Paradigm shift: Holistic approach for water management in urban environments

Conventional water infrastructure in urban environments is based on the centralized approach. This approach consists of building pipe network that provides potable water to consumers and drainage network that transport wastewater and stormwater runoff away from population centers. However, as illustrated in this article, centralized water infrastructures are not sustainable over a long period of time for a variety of reasons. This article presents the concept of a holistic approach for sustainable water management that incorporates decentralized water infrastructures into water management system design in urban environments. Decentralized water infrastructures are small to medium-scale systems that use and/or reuse local sources of water such as captured rainwater, stormwater runoff and wastewater. The holistic approach considers these waters as a valuable resource not to be wasted but utilized. This article briefly introduces various types of decentralized water infrastructures appropriate for urban settings. This article focuses on the effectiveness of rooftop rainwater harvesting systems as a decentralized water infrastructure and as a critical component of developing a holistic and sustainable water infrastructure in urban environments. Despite widespread use of rainwater harvesting systems, limited information has been published on its effectiveness for sustainable management of water resources and urban water infrastructures. This article, discusses multi-dimensional benefits of rainwater harvesting systems for sustainable management of water resources and its role as a critical component of decentralized water infrastructures in urban environments.