Decew Falls Generating Station

Continuing from previous pages on Canadian Niagara Power’s Rankine generating station, and Ontario Power Generation’s Sir Adam Beck I (SAB-1) generating station, this page outlines the oldest generating station in Ontario and one which is still producing power in 2008.

Except for the photo above (taken from an OPG brochure and showing the complete plant including the oldest section to the left, modern addition to the right, and pentstocks), all photos were taken on a open house held Nov. 1, 2008 at the plant.

Built in 1898, the Decew Falls plant was originally built by the Cataract Power Company of Hamilton, Ontario. It was originally built to provide power to the electric street railway in Hamilton – in those days many power developments in Niagara were intended for specific power markets – 34 miles away by transmission at 22,500 Volts (three-phase). Both the use of high voltage to transmit power that distance, as well as the use of three-phase and the relatively high frequency are unique features of this installation. The plant was acquired by the Hydro-Electric Power Commission (now OPG) in 1930 and continues to generate power for the province on Ontario. The plant itself was expanded several time with a second station added in 1943 to help supply power for the war effort.

This plant was monumental and was awarded an IEEE historical achievement recognition in 2004 for pioneering the long-distance transmission of energy at high voltages. In 1898 the plant transmitted two-phase electrical power at 22.5kV, 66.66Hz from St. Catharines to Hamilton, a distance of 34 miles (prior to this, transmission lines were limited to less than a third of this distance and operated at much lower voltages). A scant ten years prior to this plant being built, Nikola Tesla proposed the use of “polyphase currents” which were used here in contrast to many contemporary systems that were either DC or single-phase AC – the Decew Falls plant was one of the first uses of Nikola Tesla’s concept.

The Decew Falls plant is fed from Lake Gibson, a man-made reservoir at the top of the escarpment created in the late 1800’s to supply the city of St. Catharines with water. Lake Gibson was created by flooding the shallow valley of Beaverdam’s Creek (which originally flowed down the escarpment at Decew Falls) and is fed entirely from waste water from the Welland Canal. Historic Morningstar Mills was also fed from Lake Gibson.

The story of this generating station begins in 1898, when the Cataract Power Company built the original station at Decew Falls. Water from the Welland Canal was drawn neat Allanburg into Lake Gibson (just south of Brock University), fed a single 1.8m diameter pentstock to generating units at the bottom of the Niagara escarpment (a 260 foot drop), and discharged into Twelve Mile Creek below which leads to Lake Ontario. In 1905 the reservoir at the top of the escarpment was expanded from the original area of 40 acres to 450 acres.

The original generating station consisted of a smaller building than that of today (old photos from 1903 do not show the transformer station in front nor the expansion of the main station to the north – the “bent” structure seen on the aerial photo). In 1898 the station consisted of two small 1700hp Stilwell-Bierce turbines coupled with 1000kW Royal Electric alternators. Two more units, 3300hp Manneret turbines, were added in 1903 and within two years four 7100hp Voith turbines (coupled with 5000kW Westinghouse alternators) were added – the four turbines manufactured by Voith are still in operation today. Of the eight turbines installed by 1906, six units were fully operational with two more planned and the plant was fed by four pentstocks (with the addition of two more planned when addition units came online). Two small turbines were also included to drive 50hp DC machines to supply excitation current to the alternators. The plant was expanded in 1911 again when four new generating units were added. Over the years, more generating units were added and four of the oldest original eight generators were shutdown in 1967 and removed in 1974. Today, six units are housed in the plant of which four 5000kW units are actively generating. As well, the small building in the front which was once the original transformer house from 1898 remains as a maintenance building.