On 7 February 1921, an avalanche destroyed 23 m (75 ft) of the wooden penstock that carried water from the dam to the generating station, cutting off all electrical power to St. John's for almost five days.

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[when?]

Massey, A.C. RiceOriginal Construction: Reid Newfoundland Company Unit 1: (installed in 1902) Inward-flow Girard type (impulse turbine)

Manufactured by Voith Unit 2: (installed in 1900) Victor type (early Francis turbine)

Manufactured by Armstrong Whitworth Unit 2 (installed in 1900): 3-phase, 60 Hertz, 550 volts Manufactured by Westinghouse Replaced in 1926 with 3-phase, 60 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 48.8 metres long by 7.3 metres wide by 4.9 metres high Masonry construction 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) In 1900, rockfill with timber facing.