaluation remain important during project planning and permitting.
