FLOOD PREVENTION (Statement by the Minister for Communications and Works)

10.29 a.m.

Mr Francis Thomas: Mr Speaker, Sir, some hon. Members will probably have received, communications from their constituents as a result of the flooding caused by heavy rain on Monday last, the 3rd of November, and I think it may be useful if I make a statement on what has been achieved so far by the Government's flood control works; on what remains to be done; and on the broad picture, in short, as it is today and as far as we can forsee it for the next few years.

I had better start by enumerating some of the basic simple points to which I have referred in the past in the Assembly, but which may not be clear in hon. Members' recollection.

The first point is that we have to get the water right off the land and into the sea, or else we have to retain it in a properly planned and constructed reservoir. It would be useless to approach this flooding problem on a short-term vote-catching basis. It would be fairly easy sometimes to shift the flood water off the land of political supporters and on to the land of political opponents. But I would not wish to do that and I am sure that my honourable political opponents on the Opposition Benches would not wish me to do it to them. The only way to deal with flood problems is by proper overall schemes after a full study of the facts.

My second point is that flooding cannot be dealt with as simply as some people suppose. It is not just a matter of deepening or widening the channels of the drains. If deepening brings the bottom of the drain down to sea level, then the sea will flow up the drain at high tide, and this is not a desirable result. The only way of stopping this is to have a fairly expensive tidal gate at the mouth of the drain, such as we have put in at the mouth of the Geylang River.

Moreover, even where the land is above sea level, deepening of a drain may have serious results. It lowers the water table and dries out the subsoil. For example, in the Queenstown area, the land has been reclaimed by putting earth-fill on top of swamp mud. A deepening of the drain would lower the water table and dry out the foundations and thus affect the stability of the houses.

Even where no buildings would suffer from deepening the drains, lowering the water table will draw away the water from the roots of the farmers' crops and then they cannot grow their vegetables for the market.

The third point is that flood difficulties are very much increased as development proceeds. This operates in two ways. Firstly, every new piece of development increases both the size and the speed of the run-off of water. Along Bukit Timah Road, each new estate that is developed sends more water down more quickly to the lower parts of the roads. In the same way along Thomson Road on Sunday last I was asked by residents to look at a local flooding problem. Although it was some hours after the rain had stopped, I found a house where six inches of watery mud was still standing in and around the house and this was being accumulated by being trapped between the old and the new Thomson Roads. Residents nearby on the other side of the new Thomson Road telephoned me on Monday to say that their houses which had never been flooded before, were being flooded now. I have not yet got a final report on this particular area. I quote it because it illustrates the danger of new development sending flood waters down to people at the bottom of the hills.

Development also causes flooding difficulties when it puts valuable capital investment on to land which would otherwise have been used for drainage. For example, the flooding below the Peirce Reservoir to which I was just referring could have been dealt with by a drain out towards Ponggol but before the drain could be surveyed or constructed or even planned the appropriate line for it had been covered by development at Serangoon Garden Estate and that way out is now closed.

The fourth point I should make is the problem of achieving co-ordination between different authorities. The City Council in the City area has to deal with water which is flowing down to them from the rural area and in the rural area the decisions which have been or will be made about the three big City Council reservoirs in the centre of the island affect the planning of flood control works from Mandai right down to Potong Pasir. To co-ordinate plans between separate authorities is never easy.

My fifth general point is that adequate flood control schemes are very expensive. They not only take a lot of construction work but they also involve big requirements for land; and in the overcrowded state of Singapore, land requirement means also heavy costs for land clearance and resettlement. Hon. Members will have seen in the Press reports of the complaints by residents in the Aljunied Road area who were reluctant to move off the land required for the drains for our second tidal gate in the area.

So much for these general points which hon. Members would like to bear in mind as I go forward with a brief account of the flooding which occurred last Monday and how it is related to the plans which Government has carried out or now has in hand.

I have no reports of flooding from the eastern side of the island. The flood control scheme at Bedok seems to have been 100 per cent successful. A little further west, in the Geylang Serai area, our new tidal gate which is associated with some drainage works carried out by the City Council seems also to have been fully successful. Higher up in the Lorong Tai Seng area, there was some water lying about when I visited it and I am afraid that situation will remain and will have to be accepted until we have completed our second tidal gate in the Kallang swamp on the other side of Aljunied Road and cleared the land and dug the drains which will carry the water away from the Airport Road area.

I have no reports of significant flooding from Potong Pasir but, as I mentioned just now, there was some local flooding all the way up Thomson Road from Kampong San Teng as far as the Sembawang Hills Estate.

