Maximum discharge along the river is currently at the reporting a streamflow rate of cfs. This is also the highest stage along the Marsh River, with a gauge stage of ft at this location. This river is monitored from 1 different streamgauging stations along the Marsh River, the highest being situated at an altitude of ft, the .

The Marsh River is a 41-mile-long river located in eastern Maine. It originates in the town of Waldo and flows southeastward to empty into the Penobscot Bay. Historically, the river was used for transportation and for powering mills located along its banks. Today, the river is primarily used for recreational purposes, such as fishing, kayaking, and canoeing. The river is also used for agricultural purposes, with farms located along its banks. There are several reservoirs and dams located along the Marsh River, including the Marsh Stream Reservoir, the Branch Mills Dam, and the Sheepscot Pond Dam. These dams help regulate the flow of water and provide hydroelectric power to nearby communities.