Beaver engineering: Build your own dam
- 2 days ago
- 2 min read
As you walk along a river, you might have seen our country’s largest rodent — the beaver! If you haven’t seen the animal itself, then you might have seen evidence that it left behind — tracks in the mud or trees with gnaw marks, or beaver chews.
Those branches and trees become the beaver’s food supply, lodges, and dams. Those lodges and dam might seem like a bunch of debris piled up together, but they are useful feats of engineering.
Today, we are going to test out our own engineering skills and build a beaver dam. Before we steal the beaver’s job, let’s practice damming a river in an enclosed container.
Materials*
Container (Ideally, a long and shallow container.)
Water
Sticks
Clay
Pebbles or rocks
*You can use craft supplies like popsicle sticks, clay or decorative rocks. Or you can source your supplies from the outside: mud, twigs, wood chips, or any combination of these.
See what works best! If do you do gather materials from outside, make sure they are items that are not already in use and that you can return later. For example, pick twigs from the ground rather than breaking off a branch from a tree.
For the sample dam, an aluminum food storage was used, along with water from the Des Plaines River, twigs found on the ground, landscaping rocks and old play clay.
Instructions
Prepare your container. Aluminum catering trays work, as well as old take-out containers or plastic bins. Whatever you choose, it will get wet, so make sure it is sturdy!
To build a dam, you need a base. Should the base be some sticky mud/clay or some sturdy rocks?
After you decide your base, start building! Do you add rocks or sticks first? How many? Which direction(s) should the sticks go?
After you feel confident in your creation, put it to the test! If you are close to a natural body or water, scoop some up. If not, add some debris to your water — dried up leaves, pieces of ripped up paper, etc.
Slowly pour water into one side of your container. Does your dam hold up? Do you need to reinforce it with more materials? Try again if you need to!
Remember, a beaver dam does not completely stop all the water from coming through, so neither should yours! Dams hold back some water, slowing it down and often creating ponds from the water finding a different path to flow. This is beneficial for the whole ecosystem!
Dams also act as filters. You can see from the picture above that some of the algae is held back, perfect for small critters who don’t want to be swept away by the current. In real life dams also filter out harmful chemicals.
Just like anything else, dams might need repair over time, some extra mud here, a new branch there. Beavers have been known to respond to the sound of running water because a small leak could mean a dam breaking! However, beavers are powerful engineers. Some dams have been documented to last generations.
Will yours?
