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Comment by mabbo | Hacker News Reader

Beaver dams are a serious factor in flood prevention that we mostly removed from our world.

A pond behind a small dam will swell up and hold water when it rains, slowly releasing the water downstream over time. Thousands of such dams add up, leading to a major rainstorm's water taking a longer time to fully dissipate into the rivers downstream. The same total water (almost) will go through the river, but with a lower peak load, and over a longer time.

The rivers are less likely to burst their banks. Homes, towns, cities are saved massive damage.

And as this article shows, the areas behind the dams stay wet much longer, reducing drought and fire risks.

All we have to do is, when possible, let the beavers build their dams.

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Wetlands not only slow water, but they help to purify water by allowing it to move slowly. Plants and gravity do a wonderful job of cleaning water on its way to the sea.

On top of that, forested land is more conducive to rainfall. By allowing these areas to flourish, you not only slow and retain water but increase catchment overall as well. The chance of forest dying in drought decreases, and your chance of rainfall increases (slightly, yet meaningfully when balances are so delicate).

Beavers also produce habitat which benefits many other native species. More water is generally more life in North America.

Yeah, but the beavers don't consult with civil engineers on where to build the dams.

It's an issue for rural roads that get eroded and washed out.

The counter argument is that the civil engineers didn’t consult with the beavers on where to build their roads either.

There’s going to be some give and take here. If you want the benefit from a natural solution (beavers), you’ll have to work around whatever that solution is.

Or learn to make artificial ones better

And then you have to pay someone to maintain the artificial ones. That might be a better plan in some areas but certainly not all

This. Beavers have no agenda other than the instinct to build a dam where one is needed. I'd reroute roads if necessary

Is this really why some people view beavers as pests???

You should watch Post10 on YouTube. He's a guy who, for fun, cleans out clogged culverts. He'll find some washed out road and then figure out why. The why is usually "beavers."

Post10 is a gem of a person that helped me through the worst days of covid related anxieties.

We should set up a permitting office for them to use!

I don't disagree that they can cause problems. But there are a lot of ways to mitigate the problems.

Biologists can tell you what kinds of locations are good beaver spots - so we shouldn't just build a road too close without some planning. We also shouldn't remove beaver dams so that we can build human structures- the dam will be back soon enough.

And when you do need to build near one, there are lots of techniques to strengthen structures to avoid erosion. My favorite: plant trees. Willows will grow like mad near a pond and their root system will strengthen a bank very well.

Beavers build dams when they hear running water. The civil engineers can just play the sounds of running water where they want the dams built.

so youre saying we should leave it to beaver

There are thousands of reasons why beavers building dams is horrible for the environment. General rule of thumb, if humans do something they have better reasons than a wild animal, even if they don't know it or it's not immediately apparent to the naive observer.

Can you list some of the thousands of reasons?

I took this as an estimate of the number of dams.

Who knew conservatives long play would be to blame climate change on beavers?

> General rule of thumb

What is this rule based on?

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