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

Husnna Aishah Zabidi,Hui Weng Goh,Chun Kiat Chang,Ngai Weng Chan,Nor Azazi Zakaria

doi:10.3390/w12113163

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.

Highlights

Water security can be described as protecting the human societies against the negative impacts of water scarcity and excess, as water is precious to human life and development [1]
For Pond Harvesting System (PHS) case studies, most of the harvested rainwater is unsafe for drinking purposes, especially in Dindigul District, India, where the harvested rainwater had exceeded the allowable standard for turbidity, iron and fecal coliform [32] and in South Africa, where the water was contaminated with high level of total suspended solid (TSS) and E. coli [44]
The use of Rainwater Harvesting System (RWHS) to fulfill the domestic water demand has been clearly recognized through roof harvesting system (RHS) application, but PHS application is still in doubt, even though the only differences between these systems are the scale and the use of the conveyance system

Summary

Introduction

Water security can be described as protecting the human societies against the negative impacts of water scarcity and excess, as water is precious to human life and development [1]. The mismatch between water demand and rainfall (water availability) has resulted in the high variability of water resources in highly developed and populated areas like Selangor, Putrajaya and Kuala Lumpur in Malaysia, often leading to flash floods and water shortage issues [22]. Such issues became the main concern that opened the eyes of many authorities and researchers to turn their attention to engage in the practice of SUDS. Identify the future potentials of PHS application for better water security