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Comment by sparrish | Hacker News Reader

I find it humorous that when man makes a dam (even small ones, like on one's own property [1]) it's destroying the ecosystem and stealing water from downstream and bad but when an oversized rodent does, it's 'restoring wetlands' and 'buffers against wildfires'.

[1] https://gazette.com/news/a-pond-farewell-state-cracks-down-o...

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Beaver dams are different. They leak, let fish through, and disappear every few years. Details matter.

This is the key and overlooked part of it all. Plus they can move upstream or downstream as situations dictate.

Good point. It's almost like the word system in ecosystem is important. Haha.

Your comment makes me want to learn more about beavers. I'm interested but don't know much.

I think most dams (small low head dams, often abandoned) have those same properties.

3 years vs 30 years. And you usually regulate the river around the dam so it can't meander, beaver dams make the river meander around them. So after 30 years you maybe return to status quo with a small, abandoned human dam. In that time you would have 10 different riverbed changes with beavers and all that area is now marsh.

It seems to be ok as long as the dam is constructed in a way that mimics what beavers would do, and better yet, is something beavers can take over.

https://www.science.org/content/article/beaver-dams-without-...

Dams being bad is entirely scale-dependent. Small dams that retain water in basins without cutting off flow are definitely net positive. The retained moisture promotes growth of plants that shade and shelter the water, reducing evaporation and increasing water supply.

Human geoengineering can be a positive as well, we just have to actually... do it.

The before and after of beavers tends to show them creating and enhancing ecosystems by all of the metrics you can reasonably think of.

Humans want to create tall (ideally, hundreds of feet tall) dams which impound a lot of water with minimal effort which stand for 100 years. We're really at it, and we care next to nothing for animals which need to go upstream / downstream.

Beavers want to eliminate that damnable gurgling sound by piling a few feet of wood around it. They're not great at it, and animals are basically free to go upstream / downstream. The dams percolate through the mud, leak and rot away, lasting days to years, but not decades.

They're dramatically different activities. You're better off comparing beaver "dams" to terraced rice cultivation in hill country, where the entire valley floor turns into innumerable sheets of flat water draining into each other in six inch elevation changes held back by bamboo and mud. A two year old with water wings can destroy a whole town's paddies if allowed to run free. Repairs are a daily thing.

Making changes on your own property impacts other people's property. There isn't a conspiracy to prevent people from accumulating water. They want to prevent idiots from flooding their neighbors or completely cutting them off from water.

https://wlos.com/news/local/news-13-help-desk-waynesville-ma...

These types of laws formed when companies actually abused water rights and completely shut off access to anyone further downstream from them. Imagine a series of farms along a river. Then a mining company come along and sets up operation closer to the source. Since mining is very water intensive, they divert the river for their own uses cutting off access to the farms which used to depend on it. That's supposed to just be okay?

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