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OPG’s hydro operations working through COVID-19 challenges to manage freshet

OPG’s hydroelectric operators and water managers have been busy this spring freshet season managing water levels and ensuring the reliable production of electricity during an especially challenging time.

Pine Portage Generating Station
OPG's hydro operations manage water levels and flows during spring freshet season.

In eastern Ontario, this year’s freshet – the annual influx of water from rain and melting snow – has been largely manageable due to decreased rainfall and slower snow melt in many parts of the province. For OPG hydro staff already navigating the challenges posed by the COVID-19 pandemic, this has been a welcome respite.

“Barring any intense rain event, we are now past the peak of freshet in the region,” said Halya Petzold, a Technical Officer of Water Management in Eastern Operations. “Thankfully, the freshet season has been more normal this year and not anything on the scale of the 2019 freshet, which saw flooding in many areas of the province.”

To deal with the realities of the coronavirus, OPG’s hydro operations have had to be nimble and creative in freshet planning while working with fewer staff.

At the Eastern Operations Control Centre (EOCC) at R.H. Saunders Generating Station, which oversees power production at 22 hydroelectric stations on several river systems, enhanced measures to protect employees have included alternating shift schedules, physical distancing, temperature monitoring, and restricted access to essential operators in the control room.

“The operators in the EOCC are continually monitoring levels and flows to make sure we’re managing the water as per strategy and regulations. They also ensure the units are running safely and reliably,” said Brent Morton, Work Centre Manager – Operations at Saunders. “It’s a very busy time of year for the operators and it’s pretty impressive to see them doing all of this while short-staffed.”

To provide flexibility and minimize the need for field activities like manual log operation, sluicegates are being used to balance flows. These metal barriers control water levels and are less labour-intensive to operate as they can be raised remotely from the control room at Saunders.

An employee performing a snow survey.
An OPG employee performs a snow survey.

The use of sluicegates has also benefited the Ontario electricity system by helping scale back generation during the current reduced demand for electricity.

Meanwhile, water managers like Petzold and her colleague, Jordan Hughes, are working from home, setting up strategy for the control room on how to run the water, examining current and future conditions, and coordinating with commercial operations. They have had to be very flexible to adapt to the ever-changing conditions of freshet, while ensuring water levels meet regulatory seasonal requirements as to not impact spawning season for fish and recreational activities.

“You can never predict what can happen in a freshet as every year it’s different,” said Hughes. Initial snow surveys in the Madawaska River suggested a risk of very high flows this spring, which have not transpired. “When you’re foreseeing what’s going to happen, you can only work with what you’ve got. We have to plan for the worst and prepare for the greatest risk.”

Petzold and Hughes expect the rest of the freshet season to go smoothly in eastern Ontario, but they’re not quite out of the woods yet, as there is still quite a bit of snow intact in northern Quebec and the northern portion of the Ottawa River watershed. There is, however, a lot of room remaining in OPG’s reservoirs in northern Ottawa that can be refilled, Petzold said.

To learn more about how OPG manages water, visit