With the northernmost points of the Red River reaching flood crests this weekend and early next week, another Top 10 flood year is in the books for the Red River Basin.
Grand Forks has seen six Top 10 floods in the past 10 years, with the 2020 flood coming in at No. 8 with a crest of 47.56 feet on April 10. Grand Forks' Top 5 flood crests remain the April 22, 1997, crest at 54.35 feet, followed by the April 10, 1897, crest at 50.20 feet, the April 14, 2011, crest at 49.86 feet, the April 1, 2009 crest at 49.33 feet, and the April 26, 1979 crest at 48.81 feet.
It does seem severe spring flooding is occurring more often than decades past. National Weather Service lead meteorologist Jim Kaiser said the Northern Plains are in what climatologists call a wet cycle and has been for nearly 30 years. Kaiser said there is certainly more flooding now than there was during drier periods, such as the 1930s and 1950s.
"You can say (the floods are) getting worse. They're more frequent than we saw in the last century. They're more frequent from the '90s onward because of the wet cycle," said Kaiser, noting, however, that in 1979, 1887, 1882, those floods were all higher than this year.
Severe flood years are often the result of a number of factors coming together, Kaiser said. Flooding in the Red River Valley is caused primarily by snowmelt, so the worst flood years often happen as a result of additional precipitation, such as rain or a blizzard on top of the regular snow. That was the case this year, when a historic wet fall resulted in standing water and water-saturated soil by the time the ground froze. The National Weather Service initially predicted this would lead to a Top 5 flood in spring 2020, but a "near-perfect melt cycle" resulted in a Top 10 flood instead, Kaiser said earlier this year.
It's difficult to know how long the wet cycle will last, according to Kaiser, who said it could end soon, after a 30-year run, or it could last another 20 or 70 years.
Lindsay Pease, an assistant professor and extension specialist in nutrient and water management for the University of Minnesota - Crookston, explained that a wetter climate allows more moisture to be held in the air, which can result in more precipitation than in dry climates. She said that, as winters become warmer, especially in the southern parts of Minnesota, that could also result in higher flood levels as snow melts and returns more quickly to the water system.
But she said climate isn't the only factor impacting flood levels from year to year.
Pease said she has noticed that over the past 20 years, rises in the river at Grand Forks have nearly mirrored those at Fargo-Moorhead. She said this suggests urbanization is also impacting flood levels.
"We've got more people, and with more people come more paved surfaces or houses, and fewer places for that water to infiltrate after a rainstorm early in the year," Pease said. "That's not necessarily a bad thing, but it's something that kind of comes along with increased population."
She also suggested that increased flood controls following the devastating 1997 flood in downtown Grand Forks could be raising river levels, as artificial flood barriers force the water more quickly down a narrower path.
While floods have become more severe over the past few decades, she said she doesn't necessarily see floods continuing to worsen, though it can be hard to predict flooding in future years.
"I think what we're going to start seeing is maybe adjusting a little bit to more of a new normal as people get used to, in the spring, bridges being closed, and farms being flooded, too," Pease said. "That's something I think people are already adjusting to somewhat, and I think we're going to have to just start adjusting to these springs, like with this spring and last spring, where you have to kind of wait for the water to recede before you go about your life."