Surface water

The Hoosic River drains about 164 mi2 of northwestern Massachusetts. The relatively few lakes and ponds in the basin were mostly created or enlarged by earthen dams. There are 17 lakes and ponds, seven of which have an area of 10 acres or more. The largest lake is Cheshire Reservoir (Hoosic Reservoir) in Cheshire, which covers 418 acres.

The Hoosic River begins on the west slope of the Green Mountains in northwestern Massachusetts and flows in a northwesterly direction through southern Vermont into New York.

Although the headwater streams have very steep gradients, the overall gradient of the river is moderate, averaging about 19 ft/mi from its headwaters to the USGS streamflow-gaging station near Williamstown, a distance of about 24 river mi. The natural flow regimen along the main stem of the Hoosic has been altered by Cheshire Reservoir, by flood-control structures in Adams and North Adams, by large groundwater withdrawals, by industrial use and discharge, and by discharge of wastewater from sewage-treatment plants.