Dock, pier and float rules in Chatham, Massachusetts
It depends on where you are. Chatham bans new private piers in much of Pleasant Bay and Chatham Harbor, and new private residential piers anywhere in the Stage Harbor complex. Elsewhere a residential pier needs a ZBA special permit, must be seasonal, can be no longer than 80 feet with floats up to 300 sq ft, and needs Conservation Commission and state approvals.
| Approval | Special permit from the Zoning Board of Appeals (with Harbormaster, Shellfish and Conservation review) [1] |
| Where new private residential piers are banned | Stage Harbor complex (incl. Oyster Pond, Mill Pond, Mitchell River); all new private piers banned in parts of Pleasant Bay and Chatham Harbor [2] |
| Seasonal vs permanent | Residential piers must be seasonal [4] |
| Max length | 80 ft from Mean High Water, including stairs, ramps and floats [5] |
| Max width / float area | 4 ft wide; floats 300 sq ft total, none above Mean Low Water [5] |
| Setback from property lines | 25 ft (measured from the outer lines for a shared pier) [11] |
| Spacing from other piers, boat ramps and swimming areas | 250 ft from another pier; 100 ft from a boat ramp or public swimming area [3] |
| Water depth | At least 2½ ft at Mean Low Water at the end, without dredging [6] |
Where piers are allowed
Piers sit in Chatham's Conservancy Districts, where they need a special permit from the Zoning Board of Appeals. The Board weighs navigation safety, water quality, public access, the environment and aesthetics, plus how close the pier is to channels, moorings, sailing and swimming areas [1]. The bylaw prohibits any new private pier or pier extension in Pleasant Bay from the town line at Jackknife Harbor to 4 Minister's Lane, which includes Crows Pond, Ryders Cove, Frost Fish Creek and Bassing Harbor. The same ban covers Chatham Harbor from 4 Minister's Lane to Cow Yard Landing [10]. New private residential piers are also banned throughout the Stage Harbor complex [2]. Existing piers there may be maintained within their licensed footprint. Every new request goes to the Harbormaster, Shellfish Warden and Conservation Commission for written comment.
Design limits for new residential piers
- Location: at least 25 feet from property lines [11], 250 feet from another pier, and 100 feet from a boat ramp or public swimming area [3].
- Seasonal only: permanent residential piers aren't permitted [4].
- Size: no more than 80 feet long from Mean High Water (including stairs, ramps and floats) and 4 feet wide. Floats total 300 sq ft at most and none may sit above Mean Low Water. The deck can be no more than 4 feet above Mean High Water unless needed to protect marsh [5].
- Depth: at least 2½ feet of water at the end at Mean Low Water, without dredging [6].
- Alongshore pedestrian passage must be kept open at all tides.
Floats and other rules
A float below mean low water that's permitted by the Harbormaster is allowed in Conservancy Districts without a special permit [7]. New floats can't use bare foam flotation [8]. In the coastal floodplain the Conservation Commission may prohibit piers and stairs unless they're removable, anchored or built to let waves pass [9]. A Conservation Commission permit is required for any dock work in or within 100 feet of wetlands.
State and federal permits
Piers also need a Chapter 91 license from MassDEP and possibly U.S. Army Corps approval (see below).
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Next steps
- Check whether your shoreline is in a prohibited area (Stage Harbor complex, or the listed stretches of Pleasant Bay and Chatham Harbor) before designing anything.
- Talk to the Harbormaster and Conservation Agent early about channels, moorings, shellfish beds and eelgrass.
- Apply to the Zoning Board of Appeals for a special permit and file a Notice of Intent with the Conservation Commission, with plans showing length, width, float area, setbacks and water depth.
- Apply to MassDEP for a Chapter 91 license (and the Army Corps if required) once local approvals are in hand.
Common questions
- Can I build a private dock in Chatham, Massachusetts?
- It depends on where you are. New private piers are banned in much of Pleasant Bay and Chatham Harbor, and new private residential piers are banned throughout the Stage Harbor complex. Elsewhere a residential pier needs a Zoning Board of Appeals special permit.
- How long can a dock be in Chatham, Massachusetts?
- No more than 80 feet from Mean High Water, including stairs, ramps and floats, and 4 feet wide. Floats total 300 sq ft at most, and none may sit above Mean Low Water.
- Can a dock be permanent in Chatham, Massachusetts?
- No. Permanent residential piers aren't permitted. New residential piers must be seasonal.
- What approvals does a dock need in Chatham, Massachusetts?
- A special permit from the Zoning Board of Appeals, with Harbormaster, Shellfish Warden and Conservation Commission review. Piers also need a Chapter 91 license from MassDEP and possibly U.S. Army Corps approval.
Massachusetts state rules for docks and piers
A private dock in Massachusetts usually needs several layers of approval beyond local zoning.
