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

Chatham, Barnstable County · Bylaws checked 2026-10-03 · Reviewed · 13 cited sections

Allowed with board review

Almost any work within 100 feet of a wetland, bank, beach, pond or the ocean (200 feet of a river) needs a Chatham Conservation Commission permit. New structures, pools, fences and lawns are barred within 50 feet unless a variance is granted, and buildings must also meet a 50-foot zoning setback from the Coastal Conservancy District.

Conservation Commission jurisdictionWithin 100 ft of wetlands, banks, beaches, dunes, ponds, the ocean; 200 ft of a river [1]
No Disturb Zone50 ft from the resource area: no new structures, pools, fences, hardscape or lawn without a variance [4]
Outer buffer (50-100 ft) coverageMax 35% structures and hardscape without a variance [5]
Zoning setback from Coastal Conservancy District50 ft [8]
Zoning setback from Inland Conservancy District25 ft [9]
Tree replacement when removal is allowed1:1 (up to 10 in.), 2:1 (10-20 in.), 3:1 (20 in.+ DBH) [13]

The Wetlands Protection Bylaw text below comes from a January 2018 print and may have changed since; the Commission's regulations we used are current through July 2026.

The Conservation Commission's reach

Chatham's Wetlands Protection Bylaw (Ch. 272) bars removing, filling, dredging, building on or altering land within 100 feet of any wetland, marsh, bank, beach, dune, flat, pond or the ocean without Conservation Commission approval [1]. The same applies within 200 feet of a river, on land subject to coastal storm flowage, and in the Pleasant Bay ACEC [2]. No work may start until you have a permit [3]. You can ask the Commission in writing for a determination of whether your project is covered.

Buffer rules

  • No Disturb Zone (0-50 ft): new structures (outside an existing footprint), new hardscape, pools, fences, lawns and irrigation are prohibited without a variance [4]. Pre-existing structures and hardscape in this zone can't be enlarged without a variance [6].
  • Outer buffer (50-100 ft): no more than 35% may be covered by structures and hardscape without a variance [5]. Hardscape must be pervious and lawns must be drought-tolerant fescue, with no pesticides or fertilizer.
  • A native-plant vegetated buffer strip of at least 25 feet is normally expected next to the resource area.

Zoning: Conservancy Districts

The zoning bylaw also maps Coastal Conservancy Districts (the 100-year floodplain and submerged lands, or the top of a coastal bank) and Inland Conservancy Districts around ponds and wetlands [10]. Structures must meet the conservancy setback [7]. In Appendix II's table, the residential rows list 50 feet from the Coastal Conservancy District and 25 feet from the Inland Conservancy District (the two numbers after the road and abutter setbacks) [9]. Small older lots (built under the January 1, 1987 exemption) get 25 feet from both, but lots of 15,000 sq ft or more must still meet the 50-foot coastal setback [8]. New homes can't be built inside a Conservancy District [11].

Expanding an existing home

Any addition within a required setback, including going taller, needs a special permit from the Zoning Board of Appeals [12]. Near wetlands it also needs Conservation Commission approval.

Trees and clearing

No trees or vegetation may be cut or pruned in a resource area or buffer without Conservation Commission or agent approval. Removal is allowed only for listed reasons and must be replaced at set ratios [13].

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

Next steps

  1. Find out whether your lot is within 100 feet of a wetland, bank, beach or water body (200 feet of a river) or in a Conservancy District; the Conservation Commission office can help.
  2. If unsure, file a Request for Determination; for real work, file an application (Notice of Intent) with plans and the fee, and notify abutters.
  3. For additions within a zoning setback or uses in a Conservancy District, apply to the Zoning Board of Appeals for a special permit (it refers Conservancy cases to the Commission).
  4. Don't clear, prune or cut trees in the buffer until the Commission or Conservation Agent approves it.

Common questions

Do I need a permit to build near a wetland or the shore in Chatham, Massachusetts?
Yes. Almost any work within 100 feet of a wetland, bank, beach, pond or the ocean, or 200 feet of a river, needs a Chatham Conservation Commission permit.
What can't I build near wetlands in Chatham, Massachusetts?
New structures, pools, fences, hardscape and lawns are prohibited within the 50-foot No Disturb Zone without a variance. In the outer buffer from 50 to 100 feet, no more than 35% may be covered by structures and hardscape without a variance.
What are the zoning setbacks from the water in Chatham, Massachusetts?
Buildings must be 50 feet from the Coastal Conservancy District and 25 feet from the Inland Conservancy District. Small older lots get 25 feet from both, but lots of 15,000 sq ft or more must still meet the 50-foot coastal setback.
Can I cut trees near wetlands in Chatham, Massachusetts?
Not without Conservation Commission or agent approval. Removal is allowed only for listed reasons and must be replaced at set ratios.

