Water scarcity is a phenomenon that has generated great concern today. The drought scenario has particularly affected rural communities in the semi-arid region of northern Chile socially, economically, and environmentally as they try to adapt to climate change. This article focuses on the description and comparison of the institutional adaptive capacity of the Chilean community of Diaguitas to adapt to the effects on water resources and extreme events during two periods of time (2004–2007 and 2018–2019). This qualitative study considered the administration of interviews, field observations, and focus groups using the adaptive capacity wheel as a methodological basis. The results show differences in the ability to adapt between the two periods studied with most of the adaptive dimensions at a neutral or no effect level and the emergence of a new dimension of social capital. It was concluded that the adaptive capacity of the Diaguitas might have improved over time, influenced by the increased awareness of the consequences of climate change and the establishment of supportive institutions. It is necessary to incorporate new perspectives into water management, such as indigenous knowledge and collaborative resource management.