A major project that humans delayed for 7 years was repaired by beavers overnight?

They completed a project that had been delayed for seven years , saving the local government 30 million kronor (about 9 million RMB) in construction costs[1].

Beaver: What, I'm on the news? | Wikipedia

As early as 2018, the local government planned to build a dam to protect the Klabawa River and the endangered species in it. People also hoped to use the dam to create a wetland to improve the environment. However, the project was stuck in negotiations on land ownership and has not yet started.

While humans were still worried about the cumbersome process, beavers had already taken action. They built several dams in the planned construction area, creating the wetlands that people wanted. These beavers " finished the work as if overnight ", and the area of ​​wetlands they created was even twice the original plan.

This funny story quickly spread around the world through the Internet. It became a joke mocking the inefficiency of administrative departments, but it also reflected the amazing ability of beavers as "natural engineers."

Beavers use their big teeth to gnaw trees, and the trees fall into the river and block the water, which can become the prototype of a dam｜D. Gordon E. Robertson / Wikipedia

How good can a beaver be at building a dam?

Beavers are often praised as nature's construction engineers for their superb dam-building skills. They use trunks, branches and stones to block rivers, and then use materials such as soil and leaves to reinforce them, thus building "beaver dams".

Both the Eurasian and American beavers are good at building dams | Wikipedia

These semi-permeable dams can raise the local water level by about half a meter, allowing the water to overflow the riverbed and flow around the river bank, forming a wide "beaver pond" upstream . Beavers walk clumsily on land, but they are very good at swimming. Therefore, the widened water surface can make it easier for them to find food and avoid attacks from predators such as wolves and bears.

In addition, the deeper water table helps beavers preserve food during the winter and prevents ice from forming at the entrances to their underwater dens.

Beavers are good swimmers, and the ponds formed by dams help them escape predators on land | pixabay

Beavers are nocturnal animals, and they always work at night , so people often feel that these dams are built "unnoticed." There is little exact data on the speed of beaver construction, but water level monitoring data from Poland shows that beavers can rebuild a demolished dam in just 8 hours [2]. This shows that these animals are indeed very efficient.

The average beaver dam is between 10 and 20 meters long—but sometimes they can be incredibly large. The world’s largest beaver dam is located in Wood Buffalo National Park in Canada. It is 775 meters long and is so large that it is visible on satellite images.[3]

The world's largest beaver dam as seen from space, captured by Landsat 9 in August 2022 | NASA Landsat

After a dam is built, hardworking beavers will continue to repair it. With the careful maintenance of generations of beavers, a dam can even last for 150 years[4].

Beavers build dams to benefit the environment

In addition to being convenient for themselves, beavers building dams also brings many benefits to the surrounding environment and other creatures.

Beaver dams create entirely new wetland ecosystems in rivers, providing extensive shelter for fish, amphibians, waterfowl and mammals. One study found that plant species diversity increased by 33% in areas where beaver dams were built[5].

Dams can store water and slow down the flow of water, giving it more time to slowly penetrate the surrounding soil. This can protect surrounding plants during droughts and prevent wildfires from spreading. During flood season, beaver dams can also block floods and reduce the destructive power of flood peaks.

After a wildfire, the "beaver wetland" remains green (photo taken in Idaho, USA) | Dr. Joe Wheaton, Utah State University

Beaver dams can help purify water . Slower water flow means particles in the water can settle more fully, and microorganisms at the bottom of the water have more time to break down pollutants. In addition, the wetland environment created by beaver dams also helps absorb greenhouse gas carbon dioxide .

Beaver dams have so many advantages that humans have begun to imitate beavers in building dams. In places where beavers have not yet settled, people sometimes use materials such as stakes and branches to build " artificial beaver dams ", which is considered a low-cost and cost-effective ecological restoration method.

An "artificial beaver dam" built in Wyoming, USA | doloresstudy.com

However, these artificial imitations are still inferior to the originals. Without the constant maintenance of beavers, artificial dams always break down faster and can only play a temporary role.

Beaver: After all, you humans are still too amateurish.

References

[1] https://www.france24.com/en/live-news/20250211-dam-fine-beavers-save-czech-treasury-1-million

[2] https://link.springer.com/article/10.1007/s10452-024-10130-5

[3] https://parks.canada.ca/pn-np/nt/woodbuffalo/nature/beaver_gallery

[4] https://www.science.org/content/article/150-year-old-map-reveals-beaver-dams-can-last-centuries

[5] https://www.stir.ac.uk/news/2018/10/beavers-impact-on-biodiversity-revealed/

[6] https://news.stanford.edu/stories/2022/11/beaver-dams-buffer-rivers-climate-extremes

[7] https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2225

[8] https://pmc.ncbi.nlm.nih.gov/articles/PMC7898794/

Author: Window Knocking Rain

Editor: Mai Mai