Nassau County, NY Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing law
- Admin. Code § 12-20.0
- Enforcing agency
- Department of Public Works
- Other-agency approval
- Required under § 12-20.1 first
- Site-drainage permits
- Set by town/city/village, not county
Summary
Nassau County's Board of Supervisors may direct the Department of Public Works to build dams, culverts, ditches, and channels countywide to prevent flooding, and other public agencies need county sign-off before building competing drainage works.
The Board of Supervisors, for the purpose of drainage and to protect the property and the public health within the County from floods, freshets, and high waters, may authorize the Department of Public Works to: 1. Construct dams, culverts, ditches, sluices, and other channels for the passage of water. 2. Deepen, straighten, alter, pipe, or otherwise improve any of the lakes, ponds, streams, ditches, drains, or water courses in any part or section of the County...
Full Breakdown
Nassau County Administrative Code § 12-20.0 lets the Board of Supervisors authorize the Department of Public Works to build dams, culverts, ditches, sluices and channels, and to deepen, straighten, pipe or otherwise alter county lakes, ponds, streams, drains and watercourses to prevent flooding and protect public health. Under § 12-20.1, any city, town, village or other public corporation must submit its own drainage-improvement plan to the Commissioner of Public Works for approval before building anything the county could build under § 12-20.0. The county sets no stormwater-detention or site-drainage permit standards for private development: that's set by each town, city or village.
Violations & Fines
No fine schedule for residents. The real constraint is on other governments: a city, town or village can't build its own drainage improvement in an area the county could improve until the Commissioner of Public Works approves its plan under § 12-20.1.
Frequently Asked Questions
Does Nassau County issue stormwater permits for my property?
What does Nassau County's own drainage law cover?
Sources & Official References
Other rules in Nassau County
New York rules heatmap·Compare Nassau County to another location·View the New York environmental rules overview
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