Vulnerability of municipal freshwater provisioning in a climate uncertain future: the case of Coral Harbour, Nunavut, Arctic Canada

Climate change is likely to be an important factor affecting the ability of Arctic communities to continue supplying freshwater from single-source reservoirs; yet, infrastructure planning and assessment processes rarely take climate change into consideration for needs-based improvements. Here, we identify potential threats to the provisioning of freshwater by examining local water sources in the community of Coral Harbour, Arctic Canada. While we did not identify any concerns over water quality through the analysis of samples collected in 2021–2022, we did find that the current reservoir for the community is insufficient to continue provisioning water over a typical 20-year planning horizon. We also note that if anomalous climate conditions occur (e.g., extreme temperatures), the exhaustion of the annual water supply could occur faster than projected, causing a local water shortage until ice-off when replenishment is possible. Hydrometric data collected from Post River, the source used to replenish the reservoir, also highlight the response of river levels to both rainfall and dry periods, and thus qualitatively demonstrates the potential impacts of future episodic late-summer droughts on river water availability, which could affect resupply. These results highlight the need to include climate-based assessment in freshwater infrastructure assessment and planning processes in remote Arctic communities.