While it is a popular myth, they have not "turned off" Niagara Falls in recent history, but they have significantly "thinned" the flow. In 1969, the U.S. Army Corps of Engineers successfully "dewatered" the American Falls for six months by building a temporary cofferdam to study the erosion of the rock face and remove loose boulders at the base. During this time, the falls were essentially "turned off" on the American side, though the much larger Horseshoe Falls remained active. In 2026, the flow of the falls is heavily managed by international treaties for hydroelectric power generation; at night and during the winter, more water is diverted to power tunnels, reducing the volume over the falls to roughly 50,000 cubic feet per second. There has been ongoing discussion about "turning off" the American Falls again to repair the pedestrian bridges at Goat Island, but as of early 2026, no final date has been set for such a massive engineering undertaking, meaning the water continues to roar for the millions of tourists who visit annually.