A review of rainwater harvesting in Malaysia: Prospects and challenges

Abstract

The mismatch between freshwater demand and its availability is a major problem that causes global water scarcity. The exploration and utilization of rainwater seem to be viable options for minimizing the aforementioned issue. This manuscript reviews the prospects and challenges of the rainwater harvesting system (RWHS) in Malaysia. Malaysia can be categorized as a country that has high annual rainfall, as well as high domestic water consumption. Thus, Malaysia is well positioned to harvest rainwater for both potable and non-potable uses. Although the RWH guidelines were issued in Malaysia in 1999, the implementation of RWHS as an alternative water resource is still very limited due to its long return on investment and poor public acceptance. Major future challenges on the implementation of RWHS in Malaysia are to achieve competitive cost, the wide application of commercial buildings, a cost effective treatment system, effective policy implementation, the application of green materials, public perception improvement, and reliable first flush technology. Some recommendations such as providing appropriate subsidies and limiting the use of piped water are necessary for implementing RWHS at wider scales.