Surface water in the Erie-Niagara basin, New York

The Erie-Niagara basin contains about 2,000 square miles in western New York State. The drainage systems of the area discharge into Lake Erie and the Niagara River at an average rate of about 1,730 mgd (million gallons per day). Annual precipitation ranges from about 32 to 44 inches. Evapo-transpiration losses account for about 20 inches of water a year and the streams have an average annual runoff of about 18 inches.