Climate change is impacting Atlantic Canada’s water supplies in complex ways and adaptation planning often falls to water utilities. Adaptation can be challenging for small utilities due to limited data and capacity to perform hydrologic projections for climate circumstances. In 2023, Nova Scotia experienced historic flood conditions and unprecedented high temperatures, placing uncertainty on water management across the region. This research will analyze potential climate impacts and adaptation pathways for the Lake George Watershed in Yarmouth, NS, which provides centralized drinking water and fire suppression services to 7800 people. We will compare simple and complex tools for assessing climate change impacts on a lake water supply. To understand baseline hydrologic conditions, the watershed and stream network were delineated, and land cover was characterized using geospatial datasets. Climate data from nearby public weather stations were used to characterize climatic trends. Onsite field data was also collected, including meteorological data, lake level, groundwater level and lake outflow. To simulate this lake water balance, a simple “bucket” model and a more sophisticated HEC-HMS model will be applied and evaluated. To determine key hydrologic risks, different climate and water usage scenarios will be applied to both models and storage sensitivities will be assessed. Comparing outputs from these two models will help determine if small utilities need specialized models with high-resolution data or if a simple model can provide acceptable guidance. This work will improve the ability of small Atlantic Canadian water utilities to assess and adapt to climate change impacts on water security.