Many developing countries, Malaysia included, are constantly faced with problems in managing water resources as there is lack of integration and holistic approach with little participation from the general public and other stakeholders apart from the government. In this study, two quantitative models, which are the discrete dynamical system and moving average, is applied to obtain the forecast value of clean water in Malaysia’s river basin by using open source data with minimal cost of analysis. The findings suggested that moving average method is superior as it provides better accuracy in forecasting with small error rate. The method is easy to understand, used standard MS Excel in computing, and need only minimal requirement of the machine’s operating system. Continuous assessment to the quality level of clean water in Malaysia’s river basin should be strictly regulated to ensure the right course of action to manoeuvre effective countermeasure for this issue. Among the counter measures may be in a form of focused education towards specified target groups, regulatory exercises, as well as awareness campaigns that are more effectively arranged.