Climate change is modifying the way we design and operate water infrastructure, including reservoirs. A particular issue is that current reservoirs and their management rules will likely operate under changing conditions different to those used in their design. Thus, there is a big need to identify the obsolescence of current operation rules under climate change. Furthermore, such identification -and the corresponding uncertainty- must be clearly described and communicated, as decision making is a complex task that benefits from the scientific knowledge mainly when presented in a simple and easy-to-understand manner. This study presents a methodology to identify, in a simple and useful way, the time at which current reservoir operation rules fail under changing climate by properly treating and showing its aleatory, epistemic, and deep uncertainty. For this purpose, we use a reliability-resilience-vulnerability framework with a GCM ensemble under the four RCP scenarios to compare the historical and future long-term reservoir system performances under its current operation rule in the Limarí basin, semiarid Chile. During the 21st century, for the study case the time-based reliability changes by the 30’s, resilience between the 30’s and 40’s, volume-based reliability by the 80’s, and the maximum failure by the 70’s. Interestingly, the average failure does not worsen significantly. Overall, the approach allows the identification of the timing of systematic failures in the performance of water systems given a certain performance threshold. This identification may facilitate the planning, prioritization and implementation timing of adaptation alternatives.

Assessing Reservoir Performance Under Climate Change. When is it Too Late if Current Water Management is Not Changed?

Created in 1999, the Environmental & Water Resources Institute (EWRI) is the recognized leader within ASCE for the integration of technical expertise and public policy in the planning, design, construction, and operation of environmentally sound and sustainable infrastructure impacting air, land and water resources.

[Paper Proceedings](https://doi.org/10.1061/9780784483466)