Have you ever stared at the Niagara Falls and wondered "where does all this water come from? How does it never run out?" I think we have all wondered how one of the biggest waterfalls in the world never gets tired.

The fresh water that plunges over Niagara takes around 685,000 gallons (2.6 million litres) of water from four great lakes: Lake Superior, Lake Michigan Lake Huron and Lake Erie - in fact, ⅕ of the world’s fresh water is found in these four great lakes. Once it travels over the Falls it travels from the Niagara River, 21.7 kilometres (13 ½ miles) to Lake Ontario. From there, it makes its way down the St. Lawrence River and eventually to the Atlantic Ocean.

Interestingly enough, there is a drop in elevation between Lake Erie and Lake Ontario of 99 metres (325 feet). That’s the reason why you find the Welland Canal here. The canal includes 8 locks that gradually takes ships up or down from one lake to the other, and without it ships could not by-pass the Niagara Falls and go freely through the Great Lakes and into the Ocean!