New reclamation method aims to reduce Singapore's reliance on sand

Alice Chia Channel NewsAsia 16 Nov 16;

SINGAPORE: A new method of reclaiming land will be used on the northwestern tip of Pulau Tekong, and this aims to help Singapore reduce the amount of sand needed for such works and save on upfront costs.

The new method, called polder development method, will be adopted by the Housing and Development Board (HDB) for the project, announced National Development Minister Lawrence Wong during his visit to the polder site at Pulau Tekong on Wednesday (Nov 16).

Traditionally, sand is used to reclaim land to above sea levels, but the new method involves developing a polder - a low-lying tract of land reclaimed from the sea. A dike or wall is built to prevent seawater from entering the polder while a network of drains and pumps controls the water levels.

This reduces the amount of sand needed for reclamation and saves on upfront construction costs, HDB and the Ministry of National Development (MND) said.

Mr Wong added that sand is not always easy to come by, and the project will reduce the country's reliance on sand for reclamation works.

The reliance on sand imports was keenly felt in 2007, when Indonesia announced its decision to ban the export of land sand to Singapore. It was reported at the time that Singapore was importing six to eight million tonnes of sand, with more than 90 per cent coming from Indonesia. This led to price increases in construction works and having to source for more sand from other markets.

Mr Wong also said this new method will help build up capabilities. "We know that we are facing the threat of climate change, sea levels rising and we are low-lying in Singapore. With this project, I think the experience that we gain in learning how to build dikes, in learning how to manage coastal areas, will be very important for us as we deal with the threat of climate change in the longer term."

When the reclamation is completed around 2022, Pulau Tekong will have an additional 810 hectares of land, or about the size of two Toa Payoh towns. The land has been earmarked for military training.

To ensure the long-term safety of the polder land, the HDB drew on the experience of the Netherlands, which has used this method for land reclamation for many years, and has the world's highest standards for dike safety, HDB and MND said. An environmental study has also been carried out to ensure there will not be significant impact on the surrounding marine environment and wildlife.

The tender for the polder project is expected to be called by the end of this year, and construction will start in end-2017, HDB and MND said.

- CNA/kk


Reclamation at Tekong to give SAF more training space
FARIS MOKHTAR Today Online 16 Nov 16;

SINGAPORE — A bigger Pulau Tekong is in the works through a new land reclamation project to meet the Republic’s growing military training needs.

The additional land — measuring 810ha, or roughly the size of two Toa Payoh towns — will be reclaimed using a method that will also help the Republic reduce reliance on an increasingly uncertain supply of sand, as less of it is required. Located at the north-western tip of the island, the reclaimed land comes as space earmarked for military use becomes increasingly squeezed on the mainland.

The tender for the project will be called by the end of this year. Construction will start at the end of next year and is expected to be completed by 2022.

Speaking during a visit to Pulau Tekong on Wednesday (Nov 16), Minister for National Development Lawrence Wong, when asked why Pulau Tekong is being expanded, told reporters that Singapore is “always in need of more land”, and the additional space will help the Singapore Armed Forces with its growing training needs.

Asked whether this means more military camps will be shifted to the island, which was over 24.4ha and is growing, Mr Wong would say only that the reclaimed land will provide “some opportunity” to free up space in mainland Singapore.

Among the training areas under Ministry of Defence (Mindef) that have been affected by development is its training area in Tengah. With the development of Tengah New Town — about the size of Bishan — by the Housing and Development Board (HDB), Mindef has said that it will adjust its training accordingly.

In 2013, Prime Minister Lee Hsien Loong announced in his National Day Rally that Paya Lebar Air Base will relocate to Changi East, freeing up an area of 800 ha — bigger than Bishan or Ang Mo Kio — to build new homes, offices, factories and parks.

Responding to queries, Mindef said it works with MND to overcome physical and resource constraints, adding there are “significant requirements” for land to “train realistically”, even as it makes use of simulators and overseas training.

Commenting on the new land reclamation method being used — called empoldering — Mr Wong said it is not new, but there had been no pressing need to introduce it here as sand was “much more readily available” in the past. But circumstances have changed, he said.

Both Indonesia and Vietnam had halted sand exports in the past on the back of environmental concerns, creating a bottleneck in construction timelines in Singapore.

The new method, common in the Netherlands, will “significantly” reduce the amount of sand needed for reclamation, and it could also be employed in future reclamation projects, Mr Wong said.

The empoldering method will see a dike measuring 6m high and 10km long — about the length of the Bukit Timah Expressway — constructed to keep sea water out.

The land that is to be reclaimed will then be drained of any remaining water to create a low-lying track of land, also known as a polder, which will be 1.2 m below sea level. This is done with a network of drains, water pumping systems and canals, which will run continuously to prevent the polder from becoming waterlogged.

While the new method will generate savings in sand and construction costs, Mr Wong did not provide figures. Professor Kees d’Angremond, who is Singapore’s long-time adviser on reclamation work, acknowledged that maintenance cost will be higher because water has to be constantly drained. But the Singapore Government has done cost calculations, and the “conclusion is building a polder is the most economical way of reclaiming land”, he said.

