Beavers are mostly nocturnal, rarely seen creatures, but their handiwork is apparent on many trout streams to the benefit of fish and other aquatic life as well as waterways.

Matt Wilson, CEER Field Station and Freshwater Institute director with Susquehanna University, has closely looked at beaver dams and how they can improve watersheds.

He’s even gone as far as working with his students to create Beaver Dam Analogs that mimic the natural barriers created by the furry creatures on streams.

Wilson, speaking to the Susquehanna Chapter of Trout Unlimited, noted how heavy rainfall events and flooding have negatively impacted the natural dynamic of watersheds of central Pennsylvania through the years often to the detriment of aquatic species including wild brook trout populations.

“How do we protect streams?” Wilson asked. “To get as close to what we once had? How do we recharge groundwater?”

Beaver Dam Analogs, he feels, may be a big part of the solution.

Many years ago, beavers were in abundant numbers across the landscape of the state before trapping practices vastly diminished their populations.

Beavers created ponds and braided channels resulting in cool groundwater and low stream water temperatures conducive to brook trout.

Beaver dams can lead to increased groundwater storage, diversity in insect life, and biomass of fish. Beyond that, they help push water into the flood plain, slowing the flow and recharging the groundwater.

Wilson and his students created a series of Beaver Dam Analogs along a small stream on the Susquehanna University campus and soon realized the positive impacts of these stream structures.

As hoped, Wilson discovered sediment being trapped by the dams preventing it from going downstream with water pushed into the floodplain to form a secondary channel.

Over time, fast moving water creates a narrow and deeper channel leading to channel incision. By slowing the water, new stream banks can be formed to allow vegetation to be re-established.

Wilson noted that Beaver Dam Analogs have been embraced in the western U.S. by people and organizations concerned about stream restoration but not so much here in the East.

Never mind that Beaver Dam Analogs present a low-cost method stream restoration approach, using materials such as felled trees and other natural materials.

Wilson is particularly interested in the watersheds of Loyalsock, Pine Creek, and Kettle Creek, where a network of diverse aquatic life and fish species, have been impacted by changing climate conditions and big storm events.

He’s seen how wild brook trout populations found in many of the smaller streams of those watersheds respond to storm events over different time periods.

He recalled the devasting impacts of heavy rainfall resulting from Hurricane Irene in 2011 on the Loyalsock Creek Watershed.

But while heavy storms and flooding often result in diminished trout populations in particular streams, drought conditions can also negatively impact fish species.

“How does a stream change over time?” Wilson asked.

But the more important question might well be: What can be done to restore that stream?

Beaver Dam Analogs should be at least part of the solution, according to Wilson.