Flood Zone Mapping Tool
- Did You Know?
- Over 400,000 Massachusetts residents currently live in a 100-year flood zone, which means more than a 1 in 4 chance of a flood during a 30-year mortgage period. With climate change, this is likely to occur more frequently.
Flooding is a concern for many living in inland and coastal areas of Massachusetts. The Flood Zone Mapping Tool can help you learn if your residence sits within a Federal Emergency Management Agency (FEMA) designated flood zone or floodplain. If you know you live in a flood zone, you can better prepare yourself and your family in the event of flooding that may occur from heavy rains, poor drainage, nearby construction projects, or storm-related surges in inland and coastal areas.
How will climate change impact flooding?
Some of the most serious climate-related health hazards in Massachusetts are:
- Increasing precipitation leading to flooding
- Increasing storm-related inland and coastal flooding
- Rising sea levels which can cause increased tidal flooding and higher storm surges
Projected increases in precipitation levels may exceed the capacity of existing infrastructure, such as drainage systems, bridges, culverts, and sewers, to divert water. Flooding can result in exposure to contaminated flood water, debris and physical hazards such as downed wires, loss of electricity and/or heat, unsafe food and drinking water, and mold growth. Furthermore, flooding can temporarily or permanently displace residents. Rising sea levels may erode shorelines, threaten coastal drinking water supplies with salt-water intrusion, disrupt septic systems and sewage treatment, and displace residents. Tidal flooding can also result in the salinization of land leading to loss of shaded areas and green space.
What data are available?
The map layers provided include:
- FEMA’s National Flood Hazard Layer: a compilation of effective Flood Insurance Rate Map (FIRM) databases and any Letters of Map Revision (LOMR) that have been issued. This dataset represents the areas inundated in a 100-year and 500-year flood.
- FEMA Q3 Flood Zones: data layer showing areas for which the newer National Flood Hazard Layer are not available.
- Hurricane Inundation Zones: data representing worst-case Hurricane Surge Inundation areas for Category 1 through 4 hurricanes striking the coast of Massachusetts.
- Hurricane Evacuation Zones: data layer depicts areas that may be inundated by storm surge or isolated by storm surge waters. It provides critical information to aid local public officials in evaluating evacuation decisions as a hurricane approaches. The data also provides critical information to citizens who live or work in areas that may need to be evacuated as a hurricane approaches.
- MassDOT Roads: official state-maintained street transportation dataset developed by the Massachusetts Department of Transportation. It represents all of the public and many of the private roadways in Massachusetts.
- NOAA Sea Level Rise: data from the National Oceanic and Atmospheric Administration Office for Coastal Management depicting potential sea level rise (SLR) and its associated impacts on the nation's coastal areas.