Located on the Wahnapitae River, this station was originally opened in 1905. A second unit opened in 1907 and the third unit opened in 1915.
According to a write-up located on Ontario Power Generation's Site:
The Coniston station was built by the Wahnapitae Power Company in 1905. At the time, this station was known as the upper plant or Plant No. 1. In 1913, this power plant was supplying the Coniston Smelter with some of its electric power. With the location of the smelter, Coniston grew from a village to a town within the Township of Neelon and Garson.In 1929, an industrial change occurred, the International Nickel Company consummated a merger with the Mond Nickel Company. The Wahnapitae Power Company operated three generating stations (Coniston, McVittie and Stinson) and furnished power to the Mond Nickel Company at Coniston, the Treadwell Yukon Company, Falconbridge Nickel Mines and the City of Sudbury. The first hydroelectric power used by the Mond Nickel Company was supplied by this company. Power was furnished to the mine and smelter of the British American Nickel Corporation and to the Moose Mountain iron mine while those properties were operating. Control of the Wahnapitae Power Company's properties were acquired by the Commission in 1929. From February 1929 until April 1930, the company continued as a joint stock company with the Commission's operating department controlling the operation of the three generating stations and transmission lines, the frequency being 60 cycles. In 1930, the Commission completed the purchase on behalf of the Provincial Government, and all the generating stations and transmission lines formerly owned by this company were included in the Sudbury area of Northern Ontario properties.