Coastal Hazards

This page provides a roadmap to currently available data related to coastal hazards and hazardous areas in Maine. Please note that data will be added to this site over time; we invite you to come back to see what’s new.

The table below provides details on the different coastal inundation data sets that are either available or will shortly become available through this site. Datasets in blue are now available and clicking on the name of the dataset will take you to a map viewer where you can view the data, additional information on the development and characteristics of the data, and download the data. Additional datasets will be published as they become available. Questions on the data should be directed to

Baseline Tidal Elevation Inundation Scenarios Represented Primary Data Usages
Highest Astronomical Tide Line Highest Astronomical Tide Extent of the Highest Astronomical Tide Regulatory coastal zone boundary for the state
Sea Level Rise/Storm Surge Highest Astronomical Tide Highest Astronomical Tide, +1.2ft, +1.6ft, +3.9ft, +6.1ft, +8.8ft, or +10.9ft General planning purposes
Potential Tidal Marsh Migration 2015 Highest Annual Tide Migration with +1ft, +2ft, +3.3ft, +6ft sea level rise General planning purposes
Sea Lake and Overland Surges from Hurricanes (SLOSH) Mean High Water Category 1, 2, 3 or 4 hurricane General planning purposes
Beach Mapping Shoreline Change General planning purposes
Maine FEMA Floodplain Maps None * 100 year storm (1% annual probability) Flood insurance and local permitting purposes
* Floodplain maps are generated using statistical analyses of measured storm tides (from a combination of tidal elevation and storm surge) that differ from the static modelling of the other inundation datasets. There is no baseline tidal elevation used in the flood plain maps.

Maine Flood Resilience Checklist

The Maine Flood Resilience Checklist is a simple and practical self-assessment tool designed to assist communities evaluate how well positioned they are to prepare for, respond to, and recover from flooding events and sea level rise. It provides an integrated framework for examining local flood risk, assessing vulnerability of the natural, built, and social environments, and identifying specific opportunities, actions, and strategies to enhance community flood resilience. For more information about the Checklist, please contact the Maine Geological Survey or the Maine Municipal Planning Assistance Program. See the Checklist Overview for a quick introduction to the Checklist.

Last updated on January 9, 2019