Starting Saturday, June 11, 2022, users of the Madawaska River - between Calabogie Generating Station (GS) and Stewartville GS - may notice lower water levels as Ontario Power Generation (OPG) will utilize an expanded forebay range at Stewartville Generating Station (GS) for the foreseeable future (1-3 weeks) as recent rainfall has increased inflows.

OPG requires this range at Stewartville GS for added contingency (storage) to mitigate any high water levels at the facility due to increasing inflows. This lowered range is an operational necessity to maintain a lowered headwater level. 

Additional information:

  • The 3-day precipitation accumulations within the watershed have exceeded 50 mm and, as a result, inflows have increased significantly. 
  • OPG will be performing upstream flow increases from the reservoirs at both Bark and Kamaniskeg lakes on June 10 and inflows into Mountain Chute will increase over the next 1-3 days.
  • The range at Stewartville GS will be 144.00 m to 144.55 m.
  • This expanded range is typically employed when flows become exceedingly high.
  • This range was employed in July and September 2021 in response to significant precipitation events.

For water levels and flows, please visit

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