Water is a non substitutable resource and a social good, which governments must perforce provide to its citizens in the right quantity and quality. An integrated urban metabolism model is useful in understanding the status quo of an urban water and sanitation system. By defining and measuring the values of relevant hydrological performance indicators—deliverables of the model referred to—a thorough knowledge of the present performance and the gaps, which need to be plugged en route to a sustainable urban water infrastructure, can be obtained, as demonstrated in this paper. This then forms the bedrock for decision-making and policy formulation for change to be introduced top-down as well as advice, which would enable the much needed bottom-up support to policies. The authors have chosen Delhi as the case study city, but would like to point out that this application can be reproduced for any other town/city/region of the world. The water balance within the chosen system boundaries shows that the annual unutilized flows, amounting to 1443 million cubic meters, dominate the metabolic flows of water in Delhi, and the annual groundwater withdrawal, which exceeds 420 million cubic meters, is much greater than the recharge rate, resulting in a rapid depletion of the groundwater level. There is an urgent need thereby to improve the rate of infiltration of stormwater and reduce the rate of runoff by focusing on increasing the share of permeable surfaces in the city, as well as to consider the wastewater streams as potential sources of water, while not forgetting demand side of management measures, as the pressure on the urban water system in the city is likely to intensify with a combination of population growth, economic development, and climate change in the near future. The recommendations provided by the authors towards the end of the article, can, if suitable measures are undertaken and robust policies are implemented, result in Delhi’s enjoying a water surplus in the short term, and progressively attain complete sustainability with regard to the utilization of its water resources.

This paper presents urbanization challenges in India and initiatives taken to address them. Urbanization in India is characterized by skewed urban growth between cities by large population influx creating distinct variation in core and periphery of cities in terms of urban form and services. Key challenges include growth of slums, inadequate management of solid waste, decrease in per capita water availability and unreliable water quality, inadequate sewage coverage and deteriorating ambient air. Although, these issues are not new or specific for India, what is new are the drivers and pressures behind these problems. The paper illustrates the challenges of Indian urbanization in the light of resource inefficiency, resistance to adopt upcoming technologies that do not have direct financial benefits, weak enforcement of laws, and inadequacy in regulatory framework. It also presents instances of active participation of non–formal and formal sectors in addressing sustainability challenges. There is also a recognition of the fact that city governments are faced with multiple sustainability agendas of climate adaptation. This presents a decisional challenge for planners and city administrations. Benefits incidental to a particular policy goal can help drive the implementation of the policy and sustain it in the long term, but only when the inherent risk trade–offs, if present, can be managed.

The concept is very relevant to the present day problems. But this article cannot be accepted at this stage. The article requires substantial MAJOR CHANGES for it to be reviewd again. Comments on the articles are below: * The abstract is an execut...