Research Report

Assessment of Climate-Induced Long-term Water Availability in the Ganges Basin and the Impacts on Energy Security in South Asia

G.M. Tarekul

The Ganges basin provides essential water for drinking, irrigation, industrial use and cooling of power generation facilities. Changes in the water availability induced by global climate change will impact on economic development as well as human life in this basin and beyond. Water competition among major consumers will become fiercer in the Ganges basin in the coming decades as the three major South Asian developing countries, Nepal, India and Bangladesh focus more on poverty eradication, industrial development, food security and universal energy access for achieving their long-term social and economic development goals. These factors combined will exacerbate the existing level of water stress that has been experienced in some sub-basins of the Ganges. As one of the largest water consumers, the energy sector will thus face a big challenge in ensuring sufficient water to maintain stable operations of the existing and planned thermal power plants in the future. Quantitative knowledge on the spatial distribution of water supply, water demand, water supply-demand balance and energy water requirement is crucial to energy feasibility planning and effective water resource management. However, few studies on these practical issues can be found in existing literature.

This project, entitled “Assessment of Climate-Induced Long-term Water Availability in the Ganges Basin and the Impacts on Energy Security in South Asia”, is funded by the Asian-Pacific Network for Global Change Research (APN). The project aims to inform decision makers, relevant stakeholders and energy project investors about future water availability under climate change conditions, as well as water supply-demand balance and water risks for existing and planned power plants from the present to 2050. We developed a novel approach on an integrated assessment of the water-energy nexus by using various modelling techniques (hydrological modelling, water demand projections) together with first-hand data collection from power plant field surveys. Three case studies were conducted for India, Bangladesh and Nepal. The case study in India covering four selected sub-basins, namely Chambal, Damodar, Gandak and Yamuna, provides a detailed assessment on future water availability, water demand, water supply-demand balance and the water risks for existing and planned thermal power plants at the sub-basin and district levels. To enable effective communications with the target audience, a free on-line web tool, Water-Energy Nexus Assessment for India, was developed to help explore and visualise the spatial data and the results on maps. Through multi-stakeholder consultations in the kick-off workshops and the final workshops held in the three countries, the objective of this project, the major results and key messages have been effectively communicated with relevant policy makers from the development and planning ministry, energy sector and water supply and management department, etc., as well as academia and other stakeholders (e.g., project investors). This project has contributed to strengthening the science-policy interface in the area of water-energy nexus for the Ganges basin.

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