Zumbro River watershed research offers map for future of valley
ZUMBRO FALLS — Much of the heavy work involved in the recover from the September 2010 Zumbro River flood has been done. Some damaged buildings have been restored; others demolished.
On Aug. 22, a major step will be taken toward preventing, or at least reducing the damage from, future floods.
The result of years of work will be laid out for legislators, conservation groups and community leaders during an invitation-only presentation at the pavilion in Hammond, said John Homme, leader of Zumbro and Friends, an umbrella group of organizations working to help the valley. Once they are shown details, there will be a series of public community meetings to share the information.
The plans, developed with help of Minnesota State Mankato students and faculty, will explain how a monster storm in 2010 destroyed or damaged so much of Zumbro Falls, Hammond and Jarrett. The plans will also outline what to do next, said Janice Domke, of Hammond, one of the group's leaders.
No one is saying the plans are perfect, said Stephen J. Druschel, a Mankato associate professor of environmental engineering. But if five or six feet, had been shaved off the crest of the flood of three years ago, "it would have been just another bad one, not THE one," he said.
He and his students analyzed data from the flood and questioned residents in order to build a model of the Zumbro River watershed. In the future, rainfall totals can be plugged into the model to predict how high the river will rise and when. That could give homeowners and emergency managers time to save items and evacuate, Druschel said.
The model also factors in how wet the land is, he said. In dry years, a third of the water will run off; if the ground is wet, like before the 2010 super flood, as much as two-thirds of rain will run off.
To shave off those top feet of water, it might be necessary to widen bridges to allow water to flow faster or build dams and change farmland cropping patterns to slow down other water, he said. It's going to take a lot of time, and more study, to know what has to happen.
This model is even more important now that changes in weather patterns, smaller polar caps and shifts in ocean currents are making weather more erratic. There will be "less drizzle and more cats-and-dogs rains," Druschel said.
The group is releasing the data now to get people talking, Domke said.
The idea is to spend money upfront to change bridges or do what's needed instead of constantly spending money to fix flooded homes and businesses, Domke said.
It's critical that the Zumbro River continues to be the heart of the valley's communities because it's so important for commerce and for people's quality of life. "Hammond, without the river, is not Hammond," she said.
The decisions made now, based heavily on the Mankato State model, will determine the valley's future, Domke said. "Now, it's a matter of redefining who we are."