4/22/01
Spring Floods
Here is another thing a Midwesterner knows. After an evening thunderstorm, the cool air will have a specific smell. A weather man may tell you this is the smell of ozone, or of damp earth, but a Midwesterner will know the smell for what it is. It is the smell of earthworms, flushed up from the soil by the rain.
After the storm, children may come out to splash and play and sing, cool for the first evening in days. Their parents may come out too, in town calling to neighbors from porch to porch. And even through the dimmest twilight, after the storm, the birds will sing to each other urgently, as if they have been held back from singing to each other all their lives, and now there is suddenly so much to sing about. Tonight, I imagine they are singing about worms.
The creeks will rise, and water will not so much flood their banks as that the banks will become some deep, small part of the creek. When the banks reappear they will be new black earth, not the pale yellow straw they were before. Where the creeks were ditched straight, across the fields, they will reappear like curled peels, dark black across the corn-stubbled fields, loosened from their straight lines by the rush of the flood.
The creeks will rise, and then, if the ground is still frozen and the rains melt the snow and then they keep coming, rivers will begin to rise too.
When the rivers flood, you still know where the banks are. The cottonwoods that line the banks may now stand hip deep in water, but they hold their places for a long time, until the twisting flow of the river pulls the banks out from under them and then pulls them down too. What is harder to know is where the road has gotten to.
This spring, all the conditions were set up by February for the hydrologists to predict April floods, and sure enough here they are. Late winter and early spring have been cold, and thick drifts of snow were still standing on the edges of roadsides and in the north-facing swales of the glacial moraine. Ice out is later than anyone can remember, and although the fishermen had to have their icehouses off the lakes by early March, they would have been plenty safe for another four weeks. When the rain started, the ground was still frozen, the rivers edges still held some ice,
The Cannon River, hydrologically flashy as it is, flooded quickly after the rains. By April 8, it was over its banks, onto the fields and the river-edge roads, over the lower trail in the arboretum, and 2 feet deep over the college’s baseball field and over the old municipal lot. College kids went canoeing on the baseball field, a friend who lives on the flood plain tells me that a Hmong family was wading across the old municipal lot and caught a half-dozen carp, bare-handed. The lawyer who was soon to open a new bar on his riverfront patio had a major set-back – the bar will be a pool of muddy water for another three weeks.
But two weeks later, the excitement is mostly over for the Cannon. At least for now. Yesterday Ginger and I walked through the arboretum, me trying to stay on the upper trails, Ginger seeing, or smelling, the ponds on the floodplain and plunging down the steep hill to go swim and roll in the mud-and-algae soup. At the Iron Bridge, the floodplain is full of sand dunes, attesting to the river’s disregard for its banks last week. The dunes form gray sandy arcs across the black soil, each holding a puddle in its arc. Migrating plovers filled the puddles, but flew off in a white-rumped flock everytime a car crossed the bridge, or of course, every time Ginger came near.
Yesterday and today, the Cannon through town was decidedly back in its banks. But today’s steady drizzle and tonight’s thunderstorms will bring the Cannon back up, maybe as early as tomorrow morning. How far up? Wait and see. Neither the USGS nor the state monitor data or provide forecasts for the upper Cannon, so it’s anyone’s guess.
While the Cannon rose and fell again quickly, the Minnesota River has crested slowly, and more dangerously, and has stayed high over the last two weeks. Official crest in Mankato was last Wednesday, in Shakopee, on Thursday. The state highway 169 has been closed for more than a week. Part was reopened on Thursday, but will probably be closed again by tomorrow. Both bridges in St. Peter closed, and are probably still closed, and my morning commute has been extended by 20 minutes of going around the long way.
Early last Sunday morning, 2 brothers on their way home from a party in Shakopee thought they might be able to drive across a closed stretch of Highway 101, through the rising Minnesota River. How deep could the water across the road be? Surely not more than a couple of inches? In the dark, they must have lost track, or lost the road, and they were suddenly in deep enough water that their engine stalled. The inevitable sobering effect of this was perhaps not sobering enough: they got out to push the car back out of the water, and all three, two brothers and car, were swept away by the river. One brother was rescued from the line of trees along the river bank at 6 am. By eight o’clock the rescue team deemed it too dangerous to continue searching for the other brother or the vehicle.
Other than that, in daylight and sober, Minnesota River towns have been mostly okay, not because the flood isn’t extreme, but because after the big floods of ’93 and ’97, most of the towns raised and strengthened their levees and dikes.
But a flood on the Minnesota River doesn’t end on the Minnesota River. It goes on to become first, a flood in St. Paul (the St. Paul airfield, down on the floodplain, was closed last week) then in Hastings and Red Wing and Wabasha, and on down the Mississippi. Today the flood wave was due to hit Prairie du Chien, Wisconsin, some 100 river miles below St. Paul. Tonight’s rains have been extensive, a large thunderstorm system dumping more rain everywhere in the Upper Mississippi drainage, a huge triangle of weather – both rain and snow storms- wheeling across the plains toward the Great Lakes and beyond
This is not good. This is not just the drainages of the Minnesota, the St. Croix, the Upper Mississippi –all now within a few cubic feet per second of bankfull or already long overbank - this storm system will boost the headwaters of the Missouri, the headwaters of the Ohio. I’m no flood hydrologist, but it doesn’t take much to know that this is not a great way to start up the spring flood season.
Right now, at ten pm, the flash flood watch for a region that stretches across Morton, Redwood Falls, New Ulm along the Minnesota River, across Itasca and the upper Mississippi, across the border and the St. Croix drainage to Wisconsin. And west of here, the Red River Basin is expected to get 3-5” of wet snow. It’s April 22, Earth Day, more than a month after the first day of spring. In Fargo, flood season is just beginning.
