It regulates the outflow of water from Lake Ontario into the St. Lawrence Seaway .
The Iroquois Dam is a water reservoir located at Iroquois , Ontario , upstream of the power dam between Cornwall , Ontario , and Massena , New York .
Iroquois Dam regulates the outflow of water from Ontario   into the St. Lawrence Seaway .
The Iroquois Dam is a water reservoir located at Iroquois , Ontario , upstream of the power dam between Cornwall , Ontario , and Massena , New York .