A new holistic approach for designing sustainable rainwater management systems

Abstract

Rainwater harvesting (RWH) has long been regarded as a powerful economical, practical, and sustainable tool for domestic freshwater and potable water supply, mainly for rural areas. Rainwater is therefore a precious and limited but renewable resource, nourishing innumerable life forms. For urban areas, rainfall has been mainly perceived as a source of nuisance, causing pressure on existing drainage systems. From these perspectives, excellent approaches (e.g. low impact development, nature-based-solution, sponge cities, water-sensitive urban design) have been designed to address rainwater management in urban areas. The common thread among all these approaches is that the basis for their design was contextual water demand (e.g. population size, volume of stormwater). Therefore, despite decades of intensive research, there is still a need for context-specific unified integrated water resource management (IWRM). Three relevant primary design parameters are average annual rainfall (mm/a), catchment area (m 2 ), and geo-stability. The present communication is the first attempt to popularize a new approach called the zero-runoff-approach or the housewife-approach (“rainwater first”). In this approach, the population size is a secondary design parameter. The housewife-approach offsets the challenges posed by unsustainable groundwater withdrawal while providing a scalable model for enhancing water security through family-centered and community-based initiatives.