Cape Cod was formed between 23,000 and 15,000 years ago by the continental glacier. Each year, sands erode and accrete, but overall, the region suffers a net loss of significant proportions that affects both private property and public utilities.
The small coastal region, currently experiencing various phases of $4 billion to $8 billion worth of water and sewer projects, faces sustainability challenges over the long term due in part to serious erosion that is exacerbated by sea-level rise, according to experts.
The intense storms of just the 2009-2010 winter season caused more than $900,000 in erosion damage to municipal structures and homes and resulted in a $700,000 request to the Federal Emergency Management Agency.
But new geomorphological research advises regional planners about how erosion forces could affect Cape Cod in the future as they prepare unprecedented sewer and water projects.
Graham Giese, a senior scientist at the Provincetown Center for Coastal Studies, and Mark Adams from the National Parks Service are studying former U.S. Coast and Geodetic Survey transects -- known as the Marindin Lines -- that date from 1887 and are developing a GIS-based longshore sediment flux model that estimates the volume rate of change of Cape Cod sediments and can map possible land changes.
Since the lines were established, Cape Cod has lost 2.5 feet of sediment per year -- nearly a football field.
"The outline of the outer Cape is changing. It's changing its attitude and orientation," Giese said.
The total volume of Cape Cod and its surface area will decrease, he explained. Over time, accretion will continue in Provincetown, where the vacuum sewer system is currently being expanded. And barrier beaches in Chatham, a mid-Cape community working on a $300 million sewer expansion, are moving steadily westward.
Giese explained that over time, the geography, hydrology, and other factors of today's estuaries will change. "It's a response of the coast to sea level rise," he said.
For more about the center's research, visit CoastalStudies.org .