Building near the water in Duxbury, Massachusetts (wetlands rules)
Work within 100 feet of any wetland, bank, beach, marsh or water body in Duxbury, or within 200 feet of a river, needs Conservation Commission approval under the town wetlands bylaw. The Commission's regulations bar new foundation-built structures within 50 feet of a resource area (35 feet on open piles) and lawns or patios within 25 feet. Zoning also generally prohibits building within 25 feet of the water unless the Board of Appeals grants a special permit. In FEMA coastal velocity (V) zones, the regulations prohibit new buildings and additions.
| Wetlands bylaw jurisdiction | Resource areas plus 100-ft buffer zone; 200 ft from rivers [1] |
| Structures on wall-type foundations | Not allowed within 50 ft of a resource area [4] |
| Structures on open-pile foundations | Not allowed within 35 ft of a resource area [5] |
| Lawns, patios, walkways, driveways | Not allowed within 25 ft of a resource area [6] |
| Max coverage in buffer zone (residential) | 15% [8] |
| Zoning Wetlands Protection Overlay | Land within 25 ft of high water, mean high tide or stream banks; buildings need a special permit [9] |
| FEMA velocity (V) zones | New buildings, sheds, garages and additions prohibited; existing buildings may be rebuilt with no added square footage [15] |
The Conservation Commission regulations used here are dated August 2022; the Commission lists a June 2023 revision we could not obtain, so confirm the distances with it.
Which areas are covered
Massachusetts has no "shoreland zone." In Duxbury, work near water is controlled by the town wetlands bylaw (General By-laws Ch. 9) and the state Wetlands Protection Act, both run by the Conservation Commission. The bylaw covers banks, wetlands, beaches, dunes, marshes, flats, ponds, streams, the ocean, land subject to flooding, a 100-foot buffer zone around all of these, and land within 200 feet of a river [1]. Separately, the zoning bylaw's Wetlands Protection Overlay District takes in all land within 25 feet of the high water line, mean high tide line or stream banks, plus mapped areas [9].
Approvals
You can't start regulated work without filing a notice of intent and getting an Order of Conditions, with all appeal periods expired [2]. If you're unsure whether the bylaw applies, you can ask the Commission for a determination. It must respond within 21 days [13]. In the zoning overlay district, buildings and structures are prohibited without a Board of Appeals special permit [10]. Homes that existed before March 13, 1971 may be repaired, rebuilt or enlarged, including garages and outbuildings, without that special permit [11].
Setbacks from resource areas
The Commission's regulations set firm minimum distances:
- No structure on a wall-type foundation within 50 feet of a resource area, whatever the mitigation [4].
- No structure on an open-pile foundation within 35 feet [5].
- No lawns, patios, walkways or driveways within 25 feet [6].
- Total coverage in the buffer zone can't exceed 15% on residential lots [8].
- In FEMA velocity (V) zones on the coast, new buildings, sheds, garages and additions (including added floors) are prohibited. Existing buildings may be renovated or rebuilt with no increase in square footage, using flood-resistant construction [14][15].
Trees and vegetation
Under the bylaw, cutting or trimming trees and shrubs counts as altering a resource area [3]. Buffer zones must stay in a naturally vegetated condition [7]. Pruning for views or invasive-plant control may be allowed with approval.
Expanding a nonconforming home
A nonconforming house can be expanded with only a building permit if the addition itself conforms and doesn't add to any nonconformity. Otherwise the Board of Appeals must find the change isn't substantially more detrimental to the neighborhood [12]. Wetlands rules apply on top of that.
Source note
Zoning rules are from the June 2025 compilation.
Next steps
- Ask the Conservation Commission (Town Hall) whether your project is within 100 ft of a resource area or 200 ft of a river; file a Request for Determination if unsure.
- For regulated work, file a Notice of Intent with plans (wetland line flagged and surveyed) and get an Order of Conditions before any permits.
- If the work is within the zoning Wetlands Protection Overlay District (25 ft of the water or mapped areas), apply to the Zoning Board of Appeals for a special permit.
- Then apply to the Building Department for a building permit with a plot plan showing the overlay district lines.
Common questions
- Do I need approval to build near water or wetlands in Duxbury, Massachusetts?
- Yes. Work within 100 feet of any wetland, bank, beach, marsh or water body, or within 200 feet of a river, needs Conservation Commission approval under the town wetlands bylaw.
- How close to a wetland can I build in Duxbury, Massachusetts?
- The Commission's regulations bar new foundation-built structures within 50 feet of a resource area (35 feet on open piles) and lawns or patios within 25 feet.
- Can I build within 25 feet of the water in Duxbury, Massachusetts?
- Zoning generally prohibits it unless the Board of Appeals grants a special permit.
- Can I build in a coastal velocity zone in Duxbury, Massachusetts?
- No. In FEMA coastal velocity (V) zones, the regulations prohibit new buildings and additions.
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.