The Ministry of National Development (MND) and HDB said an environmental study has been carried out to ensure the surrounding environment, including marine life, is not adversely affected.

The HDB said the impact of polder development on the surrounding environment will be negligible. But mitigating measures such as silt screens will be put up where required, during construction.

An Environmental Monitoring and Management plan will also be implemented.

Mangroves and other plant species in surrounding areas would also be conserved and protected.


Pulau Tekong to get extra land the size of two Toa Payoh towns using new reclamation method
Yeo Sam Jo Straits Times 16 Nov 16; and AsiaOne

SINGAPORE - A new method of land reclamation will be adopted at the north-western tip of Pulau Tekong, adding new land the size of two Toa Payoh towns for military training purposes, National Development Minister Lawrence Wong said on Wednesday (Nov 16).

The empoldering method involves building a dike around the area to be reclaimed and draining water from it, creating a low-lying tract of land below sea level, called a polder. The polder is buffered from the sea by a dike, and water levels in the polder are controlled by drains and pumps.

The dike will measure 10km long, up to 15m wide at its crest and stand about 6m above sea level.

Compared to the traditional method of infilling with sand, this will reduce the amount of sand needed for reclamation and save on upfront construction costs, said the Housing Board, which is the agent appointed by the Ministry of National Development to carry out land reclamation works on behalf of the Government.

To ensure that the project is cost-effective, safe and environmentally sensitive, the HDB said it is working closely with Professor Kees d'Angremond from the Netherlands - an authority on polder development and longtime adviser to Singapore on reclamation.

Prof Kees d'Angremond on the new reclamation method for Pulau Tekong

While polders may be new to Singapore, Professor d'Angremond said they have been built in the Netherlands for the past 2,000 years.

These polders were primitive ones built by farmers who wanted to protect their land against flooding, he said.

Safety of the polders is ensured through methods such as the building of strong dikes, determining the height of the dike in relation to expected sea levels and wave action, as well as having a grass cover on the inner dike slope to ensure it does not erode, Professor d'Angremond said.

"As Dutchmen we are convinced that it is a good solution for the future, but I think it is very wise that your Government has decided to call it a pilot polder and to do quite a lot of testing on the polder before you decide to apply the method in other places."

"That means also that we will do a lot of research in polders together to see whether we can make further improvements that are really dedicated to the conditions in Singapore."

The HDB will call for a tender by the end of this year and construction will commence at the end of 2017. The reclamation project is slated for completion in 2022.

Mindef will maintain the 810ha polder land upon its completion, while the drainage system, dike, water pumping stations and canals will be maintained by national water agency PUB.

The reclaimed area on the island will also have 21km of roads - the combined length of East Coast Parkway - and 29km of drains.

Pulau Tekong as seen from a bund. The sea area will be reclaimed land by 2022. ST PHOTO: YEO SAM JO
The HDB said an environmental study has been carried out to ensure that there will not be any significant impact on the surrounding marine environment and marine life.

"The study has found that the environmental impact due to the development of the polder would be minimal," said the HDB.

It added that surrounding areas with mangroves and other plant life will be conserved and protected.

Mr Wong told reporters during a site visit on Wednesday that Singapore has been studying the empoldering method for some time to reduce its reliance on sand for reclamation purposes.

“The polder project is important also for another reason, which is that it helps us to build capabilities,” he said.

“Because in the long term, we know that we are facing the threat of climate change, sea levels rising, and we are low-lying in Singapore. So with this project, I think that the experience that we gain in learning how to build dikes, in learning how to manage coastal areas, this will be very important for us as we deal with the threat of climate change in the longer term.

“So this is really a project not just about expanding our physical space but also about building up capabilities and making ourselves a more resilient nation in the longer term."

He said he will not rule out adopting empoldering for future reclamation projects, and also cited challenges such as the disruption in sand supply as a good reason to adopt the method.

The method will lead to a "significant amount" of savings in sand and cost, Mr Wong said, but did not reveal any figures.

"But we do expect significant savings in sand and also in construction costs," he said.

When asked why Pulau Tekong needs more land, he said that the country is "always in need of more land".

"For this particular expansion, it's going to be used for Singapore Armed Forces (SAF) training. But the needs for land continue to grow, whether it's for military, for housing, for commercial uses," he said.

"We are always looking at options to expand. And by expanding Tekong, providing SAF more space for their training needs, which are growing, we can free up land in the main Singapore island for other developmental purposes," he added.




Dutch experts give advice on Tekong land reclamation
Yeo Sam Jo Straits Times 17 Nov 16;

A popular tale by American author Mary Mapes Dodge tells of a Dutch boy who saves his country by putting his finger in the hole of a leaking dyke. The Dutch have had a long history with dykes - embankment barriers - given how the Netherlands is prone to flooding.

It may come as little surprise then that Singapore's latest land reclamation venture on Pulau Tekong, which will use a 10km-long dyke, is being done in consultation with Dutch experts.

To ensure that the project is cost- effective, safe and environmentally sensitive, Singapore is working closely with Professor Kees d'Angremond from the Netherlands, a longtime adviser to the Republic on reclamation. He is also an authority on polder development - the reclamation method that will be used to create 810ha of extra land on the offshore island.

