Hydrogeology of unconsolidated deposits in Chenango County, New York

Chenango County uses ground water from unconsolidated valley-fill aquifers and from bedrock in the uplands for public water supply. Water-resources managers and planners need information on the location, thickness, and potential well yield of unconsolidated deposits throughout the county to formulate plans to protect and manage the ground-water resources. Data from 519 well sites were obtained from well drillers and several State agencies in 1989 and 1990 and combined with data from previous studies to compile a well-inventory table and maps depicting well locations, thickness of unconsolidated deposits, and potential well yields from valley-fill aquifers. Thickness of unconsolidated deposits on hilltops and in areas of steep terrain is generally less than 5 ft (feet); on north-facing hillsides it is generally less than 50 ft, whereas on south-facing hillsides and kame terraces, it typically ranges from 50 to 100 ft. Thickness of unconsolidated deposits in major stream valleys generally exceeds 100 ft and exceeds 200 ft locally. The most productive aquifers consist of coarse valley-fill sand and gravel deposits. Wells completed in aquifers that occupy minor stream valleys, such as the Genegantslet creek Valley,generally yield less than 100 gal/min (gallons per minute). Potential well yields from deposits in major stream valleys, such as the Chenango River Valley, range from 100 to 3,500 gal/min. In areas where the saturated thickness exceeds 40 ft and the drainage basin exceeds 200 square miles, the potential yield of some wells can exceed 3,500 gal/min.