Groundwater has increasingly become a water supply source in Chile. In the future this trend is expected to grow as a consequence of the increased water use due to economic growth, together with population growth, urbanization, water contamination and pollution, as well as the projected climate change impacts. The Water Code of 1981, as well as previous water codes, were in essence designed for surface water and, thus, contained only few references to groundwater. This regulatory absence has been covered with groundwater guidelines established through internal administrative acts. As it stands, the legal and institutional context considers the required instruments and mechanisms to balance growing demand and the need to protect and preserve groundwater resources. This chapter investigates whether this framework has been effective to ensure that groundwater is managed sustainably, through the analysis of two cases located in an arid region of northern Chile: the Copiapó Valley and the Pampa del Tamarugal Aquifer.