In 1896, Cascade Street Generating Station was converted into Parry Sound’s first power plant.
The mill was outfitted with two 75 kilowatt monocycle alternators which produced 2,300 volts at 60 hertz. These were installed in such a manner that they could be run by water power, or by steam when the river was being used for log driving by local lumber companies.
By 1898, two additional Charles and Barber turbines, made in Meaford, Ontario, had been added to the old gristmill, and in 1905, the flume was rebuilt. The following year, a new concrete block powerhouse, designed by civil engineer Thomas Simpson, was erected on the site. It contained a 425 kilowatt, 2200-volt Allis Chalmers alternator connected to two 10 inch turbines.
In 1914, with the timber limits becoming increasingly barren, the Town of Parry Sound purchased the Parry Sound River Development Company, ending that organization’s monopoly control over the Sequin River use.
The power plant continued to operate, reaching its full capacity by the end of the First World War. With the assistance of the Provincial Government, a new dam was built at Mill Lake, and a new powerhouse was constructed. In 1919 the Toronto-based firm of Mitchell and Mitchell was hired for $140,000 to design and build a new powerhouse, and to construct a new Cascade Street Bridge.
Although the original plans called for three generators, only two were installed. These were a 1919 Westinghouse unit with a capacity of 930 kilowatts, and a smaller Swedish electric generator with a capacity of 420 kilowatts. The smaller generator was hooked-up to the Allis Bullock Chalmers alternator, which was brought over from the 1905 plant. The Westinghouse generator was connected to an alternator of the same make.
The 1919 power plant remained the sole source of electric power for Parry Sound until 1948, when the town was connected to the larger Ontario Hydro provincial grid.
The new facility featured three pits which received water from a concrete flume. The weight of the water in these pits drives the turbines below, which in turn power the generators. Only two pits, however, were required to power the two generators.
An open concrete flume proved inadequate and was replaced almost immediately with an enclosed penstock. Similarly, the gate hoists controlling the flow of water from penstock to the pits turned out to be leaky, and were replaced with butterfly actuators. A major flood occurred in 1921 when water overflowed a portion of the dam, and entered the powerhouse through the large window on its west elevation. The Allis Chalmers Bullock alternator was ruined and had to be replaced, and, the town went without power for several weeks.
In October 2017, the Cascade Street Generating Station was recommissioned and became commercially operable.
Upgrades included replacement of the intake, penstock, turbine, generator, switchgear, controls and powerhouse. The new double regulated Kaplan turbine is capable of producing 4750 hp. The generator is connected to Lakeland Power’s distribution system through all new switchgear and substation infrastructure and is capable of producing 3260 kW. This locally produced renewable hydroelectricity supplies approximately 1100 homes with their electrical energy demands annually.
The powerhouse includes a new emergency backup generator to supply the facility and dam with power in outages or emergencies and was architecturally designed to suit the site and local area. Remnants of the previous powerhouse have been integrated into the new facility with future additional historical artifacts to be integrated into the landscape to pay tribute to the past.