Geography ALTERNATIVE ASSESSMENT Water Resources
Monday 18 March 2013 | 23:22 | 0 comments
Below are the different ways that Singapore has dealt with their water constraints.
The Public Utilities Board of Singapore (PUB) has implemented a water supply strategy known as the "Four National Taps Strategy". The "Four National Taps Strategy" is a strategy where Singapore obtains water from four different sources, i.e. local catchment areas, imported water from Johor, NEWater and desalinated water. PUB also ensure sufficient water supply for all Singaporeans needs now and in the future.
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| Marina Barrage |
Tap 1: Water from local catchment areas
Water from local catchment areas is collected in reservoirs and stormwater collection ponds. Before 1975, Singapore had only three reservoirs. Since then, 11 more reservoirs were constructed by building dams across rivers or along coastlines. They are Bedok Reservoir, Marina Reservoir, Pulau Tekong Reservoir, Lower Seletar Reservoir, Sarimbu Reservoir, Kranji Reservoir, Poyan Reservoir, Jurong Lake and Pandan Reservoir. 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. In November 2008, Singapore announced the opening of a new reservoir at the Marina Channel. The Marina Reservoir alone supplies up to 15% of Singapore's fresh water needs. In addition, Singapore has nine stormwater collection ponds to tap the storm runoffs, which will be diverted to reservoirs. Reservoir water can supply between 50% to 60% of our water needs in the future. Stormwater collection ponds have been constructed in some housing estates, which collect rainwater and channel the water to various reservoirs.
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| Singapore MacRitchie Reservoir |
Nature reserves are often used as catchment areas because forests can retain a supply of freshwater. Rainwater is intercepted by the trees and plants and is then absorbed by the soil layers on the ground. This water will eventually be drained into a reservoir for storage. An example of a catchment area is Singapore's Central Catchment area, which consists of forests around four major reservoirs, namely Upper Seletar Reservoir, Upper Pierce Reservoir, Lower Pierce Reservoir and MacRitchie Reservoir.
Another example is the Marina Barrage which creates Singapore 15th reservoir, the Marina Reservoir. It has a dam built across the Marina Channel. The barrage serves three benefits, that is, 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 the 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. Marina 'Reservoir is also a flagship projects of Active, Beautiful and Clean Waters Programme.
The advantages of local catchments is that rainwater is easier and cheaper to purify because it is much cleaner than used water and does not contain salt. There will be more recreational areas as forests are conserved when they are used as catchment areas. The disadvantage of local catchments is that It is not viable for small countries as they cannot afford to set aside too much land and thus less land will be available to build houses, industries and roads. This method is ineffective in times of drought as the amount of rainfall cannot be controlled.
Tap 2: Imported Water
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| Singapore imports water from Johor through piping |
Singapore has been buying water from the Malaysian state of Johor since the 1920s. Singapore has two water agreements with the Johor government. The first agreement was signed in 1961 and expired in 2011 while the second agreement was signed in 1962 and expire in 2061. The 1962 agreement is valid for 99 years and it gave Singapore the full and exclusive right to draw water from Johor River up to a maximum of 250 million gallons per day. In return, Johor was entitled to a daily supply of treated water from Singapore up to 2% of the raw water it supplied. Singapore has to pay an annual rent of $5 per acre for the land. Singapore buys raw water from the state of Johor at a charge of 3 cents for every 1,000 gallons and Johor buys back the water at 50 cents per 1,000 gallons after it has been treated and turned into potable water.
For example, in the Bangladesh - India water treaty signed in 1996, the two countries agreed to share and manage the water supply from the Ganges River. However, the treaty is valid for 30 years and is reviewed by the two governments every five years.
For example, in the Bangladesh - India water treaty signed in 1996, the two countries agreed to share and manage the water supply from the Ganges River. However, the treaty is valid for 30 years and is reviewed by the two governments every five years.
Another example, the Nile Basin Initiative is a collective agreement signed by nine countries where the Nile and its tributaries flow through (Egypt, Sudan, Ethiopia, Uganda, Kenya, Tanzania, Burundi, Rwanda and the Republic of Congo). The agreement seeks to develop the river in a cooperative manner, sharing substantial socio-economic benefits and promoting regional peace and security.
The advantages of imported water are that it is a convenient way of obtaining additional supplies of water and it is relatively cheaper to purify because it is much cleaner than used water and does not contain salt. The disadvantages of the imported water is that Johor government can choose not to renew the water agreement when it expires and the water supply is not in our control, thus making us more vulnerable. It is also higher cost as some countries may increase their price of water to earn more.
