Beaver Dam Analogues (BDAs) are temporary, semi-permeable structures built by humans to replicate the environmental impacts of natural beaver dams on streams. Made out of wooden posts and willow branches, BDAs are a low-tech, low-cost solution that can be implemented in streams as a restoration method, specifically in streams that experience more erosion from fast water flowing through narrow parts of the channel. BDAs are intended to reduce erosion and increase deposition in the channel. It is hypothesized that BDAs cause the stream width to increase. However, the specific impacts of BDAs on stream geomorphology are still unknown. Here we show how stream width varies in proximity to BDAs compared to how stream width fluctuates under non-BDA conditions for a restoration site along Red Canyon Creek near Lander, Wyoming, USA. We specifically examined stream widths directly at the BDA and 0.5 meters upstream of the channel for BDAs 12 through 29 using daily data for the years 2017, 2019, 2021, 2022, and 2023. We compared how the stream width for each BDA changed from 2017 to 2023. From our collected data, we found that from 2021 to 2023 100% of the stream widths measured at BDAs became wider and 94% of the stream widths measured 0.5 meters upstream of the BDA became wider. Wider stream widths likely occur as BDAs alter flow patterns, directing the stream into the side of the channel. Our results show that the installation of BDAs in streams has potential to cause the stream width to increase and to overall aid in stream restoration. Altogether, our results provide useful information regarding the impacts of beaver dam analogues as an affordable solution when considering how to improve the ecological health of streams.
Assessing the Impacts of Beaver Dam Analogues on Stream Morphology
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Student Abstract Submission