The reliability of rainwater harvesting system as an alternative source of water supply in Malaysia: A preliminary study

Rainwater harvesting system is considered as a Best Management Method or Best Management Practices ( BMP ) in Malaysia. This system is not only meant to slow down the flow of runoff but also to serve as an alternative source of water supply that is free and safe to use. Although there is the view that the system is not viable and practical in terms of the construction and maintenance costs to users, there have been studies in and outside thecountry which show that the return on capital ( ROC) of this system takes only between two to three years. This paper examines the system performance at an experimental laboratory site in the Universiti Kebangsaan Malaysia campus known as TANGKINAHRIM. The operation results of this analysis system have found consistent rainfall throughout the year (2010) and a large water catchment site sufficient for the daily needs of the Faculty of Social Sciences and Humanities. The reliability of the system was found to be high at 89.3%. Finally, the optimal water tank size of 60 to 65 cubic meters was found to be appropriate for the size of the catchment and the total population of users, signifying the strategic location of the laboratory site.