Author(s): Jolanda Jenzer Althaus; Matthias Weber; Gianluca Flepp; Dominic Grunig; Stefanie Wirth

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Keywords: BDA (Beaver Dam Analogs); Bank storage; Infiltration; Groundwater recharge

Abstract: The present study examines the hydrological effects of beaver dams and their artificial counterparts (Beaver Dam Analogs, BDAs) on groundwater and landscape water dynamics. Beavers act as ecosystem engineers: by impounding streams, they enhance infiltration, groundwater recharge, and hyporheic exchange. This raises groundwater levels, increases subsurface water retention, and improves climate resilience. Field studies show that beaver dams expand the hyporheic zone, increase water storage in soil and ground water, and create more balanced flow regimes. They stabilize low flows during droughts and attenuate flood peaks. Using a physical model in the hydraulic laboratory of the Bern University of Applied Sciences, it was shown that installing a BDA increased upstream groundwater levels by up to 72 cm (full scale), and that groundwater storage was about 2.5 times greater than surface water storage. Bank storage was also demonstrated: infiltrated water was displaced laterally and released downstream with delay. The results highlight the substantial role of beaver dams and BDAs in water retention and landscape rehydration. However, the effects are highly site -dependent, making systematic long-term studies essential.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.229

Year: 2026