Groundwater

Deep bedrock valleys along the main stem of the Hoosic River have been filled, in some places, with more than 300 ft of ice-contact deposits, outwash deposits, and glacial-lake sediments. Most of this material is fine-grained and yields very little to wells, but ice-contact deposits of sand and gravel within, bordering, or underlying fine-grained material can yield large volumes of water. Well yields as high as 2,500 gal/min have been obtained from wells in sand and gravel. In general, the tributary streams are underlain by thin deposits of sand and gravel on till and bedrock.

In the uplands, bedrock crops out or is covered by various thickness of till and yields small quantities of water that are sufficient for domestic wells. In the valleys, carbonate rock (limestone and dolomite) is favorable for obtaining large quantities of water because of the presence of cavities or fractures enlarged by solution and because recharge is readily available from overlying sand and gravel.