This is assumed to be the volume of used water that enters the water treatment plants in Singapore. The data points are obtained from various sources:
- Data for years 2011 to 2018, and 2009 are obtained from the annual publication 'Key Environmental Statistics' by the Ministry of the Environment and Water Resources for the years 2010, and 2014 to 2019.
- Datapoint for 2010 is obtained from ASEAN IWRM PERFORMANCE REPORTS & MONITORING INDICATORS - Singapore 2010 Report (Sanitation Management) https://aseaniwrm.water.gov.my/wp-content/uploads/2015/08/Singapore-2010-Report-Sanitation-Management1.pdf.
- Data for years 2003 to 2008 are obtained from Table 23.2 in the publication Lee, Poh Onn (2010) "The Four Taps: Water self-sufficiency in Singapore".