Thursday, July 10, 2014

Singapore's Water Challenges and Solutions

One of the great ironies of Singapore's island status is that despite being surrounded by water, it has little in terms of naturally occurring water resources for its 5 million inhabitants.

Consequently, Singapore has had to employ practical and innovative solutions to these water challenges.  Essentially, Singapore's water needs are met by 4 major strategies.

1.  System of Catchments and Reservoirs:  In meeting water needs, Singapore does have the significant advantage of an annual rainfall of over 90 inches.  This means that if they can successfully collect this generous rainfall and store it, then they can begin to address their water challenges.  Consequently, the entire island is served by a network of water channels, canals, and catchment reservoirs to store the abundant rainfall. 
The larger reservoirs serve as places to store Singapore's rainwater

Of these catchment reservoirs, the Marina Barrage has allowed Singapore to utilize the waters of the Singapore River and Marina Bay as a freshwater reservoir.  A barrage is a dam that keeps out seawater.  Through a process of flushing excess water, they have been able to maintain high quality freshwater source with an area that equals 1/6th the size of Singapore.  In addition to creating a large water catchment system in the city center, it also provides for recreation, as both the water and the catchment facility themselves are open for public use 24 hours a day.  The facility contains massive pumps that improve flood control and prevent contamination from nearby salt water.

School group has the Marina Barrage catchment system explained to them.
One additional flood management tool employed is the use of permeable paving.  Particularly in the case of parking spots, Singapore uses paving stones and concrete patterns that have soil in between to allow for some absorption of water and also preventing as much of the car oil and other contaminants from running directly into storm sewers and canals.

Permeable parking spaces
2.  Imported Water:  Currently about 60% of Singapore's water is purchased from Malaysia.  There is a contract for this partnership to continue until 2061, but Singapore has developed it's other water strategies in order to achieve water independence earlier.  It was explained that through catchment, reusing water, and desalinization, Singapore has the capacity today for water independence, but purchasing some of their water gives them one more dimension in meeting their water needs.

3.  Reusing Water (NEWater):  Singapore has developed a sophisticated process of processing used water and sewage through three main processes (filtration, reverse osmosis, and UV disinfection) in order to produce water that meets all health standards.  Sludge and contaminants are incinerated and used as fill for reclaimed land projects.  It takes only 5 minutes to complete the process and production capacity is 117 million gallons per day.  This entire process can be witnesses at the NEWater facility.

The basic three-step process at NEWater can be seen at the NEWater Visitor Center, which has incredible exhibits to better understand how Singapore meets its water needs.  Here's a short video about the visitor center:

4. Desalinization: Singapore does utilize salt water resources in order to produce more fresh water for its citizens.  Major efforts in this industry include expanding capacity and energy efficiency.

The Big Picture:  By combining these four strategies, Singapore is able to meet its growing water needs.  However, in the midst of this expanded production, they are also trying to promote water conservation, as well.  Grey water is used to flush toilets.  Low-flow faucets and showerheads are widespread, catchment systems harvest as much of the tropical rain as possible.

Singapore is a city of over 5 million inhabitants and is looking to grow steadily in the coming decades.  However, in conjunction with this growth is the goal Singapore remaining a "City of Gardens and Waters".  A great deal of the urban planning revolves around expanding and improving natural spaces, trail networks, and waterways, while allowing for further residential and economic development.  Long term planning and a deep analysis of the implications of development seem to be the key in meeting business, employment, residential, and recreational needs.

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