The cost of treating and supplying water has increased significantly in Singapore due to rising energy and construction expenses. Some of the key reasons for rising prices include increased consumer demand, which is expected to double by 2065, external cost pressure and climate change resulting in frequent weather extremities. 

Project elements like energy costs have increased by almost 37 per cent, construction costs have risen up by 35 per cent,  and the operating expenses for chemicals which are used in the water treatment process have risen by about 33 per cent since 2017. Moreover, the maintenance costs of the water system have also risen by 18 per cent.

This has caused the costs of key projects like Phase 2 of the Deep Tunnel Sewerage System (DTSS) to USD6.5 billion, almost twice the cost of Phase 1.