This research focuses on the public water supply system in East Timor’s capital, Dili. Through this research the performance of the current public water supply system is evaluated, shortages in system capacity and operation are identified, and the future need is analyzed. Only 41.77% of Dili’s urban population currently has access to the public water supply system. A better documentation and record keeping of the water treatment plants’ operations is needed. As the population grows and city develops, more water will be needed in the future. The current public water supply system will not be adequate to supply water in the future because the water demand outweighs the design capacity of the current system. Therefore, a proper water supply system and management is highly needed, especially if the government of East Timor wants to achieve their target to supply continuous water in East Timor’s urban areas by 2030.