Seine River Watershed Information
History

Around 1873, the Department of Public Works Canada, under the direction of Simon J. Dawson, constructed a stone dam at the outlet of Lac des Mille Lacs on the Seine River. The purpose of this dam was to allow the water levels to be increased for better navigation along the Red River Route.

1905: Canada, Ontario, the United States and an American Industrialist, E.W. Backus, entered into an agreement to permit a power dam to be built across the Rainy River at Fort Frances. The dam was completed in 1909.

1923–1926: Water control on the Seine River continued with the building of the Calm Lake, Sturgeon Falls and Moose generating stations in 1926. These power dams were built to supply power to the Fort Frances paper mill (now owned by Resolute Forest Products) and to facilitate log-driving operations. Most of the significant changes to water surface area occurred in 1926. The Marmion Reservoir was created at this time and served as the primary storage basin for power regulation at Moose, Calm and Sturgeon Falls generating stations.

1926: The Backus timber dam replaced the Dawson stone dam at Lac des Mille Lacs. This allowed water levels and flows to be modified for the purpose of power production downstream.

1943: The Moose generating station was decommissioned due to the diversion of the Seine River around the Steep Rock mining operations. The Raft Lake dam was built to replace the Moose Lake structures as the principal control works for the system.

1944–1961: The East Arm of Steep Rock was leased to Inland Steel and its subsidiary, Caland Ore Canada, commenced dewatering and dredging operations.

• The bulk of the dredge material from this mining zone was deposited in the Lower Marmion Lake area.
• Three earth-fill block dams and an overflow sill were constructed to isolate Lower Marmion from Upper Marmion. This minimized the amount of dredge material entering the Seine River.
• Further development of the Steep Rock iron deposit resulted in additional major and minor watercourse diversions and construction of settling basins for overburden dredged from Steep Rock Lake.

Mid-1950s: The timber crib dam at Lac des Mille Lacs was replaced with a concrete dam.

1980s: The Ontario government assumed ownership of most of the Steep Rock water control structures. Some minor modifications were made at this time.

1989: Abitibi-Consolidated Company of Canada assumed control of the Raft Lake Dam.

1991: The Lac des Mille Lacs Lake Management Plan was developed. New water control objectives were adopted.

1993–1994 Valerie Falls generating station and dam were built, capturing 65% of the available drop previously utilized by the Moose Lake power station.

1995–1997: The Seine River Water Level Technical Committee (SRWLTC) was formed in 1995 and operational targets for the dams on the Seine River were developed in 1997.

2001: The Ontario Government enacted legislation requiring that formal water management plans be developed for each “power” river in the province.

2007: Abitibi Consolidated Hydro Limited Partnership (ACH LP) was formed and included the transfer of ownership for Calm Lake GS, Sturgeon Falls GS, and the Raft Lake dam. The new company was created as a distinct entity with the goal of providing renewable reliable energy to its customers and the Province of Ontario.

2011: ACH LP was sold to a new group of Canadian private investors, and the company was renamed H2O Power Limited Partnership.