The construction of the landmark hydroelectric plant facility was completed in 1902. At the time of completion, the plant was the second largest hydro facility next to Niagara Falls.
The hydro plant is constructed of steel and red sandstone. The stone was excavated from the power canal. The plant is a quarter-mile long, 80-feet wide, and has 74 horizontal shaft turbines located on the generation floor level. Each turbine has four runners (blades) that drive the 60-cycle generators. The water, which flows down the power canal, drops through gates in the turbines to make them spin, like a child’s pinwheel in the wind. The turbine turns the rotor—the last moving part. The turning creates electricity.
The excavation of the hydro canal began in September 1898 and was completed in June 1902. It is lined with more than 10,000 white pine timbers native to the area to strengthen and stabilize the structure.
The canal is approximately 2 1/4 miles in length from the headgates (intake) to the hydro plant. It is approximately 24 feet deep and 200 feet wide at the water level. The canal’s entrance is located at the east end of Ashmun Bay and controlled by four steel headgates. Learn more about the powerhouse in this 10-minute documentary.
Local architect, D.J. Teague finalized plans for the hydro plant in 1899. The Romanesque design included three large pavilions and a double-pitched roof to counterbalance the length of the plant. This design was the most economical and gave the impression of power, importance and stability. Ownership Edison Sault Electric Company purchased the hydro plant and canal in 1963 from the Union Carbide Company for $1.5 million. An additional $1 million was spent to convert the plant from 25-cycle electricity to 60-cycle electricity. In 1992, the company completed an $8 million modernization and automation project in the plant which enhanced both safety and efficiency. On May 4, 2010, Cloverland Electric Cooperative purchased Edison Sault Electric Company from Wisconsin Energy Corporation.
Under the most favorable operating conditions, the hydro plant is capable of producing about 36,000 kilowatts (36 megawatts). The power output depends on the volume of water traveling through the power canal and the plant’s operating head. The operating head is the difference in water levels at the plant’s forebay (upriver) and the tailrace (downriver) on the St. Marys River. This difference is equivalent to the drop in elevation between Lake Superior and the lower Great Lakes. At peak operation, the plant discharges approximately 30,000 cubic feet of water per second, which is equivalent to about 13.5 million gallons per minute.
The Aquatic Research Laboratory (ARL), operated by Lake Superior State University (LSSU), is located in the east end of the hydro plant. LSSU students are responsible for the day-to-day operations of the ARL and receive valuable hands-on experience in freshwater research and fish culture. With the support of Cloverland Electric Cooperative and the Michigan Department of Natural Resources and Environment, the ARL performs freshwater research and stocks fish in the St. Marys River. The ARL raises and releases approximately 25,000 Atlantic salmon into the St. Marys River each year. It has helped hundreds of LSSU graduates obtain jobs in fish and wildlife management, hatchery operations, ecology and other biological sciences. It plans to relocate to the west end of the hydroelectric plant and expand its research, education and hatchery operations. View a variety of fish species on the Fish Cam.