What is a Kettle Lake?
Onondaga and Cortland Counties, are unique and beautiful regions in central New York. One of the defining characteristics is the presence of several kettle-hole or kettle lakes.
According to the United States Geological Survey (USGS), the area was formed by the advancing and retreating of glacial ice during the last glacial period in North America. To the west of us, the same glacial process formed the Finger Lakes. The process here, however, caused smaller holes to be formed when huge chunks of ice broke off the glacier. These holes, or “kettles” were then buried by till  as the glacier receded. When these ice chunks melted, the depression remained.
Each kettle lake has its own unique properties. Some have natural or created outlets, while others are landlocked. All of these lakes are, however, connected to the surficial aquifer. A surficial aquifer is generally defined by the USGS, as an “unconfined, shallow aquifer system, recharged by rainfall and leakage from surface water bodies.”
The glaciers also formed the Valley Heads Moraine, an area of sand and gravel deposited when the retreating ice paused. The moraine runs east to west and separates the Tully Valley to the north from the Tioughnioga Valley to the south. This moraine also forms the surface water divide for the St. Lawrence River drainage (north) and the Susquehanna River drainage (south).
 sediment of various particle sizes deposited by the direct action of ice
 Information from USGS