The breach in Edgartown Great Pond’s barrier beach on March 21, 2021. Photo courtesy of Denys Wortman.
Edgartown Great Pond remains open and the tidal flush continues. The Pond cut on February 28, 2021 and there has been sufficient tidal exchange to flush all regions of EGP.
Following a breach of the barrier beach on Sunday February 28th, Edgartown Great Pond (EGP) is open, tidal, and connected to the Atlantic Ocean. There are 2 phases to an opening: 1) Drainage and 2) Tidal Exchange.
Prior to the cut, EGP was ~4 feet above sea level and after draining for almost a day, it became tidal, before draining a second time and then becoming tidal again. After a couple weeks of tidal exchange the Pond, the tidal flow appears to have paused from March 18th-28th. Following a storm, the tidal exchange has resumed. This opening has provided an excellent flush of the entire pond and its success follows the Town of Edgartown’s winter dredging program. We are grateful for the continued efforts of the Town to preserve and protect Edgartown Great Pond.
Edgartown Great Pond was opened to the Atlantic Ocean on February 28th, 2021. The tidal exchange bodes well for the ecosystem.
EGP is a living ecosystem that depends on regular and effective seawater flushes for its survival. When the pond is open to the ocean, cool, clean, and salty seawater infuses EGP with salt, exchanges organisms between ocean and estuary, and reduces the nutrient load of the system.
Regular exchanges of water between the ocean and the Great Pond keep it healthy and teeming with life. Dredging of the sand that builds up in the pond north of the barrier beach increases the circulation and flushing capacity of each opening. The Great Pond is breached or cut open to the Atlantic Ocean 3-4x per year when an excavator creates a channel through the barrier beach that allows the exchange of water between pond and ocean. Without dredging, to remove the delta of sand in the pond north of the breach, the seawater does not reach all regions of the pond during a cut.
