Coastal Development: Boston vs Chelsea
How do coastal development rules compare between Boston, MA and Chelsea, MA?
Boston and Chelsea have similar restriction levels.
Boston, MA
Suffolk County
Boston regulates coastal development through Chapter 91 (the Massachusetts Public Waterfront Act), the city's Municipal Harbor Plan, and FEMA flood zone requirements. Development along Boston Harbor must preserve public access and comply with tidelands licensing from MassDEP. Climate Ready Boston has imposed additional resilience standards for coastal projects.
View full Boston rules →Chelsea, MA
Suffolk County
All four Suffolk County municipalities border Boston Harbor or tidal water, triggering Chapter 91 (MGL c. 91) Waterways licensing for work below the high water mark. The MA Wetlands Protection Act (MGL c. 131, §40) regulates work within 100 ft of coastal resources. Boston's Coastal Flood Resilience Overlay District requires elevated construction. Revere and Winthrop have strict Velocity Zone (V-Zone) FEMA requirements.
View full Chelsea rules →Key Facts Comparison
| Fact | Boston | Chelsea |
|---|---|---|
| Key Law | MGL Chapter 91 — Public Waterfront Act | - |
| License Required | MassDEP Waterways License | - |
| Public Access | Harborwalk extensions required | - |
| Flood Zones | FEMA AE and VE zones along coast | - |
| Climate Plan | Climate Ready Boston resilience standards | - |
| State License | - | Chapter 91 (310 CMR 9.00) |
| Wetlands Buffer | - | 100 ft coastal, 200 ft streams |
| Boston Overlay | - | BFE + 2 ft (Article 25A) |
| V-Zone | - | Pile/column foundations |
| Agency | - | MassDEP + local Con Com |
Highlighted rows indicate differences between cities.
Boston FAQ
What is Chapter 91 in Boston?
Chapter 91 is the Massachusetts Public Waterfront Act requiring a Waterways License from MassDEP for any development on tidelands or filled tidelands. It mandates public access to the waterfront and applies to much of Boston's harbor-adjacent land.
Are there special building requirements near Boston Harbor?
Yes. Projects near Boston Harbor must comply with Chapter 91 licensing, Municipal Harbor Plan standards, FEMA flood zone construction requirements, and Climate Ready Boston resilience standards including elevated first floors in flood zones.
Chelsea FAQ
Do I need a Chapter 91 license to rebuild my Winthrop seawall?
Yes. Any new, repaired, or maintained structure waterward of the historic high water mark requires a Chapter 91 license from MassDEP, plus an Order of Conditions.
What is the flood elevation requirement in Boston?
Under Zoning Code Article 25A, occupied floors must be elevated to BFE + 2 feet in coastal flood zones — stricter than the state code's BFE + 1.
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