Originally known as the Oil Creek Reservoir, Cuba Lake was constructed between 1852 and 1858 to serve as a feeder reservoir for the Genesee Valley Genesee Valley Canal. The reservoir was impounded by a 60-foot-tall (18 m) dam built at a cost of $150,000. When first completed, the reservoir covered 480 acres (1.9 km2); after being deepened in 1864 and 1872, the reservoir reached a high-water area of 708 acres (2.87 km2). At the time, it was claimed as the largest artificial lake in New York State.
In 1878, the Genesee Valley Canal Railroad was completed, replacing the Genesee Valley Canal. The reservoir and a portion of the former canal were retained to help maintain water levels on the Erie Canal. Later, after New York State announced their intention to drain the reservoir, lobbying by former canal superintendent Charles Wyvelle led to the reservoir being saved. The reservoir remained at its high-water mark until 1889, when the water level was lowered by 7.5 feet (2.3 m) to relieve fears raised by the Johnstown Flood that had occurred that year.
You can learn more about Cuba Lake at the links below: