New York’s freshwater wetlands rules after the 2026 court decision: which wetlands DEC regulates
New York’s Freshwater Wetlands Act (Environmental Conservation Law Article 24) protects freshwater wetlands and a 100-foot adjacent area around them. Almost any activity that may harm a protected wetland or its adjacent area, including building, placing fill, excavating, grading and draining (other than for agriculture), needs a permit from the Department of Environmental Conservation (DEC).
The Act was amended in 2022, and DEC’s implementing regulations (Part 664) took effect January 1, 2025. On April 8, 2026, the Albany County Supreme Court annulled those regulations, and DEC did not appeal. DEC now applies the Act itself: it regulates wetlands of 12.4 acres or more and wetlands it mapped before January 1, 2025, including wetlands it mapped as of unusual local importance. Smaller wetlands that DEC had not mapped, and that were regulated only as of “unusual importance” under the annulled rules, now appear to fall outside its jurisdiction (Hodgson Russ). The Act lowers the size threshold in 2028.
DEC has set up a process to reassess jurisdictional determinations it issued between January 1, 2025 and April 8, 2026, while the annulled regulations were in effect. As of May 13, 2026, at least one petitioner group had appealed constitutional and procedural claims the lower court rejected, and Hodgson Russ expected that DEC may pursue new rulemaking.
DEC does not regulate wetlands in the Adirondack Park, where the Adirondack Park Agency does. Federal permits from the U.S. Army Corps of Engineers can also apply to work in or near wet areas.
The rules
- ECL Article 24; 6 NYCRR Parts 662-665State freshwater wetlands permit
Protects larger or important freshwater wetlands and the 100 feet around them. Draining, filling, dredging, building or other harmful work there needs a DEC permit.
- Executive Law Article 27 (APA Act)Adirondack Park Agency permits
Requires an Adirondack Park Agency permit for private projects in the Park above size thresholds that depend on the land use area. APA also permits wetland development there, and shoreline setbacks apply.