In spite of the growing consensus regarding global warming and its impact upon water resources, there is still a limited understanding of the adaptive process of human communities to climate stressors. The IPCC argues that the existence of a regional adaptive capacity—the ability and predisposition to use and develop local and regional resources in the pursuit of adaptation—is fundamental for the sustainability of communities in climate change. This paper discusses the roles that local formal and informal institutions play in fostering the adaptive capacity of a set of rural communities in the semi-arid regions of Canada and Chile. The discussion is based on the initial results of a set of vulnerability assessments of rural communities in northern Chile and western Canada. The results indicate the existence of a community adaptive capacity to climate variability and extreme climate events in both countries. This adaptive capacity, however, is limited given the severity of the expected impacts of climate change.