Strange things scientists discovered after blocking the water of Niagara Falls in 1969

For centuries, Niagara Falls has witnessed some strange incidents. In 1827, a hotel owner sent a flock of wild animals down the falls in a cargo ship, and only a goose survived. But on June 12, 1969, something even stranger happened when the US Army Corps of Engineers stopped the waterfall's flow. Scientists drained Niagara Falls to conduct research, reported Business Insider.

Niagara Falls is an impressive waterfall connecting three waterfalls at the southern end of Niagara Gorge, bordering Ontario in Canada and New York in the United States. The three water bodies are named Horseshoe Falls, American Falls, and Bridal Veil Falls, in order of their size. While the Horseshoe Falls is at the border of two countries, the other two are within the United States. Bridal Veil Falls is separated from Horseshoe Falls by Goat Island and from American Falls by Luna Island, with both islands situated in New York.

According to the Bright Side, Niagara Falls was first formed around 12,000 years ago, after the last Ice Age. The falls appeared after the ice sheets covered the area of Southern Ontario, and they started moving southward, creating basins of the Great Lakes on the way. They melted and released enormous quantities of water into the basins. As the ice melted, the resulting waters started to flow down through what is known as the Niagara River, Lake Erie, and Lake Ontario.

By the 17th century, Niagara Falls started gaining popularity as a tourist attraction. In 1842, author Charles Dickens visited the site, and describing the beautiful vista, he wrote "When I felt how near to my Creator I was standing, the first effect, and the enduring one — instant lasting — of the tremendous spectacle, was Peace." The falls were not just a natural wonder, but also a bounty of natural resources. 

A few years after King C. Gillette predicted Niagara Falls could become part of a city called Metropolis, Nikola Tesla designed one of the first hydroelectric plants near the falls. He considered it a significant achievement in human history, per Smithsonian magazine. Over the years, piles of boulders had been building up at the base of the falls. In 1931, almost 76,000 tons of rock slid downwards to the base, and in 1954, 185,000 tons fell, as per Business Insider.  So, boulders were not only causing an unsightly appearance but also posed the risk that the falls would soon turn into rapids. 

So, in the summer of 1969, some scientists were tasked with removing and examining these boulders. Their goal was to analyze how they could save the falls from erosion. To do this, the US Army Corps of Engineers brought 27,000 tons of rock loaded into thousands of trucks and used these to create a dam, blocking the waters. These waters were diverted to the Horseshoe Falls that absorbed the gushing stream diligently, according to the Bright Side.

When the waterfall was drained, researchers were surprised by what they found on its dried bottom. Plenty of coins sprawled on the waterless bed that people might have thrown in the waterfall to make a wish. Apart from coins, they found the bodies of two humans. In the following few weeks, more than 100,000 people visited the spot to witness the waterless falls from a bare cliff. Most of them were curious about why the water was stopped, and how long it would remain blocked. Meanwhile, for the next five months, engineers worked relentlessly to examine the bed of boulders, and in 1974, concluded that the boulders were necessary to maintain the posture of the waterfall. The American Falls International Board declared in a report that it was against their removal.

So, on November 25, 1969, a crane arrived at the Niagara site and drilled a hole in the dam. Through the hole, water began to surge in torrential streams. The American Falls was freely gushing once again. However, scientists have estimated that the falls might need to be blocked again at some point, to repair the surrounding bridges.