In a media availability last week, members of the International Joint Commission (IJC) said given the sheer amount of rain and the natural geography of the area, little could have been done to avoid the current flooding.
The IJC is a bi-national organization, comprised of regional experts, which co-operates to manage the waters that run along the Canada-U.S. border. According to its website, “The IJC has two main responsibilities: approving projects that affect water levels and flows across the boundary and investigating transboundary issues and recommending solutions.”
A group from the IJC toured the region last week, even going as far north as Red Lake to see the flood issues there.
“The primary purpose of our visit this week is to see firsthand what’s going on with the flood and high waters,” said Colonel Karl Jansen. “What the impact is to the people, businesses and governments of this area, to see how our work impacts the region. When we’re experiencing an extreme event, what can we learn from an engineering perspective as we move forward as a combined international community.”
Jansen is the commander of the St. Paul, MN district for the Army Corps of Engineers. He is also the U.S. co-chair of the International Rainy Lake-Lake of the Woods Watershed Board.
Jansen explained that the weather experienced by the region this spring was historic in scale and nothing that the management board could have done would have prevented the flooding.
“I think the most important thing to know about this flood is that the precipitation and weather that caused it is of historic proportion,” Jansen said. “It simply overwhelmed the watershed to a degree that the infrastructure in place can simply not prevent it or withhold it.”
Matt DeWolfe is the executive engineer with the Lake of the Woods Control Board and is a Canadian Engineering Advisor to the Water Levels Committee. He has worked in water regulation on the Rainy-Namakan Basin since 2008. DeWolfe says that even without the man-made outflow restrictions on the watershed, there would still have been flooding.
“Basically, opening all the gates at Rainy Lake or pulling all the locks out of the dams at Namakan would make the system behave as if there were no dams in place right? That’s an option that people might look at,” DeWolfe said. “But it’s critical to understand that the outlets at both of these sites are very constrained. They can’t keep up with the amount of flow that we’ve seen come in, in this event and past events like 2014 or 1950.”
DeWolfe went on to say the actual constriction during this flood hasn’t been the dam, it’s actually the upstream conditions.
“This is to the extent that if someone were to wave a magic wand today and make the dam at International Falls-Fort Frances disappear, people up the lake wouldn’t even be aware that it happened because the dam is not what’s holding the water back,” he said. “It’s the constrictions at the rail bridge and a couple other points further down the upper river.”
Similarly, DeWolfe said that even opening the gates at the dam earlier in the year would not have helped.
“All the modelling that’s been done over the years after every (flooding) event shows starting much lower or opening gates faster doesn’t really have an effect,” he said. “Because, at those lower levels, the lakes can’t release water as quickly.”
Jansen said when the Water Levels Committee made decisions for the water levels in the spring on March 10, there was very little that could be done to predict the rainfall which happened afterwards.
“We feel at the time we made our decision for our order with the information available at that time,” Jansen said. “Not knowing, of course, what Mother Nature would throw at us in subsequent weeks.”
That said, it is important to note that the dams are controlled by local employees with H2O Power, according to DeWolfe.
“It doesn’t require the Water Levels Committee meeting to say ‘open gates’ or ‘close gates,’” DeWolfe said. “It’s all done by operators.”
DeWolfe also says the high flood risk curve the committee works from is in a range. Around the middle of April, the water levels seemed to be well outside that range – about eight inches (roughly 20 cm) below the middle of the range, in fact. However, the water flowing into Rainy Lake in the months from April 1 to May 31 increased rapidly.
“If you average that out over all those days, that inflow would fill that 20 centimeters of storage in one day and 1.25 days to fill that eight inches based on the amount of inflow on average,” DeWolfe said. “But at the peak, it would probably be filled in a number of hours. It really doesn’t have an effect on the peak more than probably an inch, probably less than an inch. There’s just so much flow coming into the system that that eight inches really would have had very little impact overall.”