Is it true that Niagara Falls can be turned off?

No, there is no switch. Switches are for electrical stuff. For Niagara Falls there is a huge valve they turn to shut off the water. It only happens when they need to backflush the electrical generating plants to clean out the penstocks.

They've built a dam to turn off the American falls while they stabilized the rocks, but they can't turn off the much larger Horseshoe falls.

By the way, about half the water that would otherwise go over the falls can be diverted to the power plants on each side of the river,

Yes. It's an energy saving device.

Seriously - you can't turn the falls off without shutting down the river. That would require a HUGE dam. The falls were partially turned off in 1969, to allow construction of the Goat Island project - but that wasn't the entire falls. Only a portion of it, and it wasn't 'turned off' if was diverted.

Actually, they can......but they never will, as doing so will flood out Chippawa, Navy and Grand Islands, and Fort Erie. There are several control damns already in place to significantly staunch the flow of the water, numerous more tunnels that lead to turbines that aren't in use as well as ice booms that can block to flow......if all put into use at once, the water would be slowed to a trickle.

No, its possible to build a dam to stop the flow of water, but you can't turn it off, it's an actual body of water.

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