Sep 05, 2007 — So why are the St. Lawrence River and Lake Ontario so low this summer? David Sommerstein called John Kangas. He's the U.S. Secretary of the International St. Lawrence River Board of Control. This is the agency that actually determines how much water should be let through the dam in Massena, controlling water levels all the way back to Niagara Falls. Kangas says the problems started last winter, when there was too much water. So to prevent flooding in Lake Ontario, the Board let a lot of water through the dam.