Sea Level Rise/Storm Surge

To view the data, zoom in on the map to your area of interest. The data will activate automatically while zooming in.
Please note that the maximum zoom to view data is at a scale of 1:4800 beyond which the flood layers will not draw.
To show different sea level rise/storm surge scenarios, use the Layers menu widget in the upper right of the map window.

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Data Description and Usage

This dataset approximates the potential inland extent of inundation from several scenarios (1.2, 1.6, 3.9, 6.1, 8.8 and 10.9 feet) of sea level rise or storm surge along the Maine coastline on top of the Highest Astronomical Tide. That Highest Astronomical Tide layer displays the maximum predicted astronomical high tide for the current National Tidal Datum Epoch (1983-2001). The sea level rise scenarios were developed by using available long-term sea level rise data from Portland, Bar Harbor, and Eastport tide gauges and the US Army Corps of Engineers Sea-Level Change Curve Calculator (v. 2017.55) and sea level rise scenarios established by NOAA et al. (2017) prepared for the US National Climate Assessment. Scenarios include low, intermediate low, intermediate, intermediate high, high, and extreme sea level rise at the 50% confidence interval. The data were developed with a static (“bathtub”) inundation model that uses LiDAR topographic data as a base digital elevation model, and first adjusts Highest Astronomical Tide tidal predictions to take into account variability in elevation datums along the Maine coastline, and then adds the storm surge/sea level rise scenarios to that initial starting elevation. The primary purpose of these data is to help inform storm surge and sea level rise vulnerability assessments and community planning.

Data Disclaimer

These data are meant to help inform decisions at the local, regional, and state-level for storm surge and sea level rise using the Highest Astronomical Tide as the starting point. Users must assume responsibility in determining the usability of this data for their purposes. Metadata is included for all of the downloadable layers and should be reviewed for more specifics on how these data were created. Neither the Maine Geological Survey nor the Department of Agriculture, Conservation and Forestry, nor its employees or agents: (1) make any warranty, either expressed or implied for merchantability or fitness for a particular purpose, as to the accuracy or reliability of the information shown on the map; nor are they (2) liable for any damages, including consequential damages, from using the map or the inability to use the map.

Frequently Asked Questions

The frequently asked questions provide more information about how the data layers were created, what they should be used for, usage limitations and general information on sea level rise and storm surge in Maine.

Data Download

The sea level rise/storm surge map layers can be downloaded as shapefiles for use in any GIS software to perform further spatial analysis.

More Help

Contact the Maine Geological Survey with questions at:

Last updated on January 23, 2019