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


Last updated: April 28, 2015

Park footer

Contact Info

Mailing Address:

99 Marconi Site Road
Wellfleet, MA 02667


To contact NPS Law Enforcement or report an incident, please call the 24-hour dispatch: 617-242-5659. In the event of an emergency, call 911.

Contact Us