Tekong-Ubin reservoir not practical

Letter from Ivan Kwan Wei Ming, Straits Times Forum 22 Apr 08;

I REFER to Mr Syu Ying Kwok's letter on Friday, "After Marina Barrage, Tekong-Ubin reservoir". While the need for a constant supply of fresh water will no doubt be essential to Singapore's survival, I am afraid that the idea of connecting Pulau Ubin and Tekong to mainland Singapore to form a new reservoir is simply not feasible, and overlooks many important reasons which render it an untenable idea.

Construction of the Marina Barrage involved building a dam across the mouth of the Singapore River. Ideally, over time, the saltwater in the estuary will be flushed out, to be replaced by fresh water from further upstream. Mr Syu's letter already pointed out a major difficulty with replicating this scenario for a hypothetical Ubin-Tekong reservoir: damming up an area of sea with the aim of converting all that seawater to fresh water is simply not a sound idea, especially when there are few, if any, rivers to supply fresh water to the enclosed area.

Building pumps to pump out all the seawater will involve great costs, while the cheaper alternative, letting all the seawater evaporate naturally, will take years, if not decades, and will most likely result in a giant saline lake, which defeats the whole purpose of building a reservoir to store fresh water for human consumption. Dumping in large volumes of fresh water to dilute and flush out all the seawater would be self-defeating, especially since the amount of fresh water required would probably exceed the potential capacity of the reservoir.

When reclamation at Pulau Tekong has already become the subject of territorial disputes with Malaysia, and when the issue of Pedra Branca has yet to be resolved, proposing to build such a reservoir so close to international boundaries will surely not sit easily with our neighbours. The Malaysian authorities will be unhappy for another reason: Mr Syu failed to take into account the fact that the proposed reservoir would destroy an internationally important shipping lane. Ships travelling between Pasir Gudang, Sembawang Shipyard, and the rest of the world stand to lose an essential route if the area was dammed up. Are the economic and political risks worth it?

Because the area is currently subject to heavy maritime traffic, dredging is constantly being carried out, and there is also quite a high risk of pollution. What happens if the water in the reservoir gets contaminated? The area also sits right at the mouth of the Johor River, which in recent years has experienced heavy flooding during the December monsoons. There is the chance that heavy rains will wash a mixture of floodwaters and seawater right into the reservoir. And with a sea-level rise due to climate change, or occasional storm surges, there will always be the risk of seawater breaching the dams and infiltrating the reservoir. What are the costs involved in preparing against such occurrences, or in rectifying the situation if such contamination occurs?

Lastly, building such a reservoir will severely impact a number of ecologically significant nature areas that many have come to love. Places like Chek Jawa, Changi Beach and the Pasir Ris mangroves will all be lost forever if such a scheme is ever implemented. These sites, rich in biodiversity, are irreplaceable in terms of their value as part of our natural heritage, and have also become important places for leisure and recreation. Not to mention that damming up the sea will lead to massive die-offs of marine life as the salinity of the water changes, which will present a major pollution problem.

Ultimately, in lieu of all these other points, which the original letter failed to take into consideration, are the great costs involved in constructing and maintaining such a reservoir justified?

There are simply too many costs in return for attaining self-sufficiency in our water supply. We already possess technologies like desalination and reverse-osmosis which can help us achieve this objective, without the potential economic, political and ecological nightmare that would ensue if an Ubin-Tekong reservoir was built. While it is important that we foster an environment that is receptive to new ideas that will help us maintain our competitive edge, it would be advisable that people carry out more research into the viability of their ideas before voicing them out in public spaces like the Straits Times forum.

Comments on the Straits Times Forum page in response to Ivan Kwan's letter

Marina Bay will need two heavy monsoon to convert it into fresh water.
Posted by: PiePiePie at Tue Apr 22 15:31:16 SGT 2008

I disagree with Mr(s). Syu. His proposal, if realized, will be yet another catalyst for geopolitical tension between Malaysia and Singapore. The proposed reservoir will seal up the navigable channel of the eastern Johor Straits, effectively blocking access to Pasir Gudang Port. This will be a rallying point for more Singapore bashing. Mr. Syu also seems to advocating for the mass-destruction of coastal and island ecological systems of Pulau Ubin, Pulau Tekong and Changi. Hence I am not sure as to how exactly the carbon footprint of his proposal can be considered beneficial. In addition, using Marina Bay reservoir as a gauge, it will probably take far longer for the water in the proposed reservoir to be drinkable given the natural saline dilution approach Mr. Syu is suggesting(which is not really the approach used in creating the Marina reservoir) that . We may be looking at a timeframe in excess of 100 years. During this time, new technologies will probably arise to negate the rationale for Mr. Syu's idea. A more workable idea would be the conversion of Sungei Punggol and Sungei Serangoon into reservoirs. Mr. Syu's proposal is probably well-meaning but it inherently holds many negative points that will make it impossible for any rational policy-maker to accept it.
Posted by: asgard0211 at Tue Apr 22 15:07:09 SGT 2008

Re: Mr Syu's latest reply

1) Based on expert advise from people who work on the marina barrage, this is how it works: first you need to flush out all the salt water during low tide and then let let fresh water fill it up. However, this is not a one time process. It requires long period of time before the water is 100% consumable. While it's not consumable, we can only use it for non-portable uses. So yes, you MUST "pump" out all the water or at least be able to flush it out. You cannot have a single bit of salt water inside the reservoir before you can actually consume it. You don't need to build pumps as Mr Kwan suggested but you definitely must remove all water before introducing freshwater.

