To the west, the outlet of the River Medway flows into the Estuary.

The main outlet of Hammervatnet flows into the Hoplafjorden, an arm of the Trondheimsfjord.

The outlet flows through a boulder field, becoming one of the headwaters of Torver Beck.

Its outlet flows into Vandenburgh Pond.

The lake flows south-to-north; its outlet flows into the Genesee River near Avon, New York.

This pond is fed by Beaver Dam Brook and its outlet flows into Cape Cod Bay.

The lake's only outlet flows into Great Meadow, a wetland at the northeast end of the lake.

Its outlet flows underground for half a mile and forms the Waitangi waterfall.

The lake's outlet flows below the surface through the natural dam and emerges from the mountain as a creek 1 mile (1.6 km) away.

Two small inlets enter on the east side and the outlet, Hammond Ditch, leaves the west side and flows to Waubee Lake.