Walk along the waterfront in Sault Ste. Marie and you’ll hear it. It’s not just the wind coming off Lake Superior. It is the low, constant hum of the Saint Marys Falls Hydropower Plant. Most people just call it the "Soo" plant. Honestly, it’s easy to overlook because it looks like a permanent fixture of the landscape, but this place is basically the heartbeat of the Upper Peninsula’s electrical grid. It sits right on the St. Marys River, which connects Lake Superior to Lake Huron, and it has been churning out power for over a century. That is a long time for any piece of machinery to stay relevant.
It’s old. Like, really old.
The facility is actually split into different components, but when people talk about the Saint Marys Falls Hydropower Plant, they are usually referring to the U.S. Army Corps of Engineers (USACE) facility or the Cloverland Electric Cooperative plant. Both utilize the massive drop in water levels—about 20 feet—as the river tumbles down the rapids. This isn't some massive Hoover Dam-style concrete wall. It’s a low-head operation that relies on the sheer volume of the Great Lakes.
The Engineering Behind the Saint Marys Falls Hydropower Plant
You’ve got to understand the scale here. The Saint Marys River is the only outflow for Lake Superior. Think about that for a second. Every drop of water that leaves the largest freshwater lake in the world (by surface area) has to pass through this narrow pinch point. The Saint Marys Falls Hydropower Plant taps into that relentless flow.
The USACE plant specifically has been around since the early 1900s. It houses four vertical shaft generators. These aren't the high-tech, digital-first turbines you'd see in a modern wind farm. They are heavy, cast-iron workhorses. They use Francis turbines, which are great for medium-head applications like this. Water flows in, spins the runner, and the shaft turns the generator. Simple. Elegant. It works.
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But there’s a catch.
Because the plant is located right next to the Soo Locks, the water management is a total balancing act. The International Joint Commission (IJC) actually dictates how much water goes through the turbines versus how much goes over the rapids or through the locks. If the water is too high, the Lake Superior shorelines flood. If it’s too low, the massive lake freighters get stuck in the mud. The plant operators are essentially playing a giant game of plumbing with 10% of the world’s surface freshwater.
Why the Cloverland Side is Different
While the Army Corps handles the government side, the Cloverland Electric Cooperative operates the "hydroelectric powerhouse" which is actually a world record holder. Or it was for a long time. It’s a quarter-mile long. Seriously. Built in 1902, the Cloverland plant is an architectural beast made of Michigan red sandstone. It has 74 horizontal-shaft turbines.
Most modern plants have five or maybe ten huge units. Cloverland has 74 small ones. Why? Because back in 1902, that was the most efficient way to capture power from a long, shallow canal. It’s kind of a maintenance nightmare if you think about it. Imagine having to service 74 of anything. But it works. It provides about 25 to 30 megawatts of power, which is enough to keep the lights on for a huge chunk of the Eastern Upper Peninsula. It’s the reason why electricity rates in Sault Ste. Marie are often more stable than in other parts of the country.
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The Conflict Between Power and Fish
Here is something people rarely talk about: the rapids. Before the Saint Marys Falls Hydropower Plant was built, the St. Marys Rapids were a massive, surging white-water ecosystem. It was a prime spot for Lake Sturgeon and whitefish. When you divert all that water into canals for power and locks for ships, the rapids dry up.
To fix this, they built the Compensating Works. It’s a series of 16 gates that span the river. By opening and closing these gates, the USACE can ensure that the "main" riverbed doesn't go bone dry. If they didn't do this, the local trout population would basically vanish. It’s a constant tug-of-war between the need for renewable energy and the need to keep the ecosystem from collapsing. Environmentalists often point out that while hydro is "green" in terms of carbon, it’s not exactly "neutral" for the fish.
What Happens When Things Break?
You can't run a plant for 120 years without some serious drama. In the last decade, there have been massive pushes for "Reliability Improvements." We are talking about multi-million dollar federal investments.
The USACE has had to replace aging components that were literally manufactured before the Titanic sank. They’ve been upgrading the excitation systems and the governors. You can’t just go to a hardware store and buy parts for a 1910 generator. Everything has to be custom-machined. Sometimes, they have to use 3D scanning just to figure out how the original part was shaped because the blueprints are hand-drawn on linen and falling apart.
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The Economic Reality of the Soo
Without the Saint Marys Falls Hydropower Plant, the local economy would look very different. The "Soo" is a blue-collar town. It relies on the locks and the power. The cheap electricity generated here attracts industry. It keeps the cost of living down.
Also, it's a huge part of the "Green Energy" portfolio for Michigan. As the state moves toward carbon neutrality, these old hydro plants are becoming the MVPs. They provide "baseload" power. Unlike solar or wind, which stop when the sun goes down or the breeze dies, the St. Marys River never stops flowing. It’s the ultimate battery.
Is it Open to the Public?
Not really. Post-9/11 security is tight. You can't just wander into the turbine floor and take selfies. However, you can view the Cloverland plant from the water or from the nearby parks. The USACE plant is tucked behind the high-security fences of the Soo Locks complex.
If you want to see the power in action, stand on the observation deck at the Soo Locks. When a big freighter like the Paul R. Tregurtha moves through, you can see the sheer volume of water being moved. That same force is what’s spinning those turbines just a few hundred yards away.
Surprising Facts About the Operation
- The Sandstone Secret: The Cloverland plant used the rock excavated from the power canal to build its own walls. It’s literally made of the ground it sits on.
- The Ice Problem: In the winter, "frazil ice" can clog the intakes. It’s like a slushy that freezes onto the machinery. Operators have to be incredibly careful to keep the water moving or the whole system grinds to a halt.
- The Drop: It's only a 20-foot drop. Most people think hydro needs a massive cliff. Nope. Just a lot of water and a little bit of gravity.
- The 60Hz Standard: These plants were instrumental in stabilizing the frequency of the grid in the early days of the American electrical system.
Actionable Insights for Visitors and Locals
If you are interested in the Saint Marys Falls Hydropower Plant, don't just look for a visitor center—there isn't a dedicated one for the plant itself. Instead, follow these steps to actually see the tech in context:
- Visit the Soo Locks Visitor Center: They have exhibits that explain the water levels. Since the locks and the hydro plant share the same water source, understanding one helps you understand the other.
- Walk the Power Canal: You can follow the Cloverland power canal through the city. It’s a strange sight to see a man-made river cutting through a downtown area.
- Check the IJC Reports: If you’re a data nerd, the International Joint Commission publishes "Board of Control" reports online. You can see exactly how many cubic meters per second are flowing through the turbines right now.
- Watch the Gates: Go to the foot of Ashmun Street or the parks near the rapids. If the gates of the Compensating Works are open, you’ll see the raw power of the river that isn't being captured by the turbines. It’s a loud, misty reminder of what the area looked like in the 1800s.
The Saint Marys Falls Hydropower Plant isn't just a relic. It is a functional, vibrating piece of history that proves that sometimes, the old ways of doing things—using water and gravity—are still the best. It’s reliable. It’s clean-ish. And it’s not going anywhere. As long as Lake Superior is full of water, those turbines will keep spinning.