So much for the eastern side of the island. As far as reports to me go, there was no other significant flooding there. The rainfall on the eastern side of the island was not so heavy as the rainfall on the western side of the island.

As I pointed out earlier, development along the Bukit Timah Road produces an increasingly rapid run-off and concentration of water along Bukit Timah Road and through to Orchard Road. Although the rainfall this year was very much less than it was in the serious flood period of 1954, the flood levels at the bottom of Bukit Timah Road were considerably higher than they were in 1954. For example, in front of the University of Malaya, there were 2½ feet of water and there were three feet of water at the Orchard Road/Scotts Road junction, the water coming there from the same source.

The flooding of this area is one of the major problems which will have to be dealt with in the future. The only practical solution is to get the water away from here by a very big ring drain run-fling along Whitley Road across Thomson Road through the south of Toa Payoh down to the Kallang swamp. This will involve very large works and, consequently, a lot of money.

Further south, we have the very serious and rapidly increasing flooding along the catchment of the Singapore River. At Upper Queenstown, there was a big accumulation of water and further down in the low-lying area, the floods were as much as three feet in depth.

Here again, flooding has been created where it had not previously existed by the very large development works being carried out at the head of the catchment. This is the third major flood control scheme which the Government is carrying out. Putting it briefly, we are cutting through the line of the Railway and propose to run the water away to the west into the sea.

There is also an increasing flood area in the City around Robinson Road, Boon Tat Street and Cecil Street. My colleague, the Minister for Local Government, informed this Assembly in July 1955 that the City Council had schemes for pounding areas beneath the area of Boat Quay and Telok Ayer at a cost of about $450,000. I have no recent information about City Council proposals for work in this area but the inconvenience caused to this vital commercial area by flooding must be considerable.

I have not had reports of any serious flooding further west in the Jurong and Ama Keng areas, though, no doubt, in any heavy rain there will be some accumulation of water.

I must not conceal from hon. Members that, had the tide been higher or had the rainstorm gone on longer, the flooding in the areas affected on Monday would have been considerably worse. The essential problem is that the water has to be got away to the sea, and if the drains are not big enough, it cannot get away; there is a bottleneck and the water lies around until gradually it finds its way out. This constitutes the special danger for Singapore: whilst a single storm will clear itself in a reasonable period of time, a succession of storms can lead to a very considerable accumulation of water with all the very serious danger and damage to crops, to property, to livestock and to commercial activities which are inevitably involved.

The problem of flood control will, I am afraid, remain with Singapore for a good many years to come and will involve quite considerable cost and, consequently, quite considerable taxation before it can be fully dealt with. In the 3½ years that I have been concerned with this matter, the Government has spent, exclusive of land costs, approximately $1 million on flood control works and is committed to a further $1¼ million for completion of the Geylang Flood prevention scheme and the Ulu Pandan diversion of the Queenstown flood waters. In addition, the City Council has done quite a good deal of work but I have not got precise figures for their expenditure. It is probably safe to say that the work done so far is only a small part of the work and the cost which will be necessary to give Singapore reasonable freedom from flooding in all areas.

Hon. Members are well aware of the serious effects on Singapore of the world trade recession and they are also aware of the very considerable sums which have been found, and necessarily will have to continue to be found, to provide education for our enormously expanding school-age population and for medical and other social services. I do not want to prejudge the decisions which may be made by successive Governments after the next general elections. I cannot attempt to say what priorities may in future be attached to flood control schemes on the one hand, and to social services or to other forms of development on the other.

There is, however, no immediate prospect of this Government undertaking any new major flood control schemes apart from the completion of the works I have referred to - at Paya Lebar, Geylang and Ulu Pan-dan. Because of this, I have reluctantly agreed to allow our Drainage Adviser to retire. In the 3½ years in which he has been working here, he has completed a massive job of making an overall survey of the causes of flooding on this island and he has worked out the schemes which will have to be carried out in order to remove the flood problem from us. He has also carried out the important scheme at Bedok and has got us well advanced with the schemes for the Geylang/Paya Lebar area and for Ulu Pandan. He has worked under great difficulties and his achievements have been limited not by his capacity but by the ability of Government to finance the necessary schemes. It is with the greatest regret that I have agreed to his retirement but he does leave behind him the general plans which can be brought into action at any time when the funds are available.

Mr John Ede (Tanglin): Mr Speaker, Sir, would the Minister tell us the approximate cost of dealing with the Bukit Timah Road problem?

Mr Francis Thomas: I do not think that it will be safe to give any figure which could be relied on. There are so many unsettled factors at present that I would not care to attempt to give a figure which had any serious meaning in it.