• Atlantic Ocean beach at Cape Cod National Seashore

    Cape Cod

    National Seashore Massachusetts

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  • Access at seashore locations

    Sections of the boardwalk at the Red Maple Swamp Trail have been closed due to structural deterioration and safety concerns. Check at Salt Pond Visitor Center for the current status of this trail, and for your safety, remain out of closed areas.

Hydrologic Activity

It is difficult to overstate the importance of water as a resource. Amplifying the importance of water on Cape Cod is the fact that the fresh water supply comes solely from an underground aquifer system that is recharged almost exclusively through precipitation. With this in mind, the Cape Cod National Seashore, in collaboration with the United States Geological Survey, has developed a standardized, long-term methodology of monitoring hydrological activity on the Outer Cape.

The freshwater aquifer of the Outer Cape is bound laterally and below by salt water and is divided into four distinct flow "lenses." These flow lenses are detailed in the map below. Coastal hydrological processes are also of great interest, especially as they relate to salt marsh restoration projects throughout the Seashore.

Climate change, sea-level rise, and increased withdrawal rates from groundwater all have the potential to significantly impact the fresh water resources critical to the human population and the sensitive coastal ecosystems of the Outer Cape. The Seashore's long-term hydrological monitoring program will provide a better understanding of the effects of both natural and human-induced change on groundwater levels of the Cape Cod aquifer.

Cape Cod Hydrology Map
Location of the four flow lenses of the Outer Cape aquifer system.
Courtesy USGS

Did You Know?

Old Harbor Life-Saving Station, Provincetown, MA

The Old Harbor Life-Saving Station in Provincetown, MA is one of the few surviving, unaltered life-saving stations left in the country. The station was built in 1898 and is open in the summer months with a display of rescue equipment, and NPS staff re-enact the historic Breeches Buoy rescue drill.