Coastal Atlas: Shorelines


The Coastal Atlas’ Shorelines mapping tool allows users to access state coastal hazard data including coastal inundation from storms, areas at risk to sea level rise, and shoreline erosion data.


View the mapping tool: Shorelines screen capture.


Potential applications for this tool include:

  • Identifying coastal areas subject to coastal flooding from storm inundation and sea level rise for long-range planning, floodplain management, restoration targeting and emergency management
  • Aiding shoreline management decisions by identifying areas of high erosion and to visualize potential shoreline positions in 50 years
  • Accessing the Comprehensive Shoreline Inventory - an array of information such as riparian land use, bank condition, and shoreline features (erosion control and access structures) on a county by county basis to assist policy development at local and state levels of government
  • Determining areas where living shorelines are appropriate for a limited number of counties


The Chesapeake & Coastal Service will offer training opportunities to help users make the most of the data and tools found on the Coastal Atlas. We are interested in receiving your comments and feedback on the functionality of the current Shorelines data and tools. If there are specific tools or data sets that could be developed in order to more effectively help users address specific coastal issues, please let us know.


Launch Map!


Coastal Atlas Training Video

How many miles of coastline/shoreline does Maryland have?

  • Maryland coastlineAccording to NOAA, Maryland is home to 3,190 miles of coastline – about 3.4% of the U.S. total of 95,471 miles.
  • Although it’s based on data from the 1930s, scientists deem this the best number to use for legal and regulatory purposes, in part because it helps put Maryland’s coastline in perspective with the rest of the country (the numbers are currently being updated).
  • Other commonly cited estimates include 4,360 miles (from a U.S. Army Corps of Engineers 1990 study), and 7,719 miles (from a Maryland Geological Survey 2006 report and likely the most accurate for educational/informational purposes).
  • Different survey methods and tools – such as what portion of tributaries are included and what base map is used -- yield different results.
  • The terms coastline, tidal shoreline and shoreline continue to be used interchangeably, and for us include the Maryland portions of the Atlantic Ocean, the Chesapeake and Coastal Bays, and the tidewater portion of tributaries.
  • Click here for more information.

In Focus

Shoreline Rates of Change and Erosion Transects Tools

Shoreline Rates of Change and Erosion Transects Tools The Shoreline Rates of Change tool shows the percentage of a selected county’s shoreline that has experienced various amounts of shoreline erosion in the past. To select a county, click inside the county about which you want to see shoreline change information. To change which county you are viewing, just click inside the new county. The Erosion Transects tool calculates the average amount of erosion in an area. By depicting transects from a baseline landward of the shoreline that run through the current shoreline to historical shorelines a rate of change is calculated along each transect by dividing the distance by the number of years between the two positions. To calculate the average amount of erosion on the map select transects on the map by either dragging a rectangle or drawing a polygon around the target area. At the top of the results window, you will see the average erosion rate for the selected transects and below, the individual rates for each transect. Clicking on one of the results will zoom into that transect. Click here to be directed to the entire Coastal Atlas Training Manual and Tool Index.

Download Coastal Atlas Training Manual

Coastal Atlas Training Manual

Contact Information

Chris Cortina

Chesapeake & Coastal Service

Maryland Department of Natural Resources

Tawes State Office Building E-2

580 Taylor Avenue

Annapolis, Maryland 21401

Phone 410-260-8774

Fax 410-260-8739

ccortina@dnr.state.md.us