Hemlock is one of the two Finger Lakes whose shorelines are virtually undeveloped.
Hemlock Lake is one of the sources of water for the City of Rochester.
It is typically clear, but suffers moderate, deep-water oxygen depletion in summer. This condition does not seriously threaten trout and salmon but does, temporarily, confine them to a narrow layer of the water column. The largest weedbed is located at the lake's southern extremity. There are other isolated weedbeds located in small coves along the lake's east and west sides. While the north end of the lake also has a weedbed, this area is off limits to fishermen.