Lake Surface Area 3.4 sq. Volume 21 billion gal. Watershed Area 38 sq. One way to characterize a lake is by its trophic status. A eutrophic lake is biologically productive, with much algae and aquatic plants, warm and shallow.
Oligotrophic lakes tend to be unproductive, clear, cold, and deep.
Otisco Lake is considered a mesotrophic body of water which is somewhere between eutrophic and oligotrophic. The southern end of the lake is separated from the northern portion by a causeway. The area south of the causeway is considerably different from the rest of the lake due to its origins. The underlying sediments are the organic soils from the former wetland that was there before the lake was flooded in 1869 for the Erie Canal and again in 1909 to provide a drinking water supply for Onondaga County. Just north of this area Otisco Lake empties through the outlet spillway into Nine Mile Creek.