# How Much Water Flows Over Niagara Falls?

How does “a lot” sound?

To flippant you say, then how about 3,160 tons of water flows over Niagara Falls every second.

Or, to put it another way, 75,750 U.S. gallons of water per second over the American and Bridal Veil Falls and 681,750 U.S. gallons per second over the Horseshoe Falls. Into metric, that’s 286,714 litres over the American Falls per second and 2,580,424 litres over the Canadian falls per second. Rounded numbers of course.

Now let’s add to the mystery. Is any water being diverted from going over the Falls?

Yes, a whopping 50% of the water that could/should go over Niagara Falls (all three Falls) is diverted during the hours of 10PM and 8AM in the summer which is the height of tourist season. Think about it, that means that 151,500 U.S. gallons (573,428 litres) should be going over the American Falls every second. And the Canadian Falls, 1,363,500 U.S. gallons (5,160,848 litres) should be going over the Canadian Falls every second.

And if you think a mathematician is getting carried away, in the winter, when tourism is less, but not nil, the water is diverted, same as summer nights for the creation of electricity at the hydro generating stations, but in winter only 25% flows over the Falls at night. The water is diverted from just above the Falls and flows back into the river at the generating stations down river from the Falls. The diversion is strictly regulated by an International Joint Commission. Each country, Canada and the U.S. has a quota of water that can be diverted, and it is quite common for the sides to trade back and forth depending on demand in each country.

An added benefit of the diversion is that it has slowed the erosion of the Falls to inches per year.

Once more for you. A typical large bathtub holds about 378 litres of water. Therefore, 15,172 bathtubs full of water go over the Falls every second.

Whew, wasn’t that fun, and I didn’t have to stop there.