Planning for circular water system for Bhopal city using water mass balance analysis

Abstract

With rapid urbanization, resource requirements have intensified which has resulted in unsustainable resource use patterns, exploitation, and social inequality (three fourths of the global resources are used up by the cities, which barely occupy 3-5% of the global land). High resource consumption has created stress on natural resources, resulting in the creation of waste and pollution as by-products affecting health, the environment, and the economy. In addition, water as a resource is extremely scarce. India’s 54% of the area encounters high to extremely high-water stress, which could affect food security and livelihood. Moreover, most of the cities are dependent on hinterlands for a water source, whose water flows are linear and this being unsustainable leads to its depletion. Thus, to explore solutions to the problem and make cities resource-efficient and sustainable amidst growing population pressure and rapid urbanization, the concept of circular urban metabolism is explored and utilized in the case of Bhopal city in this study. Urban metabolism sees the city as a biological unit, with sub systems in place working in close coordination with each other, as seen in any other biological unit. Thus, studies call cities complex systems with sub-systems like food, water, energy etc. working and interacting in close coordination. And Circular urban metabolism involves making this city metabolism process circular, i.e., with the use of reduce, reuse, and recycle principles (3Rs), the waste generated from one sub-system can be utilized as raw materials for the same or another sub-system, thus eliminating waste from the picture and making the system circular. Circular urban metabolism is thus essential in today’s time given the increasing consumption and production patterns. The urban water system too can be made circular mainly by recycling used water and harvesting rainwater, along with other decentralized and local water sources as practiced in the successful case studies across the world. Used water here should be seen as a valuable resource rather than a burden to the environment. It can be utilized to substitute water from hinterlands and decrease freshwater withdrawal and the associated expenses. Used water recycling also serves as an essential step for.