Twin Falls Generating Station (22 MW) - Iroquois Falls: Abitibi River

On January 1, 2015, the Ontario Power Authority merged with the Independent Electricity System Operator to create a new organization that combines the OPA and IESO mandates.

Please note that the information on this page is not current and will not be updated. A new format for contract data will be published soon.

The Twin Falls Generating Station is a five-unit hydroelectric station located on the Abitibi River. The station was built in 1922, all five generators rewound between 1982 and 1992 to increase capacity, switchgears modernized in 1999, and controls modernized in 2009. The original turbine runners remain in service and are currently being upgraded. The station has an installed capacity of 24 MW at a head of 16 metres.

Located east of the town of Iroquois Falls in Teefy Township, the station serves as a peaking station and controls the discharge of Lake Abitibi. Twin Falls regulates the water levels and flow from Lake Abitibi. Operations pertaining to levels and flows 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 coordinated with Iroquois Falls downstream, which is constrained by a 56.6 m3/s minimum flow limit. The station is remotely controlled from the H2O Power LP Operating Center located in Oshawa.

Twin Falls station is categorized as close coupled, and has no penstocks. The station consists of a powerhouse, a concrete gravity section containing the spillway, sluice gates, and an earth section. Each generating unit is provided with two head gates, which are operated by a common shaft hoist. There is a sluice gate on the spillway, and each gate is powered by a screw-operated motorized drive train. The headpond operates between the minimum elevation of 262.92 metres and maximum elevation of 265.39 metres. The summer operating range minimum is 263.7 metres.

Twin Falls is connected to the existing Hydro One 230kV circuit A931 and connects to Ansonville TS.

This hydroelectric generating station generates approximately 134,000 MWh of renewable energy per year.

Location: 1 Park St., Iroquois Falls, ON
River System: Abitibi River
Nameplate Capacity: 24 MW
OPA Contracted Capacity: 22 MW
Operator: H2O Power LP
Technology: Hydroelectric, peaking
Turbines: Five vertical Francis
Originally Built: 1922
OPA Contract Term Commencement Date: December 1, 2009

Project Status (5 MW Runner Upgrade) as of June 30, 2014. 

  • The reassembly of generator 3 was completed in April and the unit was returned to service

  • The fifth and final unit, generator 2 was shut down and disassembled

  • The onsite machining of the turbine fixed components was completed

  • The reassembly of Generator 2 was to commence in August with the arrival of the new runner


Project Contacts:

Ontario Power Authority

Media and Public Relations
T. 416-969-6307 or

H2O Power LP
Marc Mantha
Vice President, Operations
T. 905-438-8539 Ext 203