Tap 3: NEWater
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| NEWater Plant |
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| Seletar Reclamation Plant |
Water reclamation is another method that Singapore uses to ensure a constant supply of fresh water. With the help of advanced membrane technology treatment and ultra-violet disinfection making it ultra-clean and safe to drink, Singapore is able to produce a very high grade of water known as NEWater. The standard of NEWater is even higher than international drinking water standards. This water is supplied to industries such as wafer fabrication plants as well as to commercial and industrial buildings for direct non-potable use. Singapore mixes NEWater with reservoir water before it is sent to water treatment plants. This supplements reservoir water and allows additional water to be supplied to homes as potable water. Currently, Singapore has six water recycling plants. They are in Bedok, Kranji, Seletar, Ulu Pandan, Changi and Jurong. NEWater is estimated to supply up to 30% of Singapore's water needs by 2011. It will replace imported water as the 2nd largest source of water supply in Singapore. By 2060, the Singapore government plan to triple the current NEWater capacity so that NEWater can meet 50% of Singapore's future water demand. For example, the NEWater plant at Bedok costs $6.82 million to construct.
The advantages of NEWater is that the quality of the NEWater is high. The water supply is secure as Singapore do not need to rely on other countries for water supply. The disadvantages of NEWater is that the technology is costly and the cost will only be offset in the future. People are not used to the new taste of NEWater due to the removal of minerals and nutrients.
Tap 4: Desalinated Water
Singapore also carries out desalination of seawater to supply part of the nation's water needs. The cost of such plants is very high, both in construction as well as in operations. Desalinised water is estimated to supply as much as 10% of Singapore's water needs in the future. Using the reverse osmosis method, the SingSpring Desalination Plant in Tuas produces as much as 30 millions gallons of water a day and the plant is one of Asia's largest seawater reverse-osmosis plant. The second 70 mgd desalinated plant will be completed in 2013. By 2060, we intend to ramp up desalinaton capacity by almost 10 times so that desalinated water will meet at least 30% of our water demand in the long term. Countries that use desalination to provide potable water for its people include Saudi Arabia, Israel and USA.
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| Desalination Plant |
Singapore also carries out desalination of seawater to supply part of the nation's water needs. The cost of such plants is very high, both in construction as well as in operations. Desalinised water is estimated to supply as much as 10% of Singapore's water needs in the future. Using the reverse osmosis method, the SingSpring Desalination Plant in Tuas produces as much as 30 millions gallons of water a day and the plant is one of Asia's largest seawater reverse-osmosis plant. The second 70 mgd desalinated plant will be completed in 2013. By 2060, we intend to ramp up desalinaton capacity by almost 10 times so that desalinated water will meet at least 30% of our water demand in the long term. Countries that use desalination to provide potable water for its people include Saudi Arabia, Israel and USA.
The advantage of desalinated water is that the quality of the water is high and Singapore now depends less on other countries for the supply of water. The disadvantages of desalinated water is that the technology is costly and the cost will only be offset in the future e.g. SingSpring Desalination Plant in Tuas cost $200 million. People are not used to the new taste of desalinated water due to the removal of minerals and nutrients. Also, this will cause an increase in fossil fuels used to generate power for desalination plants. This will result in global warming due to the increase in carbon gases being produced and released into the atmosphere. In addition, there will be an increase in the amount of pollution as many recycling plants need to discard the waste resulting from the purifying process.
In order to select the best option, there are factors that needs to be considered. These are (i) sustainability (ii) availability (iii) cost effective (iv) able to support the Singapore's population. Out of the four national taps, imported water from Johor will be ending in 2061. Hence, this source does not meet the criteria of availability. The national tap of NEWater meets the above three criteria. It is now meeting about 30% of Singapore's water needs. However, it is not able to support all of Singapore water needs and it is only added to reservoirs and not supplied directly to households. The third national tap is desalination. It is expensive and only meets about 10% of Singapore's water needs. The fourth national tap is water from local catchment areas. Singapore started with 3 reservoirs in 1975 and the number of reservoirs increased by 11 to date. Reservoirs water can supply between 50% to 60% of water needs in future. This option is the most suitable method as it meets the criteria of sustainability, availability, cost effectiveness and supporting Singapore's population.
In order to select the best option, there are factors that needs to be considered. These are (i) sustainability (ii) availability (iii) cost effective (iv) able to support the Singapore's population. Out of the four national taps, imported water from Johor will be ending in 2061. Hence, this source does not meet the criteria of availability. The national tap of NEWater meets the above three criteria. It is now meeting about 30% of Singapore's water needs. However, it is not able to support all of Singapore water needs and it is only added to reservoirs and not supplied directly to households. The third national tap is desalination. It is expensive and only meets about 10% of Singapore's water needs. The fourth national tap is water from local catchment areas. Singapore started with 3 reservoirs in 1975 and the number of reservoirs increased by 11 to date. Reservoirs water can supply between 50% to 60% of water needs in future. This option is the most suitable method as it meets the criteria of sustainability, availability, cost effectiveness and supporting Singapore's population.
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Earth Our Home Textbook
Earth Our Home Guidebook
http://infopedia.nl.sg/articles/SIP_1533_2009-06-23.html
Geography Perfect Guide
Coral Sec School Geography Notes
Done by: Annabel,Winnie,Layxuan,Gracia