In 1969, Engineers Turned Off the Water of Niagara Falls

This little-remembered episode shows how the falls have become less and less natural.

The American Falls.
Niagara Falls, in flusher times.
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When you think of the summer of ’69, Vietnam protests, Woodstock, landing on the moon, and Bryan Adams may come to mind. But a lot happened from an environmental perspective, too. The Cuyahoga River caught on fire (again), there was an oil spill in Santa Barbara, California, and the National Environmental Policy Act was created. One of the most intriguing events of the year, though, flew under the radar: turning off Niagara’s American Falls.

On several prior occasions, the falls had slowed to a temporary halt because of ice. But starting in June 1969, the U.S. Army Corps of Engineers dewatered the American Falls—the smaller of the two main cataracts that make up Niagara Falls—to investigate the feasibility of giving it a facelift. And it may happen again: In 2016, the Niagara Frontier State Park Commission announced that it hoped to shut off the American Falls within the next few years. The reason this time: to repair the old bridges that take tourists from the New York state mainland to Goat Island. (This scheme depends on the requisite funding coming through, and that seems far from certain, though a representative from the commission tells me that they are still hoping it will happen.)

Treating a natural wonder like a faucet may seem alarming. But wonderful though it may be, Niagara Falls is hardly natural. Over the course of the 20th century, the United States and Canada repeatedly cooperated to alter the great cataract. As the birthplace of large-scale hydroelectrical production and distribution, Niagara Falls attracted companies responsible for the majority of the nation’s electrochemical and aluminum output. Water diverted from above the waterfall, then dropped to the lower gorge, was liquid gold. Well before the end of the 19th century, steps had been taken to reclaim the falls area from the ravages of unbridled industrialism. Industry just shifted location to the downstream gorge. By the early 20th century, enough water was being diverted that there were serious worries about the scenic appeal of the cataract.

But, cried factory owners, these diversions were actually saving the falls from themselves: Reducing the water flow over the lip reduced the erosion that caused the falls to move back an average of about 4½ feet a year. Decades of transborder negotiations and studies ensued, aimed at finding a way of maximizing power production while minimizing the aesthetic impact so that tourism wasn’t harmed. Diplomatic agreements to apportion Niagara’s bounty were signed in 1929, 1932, and 1941. None, however, were ratified by the U.S. Congress.

Water diversions kept increasing. Bigger hydroelectric stations—successively laying claim to the largest in the world—were built, with newer developments located even further downstream to receive the water that was now channeled through huge tunnels and conduits that ran under the sister cities flanking the gorge. Finally, in 1950 the U.S. and Canada inked a treaty to definitively deal with the tension of whether Niagara should produce power or beauty: It should be both. Or, at least, it should appear to be both.

The Niagara River Water Diversion Treaty authorized the two nations to divert between half and three-quarters of the Niagara River’s water. Since then, even at the best of times, during tourist hours, only half of the water intended for the falls actually plunges over the brink. And if you are unlucky enough to arrive in the evening or winter, you are seeing but one-quarter of the water bequeathed to the falls of Niagara.

Government planners were concerned about the aesthetics of the waterfall—especially the Horseshoe Falls, which are much bigger than the American Falls and primarily in Canadian territory. The 1950 treaty therefore also contained provisions for various remedial works in the Niagara waters of both the United States and Canada: a control dam, weirs (submerged dams), excavations, fills, and so on. All these interventions would mask the visual consequences and reduce erosion. Engineers said their goal was to create an “impression of volume” going over the waterfall. This could be achieved by spreading out the flow more evenly along the lip of the cataract so that it still looked robust, even if much less water was passing over the brink.

To do this, the Horseshoe Falls were dried out with cofferdams—the temporary structures that allow things to be built in the water—and the riverbed and cataract chiseled out and contoured. The crestline was shrunk about 15 percent by filling in the flanks of the waterfall.
Those reclaimed areas are today’s prime viewing areas. Much of it was planned on high-precision scale models of Niagara that filled entire warehouses. You might say that they were just turning the original waterfall into a very large-scale model. In the jargon of enviro-tech historians, the waterfall was a hybrid infrastructure combining the organic and the mechanical.

But Americans soon grew jealous that the Canadian waterfall had received a makeover, especially considering that tourists and honeymooners had already been heading to that side in greater numbers. Moreover, a series of rock falls from the American Falls had added to the talus—the huge pile of rock debris that formed at the base—making it more of a stepped cascade than a sheer drop. In response, in 1965, leading citizens of Niagara Falls, New York, jump-started a campaign to preserve and enhance the beauty of the American Falls. They wanted to make Niagara look more like itself.

In response, Canada and the U.S. asked the International Joint Commission, the bilateral body that oversees U.S.-Canada border waters, and the U.S. Army Corps of Engineers to investigate and report on measures necessary to preserve or enhance the beauty of the American Falls, specifically with regard to the talus. Was it feasible to remove the 280,000 cubic yards of talus that had grown to more than half of the height of the falls at some points?

To find out, in 1969, the American Falls were shut off from June to December. (See this video of the dry falls.) Some 27,000 tons of rock and earth were dumped upstream to create a 600-foot long cofferdam from the mainland to Goat Island. Millions of coins and even some bodies were found in the dry rock bed.

While some in the Niagara tourism industry worried about a detrimental drop in the 5 million people who visited annually, others thought that the waterfall renovation might actually increase tourism. (At least one newspaper editor thought this campaign to “save the Falls” from an impending “death” was a concoction meant to boost tourism and the area’s economic prospects. He was largely right.) Though many people did come for the express purpose of seeing what was hailed as a “once-in-a-lifetime” opportunity, in the end, the pessimists were proven correct, since tourism significantly declined in 1969. (This may be because people thought incorrectly that both the Horseshoe Falls and American Falls wouldn’t be in operation.)

Government planners considered the outright removal of the talus, as well as the placement of a dam downstream from the falls that would raise the Maid of the Mist pool and drown the talus (which would, of course, shrink the vertical height of the falls). The Corps of Engineers concluded that the talus was likely propping up the face of the American Falls. Based on this, as well as public input sessions and an estimated price tag of approximately $26 million, the International Joint Commission decided in 1974 against talus removal. But the dewatering wasn’t all for nothing: Engineers used the opportunity to stabilize the rock face of the American Falls with bolts, cables, and anchors, while installing electronic rockslide sensors.

The decision to leave the American Falls mostly alone was tied to the fact that the International Joint Commission wasn’t sure whether most tourists would really notice a major difference even if the talus was gone, plus the local interests that had initially pushed for the dewatering in hopes of stimulating tourism now thought that a dried waterfall would actually be bad for business. But abstaining also spoke to a conspicuous shift in attitudes, stimulated by the burgeoning environmental movement, about turning nature into infrastructure. To the International Joint Commission, it seemed “wrong to make the Falls static and unnatural, like an artificial waterfall in a garden or a park,” and the fundamental conclusion of the commission’s report was that “man should not interfere with the natural process.”

By comparison to 1969, contemporary plans to turn off the American Falls to fix a few bridges constitute a fairly minor, though probably unnecessary, intervention. Niagara Falls has already been heavily manipulated. The real waterfall—by volume, at least—is now in the penstocks of the massive hydropower stations downstream.

Over time people forgot what Niagara Falls looked like in its unadulterated state. Nonetheless, the diminished falls are, honestly, still impressive to behold. Stand on the cusp of the cataract, and the power that claims some 25 lives per year is still manifest.

Future Tense is a partnership of Slate, New America, and Arizona State University that examines emerging technologies, public policy, and society.