Stream Restoration

Using process-based approaches to rehabilitate the entire river corridor.

Stream restoration in Drylands

Healthy, heterogeneous river corridors can provide a range of ecosystem functions. In landscapes where alterations or landscape disturbance have disrupted those functions, stream restoration is increasingly being used to aid in ecosystem recovery and resilience. Along with my collaborators, I am interested in monitoring the impact and evolution of process-based stream restoration projects in water-limited environments like the American West.

Process-based stream restoration describes a suite of techniques aimed at restoring river corridor processes, including groundwater infiltration, sediment deposition, wood recruitment and more. Dozens of process-based stream restoration projects have been implemented across the western U.S. in the past few decades, providing ample opportunities to understand how and why certain restoration techniques work.

Photo above: Beaver dam analogue in Colorado.

Photo above: Rock retention structures implemented following a wildfire in Colorado.

Examples of stream restoration (including Beaver reintroduction, beaver dam analogues, and one rock dams) projects across western North America from Scamardo et al (in review).

Beavers in Colorado

Much of my stream restoration research has focused on nature's engineers - beavers! By building dams on headwater streams, beavers can transform river corridors into complex landscapes that temporarily store water, sediment, and nutrients. Because of their benefits, beaver reintroductions and human-made beaver dam mimicry structures (also referred to as beaver dam analogues) have been used to restore streams across the historical range of beaver.

Key to this type of restoration is understanding the capacity for beavers on the landscape, what is their potential impact, and how do river corridors respond to stream restoration projects.

Beaver Dam Capacity in Colorado

The Bountiful Benefits Of Bringing Back The Beavers Hundreds of millions of beavers used to populate the West but were hunted to near extinction. Turns out, beavers are critical to healthy water ecosystems, so now there are efforts to bring them back.

Video story: When in drought, call the beaversBeaver reintroduction can help with some of the West's most profound water problems, both in terms of quantity and quality.

Read about it:

Wohl, E., Uno, H., Dunn, S.B., Kemper, J.T., Marshall, A., Means-Brous, M., Scamardo, J., and Triantafillou, S. 2023. Why wood should move in rivers. River Research and Applications. https://doi.org/10.1002/rra.4114

Scamardo, J., Marshall, S., and Wohl, E. 2022. Estimating widespread beaver dam loss: habitat decline and surface storage loss at a regional scale. Ecosphere 13. https://doi.org/10.1002/ecs2.3962

Scamardo, J. and Wohl, E. 2020. Sediment storage and shallow groundwater response to beaver dam analogues in the Colorado Front Range, USA. River Research and Applications 36. https://doi.org/10.1002/rra.3592