 The Agawam River originates at Halfway Pond, east of the Myles Standish State Forest in Plymouth, flows southwest through Glen Charlie Pond and East Wareham, and drains into the Wareham River near the center of Wareham.As the estuary's major contributor of nutrients and fresh water, the Agawam was one of the most important herring rivers in Massachusetts.Its herring runs have been operated by European settlers since 1632 and were officially established as a managed run in 1832.