Wetlands in Rockingham County, New Hampshire: The Great Bay Estuary

Great Bay: a tidal estuary that reaches well inland of the ocean

Great Bay is a large tidal estuary sitting behind New Hampshire's coastline, fed by several rivers (including the Squamscott and Winnicut) and connected to the ocean through Portsmouth Harbor. Several Rockingham County towns border it directly -- Newington, Greenland, Stratham, Newfields, and Exeter, along with Portsmouth itself -- meaning tidal water and tidal wetlands reach well inland of what most people picture as "the coast." A parcel in Stratham or Newfields with no ocean view and no beach access can still sit directly against a tidal wetland, and the regulatory consequences of that are real even though the real-estate market around it looks nothing like an oceanfront listing.

RSA 482-A: New Hampshire's wetlands statute, and its 100-foot tidal buffer

New Hampshire's wetlands law is codified as RSA 482-A, "Fill and Dredge in Wetlands," administered by NHDES's Wetlands Bureau under the Env-Wt administrative rules. It applies statewide to both inland and coastal/tidal wetlands, but the tidal side carries its own specific buffer: within 100 feet of the highest observable tide line along tidal waters, the statute's protections extend to banks, upland areas, bogs, salt marsh, swamps, meadows, flats, and other lowlands subject to tidal action -- a 100-foot buffer measured from the tide line rather than from a mapped wetland edge itself. Any dredging, filling, or construction affecting a tidal wetland or that buffer requires a wetlands permit from NHDES, on top of whatever the parcel's town zoning otherwise allows.

A separate, additional layer exists on top of that statewide baseline: RSA 482-A:15 lets an individual town vote to designate specific wetlands within its borders as "prime wetlands" -- typically large, high-quality wetland areas capable of supporting rare or threatened species -- which then carry their own state-recognized protected buffer (up to 100 feet, if adopted with one) once designated. Any of Rockingham's Great Bay-adjacent towns could have made such a local designation for a specific wetland; whether a given parcel is affected is a town-specific fact to confirm rather than something to assume from the general Great Bay geography alone.

How this differs from the Shoreland Water Quality Protection Act

It's worth keeping RSA 482-A's tidal wetlands buffer distinct from New Hampshire's other major water-adjacent state law, the Shoreland Water Quality Protection Act (RSA 483-B), covered on our state hub and applicable to lakes, ponds, and larger rivers statewide. Both can apply to the same Rockingham County parcel if it happens to sit near both a tidal wetland and a qualifying lake or river, but they are administered under different statutes, different buffer distances (RSA 483-B's 250-foot protected shoreland versus RSA 482-A's 100-foot tidal buffer), and different NHDES permit programs (Wetlands Bureau versus the shoreland permitting program). Confirming "shoreland permit" status does not confirm wetlands-permit status, and vice versa -- check both separately for any parcel near Great Bay or its tributary rivers.

What to check before buying near Great Bay

• Confirm whether any part of the specific parcel falls within a tidal wetland or within 100 feet of the highest observable tide line on a tidal waterway -- don't assume "not on the ocean" means the tidal buffer doesn't apply.
• Ask the specific town (Newington, Greenland, Stratham, Newfields, Exeter, or Portsmouth) whether it has designated any local "prime wetlands" under RSA 482-A:15 that could affect the parcel or its immediate surroundings.
• Check separately whether the parcel is also near a qualifying lake, pond, or larger river subject to the Shoreland Water Quality Protection Act (RSA 483-B) -- the two buffer systems are independent of each other.
• Before any clearing, fill, dredging, or construction near a tidal wetland, confirm with NHDES's Wetlands Bureau whether a permit is required, rather than assuming a standard town building permit alone is sufficient.
• Confirm the parcel's FEMA flood-zone status separately -- tidal wetland proximity and flood-zone designation are related but not identical questions.