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

Sandwich, Barnstable County · Bylaws checked 2026-10-20 · Reviewed · 9 cited sections

Allowed with board review

Building, clearing, filling or other changes within 100 feet of any wetland, pond, stream, beach, dune, bank or salt marsh, or anywhere in the 100- or 500-year flood zone, needs a Conservation Commission permit under Sandwich's Wetlands Bylaw (Chapter 7). The Commission generally requires a 50-foot undisturbed buffer next to the resource area. Zoning also bars new principal buildings within 50 feet of freshwater ponds and lakes.

Conservation Commission jurisdictionWithin 100 ft of wetlands, water bodies, beaches, dunes, banks, marshes; all of the 100- and 500-year flood zones [1]
Undisturbed bufferAt least 50 ft between the resource area and any site disturbance [2]
Recommended structure location20 ft landward of the 50-ft buffer edge (about 70 ft from the resource) [2]
Principal structure setback from ponds and lakes (zoning)50 feet [4]
Foundations on beaches, dunes, barrier beachesDriven piles or helical anchors; no sonotubes or concrete footings; 24 in. above grade [5]
Lot clearing without a building permit (Nov. 2025)Administrative site plan review before clearing 10,000 sq ft or more [7]
Vegetated lot area (Nov. 2025)At least 30% of the lot [8]
Expanding a nonconforming homeSpecial permit from the ZBA, or a written finding if the increase is under 30% [9]

Where the rules apply

Sandwich's Wetlands Bylaw (general bylaws Chapter 7) prohibits removing, filling, dredging, building on or altering land within 100 feet of resource areas without a Conservation Commission permit. Resource areas include freshwater and coastal wetlands, ponds, the ocean, bays, streams, banks, beaches, dunes, flats, marshes and bogs. The bylaw also covers all land subject to coastal storm flowage or flooding in the 100-year and 500-year FEMA flood zones [1]. This reaches farther than the state Wetlands Protection Act.

Buffers and setbacks

Under Conservation Commission Regulation No. 9, a minimum 50-foot undisturbed buffer must be kept between the resource area and the upland limit of any site disturbance. Structures are recommended at least 20 feet landward of that buffer [2]. Elevated walkways, access paths 24 inches wide or less, limited vista pruning, and water-dependent structures may be allowed at the Commission's discretion. The Commission can require a wider buffer on slopes over 18% [3]. Separately, zoning Section 3610 bars any principal structure within 50 feet of freshwater ponds and lakes, measured from listed pond elevations (for example, Lawrence Pond 65 ft, Peters Pond 71 ft) [4].

Coastal construction

Regulation No. 13 requires foundations on coastal beaches, dunes and barrier beaches to be driven piles or helical screw anchors designed by a Massachusetts engineer. Sonotubes and concrete footings aren't permitted, and the lowest horizontal member must be at least 24 inches above grade [5]. The Board of Health bars new septic systems on coastal beaches, dunes, banks and barrier beaches, except repairs for an existing dwelling, and bars expanding systems for added bedrooms [6].

Clearing and nonconforming homes

The November 2025 Special Town Meeting amended zoning Section 3510. Without a building permit, administrative site plan review is now required before clear-cutting 10,000 sq ft or more [7]. The existing rule that at least 30% of a lot must stay vegetated was kept [8]. This amendment isn't in the posted May 2025 zoning book. Changing or extending a nonconforming structure needs a ZBA special permit. The Zoning Enforcement Officer can waive this for a single- or two-family home if the change increases the nonconformity by less than 30% [9]. Small projects (decks or sheds of 80 sq ft or less, at least 50 feet from the resource) may qualify for $75 staff administrative review.

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

Next steps

  1. Ask the Natural Resources Department (508-833-8054, conservation@sandwichmass.org) whether your lot is within 100 ft of a resource area or in the 100- or 500-year flood zone.
  2. For small work at least 50 ft from the resource area, apply for Conservation administrative review ($75, with photos); otherwise file a Request for Determination of Applicability or a Notice of Intent with the Conservation Commission.
  3. Plan to keep a 50-ft undisturbed buffer, and use pile or helical-anchor foundations on beaches, dunes or barrier beaches.
  4. Check with the Building Department (setbacks@sandwichmass.org) on the 50-ft pond setback, any nonconforming-structure finding or ZBA special permit, and the Board of Health on septic limits in coastal areas.