This involves building a dyke around the area to be reclaimed and draining water from it. It will result in a low-lying tract of land, known as a polder, that is buffered from the sea by the dyke. Water levels in the polder are then controlled by a network of drains and pumps.

While polders may be new to Singapore, Prof d'Angremond said they have been built in the Netherlands for the past 2,000 years. These polders started out as primitive ones built by farmers who wanted to protect their land against flooding, and were often a matter of trial and error, he said.

With modern technology today, safety of the polders is ensured using advanced methods. These include the building of strong dykes to ensure water does not flow in, determining the dyke's height in relation to expected sea levels and wave action, and having a grass cover on the inner dyke slope to ensure it does not erode, Prof d'Angremond said.

A stone revetment, similar to a sea wall, will protect the dyke from the sea waves, said the Housing Board, the reclamation project's appointed agent. Meanwhile, either a cement bentonite screen or a diaphragm wall will minimise the seepage of sea water through the dyke.

The professor acknowledged that Singapore has "more severe" rain than the Netherlands, which might make draining water from the polder more challenging. But he said that this could be solved with a proper pumping system.

He added: "We will do a lot of research in polders together to see whether we can make further improvements that are really dedicated to the conditions in Singapore."


Making more room on Tekong
Yeo Sam Jo Straits Times 19 Nov 16;

Pulau Tekong - the island so familiar to most Singaporean sons - will be getting bigger by 2022. It was announced this week that a plot of land will be added to the north-western tip of the island using a land reclamation technique that is new to Singapore. About 810ha - the size of two Toa Payoh towns - will be created via empoldering, which involves building a dyke around the area to be reclaimed and draining water from it.

Compared to traditional land reclamation where infill is poured onto the seabed, this method is expected to significantly reduce costs as well as the amount of sand used. If adopted for future projects, empoldering could not only help our little red dot grow, but also tackle rocky challenges ahead.

The first challenge is Singapore's quest for more space. The National Development Ministry's Land Use Plan of 2013 specified that Singapore would need to reclaim 5,200ha of land - equivalent to nine Ang Mo Kio towns - by 2030 to meet growing population needs. Pulau Tekong, which currently spans around 2,440ha, already houses four basic military training schools where recruits go to become combat-ready soldiers. The reclaimed tract of land, called a polder, will provide more space for the Singapore Armed Forces' growing training needs, said National Development Minister Lawrence Wong.

He stressed that Singapore is "always in need of more land", be it for military, housing or commercial purposes. This expansion will free up space on the mainland for other developments.

The upcoming reclamation on Tekong will also see the Republic lowering its reliance on sand, as empoldering uses less of the material. As Mr Wong noted, sand sources can be easily disrupted, leading to uncertain fluctuations in supply and price. Given how neighbouring countries such as Indonesia have banned sand exports in recent years, this could make Singapore less vulnerable to any shortages.

Lastly, empoldering could also build up local expertise in areas such as dyke construction and coastal management. This would better poise Singapore to handle problems such as rising sea levels due to climate change, Mr Wong said.


Joint Press Release by MND & HDB: HDB to adopt new land reclamation method at Pulau Tekong
HDB 16 Nov 16;

Singapore will reclaim land through the development of a polder at the north-western tip of Pulau Tekong. This innovative, cost-saving method, to be used for the first time here, will be adopted by the Housing & Development Board (HDB) for the upcoming land reclamation project. This was announced by Mr Lawrence Wong, Minister for National Development and Second Minister for Finance during his visit to the polder site at Pulau Tekong this morning.

New Polder Development First-of-Its Kind in Singapore

2 Unlike the traditional method of infilling with sand, this “empoldering” method involves creating a tract of reclaimed land from the sea or a surrounding water body, by constructing a dike and a network of drains, water pumping systems and canals. It will substantially reduce the amount of sand needed for land reclamation, and reap savings on upfront construction costs.

Please refer to the illustration below for a comparison of the traditional infilling method and polder development method.


3 The polder will be protected from the sea by a dike measuring 10 kilometres long, up to 15 metres wide at its crest, and will stand at about 6 metres above sea level. In designing the safety provision of the dike, HDB has drawn on the vast experience of the Netherlands, which currently has the world’s highest standards for dike safety, to ensure long-term safety of the polder land.

4 HDB worked closely with Professor Kees d’Angremond of the Netherlands, an authoritative figure on polder development and a long-time Adviser to Singapore on reclamation works, on the design of the polder development at Pulau Tekong to ensure that it is cost-effective, safe and environmentally-sensitive.

5 An environmental study has also been carried out to ensure that there will not be significant impact on the surrounding marine environment and marine life. The study has found that the environmental impact due to the development of the polder would be minimal. In addition, surrounding areas where mangroves and other plant life are present would be conserved and protected.


Polder Land Expected to Complete in 2022

6 Tender for the polder project is expected to be called by end 2016, and construction work will commence in end 2017. When completed around 2022, it will add an additional 810 hectares of new land to Singapore.

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