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Improving dam safety on the Lower Mattagami River

In northeast Ontario, planning is underway to improve dam safety along the Lower Mattagami River.

OPG, along with partner Moose Cree First Nation, owns and operates four hydro facilities on the river, located about 70 kilometres northeast of Kapuskasing.

Little Long Generating Station
Little Long Generating Station

The Lower Mattagami River complex includes the Little Long Generating Station (GS), Smoky Falls GS, Harmon GS, and Kipling GS. The eight-gate Adam Creek spillway structure located on the Little Long Reservoir allows OPG to safely pass water around these stations.

The Little Long Dam Safety Project proposes to increase the discharge capacity at this spillway structure to comply with updated requirements established by the Province of Ontario. The company is looking to add four new sluice gates, which control water levels and flow rates in rivers, at the Adam Creek spillway. OPG will also make reliability improvements to the existing Little Long, Smoky Falls and Adam Creek sluice gates.

OPG is actively engaging with Indigenous communities and stakeholder groups to provide information and updates on the project, said Rapin.

“We want to ensure that community members are well-informed throughout both the planning and execution of the project.”

In 2015, OPG completed the $2.6-billion Lower Mattagami Project in partnership with Moose Cree First Nation. The project involved adding a third generating unit to the Little Long, Harmon, and Kipling stations, and completely redeveloping Smoky Falls GS. Moose Cree First Nation has a 25 per cent equity share in the new generating units.