Dock, pier and float rules in Cohasset, Massachusetts
A private dock, pier or float in Cohasset needs Conservation Commission approval under the town wetlands bylaw. You must also show that state Chapter 91 and Army Corps permits have been applied for. Solid-fill docks are prohibited, and no new dock is allowed in an identified shellfish area. A float on a mooring in the harbor also needs a Harbor Master mooring permit.
| Town approval | Conservation Commission (Notice of Intent or RDA) for work in or within 100 ft of a resource area [9] |
| State/federal permits | Chapter 91 and Army Corps permits must at least be applied for [4] |
| Solid-fill docks | Prohibited [2] |
| Shellfish areas | No new dock or float in any identified shellfish area [3] |
| Seasonal docks and floats | Store off-season in an upland area, not in a resource area [5] |
| Moored floats in the harbor | Harbor Master mooring permit required [8] |
The Conservation Commission dock standards below come from its Wetland Rules and Regulations effective June 21, 2001, which may have changed since.
Who approves a dock
Under Cohasset's wetlands bylaw, nobody may build on or alter land under any lake, river, pond, stream or estuary, or land within 100 feet of a bank or other resource area, without Conservation Commission approval [9]. The Commission's regulations define a dock as any permanent or seasonal structure where boats tie up or floats attach, including the walkway or gangway leading to it [1]. A dock proposal goes through the usual Request for Determination or Notice of Intent process, with extra information: dimensions, mean high and low water lines, water depth, construction materials and methods, and winter storage plans [7]. You must also show that state Chapter 91 and Army Corps of Engineers permits have at least been applied for, and any approval depends on getting them [4].
Design limits
The regulations set no maximum length or area. Instead they impose performance standards. Solid-fill docks, piers and wharves aren't allowed [2], and no new dock or float may go in an identified shellfish area [3]. Planking must be spaced to let air and sunlight through, and the structure must be high enough for wildlife to pass under where habitat is affected [6]. The Commission can require an open-water buffer between the dock and nearby resource areas susceptible to erosion, sized case by case [11]. New filled piers and other coastal engineering structures are generally not allowed in resource areas [10].
Seasonal docks and floats
Seasonal docks, floats and catwalks must be stored off-season in an upland area, not in a resource area or on a salt marsh [5].
Harbor moorings and floats
In Cohasset Harbor, you need a Harbor Master mooring permit to install mooring tackle for any boat or float [8].
Gaps
The manifest notes a separate Zoning Board of Appeals dock special permit under the zoning bylaw. That bylaw wasn't available to us, so zoning requirements aren't covered here.
See how Cohasset compares with 8+ other Massachusetts towns on docks, piers & floats →
Next steps
- Talk with the Cohasset Conservation Commission (781-383-4100) about the dock location, shellfish areas and buffer requirements before you design.
- Ask the Zoning Board of Appeals / Building & Inspections Department whether a zoning special permit for a dock is required.
- Apply to MassDEP for a Chapter 91 license and to the Army Corps of Engineers; bring proof of those applications to the Conservation Commission.
- File a Notice of Intent with plans showing dimensions, water lines and depth, materials, plank spacing and winter storage plans; for a moored float, apply to the Harbor Master.
Common questions
- Do I need a permit for a dock in Cohasset, Massachusetts?
- Yes. A private dock, pier or float needs Conservation Commission approval under the town wetlands bylaw, and you must show that state Chapter 91 and Army Corps permits have been applied for.
- Are there size limits for docks in Cohasset, Massachusetts?
- The Commission's regulations set no maximum length or area, but impose performance standards. Solid-fill docks are prohibited, and no new dock or float is allowed in an identified shellfish area.
- Can I leave a seasonal dock in the water in Cohasset, Massachusetts?
- Seasonal docks, floats and catwalks must be stored off-season in an upland area, not in a resource area or on a salt marsh.
- Do I need a mooring permit for a float in Cohasset, Massachusetts?
- Yes. In Cohasset Harbor, you need a Harbor Master mooring permit to install mooring tackle for any boat or float. A zoning special permit may also apply, which wasn't reviewed.
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
- Wetland Regs. Section 34.A(1) Dock, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 43
Dock refers to any permanent or seasonal structure (including without limitation, Pier, wharf, bulkhead, etc.) to which boats may be tied while in the water or to which floats are attached, and the associated walkway or gangway leading to the dock.
- Wetland Regs. Section 34.C(5)(c), Cohasset Wetland Rules and Regulations (Conservation Commission), p. 45
No solid-fill docks, piers or wharves shall be permitted.
- Wetland Regs. Section 34.C(5)(a), Cohasset Wetland Rules and Regulations (Conservation Commission), p. 45
No new dock or float will be permitted within any identified shellfish area.
- Wetland Regs. Section 34.D Application Requirements, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 45
The Applicant must also demonstrate that all other applicable local, state (such as MGL c. 91) and Federal (Army Corps of Eng.) permits have at least been applied for.
- Wetland Regs. Section 34.C(4) Off-Season Storage, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 44
Off-season storage of seasonal docks, floats and catwalks must be in an upland area and not in a Resource Area.
- Wetland Regs. Section 34.C(5) Docks and catwalks, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 45
Planking must be sufficiently spaced to allow for the passage of air and sunlight, and if wildlife habitat is impacted, the structure must be of sufficient height to allow for unimpeded passage underneath by the wildlife Impacted.
- Wetland Regs. Section 34.D Application Requirements, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 45
In addition to the usual requirements of an RDA or NOI, Proposals for docks, floats and catwalks should include the following where applicable (i) length, width, height, location, mean high and low water lines, landside topography, depth of water;
- Harbor Regs. Section 6 Required Permit, Cohasset Harbor Regulations (Harbor Department; moorings, floats), p. 3
An approved mooring permit (hereinafter "permit") from the Harbor Master is required for installation of mooring tackle for any boat, float or lobster car/pound within the limits of Cohasset Harbor.
- §260-2.A(2)-(3) Regulated activities, General Bylaws Chapter 260: Wetlands Protection, p. 1
(2) Within 100 feet of any bank, lake, river, pond, stream or estuary; (3) Any land under any lake, river, pond, stream or estuary;
- Wetland Regs. Section 33 Coastal Engineering Structures, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 43
No new bulkheads, filled piers, jetties, groins, seawalls, riprap or other coastal engineering structures shall be permitted in or on any coastal or inland Resource Areas, except as follows
- Wetland Regs. Section 34.C(1) Open Water Buffer Zone, Cohasset Wetland Rules and Regulations (Conservation Commission), p. 44
The size of open water buffer zones shall be determined on a case-by-case basis as required to protect that Resource Area.