The Petty Harbour Hydro Electric Generating Station is a

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

generating station in

Petty Harbour–Maddox Cove Petty Harbour–Maddox Cove is a town of approximately 950 people located on the eastern shore of the Avalon Peninsula in the province of Newfoundland and Labrador, Canada. It is nestled deep in the heart of Motion Bay about south of St. John's. ...

Newfoundland and Labrador Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the populatio ...

. It was constructed in 1898 and it was the first hydroelectric generating station in

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

. It was built by the St. John's Street Railway Company, a company established by Robert Reid. Operation commenced on 19 April 1900. In 1920 Reid renamed the company the St. John's Light and Power Company. On 7 February 1921, an

avalanche An avalanche is a rapid flow of snow down a Grade (slope), slope, such as a hill or mountain. Avalanches can be triggered spontaneously, by factors such as increased precipitation or snowpack weakening, or by external means such as humans, othe ...

destroyed of the wooden

penstock A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is of Scots origin, and was inherited from the earlier technology of mill pond ...

that carried water from the dam to the generating station, cutting off all electrical power to St. John's for almost five days. Then, in 1924, the plant changed ownership to the

Royal Securities Corporation Royal Securities Corporation Limited was a stock brokerage firm founded in Halifax, Nova Scotia, Canada in early 1903 by John F. Stairs, its first president. The company was the first brokerage firm to be opened east of Montreal, Quebec, the then ...

Montreal Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...

, where they began extensive reconstruction of the plant and watershed area. On 1 May 1978, the plant was entered in the Canadian Engineering Heritage Record as a model reflecting progressive adaptation to emerging technology, and remains today as one of the few plants of its type still in active service.

General Information

Location:

Petty Harbour-Maddox Cove, Newfoundland and Labrador Petty may refer to: People * Bruce Petty (1929–2023), Australian political satirist and cartoonist * Bryce Petty (born 1991), American football player * Dini Petty (born 1945), Canadian television and radio host * Eric D. Petty (born 1954), A ...

Owner: Newfoundland Power
Capacity: 5.3 MW
Average Yearly Output: 18 gigawatt-hours
Head: 57.9 metres
Average Streamflow: 5.6 cms
On-Line: 1900
Original Design: G.H. Massey, A.C. Rice
Original Construction: Reid Newfoundland Company

Equipment

Turbines

Unit 1: (installed in 1902) Inward-flow Girard type (impulse turbine) 1.4 MW Manufactured by Stillwell, Bierce & Smith Vaille Co. Replaced in 1912 with Horizontal

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The pro ...

1.57 MW Manufactured by

Voith The Voith Group is a global technology company. With its broad portfolio of systems, products, services and digital applications, Voith trades in the markets of energy, paper, raw materials and transport. Founded in 1867, Voith today has aroun ...

Unit 2: (installed in 1900) Victor type (early Francis turbine) 1.4 MW Manufactured by Stillwell, Bierce & Smith Vaille Co. Replaced in 1908 with Horizontal Francis 1.57 MW Manufactured by Voith
Unit 3: (installed in 1926) Horizontal Francis 2.05 MW Manufactured by Armstrong Whitworth

Generators

Unit 2 (installed in 1900): 3-phase, 50 Hertz, 550 volts Manufactured by Westinghouse Replaced in 1926 with 3-phase, 50 Hertz, 2,300 volts Manufactured by General Electric
Unit 1 (installed in 1902): 3-phase, 60 Hertz, 550 volts Manufactured by Westinghouse Rewound in 1926 to 2,300 volts
Unit 3 (installed in 1926): 3-phase, 60 Hertz, 2,300 volts Manufactured by

General Electric General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston. Over the year ...

Construction

Powerhouse

48.8 metres long by 7.3 metres wide by 4.9 metres high Masonry construction

Penstock

Original:
1,057 metres long, 2.4-meter by 2.4-meter cross-section wooden flume
112.2 metres long, 2.4-meter by 2.4-meter cross-section rock tunnel
115.2 metres long, 2-meter-diameter steel penstock
Replacements:
1926: 975-metre-long, 2.3-meter-diameter wood stave penstock
1953: Steel penstock (surge tank riser) replaced with 2.3-metre-diameter steel pipe
1999: Lower 740.7 metres of penstock replaced with 2.3-metre-diameter steel pipe
2021: Remainder of penstock replaced with 2.3-metre-diameter steel pipe
Intake Structure:
Concrete with steel gate and lift (integral to forebay dam)

Dams & Reservoirs

Forebay

In 1900, rockfill with timber facing. Replaced in 1926 with concrete gravity. Steel anchors added in 1992. 9.1-meter maximum height.

Bay Bulls Big Pond

Zoned earthfill (rebuilt 1998–1999) Concrete outlet conduit

Cochrane Pond

Earthfill with concrete overflow spillway and timber crib outlet.

Tailrace

Unlined canal excavated in rock 137 metres long

References

{{stack, {{Portal, Canada, Water, Renewable energy Hydroelectric power stations in Newfoundland and Labrador