Singapore's journey in used water management started during the early twentieth century when the country was faced with the urgent need to tackle its hygiene and sanitation problems — issues brought about by rapid population growth in its tropical environment and concerns over public health.

After independence in 1965, the government realized that the development of a world-class used water management system was crucial not only in improving the quality of life for its people but also in sustaining the economic growth of the country. A comprehensive Sewerage Master Plan was thus developed and the necessary investments made to extend the used water infrastructure so that 100 per cent of the population would have access to modern sanitation.

Increasing water demand has also necessitated reclaiming water from used water to augment water supply. Singapore's fully sewered system offered the opportunity for large-scale used water recycling and water reclamation to be carried out. Recent breakthroughs allowed for the development of more advanced water reclamation facilities, namely, the NEWater factories, which are located adjacent to the Water Reclamation Plants (WRPs). These were formerly known as Sewage Treatment Works but they were renamed WRPs in 2001 to reinforce the idea that used water is a resource to be reclaimed. The NEWater factories receive the treated used water effluent and treat (reclaim) it further using advanced membrane technology. The resulting product is high-grade water known as NEWater, which is channelled for both direct non-potable and indirect potable uses. Chapter 5 elaborates on NEWater.

This chapter provides insights into how the management of used water in Singapore evolved over the years and the key considerations behind the government's decisions in adopting various solutions as the country progressed from a simple fishing village to one which was rapidly industrializing, and eventually to the modern, cosmopolitan city of today.