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Lac des Mille Lacs Dam
Raft Lake Dam
Marmion Sluiceway
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Sturgeon Falls Dam

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Seine River Watershed
Raft Lake Dam

Seine River Watershed Information H2O Power LP is the owner and operator of the Raft Lake dam. The dam was built by Steep Rock Iron Mines in 1943, as part of legal requirement to achieve the diversion.  Ontario Hydro operated the dam from 1980 to 1989, when the current company's predecessor
(Boise Cascade Canada) acquired it.

Upper Marmion Lake: The Raft Lake dam controls the water levels and outflows of Upper Marmion Lake (5,525 ha). Unlike the other 2 reservoirs, Upper Marmion Lake makes up a small proportion (1.2%) of its total watershed area (442,575 ha). This means that it takes a relatively short time to replace water removed from the lake, giving a much larger range of potential water level fluctuation relative to Lac des Mille Lacs.

Besides water from the other 2 reservoirs, there is significant inflow to Upper Marmion Lake from uncontrolled sources including the Firesteel River and the Mercutio River. Altogether, uncontrolled inflows account for 56% of the watershed area.

Reservoir (storage)
1,500 m3/sec/days
# of  sluices
1 slot with 12 logs
3 slots with 20 logs
discharge capacity 580 m3/sec
maximum 24-hour flow on record (June 3, 1970) is 246 m3/sec
Level at top of log with all logs in
415.89 metres
Level of sill with all logs out
Sluice 1 is 411.8 metres; sluices 2,3 and 4 are 408.15 metres
Discharge control diminishes progressively as lake level rises above 415.17m; spillwall crest is 415.17m (244m in length).

  Current level & flow data

2021 level and flow data
2020 level and flow data
2019 level and flow data
2018 level and flow data
2017 level and flow data

2016 level and flow data
2015 level and flow data
2014 level and flow data
2013 level and flow data
2012 level and flow data
2011 level data      2011 flow data
2010 level data      2010 flow data
2009 level data      2009 flow data
2008 level and flow data
2007 level and flow data
2006 level and flow data
2005 level and flow data
2004 level and flow data