2) Those estuaries you mentioned are already going to be dammed up. Furthermore, would you want heavy industries and airports to form the catchment of which your water comes from? Chemicals and pollutants infiltrate through the ground and ends up in your waterbodies.

3) The straits of Johor does not belong to Singapore. There is an international boundary in the middle of the straits. Furthermore, the reason why the shipping lane is between Singapore-Ubin is because the channel there is deeper. Deep channels are required for ships to pass through. The Johor-Ubin waters are too shallow!

4) Would the economic and environmental cost for building the reservoir be even more than the carbon footprint of desalinization? What is more important?
Posted by: micamonkey at Tue Apr 22 14:58:14 SGT 2008

Tekong-Ubin reservoir is conceived as an idea to retain precious fresh water for Singapore’s future needs. I fully agreed that educating our people to save the precious little fresh water is one very important aspect for water independence. Yet even when everyone is able to use only as much as they need, Singapore still needs to find new source of water for our children and future generation, including you.

If build, water inside the Tekong Ubin reservoir will not be pump dry and fill with fresh water (this is silly and wasteful). Estuaries from the entire north east part of Singapore, including Tekong, Ubin Island and the entire Changi Airport area, will serve as a water catchment area. Fresh rain water from these areas will be diverted into this new reservoir.

This entire area easily represents more than 20% of land in Singapore and we have many man made canals and even other canals as source of fresh water. Fresh water from Sungei Pungol, Sungei Serangoon, Sungei Tampines and even Sungei Seletar can be diverted into this reservoir.

With our heavy annual rainfall, over time the inflow of fresh water will reduce the salinity of this reservoir until we have fresh consumable water.

Pedra Branca will be resolve over time. Singapore will let international law decide on areas of dispute. Our Malaysian neighbors will in the future realize that it will benefit more for both countries to work together. It is up to you and future generations of Singaporeans and Malaysians to work together.

The dams if built will be within our own territorial waters and connected to our own islands. Singapore is not a country that will infringe on others legal territory.

The water between Singapore, Tekong and Ubin belongs to Singapore, it is not international territory. Ships and boats can move in and out of Sembawang Shipyard and southern tip of Malaysia thru the passage way north of Tekong and Ubin Island. Maritime operations will not be hindered.

Unknown to many Singaporeans, Singapore has one of the best civil works authority in the world. The number of flooding incident in Singapore is so small that when it happens, it becomes a spectacle. Those with experience living in other low lying coastal city, like Jakarta and even Johore will tell you how luck we are. Thus I have utmost confidence on them to make it proper if such dams were to be built.

There is a very good reason why Singapore should pursue the less costly alternative for fresh water. Yes we have desalination plants and reverse-osmosis technology can be use to get fresh water. But these are costly methods because both are energy and resource intensive. For each litre of water from desalination plant, we will have to burn more fossil fuel in generating enough energy for desalination, thus we will put more carbon dioxide into the atmosphere indirectly.

To put it simply, the carbon foot print for each litre of water from desalination is many times more than that from a reservoir. Indirectly, Singapore will destroy more of mother nature using desalination.

The cost saving by using a reservoir, which will be very significant in the long run when compared to desalination, can be used to buy more land of virgin rain forest and will help even more on our efforts to save our planet.

Ultimately, Tekong Ubin reservoir is only a suggestion for our government to consider. Knowing our Government, a very extensive study will be done before a project like this, which is very large and complex is even considered. You must have faith in our Government to do the correct thing after weighing all the pros and cons. Chek Jawa would have been destroyed long ago if our Minister has not considered our people’s opinion. What ever the decision by our Government, Singaporean must also know that we must take collective interest of everyone and not just interest of our own.

Syu Ying Kwok.
Posted by: IIVII at Tue Apr 22 09:31:50 SGT 2008

For the unenlightened, pls read the article in micamonkey's post link.

Forum writers really should do basic information-gathering before launching into such fantastical spiels. How the writer got the idea, I really don't know. But a logical think-through would quickly result in the idea being shot down.

Environmental, political, technological and social factors were completely left out in the forum letter.
Posted by: flameback at Mon Apr 21 17:42:01 SGT 2008

moreover, damming the place up to store freshwater is not the solution to our problem. the solution lies in the education of the people - teach everyone to consume less!
Posted by: pricillaseah at Sat Apr 19 16:44:47 SGT 2008

and then what will happen to all the wildlife and biodiversity of the area? the corals, the forest-dwelling animals in Tekong and the mangroves that will need to salinity to survive? I urge the authorities to think twice, thrice, many many many times before making this decision, before they regret it later and spend even more money to restore the place to it's original state.
Posted by: pricillaseah at Sat Apr 19 16:44:02 SGT 2008

I totally agree with mbkho, What about the environmental impact?
All the remaining natural mangroves in Pasir Ris Park and along Sungei Serangoon will be destroyed due to the new freshwater conditions. What about the beaches along Pasir Ris and Changi? The patch of beach forest along Changi, which is adapted to shoreline conditions will be affected. SO much of our nature is at stake. I don't think this is should be implemented.
Posted by: JuzKeiko at Sat Apr 19 14:39:43 SGT 2008