Here at 45 degrees north latitude, a raw wind has us scrambling to store hoses, flag for the snowplow, and do other tasks before winter settles in. One of those tasks is checking our culvert.
A culvert is a man-made structure generally used to channel surface water. Culverts come in different sizes, shapes, and materials, and have purposes beyond drainage – for example, allowing fish to pass through an area that would otherwise be blocked. For many of us the most common type of culvert is a barrel-shaped tube that runs under a road or driveway to channel runoff below rather than over infrastructure that’s hard enough to maintain without being underwater.
One of the perks of living on sandy soil is how well it drains. Except when it doesn’t. When the ground is frozen under deep snow cover, a quick melt doesn’t percolate down. Instead, it runs off. With a little gradient and some volume, that snowmelt can run at a pretty good clip. We don’t want it running through our basement or grade-level buildings as it travels from the field behind us, which is higher, to the lowest point in the area – a field on the other side of the highway. Even with a culvert under the road, there are times when we can canoe on both Lake Kallner (the big puddle) to Little Lake Kallner (not so big) without a portage at the driveway.
But mostly, this system works as it should. For us, anyway. The previous owner of the field across the road had it in pasture for her expensive dressage horses. We had a quick thaw once and water that flowed through the culvert to the low spot in her pasture froze into as nice a skating rink as you could hope for. Unless you have horses. She called for help when one of her old brood mares went down and couldn’t get back up. My husband was able to help tow the animal across the ice to where they could help her back on her feet. We try to be good neighbors.
Water seeks the lowest level, so there’s not much we could do to stop it flowing from another farmer’s property (the high field behind us), over our land, and toward that lowest point, which is now in row crops instead of pasture. But if our culvert was plugged, that water would have backed up on our side of the road, possibly into our buildings and possibly over the highway. And it’s no fun standing in waist-deep slush trying to unplug a culvert.
So the responsible thing to do this time of year is make sure the culvert is clear of debris that could restrict the flow. We don’t have trees close enough to ours to worry about leaf litter. But it is a highway, so other types of litter are sometimes present.
A greater concern is hibernating animals. I think (hope) the big black bear that’s been hanging around would find that spot a bit cramped. But an animal that’s been injured may take up residence even if it’s not ideal.
So when I went out to the mailbox the other day I checked that culvert. That means stomping through dead goldenrod and tansy and the small staghorn sumacs that have based their bid for a global takeover on our property. That ditch only gets mowed about once a year: We think those “weeds” help hold the soil and buffer the flow on the intake side of the culvert. Then we cross the road to peek in the outflow side. So far, no squatters. But we’ll keep checking. Carefully, just in case someone takes up residence.
I come from a long tradition of farming families who ditched, diverted, tiled, filled and otherwise made it their life’s work to prevent soil erosion by controlling surface water. Or trying to, anyway. By the time I was growing up in central Indiana, the land had been profoundly altered by drainage efforts. It’s hard to even imagine what it looked like before. James Alexander Thom’s novel Long Knife, about George Rogers Clark, paints a vivid picture, though, of men marching day after day through deep, icy water before the Battle of Vincennes.
Rural northern Wisconsin might as well be on a different planet. Here, you can definitely imagine what it might be like to march through chest-deep icy water, although I try to avoid that. We still have swamps aplenty, and an appreciation for their place in the general scheme of things. For example, the headwaters of the river I live on is a vast swamp that helps maintain some flow even in extreme drought.
I once read in a history of Langlade County that winter was the busy social season for the area’s early European settlers. Once the swamps were frozen it was easier to get around to visit neighbors.
Nowadays we appreciate that our culverts help make that easier year-round. But I really would prefer that my neighbors don’t include a bear hibernating in our culvert.
Donna Kallner writes from Langlade County in rural northern Wisconsin.