Integrating Hydrologic Climate Projections into Source Water Protection Planning in Small Atlantic Canadian Communities

Abstract

Climate change is a critical driver of hydrologic change in Atlantic Canada, where small utilities often manage source water with limited capacity. This research supports small communities in assessing climate change impacts on water supplies and identifies efficient modelling approaches. Lake George, the water source for Yarmouth, Nova Scotia, served as the study site. The hydrological system was characterized using public data and field observations, followed by three modelling schemes of varying complexity to simulate lake water balance. Downscaled climate projections were applied to evaluate future impacts. Lake levels were most sensitive to summer precipitation, followed by temperature and usage. Complex models with site-specific hourly data outperformed the simpler daily model, projecting more extreme impacts, including levels dropping below an outlet but not the treatment intake. While complex models provide quantitative insight, simpler models can guide qualitative assessments. Findings informed Yarmouth's Source Water Protection Plan and can guide similar communities.