Niagara Falls FAQ: Power Generation

The simple answer is: most of it.

At any given moment the water diverted upstream from the falls, to run the various power plants, is anywhere from 60 to 75%. That’s an average of 1,200,000 gallons (4,542,500 liters) of water per second with only 600,000 gal/sec (2,271,250 liters/sec) left to run over the Horseshoe Falls and a mere 150,000 gal/sec (567,811 liters/sec) for the American Falls. Although it may seem as though the Falls are being deprived of their natural flow, the water that remains to cover the falls is still an impressive sight. Many waterfall enthusiasts agree that reduced flow makes for waterfalls with more “character.”

Although mills have been using diverted water from the Falls as a source of hydraulic power since 1759, it wasn’t until 1882 that the Falls were used to generate electricity.

The Niagara Falls Hydraulic Power & Manufacturing Company, which constructed a canal for hydraulic power generation nearly 20 year prior, began operating a small electrical plant in Niagara Falls, New York in 1882. The plant, which generated direct current (DC), could only distribute current a distance of 2 miles. Despite this limitation, it was a big hit for both its utility and as a tourist attraction. It was this small plant that demonstrated the potential for hydro-electric power from Niagara Falls.

There are a total of 5 power stations on the Niagara River. 2 of which are on the US side and 3 on the Canadian side.

How does Niagara Falls Generate Electricity?

Hydroelectric power plants are usually built around waterfalls because they take advantage of the drop in water, more precisely: the power of gravity, to use the force of falling water to generate electricity. While waterfalls can be tapped directly, and many have been, by installing a water wheel directly into the falling water, it’s typically risky as the water flow can vary and logs and other debris can hit the wheel. So typically, water is diverted from the stream of river, often stored in pools for when water flow is low, and then run through a turbine a distance away from the waterfall.

Niagara Falls is surrounded by dams and pumps that divert water from the river upstream from the falls to reservoirs and other dams downstream (but still on top of the Niagara Escarpment, so they are at a high elevation compared to the river below the falls). Those dams drop their stored water through the turbines and back into the river below. While water is what stores the energy and drives the turbines, the gravity of the water falling the distance down the Niagara escarpment is the real hero.

Here’s a more detailed breakdown of how dams and turbines turn the Niagara River’s flow and change in elevation into electricity.

1. A dam built across the river diverts water into a reservoir, forming a large body of water at a higher elevation than the downstream river. In the case of Niagara Falls, The International Control Dam and a system of pumps upstream divert the river through large underground tunnels downstream to the Sir Adam Beck and Robert Moses Niagara Reservoirs north of Devil’s Hole. Both Reservoirs sit on the cliffs above the river.
2. Between the reservoirs and the Niagara River are two power plants, the Sir Adam Beck in Ontario, and the Robert Moses plant in New York. They serve as both generators containing turbines and dams to hold back the reservoirs. Water is diverted from the reservoir through intake structures or tunnels and channeled towards the power plant. The intake structures are typically equipped with gates or control mechanisms to regulate the flow of water.
3. The diverted water is directed to flow through large pipes or penstocks, which lead to the turbines. The force of the water causes the turbines to rotate.
4. The rotating turbines are connected to generators. As the turbines spin, they turn the generators, which are essentially large electromagnets. This rotation induces the generation of electricity through the principles of electromagnetic induction.
5. The generated electricity is then sent through transformers to increase its voltage for efficient transmission over long distances. It is then transported via transmission lines to the electrical grid, where it can be distributed to homes, businesses, and other consumers. These huge networks of transformers can be seen from NY I-190 (to the west) as you pass by the reservoirs, and Ontario’s can be seen from the park containing the Floral Clock, off of Heath Lane.

The amount of electricity the power plants at Niagara Falls have the capacity to output is close to 4.9 million kilowatts. That’s enough to power 3.8 millions homes.

On the US side, plants have a capacity of roughly 2.7 million Kilowatts, while the Canadian side’s combined capacity is close to 2.2 million kilowatts.

This number does not include the two Decew Falls stations in St. Catherines, ON that have a total capacity of roughly 167,000 kilowatts generated from the Welland River’s drop over the Niagara escarpment.

The numbers above represent capacity, not actual power generation. The power generated by the plants on the Niagara varies on a daily, monthly and yearly basis. Factors that affect actual power generation can be anything from demand, to river flow, to tourism season.

Most of the water that would flow naturally over Niagara Falls is diverted for power generation. Not only does this reduction tame the appearance of the cataract, but it also curbs the erosive action and thus recession speed of the Falls, which has slowed to a relative crawl since the power plants were constructed.

The diversion of the Niagara River is acceptable to most tourists. Having never seen the Falls at full flow, most people just accept them the way they are – perhaps not even giving it a second thought. Some (including the author) think that a moderate flow gives the Falls character. It defines the edges, increases the definition of the drop, and reveals more of the gorge below (including the rock piles below the American Falls).

Others feel that the Falls in the diverted state is just “unnatural” and that they could be larger, louder, and more powerful if reverted back to their original state. Although this is an interesting concept, realizing it would not only eliminate the region’s largest supply of power, but also put the current infrastructure around the Falls and the Falls themselves in jeopardy of destruction by swift erosion. Those are giant roadblocks for returning the Falls to its original grandeur, but perhaps it wouldn’t be unthinkable to crank up the spigot a few hours or days a year to give tourists another reason to visit the Falls.

Two tall, windowless, rectangular structures can be found at a small park along the Niagara River upstream from the falls just west of the North Grand Island Bridge. Those traveling from New York will drive past them on the Niagara Scenic Parkway. 

These ominous structures look like they are out of a sci-fi series, but they are actually very practical. They are located in the Upper Niagara Intake Observation Area, a small park built on top of the intake for water leading to the Robert Moses Power Plant Downstream. These two buildings house gates that can be raised and lowered to control the intake of water into the power project.

A pair of similar structures can be found on the Canadian side along the Niagara River Parkway and are more open to reveal the massive gate (or sluice) that is lowered to block the intake pipe underground.

Also known as the International Control Structure, this dam is located upstream from the Canadian (Horseshoe Falls) and can be seen from walkways along the falls and rivers on both sides. It is a dam full of gates and stretches only halfway across the river, spanning the Canadian side. Built in 1954 and operated by Ontario Power Generation, it is used to control the amount of water diverted to both the US and Canadian power plants, and as a result also controls how much water is left to flow over the falls. 

The 1950 Niagara Treaty not only determined how much water is allocated to power generation on either side, it also put limits on how much can be diverted, as to not interrupt the “unbroken curtain of water” flowing over the falls for tourist enjoyment. 

On some occasions the dam has been used to divert an excess amount of water away from the falls to ground and stop an out-of-control vessel, suicide or daredevil attempt and to aid in rescue.