Common questions

Do I need a permit to build near wetlands in Sandwich, Massachusetts?
Yes. Building, clearing, filling or other changes within 100 feet of any wetland, pond, stream, beach, dune, bank or salt marsh, or anywhere in the 100- or 500-year flood zone, needs a Conservation Commission permit under Sandwich's Wetlands Bylaw.
What is the wetland buffer in Sandwich, MA?
The Conservation Commission generally requires at least a 50-foot undisturbed buffer between the resource area and any site disturbance. It recommends structures sit 20 feet landward of that buffer, and it can require a wider buffer on slopes over 18%.
How close to a pond can I build in Sandwich, Massachusetts?
Zoning bars new principal buildings within 50 feet of freshwater ponds and lakes. Work within 100 feet also needs Conservation Commission approval.
Can I build on a beach or dune in Sandwich, MA?
Only with Conservation Commission approval, and foundations must be driven piles or helical screw anchors designed by a Massachusetts engineer, with no sonotubes or concrete footings. The lowest member must be at least 24 inches above grade. New septic systems are barred there except repairs for an existing dwelling.

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

  1. Ch. 7, Section 7.10 Jurisdiction, Part 1, Town of Sandwich Town Bylaws (Town Clerk edition dated May 4, 2026), p. 64
    Except as permitted by the Conservation Commission or provided in this bylaw, no person shall remove, fill, dredge, build upon, or alter land in or within one hundred (100) feet of the following resource areas: freshwater wetland, coastal wetland, vegetated wetland, unvegetated wetland, surface water body, ocean, bay, estuary, stream/creek (intermittent or continuous, natural or manmade), and land under said water, any bank, beach, dune, flat, marsh, wet meadow, bog, swamp, or any land subject to coastal action, or inundation by groundwater, surface water, tidal action, coastal storm flowage or land subject to flooding within the one-hundred (100) year and five-hundred (500) year flood zone as identified on the most recent FIRM (Flood Insurance Rate Maps) for the Town of Sandwich as established by FEMA (Federal Emergency Management Agency).
  2. Regulation No. 9, Part 1, Sandwich Conservation Commission Regulations (Regulations No. 1-13), p. 11
    At a minimum, an undisturbed buffer area of, a minimum of fifty (50) feet in width shall be provided between wetland resource areas and the upland limit of any site disturbance. [It is recommended that the proposed structure(s) within the buffer zone be located no closer than twenty (20) feet from the landward edge of the buffer, so that the proposed construction, landscaping and maintenance activities may ensue without a buffer zone violation].
  3. Regulation No. 9, Part 1, Sandwich Conservation Commission Regulations (Regulations No. 1-13), p. 11
    In cases where the slope of undisturbed buffer exceeds eighteen (18) percent, or in any instance where the scope or nature of a project is likely to require a greater distance to wetland resource areas, the Commission reserves the right to increase the width of the undisturbed buffer zone.
  4. Sec. 3610 Pond Setback, Protective Zoning By-law (May 2025 edition), p. 29
    No principal structure shall be erected less than fifty (50) feet from the waters of fresh water ponds and lakes.
  5. Regulation No. 13, Part I, Sandwich Conservation Commission Regulations (Regulations No. 1-13), p. 19
    Sono tubes and concrete footings are not permitted. The lowest horizontal member of said structure must be elevated a minimum of twenty four (24) inches over existing grade, at installation.
  6. Coastal: Beaches, Dunes, Banks, and Barrier Beach Regulation, Board of Health Regulations, Policies and Clarification of Policies (revised August 14, 2023), p. 24
    no newly constructed Title V septic system shall be permitted/installed except to repair a system for an existing dwelling
  7. Nov 17, 2025 STM, Article 3 (zoning Sec. 3510a), 2025 Town Meeting Results (Jan 13, 2025 STM; May 5, 2025 ATM; Nov 17, 2025 STM) - certified votes and article text, p. 31
    In absence of a building permit, administrative site plan review is required prior to any clear cutting of trees or understory on a lot that disturbs 10,000 square feet or more and shall be subject to Section 3530.
  8. Nov 17, 2025 STM, Article 3 (zoning Sec. 3510b), 2025 Town Meeting Results (Jan 13, 2025 STM; May 5, 2025 ATM; Nov 17, 2025 STM) - certified votes and article text, p. 32
    Not less than thirty (30) percent of lot area shall be retained in a vegetated condition unless reduced by special permit.
  9. Sec. 2420 Change, Extension or Alteration, Protective Zoning By-law (May 2025 edition), p. 23
    The Zoning Enforcement Officer may provide a written finding that any alteration, reconstruction, extension or structural change to a lawfully existing single or two-family residential structure shall not be subject to the special permit requirements of this Section 2420 if the alteration, reconstruction, extension or structural change does not increase the nonconforming nature of the structure by 30% or more.
This page summarizes Sandwich'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 administers and enforces the Protective Zoning By-law, incl. s.4130 ADUs, and the general bylaw Ch. 12 Short-Term Rentals; zoning complaints on the Zoning Complaint Form), Town Hall Annex, 100 Route 6A, Sandwich MA 02563; email building@sandwichmass.org; setback questions setbacks@sandwichmass.org (508-888-4200) before you build. Spot an error?