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 Chatham's published bylaws. Section numbers are as printed in the source.

  1. Ch. 272, §272-3 Jurisdiction (A)-(D), General Bylaws Chapter 272: Wetlands Protection, p. 2
    Except as permitted by the Commission or as provided in this chapter, no person shall remove, fill, dredge, build upon, or alter the following resource areas: A. Upon or within 100 feet of any freshwater wetland, coastal wetland, marsh, wet meadow, vernal pool, bog or swamp; B. Upon or within 100 feet of any bank, beach, dune or flat;
  2. Ch. 272, §272-3 Jurisdiction (E)-(I), General Bylaws Chapter 272: Wetlands Protection, p. 3
    E. Within 200 feet of any river; F. Any land under said waters; G. Upon or within 100 feet of any land subject to flooding or inundation by groundwater, surface water, or tidal action; H. Any land subject to coastal storm flowage;
  3. Ch. 272, §272-5(A)(2) Application for permit, General Bylaws Chapter 272: Wetlands Protection, p. 4
    No activities shall commence without receiving and complying with a permit issued pursuant to this chapter.
  4. Wetlands Protection Regulations Sec. 4.01(6)(c) No Disturb Zones, Chatham Wetlands Protection Regulations (Rev. 6/11/2025, 1/14/2026, 7/1/2026), p. 69
    Specifically, within the NDZ, the following are prohibited unless authorized by the issuance of a variance pursuant to Section 1.12 of these regulations. (1) New structures (unless limited to the footprint of an existing structure) (2) new impervious or semi-pervious hardscape (3) new swimming pools (4) new fences (5) new turf or sod lawns
  5. Wetlands Protection Regulations Sec. 4.01(5)(a)(1)(ii) Outer AURAs, Chatham Wetlands Protection Regulations (Rev. 6/11/2025, 1/14/2026, 7/1/2026), p. 68
    In any case, no more than 35% of the Outer AURA may be covered by any combination of structure and hardscape without a Variance.
  6. Wetlands Protection Regulations Sec. 4.01(6)(f)(3) Previously altered No Disturb Zones, Chatham Wetlands Protection Regulations (Rev. 6/11/2025, 1/14/2026, 7/1/2026), p. 70
    No enlargement of pre-existing structures or hardscape will be permitted without issuance of a Variance pursuant to Section 1.12 of these regulations.
  7. Sec. IV.A.6.b Conservancy Districts, Setbacks, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 36
    Other than structures listed in Section IV.2 and Section IV.3, structures shall meet the Conservancy District Setback as required for buildings and structures in Appendix II, Schedule of Dimensional Requirements.
  8. Sec. V.D.4.b Nonconforming Lots (lots existing as of January 1, 1987), Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 58
    Inland and Coastal Conservancy Districts: 25 feet Lots of fifteen thousand (15,000) square feet or more shall comply with the fifty (50) foot setback requirement of the Coastal Conservancy District.
  9. Appendix II Schedule of Dimensional Requirements, Conservancy District Setbacks (Coastal, Inland), Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 106
    R3013 30,000 100 25 15 50 25 N/A 10%12 N/A 2 ½ 30 2011 1011 R2013 20,000 100 25 15 50 25 N/A 10%12 N/A 2 ½ 30 2011 1011
  10. Sec. IV.A.5.a Conservancy Districts, Location, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 36
    The Coastal Conservancy Districts shall consist of all the submerged lands along the coast of Town, and areas subject to flooding including:
  11. Sec. IV.A.4.d Conservancy Districts, Prohibited Uses, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 35
    No person shall construct a new residential dwelling unit, or use a houseboat or barge designed or used as a dwelling unit in the Conservancy District.
  12. Sec. V.B Nonconforming Buildings, Enlargement, Extension or Change, Protective Zoning Bylaw, as amended through May 2025 (attested 09/03/2025), p. 56
    For dwellings with setback nonconformities, any addition within the required setback area (including an increase in building height) shall be deemed to increase the nonconforming nature of the dwelling. Such alterations, extensions or changes shall require a Special Permit from the Zoning Board of Appeals.
  13. Wetlands Protection Regulations Sec. 5.02(5)(c) Replacement Ratios for Tree Removal, Chatham Wetlands Protection Regulations (Rev. 6/11/2025, 1/14/2026, 7/1/2026), p. 75
    i. Trees with trunks over 1 1/2” up to 10” DBH: replacement ratio of at least 1:1 is required. ii. Trees with trunks over 10” DBH up to 20” DBH: replacement ratio of at least 2:1 is required. iii. Trees with trunks of 20” DBH or larger: replacement ratio of at least 3:1 is required.
This page summarizes Chatham's posted bylaws as of 2026-10-03. Bylaws are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with Community Development - Building Division (Building Commissioner) (508-945-5168) before you build. Spot an error?