Information from Ontario Power Generation re: Rising Water Levels on Lake Temagami

Due to recent rainfall over the past couple of weeks, we are experiencing high rates of runoff in many areas across the region – particularly on the Sturgeon watershed. As a result, the water level on Lake Temagami has risen quickly due to high inflows, and the elevation is currently above the normal operating maximum.

We are utilizing the flood allowance at Lake Temagami, which is a 20-cm range between 294.00 m and 294.20 m (above sea level). The current elevation at Lake Temagami is 294.02 m (i.e., 2 cm into the flood allowance). Due to a natural restriction in the water body at the Cross Lake Dam, it is challenging to discharge a higher flow from the Lake. We are, however, currently discharging the maximum amount possible.

Rain is forecast for this week-end and into early next week, and could bring anywhere from 10 mm – 35 mm of precipitation to the area. If higher amounts of precipitation materialize, we will see further increases in water levels and flows.

As a reminder, you can access the water-level and flow graphs online at: https://files.opg.com/wp-content/uploads/2024/04/SturgRiver_240423_153928.pdf

Please reach out to me (kate.cantin@opg.com) if you have any questions.

Thank you,

Kate Cantin, Ontario Power Generation