As European countries look for solutions to avoid climate change-related disasters such as floods and fires, the appearance of a once-maligned small rodent may offer several solutions: the beaver. And when he doesn’t like an area, sometimes it is possible to copy it.
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(on video) Beavers of the Rhône with Rémy Maison Finally, despite their growing presence in our waterways, a little-known rodent, the beaver…
The positive impact of beaver work in nature is no longer proven, so much so that this mammal is now one of the most important animals in the world for fighting weather disasters.
Beaver-inspired mini-dam to stop floods in Europe
The branches and the wooden barriers that they form allow the formation of small water holding basins, and thus, limit the overflow of rivers in the event of heavy rainfall. For many years, scientists have been observing beaver dams in an attempt to learn lessons that can be used in agriculture and urban areas. Cardiff and Worcester universities in England recently published a joint study on natural flood risk management in the journal Journal of Hydrology,
They conducted an experimental test over a two-year period on the River Shropshire: since there are no beavers in England, they placed 105 barriers over a distance of about 5 kilometres. These artificial barriers, imitating beavers, made it possible to slow down the flow of the river, by pooling water in some areas and diverting it to other areas. In addition to preventing flooding during Hurricane Dennis that hit the British Isles in February 2020, the barriers were able to store additional water equivalent to 4 Olympic swimming pools. Thanks to these nature-inspired mini-dams, the water rose 80 centimeters near each element, and then slowly receded over 7 to 10 days. This very gradual return to normal made it possible to avoid any violent overflow during bad weather. The research team specifies that in addition to being effective, these small barriers are very inexpensive. It is therefore a solution that can be easily implemented in high-risk areas. And like real natural beaver dams, the process has other advantages: The small retention basins created make it possible to shelter biodiversity and provide water for many animal species.
beavers moisten the ground and limit fires
After decades of being considered a pest in North America, the beaver is now the center of attention. Especially in California, a US state that is ravaged by fires every summer. This animal is not protected in the United States and can still be hunted, but only with special permission. some American scientists, like Emily FairfaxStruggle to make the public aware of the invaluable role of beavers in the fight against drought and fire.
An animation showing how otters help limit the spread of fires. © Emily Fairfax
The many small pools of water created by beavers make up the true wetlands on a large scale: the water slowly seeps into the surrounding soil and the soil becomes moist, as well as the vegetation. In the event of a wildfire, these areas are the only areas that do not burn and they make it possible to stop the progress of the fire.
An example of an untouched area caused by beavers, in the middle of a burned area. © Emily Fairfax
In France, European beaver populations are restricted to a few central and eastern rivers: the Loire, Rhône, Saône, Tarn, Aulne, Meuse and Rhine and some tributaries. It is a protected mammal in our country, very suspicious of humans and therefore rarely seen. Despite their safety, some still consider them responsible for significant damage. Given its key role in limiting floods and fires, some associations are campaigning for its reintroduction in areas where it is no longer present.