Read this first. This page is a plain-language summary written for orientation. It is not legal advice, it is not a permit, and it cannot account for the specifics of your property. Prime wetlands, shoreland conditions, existing structures, local ordinances and conservation commission requirements can all change the answer. NHDES administers these rules and is the authority.
Everything in the Water Is Regulated
The single most common misunderstanding in this subject is that “seasonal” means “unregulated.” It does not.
Wetlands permitting applies to all new docking structures and modifications of docking structures — seasonal and permanent — and to all boat and jet-ski lifts.
Docks in New Hampshire sit under two regimes at once: RSA 482-A, the wetlands statute administered by the NHDES Wetlands Bureau, and RSA 483-B, the Shoreland Water Quality Protection Act. A project generally has to satisfy both, and neither replaces whatever your town requires.
What varies is not whether you need authorisation but which route you take to get it. There are three, and the difference between them is substantial in both time and cost.
Seasonal Dock Permit by Notification
The simplest route, available under RSA 482-A:3, IV-a for seasonal docks that meet a specific set of criteria. If your project qualifies, this is a far lighter process than a full application.
The published criteria are, broadly:
- The dock is on a lake or pond
- It is the only docking structure on that frontage
- It is constructed to be removed, and is removed for at least five months each year
- It is narrow, rectangular and perpendicular to the shoreline
- It is on a parcel with 75 feet or more of shoreline frontage
- It is no more than 6 feet wide, and no longer than 40 feet on a waterbody of 1,000 acres or more, or 30 feet on a smaller one
- It sits at least 20 feet from an abutting property line, or the imaginary extension of that line
- Installation requires no modification, regrading or re-contouring of the shoreline — including no concrete pad for a hinged dock
- It complies with RSA 483-B, the Shoreland Water Quality Protection Act
- It is not in or within 100 feet of a municipally designated prime wetland
Size follows the waterbody. On waterbodies of 1,000 acres or larger, a qualifying seasonal dock may be up to 6 feet wide by 40 feet long. On a waterbody under 1,000 acres the same dock is limited to 6 feet wide by 30 feet long. Either way the parcel must carry 75 feet or more of shoreline frontage — that is one of the criteria itself, not merely a size allowance.
Criteria and both length allowances per RSA 482-A:3, IV-a, cross-checked against the NHDES seasonal dock notification form for lakes and ponds (NHDES-W-06-035), which carries the department’s list of waterbodies over 1,000 acres.
Two things people miss. First, the five-month removal is a condition of the authorisation, not a suggestion — a dock that stays in has stopped meeting the basis on which it was allowed. Second, a notification does not relieve you of the obligation to obtain other local, state or federal permits that may apply to your property.
Standard Wetlands Permit
The full application. You are here if the project is permanent, if it exceeds the seasonal criteria in any respect, or generally if it expands beyond an existing footprint.
Permanent docks are narrowly available
This is the threshold most people are unaware of, and it decides a great many projects before they begin:
Permanent docks may be permitted only on lakes larger than 1,000 acres, and only in areas where wind or wave conditions may prevent the use of a seasonal dock.
Both halves matter. The 1,000-acre threshold rules out permanent structures on smaller waters entirely — in our service area that means Lake Waukewan, the Suncook Lakes and Webster Lake, among others. And on the larger lakes, the burden is on demonstrating that a seasonal dock would not work at your frontage — not merely that you would prefer something permanent.
On large waterbodies with over 75 feet of frontage, published guidance indicates a permanent dock allowance of around 6 feet by 30 feet — notably shorter than the seasonal allowance.
Expect months, not weeks. This is why we tell people to start a new dock conversation in autumn for the following summer. The construction is rarely the constraint.
Voluntary Non-Tidal Dock Registration
The least known of the three and, for owners of older structures, frequently the most useful.
NHDES operates a voluntary registration for existing, legal, non-tidal docking structures. Once a registration is accepted, the registered structure is exempt from the requirement to obtain future NHDES repair or replacement permits for the duration of the registration — typically five years. Published material puts the process as simpler and less expensive than the notification, expedited or standard permitting routes, at a fee in the region of $200.
If you own an older dock that you expect to maintain and repair over the coming years, this is worth understanding. It converts a series of future permitting questions into one process now.
The load-bearing word is legal. Registration is for structures that were properly authorised. If a dock was never permitted, that is a different conversation and one worth having deliberately rather than discovering during a repair.
Repair in Kind vs. Reconstruction
On older structures this is the question that should be settled before anyone orders materials, and it is settled far too often afterwards.
Repair in kind of an existing legal structure — replacing deteriorated components with equivalent ones, in the same footprint — sits in a different regulatory position from reconstruction or expansion. An existing legal dock may carry a status that a replacement would not inherit, which means a decision made casually on site can have consequences that outlast the dock itself.
The practical advice is simple: if you have an older dock and you are contemplating anything beyond swapping boards, establish first whether what you are planning is repair or reconstruction, and what the structure's existing status actually is. That is a conversation, not a form, and it is considerably cheaper than the alternative.
The Thresholds That Decide Most Projects
| Threshold | Value | What it governs |
|---|---|---|
| Waterbody size | 1,000 acres | Permanent docks only above it; also gates the seasonal size allowance |
| Shoreline frontage | 75 feet | A criterion of the seasonal notification in its own right |
| Seasonal dock size | 6 ft × 40 ft | Maximum for a qualifying notification dock on a waterbody of 1,000 acres or more |
| Seasonal dock size | 6 ft × 30 ft | Maximum for a qualifying notification dock on a waterbody under 1,000 acres |
| Permanent dock size | ~6 ft × 30 ft | Indicative allowance on large waterbodies with 75 ft+ frontage |
| Property line setback | 20 feet | From the line or its imaginary extension into the water |
| Removal period | 5 months minimum | How long a seasonal dock must be out each year |
| Prime wetland buffer | 100 feet | Proximity to a municipally designated prime wetland disqualifies notification |
| Dock registration term | ~5 years | Exemption period from future repair/replacement permits |
Which of our waters are over 1,000 acres?
| Water | Approximate size | Permanent dock possible? |
|---|---|---|
| Lake Winnipesaukee | ~72 sq mi | Yes, subject to the wind/wave test |
| Squam Lake | ~6,800 acres | Yes, subject to the wind/wave test |
| Lake Winnisquam | ~4,300 acres | Yes, subject to the wind/wave test |
| Newfound Lake | ~4,100 acres | Yes, subject to the wind/wave test |
| Lake Wentworth | ~3,000 acres | Yes, subject to the wind/wave test |
| Lake Waukewan | ~900 acres | Below the threshold — seasonal only |
| Pemigewasset Lake, Meredith | Below 1,000 acres | Below the threshold — seasonal only |
| The Suncook Lakes | Below 1,000 acres | Below the threshold — seasonal only |
Sizes are approximate and given for orientation on which side of the statutory threshold a water sits. The waters shown as below the threshold do not appear on the NHDES list of waterbodies over 1,000 acres published with the seasonal dock notification form. Confirm anything that matters with NHDES.
Where This Comes From
Everything above is drawn from published New Hampshire statute and NHDES material. The primary references are:
- NHDES — Docking Structures and Shoreline Stabilization
- NHDES — Docks in Non-Tidal Areas FAQs
- RSA 482-A:3 — Excavating and Dredging Permit; Certain Exemptions
- NHDES WB-28 — Voluntary Non-Tidal Dock Registration
Rules change, and summaries age. If you are relying on anything here for a decision, check it against the current NHDES material or ask us to check it with you. We would rather spend twenty minutes on that than have you order a dock you cannot install.