Flood Zones: Cambridge vs Waltham
How do flood zones rules compare between Cambridge, MA and Waltham, MA?
Cambridge and Waltham have similar restriction levels.
Cambridge, MA
Middlesex County
Cambridge participates in the National Flood Insurance Program and enforces a Flood Plain Overlay District covering FEMA Special Flood Hazard Areas along the Charles River and Alewife Brook.
View full Cambridge rules →Waltham, MA
Middlesex County
Waltham enforces FEMA floodplain regulations along the Charles River and its tributaries, requiring flood elevation certificates and floodproofing for development in A and AE zones.
View full Waltham rules →Key Facts Comparison
| Fact | Cambridge | Waltham |
|---|---|---|
| Program | NFIP participant | - |
| Main flood areas | Charles, Alewife | - |
| Elevation | Above BFE plus freeboard | - |
| Insurance | Required for SFHA mortgages | - |
| Future risk | Climate Vuln Assessment | - |
| Main Floodplain | - | Charles River Zone AE |
| Freeboard | - | 1 foot above BFE |
| Substantial Improvement | - | 50 percent market value |
| Floodway Fill | - | Prohibited |
| FIRM Update | - | 2021 effective maps |
Highlighted rows indicate differences between cities.
Cambridge FAQ
Is my Cambridge property in a flood zone?
Check the FEMA Map Service Center and the Cambridge GIS portal using your address to see FEMA zone designation.
Do I need flood insurance?
Federally-backed mortgages in SFHAs require flood insurance; it is recommended even in moderate-risk areas.
Waltham FAQ
How do I know if my Waltham property is in a flood zone?
Check the FEMA Flood Map Service Center online by address, or contact the Waltham Conservation Commission for assistance reading the FIRM.
Do I need flood insurance in Waltham?
Federal law requires it for mortgaged properties in Zone AE. Even outside mapped zones, flood insurance is recommended near the Charles River or its tributaries.
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