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Building near the water in Plymouth, Massachusetts (wetlands rules)

Plymouth, Plymouth County · Bylaws checked 2026-10-15 · Reviewed · 7 cited sections

Allowed with board review

Work within 100 feet of a wetland, pond, stream, coastal bank, beach, dune or flood zone (200 feet of a vernal pool) needs a permit from the Plymouth Conservation Commission. The first 35 feet from the resource area is a no-touch zone, 35 to 50 feet is a no-build zone, and work from 50 to 100 feet is allowed only if there's no practical alternative.

JurisdictionWithin 100 ft of wetlands, waterbodies, banks, beaches, dunes and flood zones; 200 ft for vernal pools [1]
No-touch zone0-35 ft from the resource area [3]
No-build zone35-50 ft [3]
50-100 ftAllowed only if no practical alternative; mitigation may be required [4]
Vernal poolsFirst 100 ft of the 200-ft radius is no-touch [6]
PermitNotice of Intent to the Conservation Commission, with public hearing [2]
Nonconforming homesBy right if not more nonconforming; otherwise ZBA special permit [7]

Where the rules apply

Plymouth's Wetlands Protection bylaw (Chapter 196) bars anyone from removing, filling, dredging or altering land within 100 feet of a long list of resource areas: ponds, lakes, streams, wetlands, coastal banks, beaches, dunes, marshes, land under water, tidal areas and FEMA flood zones. Vernal pools get a 200-foot protection area [1]. This is in addition to the state Wetlands Protection Act.

Buffer zone limits

The Conservation Commission's 2025 regulations presume an undisturbed, naturally vegetated 100-foot buffer is needed. Within 35 feet of a resource area, no development, alteration, filling, dredging or removal (including clearing) is allowed; 35 to 50 feet is a no-build zone [3]. Work 50 to 100 feet away is allowed only if you show there's no practical alternative, and the Commission may require mitigation [4]. Some minor activities in the 35-100 foot area aren't regulated, including converting lawn to decks, sheds, patios and pools accessory to a single-family home, wildlife-passable fencing, unpaved walkways and planting native vegetation [5]. Vista pruning is on that list only when it is more than 50 feet from a river or vegetated wetland. The regulations don't say how that list squares with the 35-50 foot no-build zone, so before putting a shed, deck or pool within 50 feet, ask the Conservation Commission whether it needs a filing. For vernal pools, the first 100 feet of the 200-foot radius is a no-touch zone [6].

Permits

You must file a Notice of Intent with plans and a fee, and the Commission holds a public hearing; regulated work can't start without a permit [2].

Expanding an existing home

Under zoning, a nonconforming single- or two-family home can be altered or enlarged by right if the Building Commissioner finds it doesn't increase the nonconformity, or if the change meets the yard setbacks in effect when it was built (or 20 feet front and 10 feet side and rear if there were none). Otherwise a special permit from the Zoning Board of Appeals is required [7]. Plymouth also has a Waterfront zoning district and a Floodplain overlay district with their own rules, and state Chapter 91 licensing applies to work on tidelands.

See how Plymouth compares with 8+ other Massachusetts towns on building near the water (wetlands rules) →

Next steps

  1. Check whether your project is within 100 feet of a wetland, pond, stream, coastal bank, beach or flood zone (200 feet of a vernal pool); ask the Conservation Commission if unsure.
  2. Keep all work and clearing out of the 35-foot no-touch zone and new structures out of the 35-50 foot no-build zone.
  3. File a Notice of Intent (with plans and the fee) with the Plymouth Conservation Commission and attend the public hearing.
  4. For an addition to a nonconforming house, ask Inspectional Services whether it's by right or needs a ZBA special permit.

Common questions

Do I need a permit to build near wetlands in Plymouth, MA?
Yes. Work within 100 feet of a wetland, pond, stream, coastal bank, beach, dune or flood zone, or 200 feet of a vernal pool, needs a Plymouth Conservation Commission permit. You file a Notice of Intent and the Commission holds a public hearing.
How close to a pond or wetland can I build in Plymouth, Massachusetts?
The first 35 feet from the resource area is a no-touch zone, 35 to 50 feet is a no-build zone, and work from 50 to 100 feet is allowed only if there's no practical alternative, possibly with mitigation.
Can I put a shed or deck near wetlands in Plymouth, MA?
It depends. Some minor activities in the 35-100 foot area, like sheds, decks, patios and pools accessory to a single-family home, aren't regulated, but the rules don't say how that squares with the 35-50 foot no-build zone. Ask the Conservation Commission before building within 50 feet.
Can I expand a nonconforming house near the water in Plymouth, Massachusetts?
Possibly. Under zoning, a nonconforming home can be enlarged by right if it isn't made more nonconforming; otherwise it needs a ZBA special permit. Conservation Commission rules still apply within the buffer.

Massachusetts wetlands rules and the Conservation Commission

Massachusetts has no "shoreland zoning" like some states. Instead, the Wetlands Protection Act (M.G.L. c. 131, §40) and MassDEP's regulations (310 CMR 10.00) control work near water, and your local Conservation Commission enforces them.

