Environmental Flow Estimation of Brunei River Based on Climate Change

The concept of environmental flows and its application and enforcement is a main challenge in several developing countries. The services and benefits derived from the ecosystem are indispensable for sustaining the livelihood of people particularly living in coastal areas. Decision-makers often ignore ecosystems when referring to water allocation, as the supporters of ecosystems are less vocal as compared to other stakeholders. This study focuses on establishing guidelines for maintaining the minimum amount of flow known as environmental flow of Brunei River in Brunei Darussalam for the sustainability of its rich ecosystem. In this study, the flow of the river was simulated based on land use, climate change, and potential growth of industries using a Water Evaluation and Planning System as a computing tool. The study finds that the months of March and June (1.48 and 3.92 m3/s) are more vulnerable to low flow. It recommends a threshold value of 2.7 m3/s for the environmental flow of Brunei River essential to preserve its rich and diversified ecosystem.