The Island Falls Generating Station is a four-unit hydroelectric station located on the Abitibi River in Tolmie and Menapia Townships.
The station was built in 1925, with two of the four units operating at 25 Hz. In 1996, the station was modernized and all units were converted to 60 Hz operation. In 2018 one turbine was replaced and the unit rewound, with a second to be completed soon. The station has an installed capacity of 44.3 MW at a gross head of 19 meters.
Located 30 km north of the confluence of the Abitibi and Frederickhouse Rivers, the station is a run-of-river plant. Local storage capability allows a moderate level of peaking performance during all but freshet conditions. Operation pertaining to levels and flow are governed under the 2004-2014 Abitibi River Water Management Plan.
The site is restricted by a maximum water elevation due to flood constraints and a summer minimum elevation to respect navigational constraints. Operation of the station is primarily coordinated with Iroquois Falls GS upstream and other area storage facilities. The station is subject to a daily average minimum flow of 10 m3/s for fisheries concerns.
The Island Falls station consists of a powerhouse, a concrete gravity section containing the spillway and sluice gates, and a short earth section. H2O Power unit has two head gates, which are powered by an overhead crane. Four screw operated motorized sluice gates allow the passing of excess flows. There are ten bays of stop logs, which are handled by two mechanical lifters.
The station has a unique feature known as an ejector gate which is installed on each turbine, and can each pass an additional 30 m3/s flow when inflows are in excess of normal turbine capacity. The head pond operates between the minimum elevation of 215.03 meters and maximum elevation of 215.28 meters.
Island Falls is connected to the existing Hydro One 230kV circuit A93I and connects to Ansonville TS.
- Location: Tolmie and Menapia Townships, ON
- River System: Abitibi River
- Capacity: 44.3 MW
- Turbines: 4 vertical Francis
- Originally Built: 1925