NYC Unified Stormwater Rule

07/05/25

“How can NYC unify its stormwater regulations to cover both its combined and separated sewers under one regulation?”

Historically, NYC regulated stormwater in its combined sewer overflows differently than its municipal separate stormwater sanitary systems. But on February 15, 2022, NYC unveiled its NYC Unified Stormwater Rule. This regulation brought RCNY Title 15 Chapter 19.1 enforcement to the entire city and reduced the minimum qualification to 20,000 square feet. This shifted NYC’s stormwater pollution focus from off-site treatment to on-site treatment, putting NYC on a path to a more just and sustainable future. The NYC unified stormwater rule can increase equity in environmental justice communities due to their sizable presence in older combined sewer overflow neighborhoods.