What the bylaw says
- Ch. 9.1.2 (Wetlands Protection, Jurisdiction), General By-laws, revised 10-23-25 (incl. Ch. 9 Wetlands Protection, Ch. 7.1 Animal Control, Ch. 11 Right-to-Farm), p. 82
Except as permitted by the Conservation Commission or as provided in this Bylaw, no person shall remove, fill, dredge, build upon, degrade, discharge into, or otherwise alter the following resource areas: any bank, fresh water or coastal wetland, isolated wetland, beach, dune, flat, marsh, wet meadow, bog, swamp, vernal pool, the ocean, estuary, creek, river, stream, pond or lake, land under water body, land subject to tidal action, coastal storm flowage, or flooding, land subject to flooding or inundation by ground water or surface water, land within a minimum distance of 100 feet from any of the aforesaid resource areas (buffer zone), and land within 200 feet of a river (collectively the “resource areas protected by this bylaw”).
- Ch. 9.1.6, General By-laws, revised 10-23-25 (incl. Ch. 9 Wetlands Protection, Ch. 7.1 Animal Control, Ch. 11 Right-to-Farm), p. 83
No one intending to conduct any of the above named activities may commence such activity within the jurisdiction of this Bylaw without filing written notice of their intention so to remove, fill, dredge or alter and without receiving and complying with an order of conditions and provided all appeal periods have elapsed.
- Ch. 9.1.5 (Definitions, Alter), General By-laws, revised 10-23-25 (incl. Ch. 9 Wetlands Protection, Ch. 7.1 Animal Control, Ch. 11 Right-to-Farm), p. 83
(h) Destruction or removal of plant life, including, but not limited to, cutting or trimming of trees and shrubs;
- DWR 23.9(c) (Structures), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 65
c) No mitigation is sufficient to allow a structure on a wall-type foundation less than 50 feet to a Resource Area, as defined in DWR 2.0 (1-5).
- DWR 23.9(e), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 66
e) No mitigation is sufficient to allow a structure on an open pile foundation less than 35 feet to a Resource Area, as defined in DWR 2.0 (1-5).
- DWR 23.3 (Landscaping), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 62
No lawns, patios, walkways, driveways, or similar structures may be constructed within 25 feet of any Resource Area, as defined in DWR 2.00 (1-5).
- DWR 22.0(d)(2) (Buffer Zone performance standards), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 59
2) Buffer zones shall be retained and maintained in a Naturally Vegetated Condition.
- DWR 23.4 (Coverage), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 62
Total coverage of any type shall not exceed 15% in residential zoned areas in the Buffer Zone to any Resource Area as defined in DWR 2.00(6).
- Sec. 202.2(8), Protective (Zoning) Bylaws, amended through June STM 2025, p. 9
8. All land within twenty-five feet, measured horizontally, of the high water line of all waterbodies, the mean high tide line and the banks of all watercourses is within the Wetlands Protection District, unless specifically excluded.
- Sec. 404.5(4), Protective (Zoning) Bylaws, amended through June STM 2025, p. 38
4. Buildings or structures except those permitted by Sections 404.4 and permitted by special permit by Sections 404.6 and 404.9.
- Sec. 404.11 (Exemptions), Protective (Zoning) Bylaws, amended through June STM 2025, p. 40
All residential dwellings, commercial and business buildings existing in the Wetlands Protection Overlay District on March 13, 1971, or building permits for which were issued prior to March 13, 1971, and those portions only of the lots needed to repair, rebuild, modify or enlarge, any such buildings, including but not limited to, the addition of garage and living space and construction of appurtenant outbuildings, together with such filling, diking, and/or drainage as may be necessary for the protection of said structures from flood inundation, provided that all construction of any type is consistent with the laws of the Commonwealth of Massachusetts, in compliance with all other zoning requirements, and does not affect the natural flow pattern of any watercourse.
- Sec. 401.2(4)(a), Protective (Zoning) Bylaws, amended through June STM 2025, p. 21
a) As provided for in G. L. c. 40A sec. 6, a nonconforming single or two-family dwelling or structure accessory thereto may be altered, reconstructed, extended or otherwise structurally changed provided that: (1) the proposed alteration, extension or structural change itself conforms to the requirements of the present Bylaw and does not intensify any existing non-conformities or result in any additional non-conformities in which event the Zoning Enforcement Officer may issue a building permit and an application to the Board of Appeals need not be made; or (2) as provided below the Board of Appeals finds that (i) there is no substantial increase in the nonconforming nature of said structure; and (ii) such reconstruction, alteration or extension will not be substantially more detrimental to the neighborhood than the existing nonconforming structure or use.
- Ch. 9.1.6, General By-laws, revised 10-23-25 (incl. Ch. 9 Wetlands Protection, Ch. 7.1 Animal Control, Ch. 11 Right-to-Farm), p. 84
The Conservation Commission shall make a determination as to whether or not this Bylaw applies to a specific situation prior to the filing of a written notice of intent under the provisions hereof, within twenty-one (21) days of the receipt of a written request sent by certified mail or hand delivered from any person desiring such determination.
- DWR 20.1(d)(5) (Land Subject to Coastal Storm Flowage, V-Zones), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 50
5) The following activities proposed within Velocity Zones (V-Zones) are likely to have an adverse effect on the protected values and are therefore prohibited:
- DWR 20.1(d)(5)(a)-(b), Duxbury Wetlands Regulations (Conservation Commission), revised 07/12/2022, approved 08/09/2022, p. 50
(a) New construction or placement of new structures, including buildings, sheds, and garages. Existing buildings may be renovated or reconstructed with no increase in square footage but must be built using flood-resistant construction. (b) Additions to existing structures, including additional floors on the existing structures.