Sea Level Rise

Tidal flooding inundates the streets of downtown Annapolis

Courtesy Will Parson/Chesapeake Bay Program Photo

What does Sea Level Rise look like?

As the planet warms, melting glaciers and warming waters are causing sea levels to rise. Much of the Star-Spangled Banner Trail is located on or near the Chesapeake Bay and its tributaries meaning the infrastructure and cultural landscapes of the sites are threatened by inundation from rising sea levels. Since 1902 sea levels in the Chesapeake have risen .12 inches a year, a foot each century (source), and are projected to rise another 2-6.5 feet by 2100 (source). Due to a combination of factors such as land subsidence and ocean currents, the Chesapeake Bay region is particularly vulnerable to sea level rise.

The region is projected to experience relative sea-level rise at twice rate of the absolute global average (3.4mm/yr) vs (1.7mm/yr) (source).

Sea level rise causes tidal flooding, also known as “sunny day” or “nuisance” flooding. This is when areas previously above the high tide line are now intertidal, resulting in regular flooding. Tidal flooding causes shoreline erosion, property damage and can deposit debris like driftwood and trash. Higher sea levels can backup drainage systems, breach coastal barriers and inundate low-lying areas like archaeological sites. Higher average sea levels mean particularly bad storm surges . Additionally, rising sea levels will lead to loss of land and habitat.