New Jersey has some of the strictest freshwater wetlands protections in the country. The Freshwater Wetlands Protection Act regulates not just the wetlands themselves, but the "Transition Area" (buffer) around them.
The Letter of Interpretation (LOI)
An LOI is the official document from NJDEP confirming the boundaries and resource value of wetlands on your site. You should never buy raw land without one.
Resource Value & Buffers
The size of the buffer depends on the "Resource Value" of the wetland:
- Exceptional Value (150' Buffer): Wetlands that discharge into trout production waters or are habitat for threatened/endangered species.
- Intermediate Value (50' Buffer): Most standard wetlands.
- Ordinary Value (0' Buffer): Certain isolated wetlands, ditches, or swales.
Transition Area Waivers
You generally cannot build in the wetland, but you can often build in the buffer with a "Transition Area Waiver." The most common is "Buffer Averaging."
Buffer Averaging: You can reduce the buffer in one area (e.g., to fit a building corner) as long as you expand it in another area, maintaining the total square footage and function of the buffer.
General Permits (GPs)
For minor impacts (e.g., a road crossing or filling a small isolated wetland), you may qualify for a General Permit. GP6 (Isolated Wetlands) and GP10 (Road Crossings) are the most commonly used by developers.
Conclusion
Wetlands don't always mean "no build," but they definitely mean "build carefully." Early delineation is key to a viable site plan.