You’re listening to Parks and Landmarks, an exploration of the underrated, outdoors. I’m Sean Bull.
Madison is defined by its lakes. Without our four-ish lakes, and the Yahara river which links and feeds them, we would be no better than Lincoln, Nebraska. A C-tier city, known only for its state government, and better than average football team. The lakes bless us with recreation opportunities, and a picturesque skyline, but they don’t always work in our favor.
Madison and its surrounding communities were largely built upon wetlands, so it’s not infrequent that some of the land attempts to return to being wet. As recently as 2018, the city saw catastrophic flooding, as Mendota surged over its imposed boundaries, and swept into low-lying isthmus neighborhoods. The flood has since receded, our basements have dried, but it’s a constant battle to ensure that this sort of thing doesn’t happen again.
One way to prevent future floods would be to allow Lake Mendota to lose some water. A lower lake, after all, can hold more rain. But it’s not, unfortunately, as simple as just opening the Tenney Lock and Dam. Mendota’s level is controlled by the state, and there’s opposition from local homeowners, who prefer high waters for boating. I’ve talked about this before, and likely will again, but not today. Instead, I’d like to highlight another way to prevent floods: cutting plants out of the river system.
The principle behind it is simple. Water can flow through the river and lakes faster if any plants in the way are removed. The faster water can flow, the less the system might flood in the future. In the Yahara chain and beyond, plant removal is handled by the Dane County Land and Water Resources Department. The county has a fleet of boats, purpose built for this task. If you’ve visited a waterfront park over the summer, you’ve probably seen one parked at least once.
Each weed harvester looks slightly different, but you’ll know one when you see it. The boats are about 40 feet long and 8 feet wide, flat bottomed and with a hydraulically controlled ramp on either end. The front ramp can be lowered into the water, and its leading edge is lined with two-inch metal teeth, which make short work of any weed our lakes can produce. These teeth would perhaps be most directly compared to a hedge trimmer, but to me, they look like a giant barber’s clippers. At the flip of a switch, two rows of teeth slide back and forth over each other, neatly slicing whatever crosses their path.
The whole boat is basically a big grocery store conveyor belt, meant to efficiently pull plants from the water. But instead of vinyl, or whatever normal conveyor belts are made of, these are all metal links, visually a cross between a bicycle chain, and a chain link fence. The operators call them “screens” These screens move just like a normal conveyor, but are strong enough to hold a literal ton of waterlogged plant cuttings. And more importantly, the holes allow water to drain right back into the lake, so the boat doesn’t become any heavier than it needs to.
The flat middle of the boat is layered, with another screen on the bottom, then a frame and catwalk for the engine and pilot three feet above. A diesel engine runs constantly to power the hydraulics, which power everything else The operator sits in a chair with a lever on either side, a few pedals at their feet, and a few more switches on an instrument panel, off to the right. The left and right lever each control the speed and direction of a corresponding paddlewheel, which are the cutter’s method of locomotion, and one of their most distinctive outward features.
These bright red wheels, each maybe five feet across, are slow, and somewhat inefficient, but they only skim a few inches into the water, helping the cutters navigate even the shallowest of bays. And unlike propellers, they’ll never get bound up in weeds, which is, like, the main requirement for a boat in this line of work. Additionally, being mounted on either side in the middle of the boat, they allow the harvester to turn on a dime, as one wheel paddles forward, and one in reverse. These boats are a lot more nimble than their size and shape would imply.
I know this firsthand, because I got to drive one. I’m still not sure how this was approved. Don’t get me wrong, I’m about as qualified as any pretend journalist could be. But I didn’t flash my forklift certification, or my boating license, beforehand. I don’t think I have a particularly trustworthy face… I guess what it comes down to is that the folks at the LWRD are just nice people.
That, and these boats just aren’t that hard to drive. I got the hang of it pretty quick, and soon, I was cutting and collecting weeds of my own. As I went along, I would look down every few seconds, and inspect my haul. As the front screen rolls upwards, it carries a mat of cut weeds into the belly of the boat, beneath my feet. Sometimes, it caught other things that happened to float near the surface. The occasional stick isn’t uncommon. And sometimes, it would carry up a small, silver fish or two, still alive, and flopping in shock at their sudden change of scenery.
The fish didn’t suffer for long, as the boat is watched at all times by hungry pairs of eyes. Most animals seem to be wary of the weed harvesters, but Lake Monona’s grackles are fearless. They race out from the shore, just inches from the water, then swoop up to land on one of the boat’s outer rails. Often, they sit just feet from the operator, with no fear of getting eaten, themselves. Obviously, the weed cutter drivers are always deferential to local wildlife, but most birds don’t know that. Heck, it isn’t even that grackles are a particularly brave species. My ride-along partner, Don, told me that this only happens on lake Monona, and nowhere else. Somehow, these specific birds have gotten it through their iridescent blue heads that the harvesters are their friends, and you know what? They’re absolutely right.
As I went about my harvesting business, I was struck by how comfortable I was. It happened to be an exceptionally calm day on Lake Monona, but even so, I expected my seat to be vibrating from the engine. I expected the wheels to spray me every time I went into reverse. I expected to not be able to escape the smell of rotting lake-weed. Yet, I cruised across the lake, comfy, dry, and more or less smell-free.The task is akin to mowing my parents’ lawn, but this was the most relaxed I’ve ever been doing any kind of yard work.
After collecting all the grass we had cut, I was driven back to shore, and dropped off next to a waiting dump truck. The second half of the weed harvesting team is a small fleet of trucks, and trailers with another conveyor, to lift weeds in, over the back. Weeds are expelled off the boat’s rear ramp, elevated into the dump truck, and hauled off to a remote site, where people don’t have to smell them decomposing.
It’s hard to know just how effective this program really is. Dane County has been removing weeds this way for decades, but we do still get floods sometimes. Are these floods less bad than they could be, because the weeds are cut out? Likely yes, but it’s hard to compare apples to apples with any other city. The program could always be expanded, but we already have the largest fleet of weed cutter boats anywhere in the country. If we really want to prevent floods, this can’t be our only tool. A holistic approach would include protecting and restoring wetlands, and lowering the lakes, so that they can handle more rain.
But until we can make that happen, the weed cutting team is doing good work. Next time you’re out by the water, and you spot one of these peculiar paddle boats, give the driver a wave, or a thumbs up. They’ll appreciate it, I’m sure. And if you want to be one of those people, keep an eye out for Dane County job postings in February and March.
On that note, I’d like to give a special thanks to Pete and Don at the County Land and Water Resources Department. Without all they did to accommodate me, this story would have been a lot less interesting to listen to. If you’d like to suggest a topic for Parks and Landmarks to cover, please send it my way, at firstname.lastname@example.org. Tell me about your favorite underrated spot outdoors, or whatever you feel is related. This segment’s title is intentionally broad, so just go for it. I’d love to hear from you guys.