Chapter 91 waterways license (MassDEP): any structure, regardless of size, permanent or seasonal, in tidal waters, in a great pond (a pond over 10 acres in its natural state), or in certain navigable rivers needs Chapter 91 authorization (M.G.L. c. 91; 310 CMR 9.00). For small residential docks there are simpler routes:
- a General License certification for pile-supported residential docks, piers, ramps and floats with no fill or dredging, outside ACECs and Designated Port Areas (310 CMR 9.29)
- a Simplified License for residential docks up to 600 sq ft below the high-water line (310 CMR 9.10)
Licenses must be recorded at the Registry of Deeds, and Chapter 91 protects public rights to fish, fowl and navigate.
Conservation Commission: dock work in or near wetlands, banks or land under water needs an Order of Conditions under the Wetlands Protection Act (c. 131, §40).
Harbormaster: bottom-anchored moorings, floats and rafts (no pilings) can be authorized by an annual permit from the local harbormaster instead of a Chapter 91 license (c. 91, §10A). Mooring fees can't discriminate based on residence.
U.S. Army Corps of Engineers: work in navigable waters may also need federal approval. Small private piers and floats are often covered by the Corps' Massachusetts General Permits, which can involve self-verification or pre-construction notification.
What the bylaw says
- Sec. IV.A.6.d Private Piers (Commercial and Residential), Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 37
The Zoning Board of Appeals may authorize a Special Permit for the construction of a private pier if it is found that the proposed structure will not be detrimental to safety on waterways, preservation of water quality, ease of access to and on waterways, equity of interest in utilizing waterways, the protection of the natural environment, and the protection of the aesthetic values of the Town.
- Sec. IV.A.6.d Private Piers, prohibited locations, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 37
Additionally, the construction of new private residential piers shall be specifically prohibited in the following locations: ▪ Marine waters located northerly of an imaginary line across the mouth of Stage Harbor Inlet, separating the Stage Harbor Complex from Nantucket Sound, including but not limited to the following waterways: Stage Harbor Inlet, Oyster Pond, Stetson Cove, Oyster River, Little Mill Pond, Mill Pond, Mitchell River and the total Stage Harbor including Snake River and all other tidal embayments within the Complex.
- Sec. IV.A.6.d.a Private Piers, Location, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 38
b. No new pier or float system shall be located closer at any point than two hundred fifty (250) feet to another pier. c. No new pier shall be located closer at any point than one hundred (100) feet to a boat ramp. d. No new pier or float system shall be located closer at any point than one hundred (100) feet to a public swimming area.
- Sec. IV.A.6.d.b Private Piers, Construction, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 38
Construction – All private residential piers shall be seasonal. Permanent piers shall not be permitted.
- Sec. IV.A.6.d.c Private Piers, Size, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 38
a. No pier shall exceed eighty (80) feet in overall length (including stairs, ramps and floats) measured from the Mean High Water (MHW) line. b. No stairs, pier or ramp shall exceed four (4) feet in width, measured outside the support structure (pilings, posts, railings). c. The total area of any and all floats associated with a pier shall not exceed three hundred (300) square feet,
- Sec. IV.A.6.d.d Private Piers, Depth of Water, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 38
Depth of Water – At Mean Low Water (MLW) there shall be, without benefit of dredging, at least two and one half (2 ½) feet of water at the end of the pier and/or float system.
- Sec. IV.A.2.c Conservancy Districts, Permitted Uses, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 33
The installation of floats, provided they are located below mean low water, or the Natural High Water Mark on fresh water ponds, and are permitted by the Harbormaster.
- Ch. 265, §265-10(B) Pollution, General Bylaws Chapter 265: Waterways, p. 5
The use of bare foam flotation for constructing new floating docks or swim floats or floats attached to a land-accessed structure (except floats held in place with single point mooring anchors already regulated by Consolidated Waterways Regulations §1011 6.g.) is prohibited in all tidal and fresh waters.
- Wetlands Protection Regulations Sec. 2.10 Coastal Floodplain, performance standard (f), Chatham Wetlands Protection Regulations (Rev. 6/11/2025, 1/14/2026, 7/1/2026), p. 47
Stairs, boardwalks, piers and catwalks may be prohibited unless they are designed to be (i) removed and placed in a secure location either outside of the Coastal Floodplain or secured above the Base Flood Elevation as defined in the State Building Code in advance of a storm or other extreme high tide;
- Sec. IV.A.6.d Private Piers, prohibited locations, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 37
The construction of private piers or the extension of existing piers shall be specifically prohibited in the following locations: ▪ In Pleasant Bay from the Town line at Jackknife Harbor to the southerly property line of 4 Minister’s Lane, including Crows Pond, Ryders Cove, Frost Fish Creek, and Bassing Harbor; and ▪ In Chatham Harbor from the southerly property line of 4 Minister’s Lane to Cow Yard Landing.
- Sec. IV.A.6.d.a Private Piers, Location, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 38
No new pier or float system shall be located closer at any point than twenty-five (25) feet to a property line, except, for a pier jointly owned and used by two (2) or more contiguous shorefront properties, the twenty-five (25) foot setback shall be measured from the outermost property lines of the applicable properties.