Developments such as climate change and a growing demand for drinking water threaten the sustainability of drinking water supply worldwide. To deal with this threat, adaptation of drinking water supply systems is imperative, not only on a global and national scale but particularly on a local scale. This investigation sought to establish characteristics that describe the sustainability of local drinking water supply. The hypothesis of this research was that sustainability characteristics depend on the context that is analysed, and therefore, a variety of cases must be analysed to reach a better understanding of the sustainability of drinking water supply in the Netherlands. Therefore, three divergent cases on drinking water supply in the Netherlands were analysed. One case related to a short-term development (2018 summer drought), and two concerned long-term phenomena (changes in water quality and growth in drinking water demand). We used an integrated systems approach, describing the local drinking water supply system in terms of hydrological, technical, and socio-economic characteristics that determine the sustainability of a local drinking water supply system. To gain a perspective on the case study findings that are broader than the Dutch context, the sustainability aspects identified were paired with global aspects concerning sustainable drinking water supply. This resulted in the following set of hydrological, technical, and socio-economic sustainability characteristics: (1) water quality, water resource availability, and impact of drinking water abstraction; (2) reliability and resilience of the technical system and energy use and environmental impact; (3) drinking water availability, water governance, and land and water use. Elaboration of these sustainability characteristics and criteria into a sustainability assessment can provide information on the challenges and trade-offs inherent in the sustainable development and management of a local drinking water supply system.@en

Concerned decision makers increasingly pose questions as to whether current management practices are able to cope with climate change and increased climate variability. This signifies a shift in the framing of climate change from asking what its potential impacts are to asking whether it induces policy failure and unacceptable change. In this paper, we explore the background, feasibility, and consequences of this new framing. We focus on the specific situation in which a social-political threshold of concern is likely to be exceeded as a result of climate change, requiring consideration of alternative strategies. Action is imperative when such a situation is conceivable, and at this point climate change becomes particularly relevant to decision makers. We call this situation an “adaptation turning point.” The assessment of adaptation turning points converts uncertainty surrounding the extent of a climate impact into a time range over which it is likely that specific thresholds will be exceeded. This can then be used to take adaptive action. Despite the difficulty in identifying adaptation turning points and the relative newness of the approach, experience so far suggests that the assessment generates a meaningful dialogue between stakeholders and scientists. Discussion revolves around the amount of change that is acceptable; how likely it is that unacceptable, or more favorable, conditions will be reached; and the adaptation pathways that need to be considered under these circumstances. Defining and renegotiating policy objectives under climate change are important topics in the governance of adaptation.@en