Cobbs Hill Reservoir is a reservoir located in Cobbs Hill Park in Rochester, New York, United States. The reservoir is used to supply drinking water to the city of Rochester. The source of the water is Hemlock Lake, which lies 30 miles due south of and 400 feet higher elevation than Rochester.Construction was completed in 1908. The smaller Lake Riley north of it was part of the old Erie Canal system. I-490 now runs on the old canal bed here.
The land comprising modern-day Cobbs Hill Park belonged to Gideon Cobb, an earlier settler of Rochester.
Coordinates 43°8'21.82" N -77°34'15.12" E