Water Decision Support System for Urban Water Security under Uncertain Future: A Case Study of Upper Yamuna River Basin, India

Ensuring water security considering the near- and far-future climatic and socio-economic uncertainties, is one of the grand global challenges. In developing countries, supply-side management like the construction of new dams, rehabilitation and augmentation of the existing water resources and supply infrastructure are the widely adopted solutions. Often, the importance of the requirement of water for environmental well-being is neglected. Here, we develop a modelling framework using Water Evaluation and Planning and Qual2K models, considering ‘environment’ also as a stakeholder. This water decision support system is demonstrated on the Upper Yamuna River Basin, a complex and polluted river system in India. Further, to raise risk awareness among stakeholders about the extreme plausible future conditions, the storyline-based approach is adopted to develop future scenarios. The developed framework is deployed to explore the National Capital Territory of Delhi's urban water security for different plausible future scenarios. Based on this, reliability of different policy management options and strategies are explored. The simulated results show that the localized (urban level) management strategies are more reliable than the basin level management strategies, especially under a prolonged plausible warmer climate and better standard of living based socio-economic development conditions. The model building, scenario development, and analysis demonstrate the importance of incorporating the local system knowledge to build an effective decision support system for physically and legally complex river basins.