Flood Zones: Lowell vs Waltham
How do flood zones rules compare between Lowell, MA and Waltham, MA?
Lowell and Waltham have similar restriction levels.
Lowell, MA
Middlesex County
Lowell lies along the Merrimack and Concord Rivers with extensive FEMA Special Flood Hazard Areas, and all construction in those zones must meet the Massachusetts Floodplain Overlay and NFIP standards.
View full Lowell 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 | Lowell | Waltham |
|---|---|---|
| Primary river | Merrimack River | - |
| Freeboard | 1 foot above BFE | 1 foot above BFE |
| Historic floods | 1936, 1987, 2006, 2007 | - |
| Insurance | Required in SFHA | - |
| Main Floodplain | - | Charles River Zone AE |
| Substantial Improvement | - | 50 percent market value |
| Floodway Fill | - | Prohibited |
| FIRM Update | - | 2021 effective maps |
Highlighted rows indicate differences between cities.
Lowell FAQ
How do I check if my Lowell property is in a flood zone?
Use the FEMA Flood Map Service Center at msc.fema.gov and enter your address; also confirm with Lowell Development Services.
Can I build an addition in a Lowell flood zone?
Yes if it meets the Floodplain Overlay standards including elevation above BFE plus 1 foot of freeboard and flood-resistant materials.
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.
Compare other topics
See how Lowell and Waltham compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool