Barnstable County, MA Environmental Rules: Flood Zones (2026)

Barnstable County comprises 15 towns (Barnstable, Bourne, Brewster, Chatham, Dennis, Eastham, Falmouth, Harwich, Mashpee, Orleans, Provincetown, Sandwich, Truro, Wellfleet, and Yarmouth) and roughly 560 miles of tidal shoreline. All towns participate in the National Flood Insurance Program (NFIP), and FEMA's countywide Flood Insurance Rate Maps (FIRMs) and Flood Insurance Study became effective July 16, 2014. Mapped zones include VE (coastal high-hazard with 3-foot+ wave action), AE (1% annual chance flood with established Base Flood Elevation), AO/AH (shallow flooding), Coastal A / LiMWA (Limit of Moderate Wave Action), and X (areas of reduced or minimal hazard). Floodplain administration is delegated to each town - typically the building commissioner, conservation agent, or designated floodplain administrator. Massachusetts adopts flood-resistant construction through the 9th Edition Massachusetts State Building Code 780 CMR Chapters 51 (residential, R322) and 1612 / Appendix G (commercial), which incorporate ASCE 24-14 by reference. The Massachusetts code is more stringent than the NFIP minimum, requiring the Design Flood Elevation to equal the FEMA Base Flood Elevation plus 3 feet of freeboard in V Zones and Coastal A Zones, with breakaway walls, pile or column foundations, and flood-damage-resistant materials below the DFE. Independently, the Massachusetts Wetlands Protection Act (M.G.L. c. 131 sec. 40) and its regulations at 310 CMR 10.00 prohibit any removal, fill, dredge, or alteration of coastal banks, beaches, dunes, barrier beaches, salt marshes, land under the ocean, or land subject to coastal storm flowage without a Notice of Intent and Order of Conditions from the local Conservation Commission, with appeal to the Massachusetts Department of Environmental Protection (MassDEP). Many Cape Cod towns also have local wetlands bylaws (Barnstable Chapters 237 and 704, for example) with stricter buffer-zone setbacks (commonly 35-100 feet) than state law. The Cape Cod Commission, the regional planning agency for Barnstable County, has issued a 2021 Model Coastal Resilience Bylaw, 2024 Model Wetlands Regulations, and a Model Floodplain Zoning Bylaw (Higher Standards) that towns may adopt to require additional freeboard, prohibit new development on barrier beaches and coastal dunes, and incorporate Massachusetts Coast Flood Risk Model (MC-FRM) projections of 2.5 feet of sea level rise by 2050 and 4.3 feet by 2070. The County has designated 12 Districts of Critical Planning Concern (DCPCs), several with explicit flood-protection purposes such as the Black Beach / Great Sippewissett Marsh DCPC in Falmouth (designated January 1996). The 50% substantial improvement / substantial damage rule of the NFIP (44 CFR 60.3) applies: when the cost of improvements or repairs to a structure within an SFHA reaches half of its market value, the entire structure must be brought into full compliance with current floodplain standards. Nine Cape Cod towns participate in the FEMA Community Rating System (CRS) for 5 to 20 percent flood-insurance discounts, coordinated regionally by the Cape Cod Cooperative Extension Floodplain Specialist (508-375-6952).