Did the historic flooding on Rainy Lake this summer have to be so bad? 

Homeowners on the south shore of Rainy Lake along the Canadian border near International Falls, Minn., are battling exhaustion and fatigue in addition to the record setting floodwaters that have threatened their properties for the past two months. 

They’re also fighting a mounting sense of frustration. 

"It’s been awful. We've had five high water events in the last 20 years with this rule curve that they've come up with,” said 83-year old Gary Sullivan, who built a 10-foot high sandbag wall in his backyard to protect his home from the lake. 

“And prior to that we had one high water event in 100 years."

The rule curve that angers Sullivan and other local residents so much was put in place by the International Joint Commission in 2000, and revised five years ago. 

The IJC manages water levels on the giant 50-mile long border lake to try to keep the water levels within that curve, between maximum and minimum water levels agreed to by the U.S. and Canadian governments. 

They do that by releasing water through dams on either end of Rainy Lake. 

It’s a delicate balancing act that takes into account a number of different stakeholders, including property owners on Rainy Lake and other large lakes along the border. The list also includes: the dams that generate electricity, recreation and tourism, fish and wildlife and Indigenous First Nations located on the Canadian side of the lake, who harvest wild rice from the region’s interconnected lakes and rivers.

But sometimes, Mother Nature can thwart the best-laid plans.

This year, so much water poured into the Rainy Lake basin, that everyone agrees major flooding was inevitable. Still, some believe that steps could have been taken to lessen the impact on the more than 200 residents whose homes and businesses are still threatened.   

“There are some things that could have been done that may have helped the situation a bit,” said Tom Dougherty, co-owner of Rainy Lake Houseboats. 

“It would have made a difference of maybe seven to eight inches, maybe more? Nobody really knows. But I’ll tell you what, to those folks [like Gary Sullivan] on County Road 20, inches matter.”

Long history of water management

The U.S. and Canadian governments first put in place a rule curve in 1949 to manage water levels on Rainy Lake. 

It was revised in the 1970s, and again in 2000, when the International Joint Commission made changes to keep more water in the big lakes upstream from Rainy Lake – Kabetogama and Namakan Lakes — during the winter. 

Property owners there had long complained that too much water was being let out of those lakes in the winter to generate power at the dams. That meant those lakes sometimes didn't fill back up with water to reach their normal summertime levels until July.

There was also a major concern that those low springtime water levels had a negative impact on fish spawning. 

Larry Kec, who’s run his family’s Kec's Kove Resort on Lake Kabetogama since 1985, said often his docks would be 100-200 feet out of the water. 

"I actually walked to the island in our bay in tennis shoes, the one year, and never got wet feet,” he recalled. “So I mean, it was extremely low for years."

After the rule curve change in 2000, Kec says it's been much better. There's been more water at his resort early in the summer. 

The change in water levels management also had a number of other benefits. A 2017 report found that it improved fish population and spawning habitat of several key species, improved conditions for wildlife, increased tourism and recreation benefits, improved water quality, and better preserved archaeological and cultural sites along shorelines. 

But those benefits came at the expense of property owners on Rainy Lake. They've experienced more high water years since the rule curve was changed, because now there's more water in the entire system, and less room for spring flood storage.

Dougherty, of Rainy Lake Houseboats, was part of a group that formed the Rainy Lake Property Owners Association in 2014 to have a stronger voice in how water levels are managed.

"Oftentimes, [the IJC is] looking at data that's on a computer,” he said. “And we’re here year after year, we're out in the bush, we know how much snow there is, we know how much rain we had in the fall. We have a pretty good idea of what's going to happen."

About five years ago the International Joint Commission did make a change that gives them more flexibility to help alleviate potential flooding. Now, in March, the IJC can implement something called a high risk rule curve if the conditions are right for serious flooding. 

Dougherty and other locals asked the IJC to implement that curve this spring, which would have drawn down Rainy Lake to create more room for it to receive spring runoff. They pointed to deep snow still on the ground, and what looked like a late spring thaw. 

But the IJC declined. U.S. Army Corps of Engineers Colonel Karl Jansen, who's the U.S. co-chair of the International Rainy Lake of the Woods Watershed Board, said they took into account several factors, including the fact that the region experienced a severe drought just last year. 

“And at the time of our decision, portions of Canada and portions of the United States were still rated in moderate to severe drought. So we were concerned about the potential for a back to back drought period,” Jansen said. 

Even if the IJC would have implemented the high-risk curve, Jansen said its impact would likely have been miniscule. 

“That additional storage would have been consumed in about one, or one and a half days of the type of inflow that was arriving into Rainy Lake,” Jansen said. “A lot of people think that implementing it would have prevented or significantly reduced the impact of this extraordinary event. But it's just not true.”

Jansen said if anything it would have only delayed the peak of the flooding. That’s because in extreme high water years like this one, water pours into Rainy Lake much faster than it can escape through the Rainy River, which acts as a natural pinch point. 

Some local residents have suggested that the IJC delay its decision on when to implement the high risk curve. It makes its decision on March 10, but this year the region didn’t start to see heavy spring rains until April. 

To implement the high risk curve, Jansen said that decision needs to be made in March, because it would take time to draw the lake’s level down in time to prepare for it to receive spring runoff. 

“Inches absolutely matter,” said Jansen, adding that the IJC plans to examine exactly what the difference would have been in flood levels if water managers had implemented the high risk rule curve.

“But we do think it would be very modest and that it would not have been a silver bullet for the suffering that people are going through right now."

‘Unprecedented wetness’

The International Joint Commission contends that it’s not water levels management that's caused more flooding in recent years, it's more precipitation. 

This year has been the wettest year on record in International Falls. Through June 19, year-to-date precipitation at International Falls was nearly 19 inches, which is almost two times times greater than normal over the past three decades.

And four of the top 10 wettest years ever occurred during the 2010s, said Minnesota Department of Natural Resources senior climatologist Kenny Blumenfeld.

"The unprecedented or nearly unprecedented flooding that we've been seeing in that area is at least partially in response to the unprecedented wetness that we've seen,” Blumenfeld said. 

The National Weather Service says the historic flooding on Rainy Lake was caused by a deep snowpack across the entire basin, followed by record-setting rains in April and May that fell on still frozen ground. The snow then melted at the same time, sending huge quantities of water gushing into the basin. 

“These are the sorts of conditions that we've seen with other major catastrophic flooding events that are kind of famous in the region,” said Blumenfeld, “including the Red River floods of 1997 and 2009, and the Mississippi River flooding of 1965. That’s kind of the wicked checklist you end up with.”

Blumenfeld said he can't tie this year's flooding definitively to climate change. But he said it's plausible it played a role, because a warmer planet means extra water vapor is available to passing storms. 

Minnesota has seen more heavy, intense rains recently than at any time on record, and climate projections indicate those big rains will become more frequent in the future. 

That means more uncertainty for Rainy Lake homeowners, even after the lake finally recedes later this summer. According to the National Weather Service, the lake may not return to normal summertime levels until August. 

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