A Tale of Two Streams

Follow two streams, one with and one without beavers, through their year and into the future.

Bark advocates for proactive restoration that prioritizes the health of watersheds and forests for decades to come. For the last two years, Bark has worked to identify beaver habitats and prepare to reintroduce beavers to Mt. Hood National Forest. Beavers' effect on ecosystems makes them powerful partners in mitigating the effects of climate change. Observe the benefits beavers bring to their environments in this Tale of Two Streams.

Illustration of beavers in a winter lode by Deborah Hocking, 2016.

Illustration of beavers in a winter lode by Deborah Hocking, 2016.

It is late December. The two streams are again filled to the brim with cold water after the dry, hot summer. High on the mountain, the thickening snowpack represents a steady supply of water for the year to come. In one of the streams, there are beavers and in the other there are none. In the beavers' stream, cozy lodges of mud and sticks protect furry families safely nesting in the center of a pond. Beavers' ponds act like moats, a barrier to the cougars, wolves, and bears that would happily gobble up the beaver family during these frigid months. The beavers shaped not only the main pond but also the channels of water that radiate outward, creating wetlands blanketed with yellowed sedges now dusted with snow.  

As spring approaches, the two streams swell as rain melts the snowpack. In the beavers' lodge, a litter of kits is born and the older beavers, excited to munch on fresh grasses, start venturing out. In the ponds and channels, salmon eggs hatch! Baby salmon are happy in a beaver pond where they can grow without fighting the current. 

Slowly but surely, the snowpack disappears and dry summer months begin. The beavers collect mud and sticks to patch holes in their dams and lodges. The stream without beavers slows to a trickle as its tributaries dry up and the nearby plants absorb the groundwater, while the beavers' stream continues to flow. All those beaver-crafted ponds, dams, and channels create a wide and meandering stream. This keeps the water from rushing downstream during winter and spring storms, giving it time to soak into the ground and raise the water table. Even in the driest of months, the beavers' stream will have a higher water table and a stronger flow that benefits the salmon that travel it, the plants that surround it, and the humans that drink it. 

Diagram by Emily Fairfax showing the stream impact on ground water with and without beavers

Diagram by Emily Fairfax

Late one August morning, a fire starts burning through the forest.  As the fire approaches the beavers' stream, they begin to worry, “What will happen to our trees?!” Not to worry, beavers! Your damming keeps your home more moist than anywhere else in the forest. Thanks to all this water, your home is much less likely to burn. The other forest animals know this and travel to the beaver ponds for refuge. The fire reaches the edges of the wetlands and burns out. The beavers' stream will have more plants, animals, and moisture, making it easier for the stream to return to its pre-fire conditions. As erosion follows in the months after the fire, the beaver dams filter sediment, keeping the streams clear for the fish and the humans who depend on them. By holding nutrient-rich sediment in the ponds, the beavers nourish their environments. 

Unburned area with beaver presence after the Sharps Creek Fire in Idaho. Photo by Joe Wheaton, Utah State University Department of Watershed Sciences

Unburned area with beaver presence after the Sharps Creek Fire in Idaho. Photo by Joe Wheaton, Utah State University Department of Watershed Sciences

In a changing climate, the two streams will experience drastically different conditions. Winter storms which once led to large snowpack will become rain events that cause flash flooding throughout the fall, winter, and spring. Flooding will lead to more road washouts and damage to other human structures. Summers will become longer, warmer, and drier leading to extended drought conditions. All of this leaves forests more susceptible to high severity fires while decreasing the availability of water for humans, water-loving plants, and animals (like migrating fish species) whose lives depend on these streams. 

Bark is working to change Mt. Hood’s 30-year-old Forest Plan to prioritize caring for water. This is particularly important as the metro area grows, climate change puts stressors on drinking water supplies, and industries damage water quality. We work to reintroduce beavers to Mt. Hood National Forest because they are one of our greatest partners in mitigating the effects of climate change on streamflow, water quality, and fire intensity. 

Support Bark’s work to reintroduce beavers and prioritize climate resiliency in the Mt. Hood Forest Plan!

Thanks for all you do,

misha's staff photo and signature

     Misha VanEaton, Bark Forest Watch Assistant