Linking water-society interactions in Chennai, India through the DPSIR framework

Cities in all continents are suffering from water scarcity. Projected rapid population growth and urbanization together with climate change will put even more pressure on urban water resources and, therefore, the number of large cities and global urban population facing water scarcity will significantly increase by 2050. Forecasts look particularly worrying in India, where the urban population facing water scarcity is expected to be the highest in the world by 2050. Chennai, India´s fourth-largest urban agglomeration, had in 2019 its worst water crisis in 30 years, after its four major reservoirs dried up and the city was relying solely on water tankers.Although addressing water management in cities with complex scenarios requires applying an integrated urban water management approach, there is no internationally standardized indicator framework for it. Therefore, this study aims at applying the Drivers-Pressures-States-Impacts-Responses (DPSIR) framework, a causal framework adopted by the European Environment Agency for describing the interactions between society and the environment, on Chennai’s water resources to help stakeholders implementing sustainable management strategies.Scientific literature, public administration and interested parties were consulted. The main drivers identified were population growth and economic development which generate pressures on land use, water demand and waste generation. Due to these pressures, Chennai experiences rapid urbanization, water scarcity and pollution, and biodiversity loss. This has led to impacts such as the loss of aquatic ecosystems, low water table and quality, and reduction in biodiversity and human health. As a response, authorities and non-governmental organizations implemented measures to increase the availability of drinking water like dams, inter-basin transfers, desalination plants, groundwater pumping, and rainwater harvesting. Also, the conditions of aquatic ecosystems have been improved through urban planning, new sewage treatment plants, ecosystem restoration projects and the implementation of water regulations. However, Chennai is expected to keep facing difficulties to achieve a proper water management. A mix of measures such as more infrastructure for water harvesting, new sewage treatment plants, or a more efficient waste management system are recommended.