A Review of Roof and Pond Rainwater Harvesting Systems for Water Security: The Design, Performance and Way Forward

Abstract

Rapid urbanization, population explosion and climate change have threatened water security globally, regionally and locally. While there are many ways of addressing these problems, one of the innovative techniques is the recent employment of Sustainable Urban Drainage Systems (SUDS) which include rainwater harvesting systems (RWHS). Therefore, this paper reviews the design and component of two types of RWHS, the namely roof harvesting system (RHS) and the pond harvesting system (PHS). The performance in terms of quantity and quality of collected rainwater and energy consumption for RWHS with different capacities were evaluated, as well as the benefits and challenges particularly in environmental, economic and social aspects. Presently, the RHS is more commonly applied but its effectiveness is limited by its small scale. The PHS is of larger scale and has greater potentials and effectiveness as an alternative water supply system. Results also indicate the many advantages of the PHS especially in terms of economics, environmental aspects and volume of water harvested. While the RHS may be suited to individual or existing buildings, the PHS has greater potentials and should be applied in newly developed urban areas with wet equatorial climate.

Integrated Water Resource Management: Rethinking the Contribution of Rainwater Harvesting

“…Because climate change will impact rainfall patterns, the need to maintain a sustainable water supply in future has motivated the development of new water management strategies in which recycling and reusing stormwater are key issues [46]. At least three different strategies have been developed to increase rainwater storage: (i) sponge city (China) [47,48], (ii) sustainable urban drainage systems (SUDS) (UK) [49], (iii) and low-impact development (LID) (USA) [10,26]. Interested readers are referred to Zabidi et al [26], who give an excellent overview on the state-of-the-art knowledge on rainwater management.…”

“…At least three different strategies have been developed to increase rainwater storage: (i) sponge city (China) [47,48], (ii) sustainable urban drainage systems (SUDS) (UK) [49], (iii) and low-impact development (LID) (USA) [10,26]. Interested readers are referred to Zabidi et al [26], who give an excellent overview on the state-of-the-art knowledge on rainwater management. The same authors insist on the importance of ensuring water security in Sustainable Urban Drainage Systems (SUDS) by including a range of drainage techniques and devices.…”

“…A negative side effect was that rainwater became a waste, augmenting urban stormwater, for example. This paradigm is still prevailing [26,32].…”

“…However, the perception persists as to whether this approach provides a sustainable alternative in the modern world [8]. In the developed world, despite the development of excellent strategies for stormwater management (e.g., LID, sponge city, SUDS) during the past two to three decades [26], their real implementation is still suffering from the lack of a regulatory framework [28,29]. However, as discussed herein, some existing regulatory policies are based on wrong scientific information on rainwater quality.…”

“…The objective of this communication is to demonstrate that despite the broad application of RWH worldwide, rainwater is still an underestimated and thus under exploited "help from above" [18,23,24] in integrated water management. RWH is acknowledged as an option for decentralized water provision, but debates exist about its benefits and costs [25,26]. Moreover, even in developed countries, there are still doubts about its relevance, mainly because the way of supplying water in many of these countries is based on a centralized infrastructure and a single use of water [27,28].…”