What's protected:

  • Wetlands, banks, beaches, dunes, marshes, land under ponds and streams, and 100-year floodplains.
  • The riverfront area: 200 feet from a perennial river or stream, shrinking to 25 feet in certain dense urban areas.
  • The buffer zone: land within 100 feet of a wetland, bank, beach or similar resource area. Most work here needs Conservation Commission review.

How approval works:

  • Contact the Conservation Commission before starting any work in these areas. That includes additions, decks, sheds, driveways, regrading and clearing vegetation.
  • If you're unsure whether the law applies, file a Request for Determination of Applicability (RDA).
  • If the work will affect a resource area, file a Notice of Intent (NOI) with plans and a fee. A public hearing follows, and the commission issues an Order of Conditions approving (with conditions) or denying the project.
  • Applicants, abutters, groups of 10 residents or MassDEP can appeal to MassDEP.

Local bylaws can be stricter. Many towns have their own wetlands bylaw with larger buffers or no-build zones, and the Conservation Commission enforces those too.

State sources: M.G.L. c. 131, §40 (Wetlands Protection Act) · 310 CMR 10.00, Wetlands Protection Act Regulations · MassDEP, Protecting Wetlands in Massachusetts

What the bylaw says

Exact text from Plymouth's published bylaws. Section numbers are as printed in the source.

  1. § 196-4 Jurisdiction, General Bylaws Chapter 196, Wetlands Protection, p. 5
    No person shall remove, fill, dredge or alter within 100 feet, with the exception of Vernal Pools, which shall have 200 foot protection, of the following resource areas: a surface water body, vegetated wetland or unvegetated wetland; any bank, freshwater wetland, coastal wetland, coastal bank, beach, dune, flat, marsh, meadow, bog, swamp or isolated land subject to flooding, lands adjoining the ocean; any estuary, creek, river, stream (whether intermittent or continuous, natural or man-made), pond or lake; any land under said waters; or any land subject to tidal action, coastal action, coastal storm flowage or flooding, as defined by the Federal Emergency Management Agency and designated as Zones A, A1-A30 and V1-V30 and Zone B on the Town of Plymouth, Massachusetts, Flood Insurance Rate Maps and the Flood Boundary and Floodway Maps, as amended, on file with the Town Clerk, and related documents, except as provided in §§ 196-6 and 196-7 or as permitted by the Conservation Commission in § 196-8.
  2. § 196-8.A Notice of intent, General Bylaws Chapter 196, Wetlands Protection, p. 7
    A. A notice of intent (hereinafter referred to as a "notice") shall be filed with the Commission to perform any activity regulated by this chapter, including such plans as may be necessary to describe such proposed activity, the ultimate use of the land and its effect on the environment.
  3. Section 10, Part III, Buffer Zone Resource Area Performance Standards (1)(a)1-2, Rules and Regulations for Plymouth Wetlands Protection Bylaw (Current Version 2025, incl. FTM 2024 Art. 8 vernal pool revision), p. 56
    1. The area within 35 feet of a resource area is a no-touch zone. No development, alteration, filling, dredging, or removal is permitted within the 35-foot no-touch zone. 2. Areas within 35-50 feet of the 100-foot Buffer Zone Resource Area shall be no build zones.
  4. Section 10, Part III, Buffer Zone Resource Area Performance Standards (1)(a)3, Rules and Regulations for Plymouth Wetlands Protection Bylaw (Current Version 2025, incl. FTM 2024 Art. 8 vernal pool revision), p. 56
    3. For work within 50-100 feet of the 100-foot Buffer Zone Resource Area, the Commission may allow activities provided the applicant demonstrates that there are no practical alternatives to locating the activity within the Buffer Zone Resource Area.
  5. Section 10, Part III, Buffer Zone Resource Area Performance Standards (1)(a)5, Rules and Regulations for Plymouth Wetlands Protection Bylaw (Current Version 2025, incl. FTM 2024 Art. 8 vernal pool revision), p. 56
    5. Minor activities within the 35-100 foot area within the Buffer Zone Resource Area and outside any area specified in Section 3A 1 through 5 shall not be subject to regulation.
  6. Section 11.D Vernal Pools, (b), Rules and Regulations for Plymouth Wetlands Protection Bylaw (Current Version 2025, incl. FTM 2024 Art. 8 vernal pool revision), p. 61
    (b) Notwithstanding the above, the first 100 feet of the 200-foot protective radius shall be a no-touch zone.
  7. §203-9.D Exception for Nonconforming Single- and Two-Family Dwellings, Zoning Bylaw of the Town of Plymouth (as amended through October 2025), p. 64
    1. Notwithstanding the foregoing requirements, a Pre-existing Nonconforming Single- or Two-Family Residence may be reconstructed, extended, altered, or structurally changed by-right, as follows: a. upon a determination by the Building Commissioner that such proposed reconstruction, extension, alteration, or change does not increase the nonconforming nature of the residential Structure, or,
This page summarizes Plymouth's posted bylaws as of 2026-10-15. Bylaws are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with Department of Inspectional Services (Building Commissioner / zoning enforcement), 26 Court Street (508-747-1620) before you build. Spot an error?