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

Mashpee, Barnstable County · Bylaws checked 2026-10-20 · Reviewed · 8 cited sections

Allowed with board review

Almost any work within 150 feet of a wetland, pond, beach, bank or the ocean (200 feet of a river) in Mashpee needs Conservation Commission approval under the town's wetlands bylaw (Chapter 172). The Commission generally requires an undisturbed naturally vegetated buffer strip at least 75 feet wide, and zoning requires buildings and structures (other than docks and piers) to be at least 50 feet from water or wetlands.

Local wetlands jurisdictionResource areas plus land within 150 ft; rivers plus land within 200 ft [1]
Naturally vegetated buffer strip (NVBS)At least 75 ft wide unless the Commission is convinced otherwise [2]
NVBS under 75 ftPresumed to have unacceptable effects [3]
Zoning setback from water/wetlands50 ft for any building or structure (docks, piers excepted) [4]
Shoreline access path through the NVBSUp to 4 ft wide; may be approved through an RDA [5]
Small projects 50+ ft from resourcesMay use a Request for Determination of Applicability [6]
FinesUp to $300 per day [8]

What's covered

Mashpee's Wetlands Protection Bylaw (Chapter 172, last amended at the May 1, 2023 Town Meeting) is stricter than the state Wetlands Protection Act. No one may remove, fill, dredge, build on or otherwise alter wetlands, marshes, banks, ponds, beaches, dunes, estuaries, the ocean, land subject to tidal action or flooding, land within 150 ft of those areas, rivers, or land within 200 ft of rivers without Commission approval [1].

Buffer strips

Land within 150 ft of a resource area is presumed important, and the Commission may require a continuous naturally vegetated buffer strip (NVBS) that is a minimum of 75 ft wide unless you show it can be reduced without harm or the work can't be scaled back [2]. Under Regulation 29 the Commission presumes any NVBS under 75 ft has unacceptable effects and may require more where the lot allows [3]. Shoreline access paths up to 4 ft wide may be approved through a Request for Determination of Applicability [5]; the regulation allows one 4-ft or two 2-ft paths per parcel. Within 200 ft of a river, you must also prove there's no practicable alternative.

Zoning setbacks

Zoning §174-33 requires any building or structure, except piers, wharves, docks, bridges or boardwalks, to be at least 50 ft from any water or wetland [4]. Overlay districts (floodplain, Mashpee and Quashnet River protective districts, Waquoit Bay ACEC) add further rules.

Expanding an existing home

Under zoning §174-17 (amended May 4, 2026, AG approved 6-2-2026), a nonconforming single- or two-family home can be altered as of right if the change meets current dimensional rules; increasing an existing nonconformity needs a Zoning Board of Appeals finding that it isn't substantially more detrimental [7]. Wetlands approval is still separate.

Which filing

Small projects 50 ft or more from wetland resources, such as decks or sheds, may use a Request for Determination of Applicability; dwellings, additions, vegetation removal and regrading need a Notice of Intent with engineered plans, abutter notice and a hearing [6]. Some minor buffer-zone work can be approved administratively. Violations can be fined up to $300 a day [8].

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

Next steps

  1. Find out whether your lot is within 150 ft of a wetland, bank, beach or pond (200 ft of a river); ask the Conservation Department (508-539-1400 x8539, conservation@mashpeema.gov).
  2. Email WPA Form 2 with a narrative and plan to the Building Department two weeks before filing with Conservation.
  3. File an RDA for small projects 50+ ft from the resource, or a Notice of Intent with engineered plans for additions, new homes, clearing or regrading.
  4. If the home is nonconforming and the work increases the nonconformity, also apply to the Zoning Board of Appeals for a §174-17 finding.

Common questions

Do I need Conservation Commission approval to build near wetlands in Mashpee, Massachusetts?
Yes. Almost any work within 150 feet of a wetland, pond, beach, bank or the ocean, or 200 feet of a river, needs Conservation Commission approval under the town's wetlands bylaw (Chapter 172).
What is the wetland buffer in Mashpee, MA?
The Commission generally requires an undisturbed naturally vegetated buffer strip at least 75 feet wide and presumes a narrower strip has unacceptable effects. Zoning also requires buildings and structures, other than docks and piers, to be at least 50 feet from water or wetlands.
Can I build a path to the water in Mashpee, Massachusetts?
Shoreline access paths up to 4 feet wide may be approved through a Request for Determination of Applicability; the regulation allows one 4-foot or two 2-foot paths per parcel.
Do I need a Notice of Intent for an addition near wetlands in Mashpee, Massachusetts?
Yes. Dwellings, additions, vegetation removal and regrading need a Notice of Intent with engineered plans, abutter notice and a hearing; small projects 50 feet or more from resources may use a Request for Determination of Applicability. Violations can be fined up to $300 a day.

