Towards a new era of rainwater utilization: implementation status, barriers, and prospects of decentralized rainwater harvesting systems in China
Chen Shiguang, Hongwei Sun, Xuebin Chen
Abstract
This article explores the potential of decentralized rainwater harvesting (RWH) systems as an extension of conventional water sources in China. Through a comprehensive literature review, we identify key economic, technical, and social barriers hindering widespread adoption, including high costs, lack of standardized design tools, and low public awareness. Our analysis reveals significant regional disparities in economic viability, with benefit–cost ratios ranging from 0.16 in arid regions to 3.2 in humid areas, influenced by factors such as rainfall patterns, roof area, and water demand. The study highlights innovative solutions to address these challenges, including low-cost treatment technologies (e.g., gravity-driven microfiltration and solar disinfection), gravity-based distribution systems for high-rise buildings, and neighborhood-scale approaches to enhance cost-effectiveness. Additionally, we propose decision–support tools and regionalized design aids to optimize system performance. Policy measures such as subsidies, tax incentives, and mandatory installation in new buildings are recommended to accelerate adoption. These findings offer valuable guidance for the implementation of decentralized RWH systems, emphasizing the need for interdisciplinary collaboration to overcome barriers and promote RWH as a sustainable solution for urban water management challenges, not only in China but also in other parts of the world.