The South Saskatchewan River Basin is one of Canada’s most threatened watersheds, with water supplies in most subbasins over-allocated. In 2013, stakeholders representing irrigation districts, the environment, and municipalities collaborated with researchers and consultants to explore opportunities to improve the resiliency of the management of the Oldman and South Saskatchewan River subbasins. Streamflow scenarios for 2025-2054 were constructed by the novel approach of regressing historical river flows against indices of large-scale ocean-atmosphere climate oscillations to derive statistical streamflow models, which were then run using projected climate indices from global climate models.