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

  1. §172-2 Jurisdiction, Chapter 172 Mashpee Wetlands Protection Bylaw (Conservation Commission copy), p. 1
    lands within one hundred and fifty (150’) feet of any of the aforesaid resource areas; rivers; and lands within two hundred (200’) feet of rivers (collectively the “resource areas protected by this bylaw”).
  2. §172-7 A(1), Chapter 172 Mashpee Wetlands Protection Bylaw (Conservation Commission copy), p. 6
    Said NVBS shall be a minimum of seventy five (75’) feet in width unless the applicant convinces the Commission (as per the provisions of Section 12 of this Chapter) that:
  3. Regulation 29 B. Naturally Vegetated Buffer Strips, Mashpee Wetlands Protection Regulations under Chapter 172 (2025 revision, Regulations 1-33), p. 88
    The Commission may require more than 75 feet where conditions on a lot make such possible. Table 29-1 (below) shall be used by the Commission in determining impacts and the widths of NVBS required to carry out the mandates of section 1 of Chapter 172. The Commission shall presume that any NVBS of less than 75 feet will have unacceptable effects upon the wetland values of Chapter 172.
  4. §174-33 Setback from water and wetlands, Zoning Bylaws of the Town of Mashpee, Chapter 174 (2026 edition, updated as of the May 4, 2026 Annual Town Meeting), p. 62
    Any building or structure, exclusive of fixed or floating piers, wharves, docks, bridges or boardwalks, shall be set back at least fifty (50’) feet from any water or wetland as defined by MGL C. 131, §40.
  5. Regulation 29 C. Shoreline Access Paths/Fencing, Mashpee Wetlands Protection Regulations under Chapter 172 (2025 revision, Regulations 1-33), p. 88
    Pathways which provide access to the shoreline may be approved under a Request for Determination of Applicability filing. Pathways may be 4 feet in width or smaller and they should be designed to minimize the amount of vegetation to be removed.
  6. When am I required to file an application with the Conservation Commission?, Conservation Commission FAQs (when to file)
    For small projects 50 feet and greater away from wetland resources a Request for Determination of Applicability may be filed. Examples of small projects that may fall under this category could be the construction of decks, sheds, and native landscaping.
  7. §174-17 C. Continuance; Extensions; Alterations, Zoning Bylaws of the Town of Mashpee, Chapter 174 (2026 edition, updated as of the May 4, 2026 Annual Town Meeting), p. 21
    Changes, extensions or alterations of nonconforming single- or two-family dwelling structures which do not meet the applicable dimensional requirements as set forth above, such that they increase a lawfully preexisting non-conformity without creating a new non-conformity, as well as changes, extensions or alterations of all other nonconforming structures, or nonconforming uses, may not be made unless there is a written finding pursuant to M.G.L. Ch. 40A §6 by the Board of Appeals that such change, extension or alteration shall not be substantially more detrimental to the neighborhood than the existing nonconforming structure or use to the neighborhood and that there is adequate land area to provide sufficient parking and setbacks as may be required all per Subsection D below.
  8. §172-11 E. Enforcement; Violations and Penalties, Chapter 172 Mashpee Wetlands Protection Bylaw (Conservation Commission copy), p. 11
    Any person who violates any provision of this chapter, regulations thereunder or permits issued thereunder shall be punished by a fine of not more than three hundred dollars ($300). Each day a portion thereof during which a violation continues shall constitute a separate offense, and each provision of the chapter, regulations or permit violation shall constitute a separate offense.
This page summarizes Mashpee's posted bylaws as of 2026-10-20. Bylaws are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with Building Department (Building Commissioner David Morris is also the Zoning Official/zoning enforcement officer and staffs the ZBA; Request for Enforcement/Complaint Form at https://www.mashpeema.gov/DocumentCenter/View/5330), Town Hall, 16 Great Neck Road North, Mashpee MA 02649; rental/STR code compliance: Code Compliance Inspector Joseph Callahan, 508-539-1400 x8596, Board of Health 508-539-1426 (508-539-1406) before you build. Spot an error?