Evaluating Rainwater Harvesting Suitability in Educational Institutions using Tangki NAHRIM 2.0 for Sustainable Water Management Approach

El Nino frequently results in protracted droughts through decreased rainfall concentration, which may cause rivers, lakes, and reservoirs to become depleted. One of the mitigation plans to reduce this impact is by applying the sustainable water management solution. Rainwater Harvesting system has been proposed where the system can directly collect rainfall. This water can be stored for later use or returned into the groundwater system. With additional financial advantages, rainwater harvesting systems (RWHS) can increase water supply to suit urban and rural demands. However, the application of RWHS for the large scale of water demand such as educational institution have been scanty, therefore the aims of the study are to evaluate the suitability of rainwater harvesting installation in educational institutions, thus able to propose the suitable number of tanks. The analysis using Tangki NAHRIM 2.0 software was conducted to determine the suitability of the implementation. Rainfall at location, roof information, water demand, and tank capacity were the data that needed to be input in the software. Then, the data were analysed to evaluate the suitable rainwater harvesting tank for the selected building, and results indicate the RWH is suitable to be placed with the minimum tank provided being 2 tanks and the maximum tank being 3 tanks. In a nutshell, the Tangki NAHRIM 2.0 successfully identified the optimum tank size, indicates the accuracy and cost-effectiveness thus able to benefit the management in order to provide a suitable volume of tank and be able to reduce the consumption of treated water.