Nature Nut: Behold, the power of ice

March 24, 2019 GMT

I’d been thinking about doing this week’s column on rabbits, but revelations last weekend convinced me otherwise.

I figured by the time this column was released, we would have gone through a second local thaw that might melt much of the remaining area snow. In addition, there would undoubtedly be careful eyes watching a rising Mississippi River heading our way, so rabbits could wait for another time.

But it was a trip through the region last weekend that also made me aware of “Ice Power.” In addition to high water, ice is a major flood factor, something many in Iowa and Nebraska have been learning recently.

For me, ice awareness from recent thaws started after the JM basketball game at the Mayo Civic Center. Walking to my car in the dark, I noticed piles of ice piling up just upstream of the Center Street bridge.

So, the next morning I thought I’d check out Silver Lake to see what was happening there. My first stop at the Broadway bridge glued me to a half hour of watching something quite spectacular, the breakup and flow of thousands of tons of ice over the Silver Lake dam.

I watched Rochester Public Utilities maintenance staff working on the three unraised gates on the south side of the dam which were backing up ice behind them. I also spoke with a public works employee who said he was watching for ice against the bridge, as it had previously been backed up on the Seventh Street bridge.

All the while, I was watching the movement of ice chunks, most 15 to 20 inches thick, and some 10-by-20 feet in size, flowing over the dam. I couldn’t help but wonder how the proposed rock and earthen dam replacement for the Silver Lake dam I wrote about last week would stand up to such force. But once most of the ice was over the dam, I decided to head north to see how the high water and ice flow might be impacting areas like Zumbro Falls, the power dam, and spots on Lake Zumbro.

Zumbro Falls had fast water flow, not flooding height yet, but very little sign of ice. The power dam was quite spectacular, with 4 feet of water flowing over the top, but again no sign of ice. Then I headed to Cedar Beach, which is high upstream on Lake Zumbro. No ice flow there, but was told it broke up a couple hours earlier.

But, it was a few minutes later at the dead-end road by Fisherman’s Inn that I was treated to the scene of a massive ice backup. Here, a few acres of big and bigger ice chunks were backed up against the large body of Lake Zumbro, still frozen over with 18 inches of ice, according to locals I spoke with.

In the midst of the massive ice field, I could see how its power, and maybe humans underestimating nature, had caused docks and watercraft from upstream shorelines to be pulled by ice into the river as it rose. I talked with locals who lived on the river, concerned the ice might start backing up water and flooding their basements.

Once done with that very interesting northward tour, I headed home and got on my bike to check out Silver Lake again. Although there was very little ice flow, there was plenty of big ice that had been grounded and was now sitting in shallow water or on the shoreline. Unfortunately, I had to text the owner of the paddleboat business, one of our Silver Lake Friends, to tell him that ice had pushed some of his boats up on shore.

With cooler temps over the weekend, things calmed down somewhat. However, a drive to my Mississippi backwaters cabin revealed lots of still-standing water, flooded farm fields, closed roads, and, again, ice that had been broken up, raised, and was now stranded.

So, I will look forward to seeing how the ice dam at Fisherman’s Inn fares this week, and will be keeping an eye on Mississippi River flooding forecasts. Meanwhile, I will probably move some things out of my “duckshack” basement to prepare for what might be coming down our nation’s biggest river next week. And, I will wonder if ice will be a major factor.