Quest for a Diversified and Sustainable Supply of Water
Over the last 50 years, through strategic planning and investment in research and technology, Singapore’s national water agency PUB has built a robust and diversified supply of water known as the ‘Four National Taps’. The water supply comprises (1) local catchment water, (2) imported water, (3) highly-purified reclaimed water known as NEWater, and (4) desalinated water.
Local Catchment Water
Singapore has two separate systems to collect rainwater and used water. Rainwater is collected through a comprehensive network of drains, canals, rivers, storm-water collection ponds and reservoirs before it is treated for drinking water supply. This makes Singapore one of the few countries in the world to harvest urban storm-water on a large-scale for its water supply.
Local catchment water is a pillar of our sustainable water supply. Since 2011, the water catchment area has been increased from half to two-thirds of Singapore’s land surface with the completion of the Marina, Punggol and Serangoon Reservoir.
With all the major estuaries already dammed to create reservoirs, PUB aims to harness water from the remaining streams and rivulets near the shoreline using technology that can treat water of varying salinity. This will boost Singapore’s water catchment area to 90% in the long term.
Singapore has been importing water from Johor, Malaysia, under two bilateral agreements. The first agreement expired in August 2011 and second agreement will expire in 2061.
A Singapore success story and the pillar of Singapore’s water sustainability, NEWater is high-grade reclaimed water produced from treated used water that is further purified using advanced membrane technologies and ultra-violet disinfection, making it ultra-clean and safe to drink.
In 2010, Singapore’s latest and largest NEWater plant was completed. Together, Singapore's four NEWater plants can meet up to 30% of the nation’s current water needs.
By 2060, we plan to expand the current NEWater capacity so that NEWater can meet up to 55% of our future water demand.
Another technology-based water source is desalinated water. Singapore has one of Asia’s largest seawater reverse-osmosis plant, which produces 30 million gallons of water a day (136,000 cubic metres) to meet about 10% of Singapore’s water needs. A second and larger desalination plant with a capacity of 70 million gallons of water a day or 318,500 cubic metres of desalinated water per day, the Tuaspring Desalination Plant opened in September 2013. Today, desalinated water with a total capacity of 100 million gallons of water a day from two plants can meet up to 25% of Singapore’s current water demand.
By 2060, we intend to ramp up desalination capacity so that desalinated water can meet up to 25% of our water demand in the long term.
Multiple water projects were also initiated to ensure a sustainable water supply for Singapore. These include clean-up of the Singapore River, building the Marina Barrage and creating the Deep Tunnel Sewerage System.
Reservoir In the City
An iconic structure at the mouth of the Marina Channel and the vision of Minister Mentor Lee Kuan Yew more than twenty years ago, Marina Barrage creates Singapore’s fifteenth reservoir, the Marina Reservoir.
The barrage serves three benefits: it creates a freshwater lake to boost Singapore’s water supply, acts as a tidal barrier to prevent flooding in low-lying city areas, and keeps the water level consistent, offering a venue for water-based activities in the heart of the city. In addition, there are opportunities abound for people to connect with water at the barrage. This helps to nurture ownership of Singapore’s precious water resources, so people will do their part to keep our waters clean. At the same time, it is also a celebration of the beauty and preciousness of Singapore’s waters.
The variety of recreational activities available at the barrage has made it the new hotspot in the city centre, with more than 3.5 million visitors since its opening.
In 2011, Marina Reservoir with Punggol and Serangoon Reservoirs, which are our 16th and 17th reservoirs, increased Singapore’s water catchment from half to two-thirds of Singapore’s land surface.
Used Water Superhighway
The Deep Tunnel Sewerage System (DTSS), a 48-kilometer-long used water superhighway, conveys used water from the northern and eastern parts of Singapore to the centralised Changi Water Reclamation Plant for treatment before the treated used water is further purified into NEWater.
We are now planning for Phase 2 of the DTSS. Similar to DTSS Phase 1, DTSS Phase 2 will consist of four components: a deep tunnel (South Tunnel), associated link sewers, a centralized WRP integrated with NEWater facilities and deep sea outfall. It will cover the western part of Singapore, including the downtown city area and major upcoming developments such as Tengah New Town, and is targeted for completion in 2022.
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