Harvested Rainwater Volume Estimation Using Tangki Nahrim Software : Calculation of the Optimum Tank Size in Terms of Water Security

Water is fundamental to our quality of life, to economic growth and to environment. Rainwater is one of the primary sources of all usable water in the planet. Rainwater harvesting (RWH) is an ancient practice of capturing rain runoff from roofs and other surfaces and storing it for later purposes. A variety of issues, such as: i) Urban growth, ii) Limited water supplies, iii) Ageing stormwater infrastructure and iv) Environmental sustainability, have prompted a renewed interest in this practice, which has become common in the developed countries such as Germany, Japan, and Australia and in developing countries such as India and Malaysia. In this study, we use Tangki NAHRIM software to calculate the captured rainwater volume, optimum rainwater tank size; quantify the impact of rainwater demand, captured rainwater volume, and tanks in managing institutional water demand at IUKL Campus in Selangor, Malaysia. This project achieves several goals such as: i) Promote environmental awareness through actively participating in storm water management, ii) Utilizing rainwater collected from building’s roof as a catchment area which deliver relatively clean water source, iii) Reduce reliance and consequently the pressure on municipal water resource and iv) Avoiding the use of relatively expensive water source for toilet flushing within nonpotable category application