A Study of Urban Water Supply System Resilience for the Capital City of Delhi, India

India is the second largest democracy with a population of about 1325 million. About 30% (around 400 million) population is living in cities, out of which around one-third is living in urban slums. The country has more than 65 million-plus cities, out of which 8 cities are mega-cities. Delhi (also known as the National Capital Territory of India) is a metropolitan region in India that includes the national capital city, New Delhi. It is the world’s second most populous city and the largest city in India in terms of area. Delhi has a population of around 19 million with the population growth rate of 2.1% per annum during the decade 2001–2011 with a population density of 11297 persons/sq. km area. Providing sustainable water supply to this capital city is a major challenge. The source of raw water for producing potable water in Delhi is Yamuna River, Upper Ganga Canal, and Satluj River through Bhakra Dam (Govind Sagar reservoir) as well as through local Ranney and tube wells. The Delhi Jal Board (DJB) is responsible for distributing clean and pure water in Delhi. However, it is a great challenge for managing drinking water to this National Capital Territory of Delhi in India due to various reasons such as heavy permanent and floating population, large expansion, environment deterioration, large competing demands, and depleting raw water sources under changing climatic conditions. At present, DJB is only able to distribute about 848 million gallons per day (MGD) which includes 100 MGD of groundwater. Further, there are only 4 to 6 hours of water supply in some of the important areas of South Delhi. The objective of this paper is to perform a quantitative assessment of water supply in Delhi using Water Evaluation and Planning System (WEAP) software under different climatic conditions.