Beavers and the dams they build keep water on the landscape, increasing stability and resiliency, which benefits ecosystems, landowners, and land managers. Therefore, beavers are gaining recognition as a climate change adaptation tool, with an interest in Western Canada to encourage beaver habitation to capture spring runoff and store flows as groundwater for release in the drier summer months. In order to use this nature-based solution to mitigate climate change impacts and inform Western Canadian beaver management policies, it is critical to first address foundational questions of the capacity of stream networks to support beaver dams. We used a field and modelling approach to estimate beaver dam capacity of two headwaters of the Bow River � Upper Jumpingpound and Waiparous � to identify stream reaches to be prioritized for beaver-based restoration as part of a climate change mitigation strategy. At capacity, the stream network of Upper Jumpingpound watershed (222 stream km) can support 1802 and Waiparous watershed (292 stream km) can support 2443 beaver dams. Observed beaver dam density is less than capacity in ~65% of each watershed. The addition of beaver dams is likely to be hydrologically significant, as the median height of beaver dams (0.7 m) is greater than median bank height in both watersheds, indicating beaver dams typically trigger overbank flooding in these watersheds. However, beaver reintroductions are unlikely to be successful in all prioritized stream reaches owing to unhealthy riparian or degraded channel conditions. These places might be targeted for restoration, perhaps using beaver dam analogues.