Coastal Bluff Survey Tool

What is a coastal bluff and what is the Coastal Bluff Survey Tool?

A bluff is defined as a steep shoreline slope formed in sediment (loose material such as clay, sand, and gravel) that has three feet or more of vertical elevation just above the high tide line. The Maine Geological Survey (MGS) produces Coastal Bluff Maps which interpret coastal bluff stability and sediment supply. These maps were originally created in 2000-2005 and are in the process of being updated in 2026-2029 using visual and terrain characteristics.

The Coastal Bluff Survey Tool (CBST) is an online survey tool which allows users to visually assess and submit information on coastal bluff stability at locations along the Maine shoreline. The CBST allows for continued updating of bluff information without having to undertake large-scale remapping efforts.

How does the CBST work?

The tool uses ArcGIS’s Survey123 software to ask users a series of key questions relating to bluff stability and sediment supply. It also allows users to take and upload georeferenced photographs using a cellular device. Users can access the CBST using the link provided. Survey responses and photographs submitted through the CBST are uploaded into an MGS database. MGS geologists review these submissions and utilize the information to update bluff stability maps and related information on a quarterly basis. The location of each georeferenced CBST assessment is visible in an accompanying map viewer (embedded below), which is available to all users.

Is there anything special I need to do with my cellular device?

If submitting photographs, please make sure your device is set to provide your location. This may require enabling location services on your device’s camera app or turning on the GPS setting in your standalone camera. On an Android device, open your device Settings, go to Location and make sure it is turned on. Next, open your Camera app, open its internal Settings or gear icon, and toggle on Save location or Tag locations. On an iPhone, open Settings, tap Privacy & Security, then Location Services. Select Camera and set access to While Using the App.

If you lose your cellular signal or have a bad signal while compiling information, continue to fill out the form and wait until you are in adequate coverage and then click Submit. If you get a “Failed to Submit” message, that means your coverage isn’t adequate – keep the page open until you have adequate coverage, then hit “Submit” again. You should receive a notification with a green checkmark and the note “Thank You. Your response was submitted successfully”.

View Map Full Screen

Data Disclaimer

Users understand that this data is contributed by the public and has not been verified in all cases by the Maine Geological Survey. Usage of this data is limited to general planning purposes only. Users must assume responsibility in determining the usability of this data for their purposes. The Maine Geological Survey, 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.

More Help

Contact the Maine Geological Survey with questions at: mgs@maine.gov

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