HL Deb 19 November 1970 vol 312 cc1358-82

8.55 p.m.

LORD BOWDEN rose to ask Her Majesty's Government: Whether they are satisfied that the statutory defence levels which have been established by the Greater London Council are adequate to protect the occupants of the London flood plain from the risks to their lives and property which are undoubtedly to be expected if a tidal flood occurs this winter; and whether they are satisfied that arrangements which have been made by the police will be adequate to remove those whose lives will be in danger by a very high tide.

The noble Lord said: My Lords, I am sorry that what I believe to be one of the most: urgent matters which have been before the House for many years should come to be discussed at such a late hour. Nevertheless, I have to draw your Lordships' attention to what I believe to be the very great danger which confronts this city of ours at this very moment.

Last week, on November 13, a great wind of cyclonic force in a sea which shelves at one end created the most devastating floods in Pakistan and. as we have already heard this afternoon, killed a number of people estimated at perhaps 100,000, 200,000 or 300,000. As the noble Lord, Lord Aberdare, said some hours ago, this may prove to be one of the greatest disasters of which history has record. It may come to rank with the effect of a great cyclonic storm in the 16th century in another shelving sea, which drowned something like 200,000 people on the East coast of England and in the Low Countries. Storms of this magnitude occur from time to time in all parts of the world. Their effect can be devastating; their incidence is unpredictable, and they are among the hazards with which mankind must learn to live.

The last great storm of this kind occurred in the North Sea in 1962, and devastated the port of Hamburg, drowning several hundreds of people. In the winter of 1953 there was a great storm which, as your Lordships may remember, caused devastation on the East coast of England, caused a certain amount of flooding in the River Thames and devastated part of Holland. The Dutch discovered that the flood water had risen to within two or three inches of the top of the great dyke which protects the ports of Amsterdam and Rotterdam, and they knew that had the great storm occurred a month earlier or a month later, at the time of spring tides, the water would have risen several feet higher and almost the whole of Holland would have been inundated.

The Dutch realise that such a storm is very improbable, but they decided forthwith to protect themselves against it. Since 1953 they have raised by about six feet the height of the dykes which protect Holland, and they have nearly completed the most tremendous programme of dams and barrages to close off the waters of the estuaries of the Rhine and the Meuse—the so-called Delta Plan. They can now await with some confidence the onslaught of a storm which is unlikely to occur more often than once in a thousand years.

If this thousand-year storm, if I may so describe it, were to come next week, Holland would be safe. But what would happen in London? The answer to this extraordinary and appalling question is to be found in a large document which

I have in my hand, which is called, rather oddly, Thames Flood Prevention. It might be better described as a prospectus for a catastrophe. There can be no doubt at all that, were such a storm to occur, large parts of the flood plain of London—an area perhaps 10 miles long and up to 2 miles wide, which includes Wapping, the Isle of Dogs, Tower Hamlets and large areas of Richmond, South Kensington, and even Westminster—would be flooded to a depth of perhaps 10 feet.

The document states that large parts of the Underground, all the way from Hammersmith to Mile End and from King's Cross to Clapham, as well as the Rother-hithe and Blackwall Tunnels, would be flooded. It is very probable, if the flood in Hamburg is to be taken as any guide, that the number of casualties would be at least comparable to the number of people who have been drowned in the devastating floods in Pakistan; in other words, a number of the order of 100,000, 200,000 or 300,000 people.


My Lords, is the noble Lord saying that in his opinion 100,000, 200,000 or 300,000 people would lose their lives in such an event?


My Lords, I say that the risk is very real. The order of casualties cannot be predicted, but it may well amount to something like that were a thousand-year-storm to fall on London at any time within the next few years. Your Lordships may say that this risk is extremely improbable; that we have lived with it for many years, and we have never been so devastated—and of course that is true. But this is the risk against which the Dutch felt it worth their while to protect themselves. Of course, the Dutch understand these things better than we do. There is an old proverb: Though God made the earth, the Dutch made Holland"; and it is worth remarking, too, that the engineer who is in charge of the water defences of Holland is a Cabinet Minister. We have never expected devastation on this scale; we have never guarded against it; and we have always felt that the risk was one we may have to live with.

My Lords, this may seem to be simply scaremongering. On the other hand, what would happen if there were some time this next winter a flood on the scale of 1953? The answer is that a large area of London—evidently much smaller than the area to which I have referred, but a fairly substantial area of London—would be flooded; and there is considerable risk that the Tubes would be flooded as well. One could expect, in fact, that a flood of that order would do harm at least on the scale, let us say, of the disaster in Aberfan. These are the points to which I feel we must devote our attention.

May I now pause for a moment to consider some other implications of this Report—and may I say that it is, I think, the most sombre document I have ever read: a document prepared with great care under the auspices of the G.L.C., a document which has been studied at great length by its engineers and all the advisers they could find, and a document which in fact describes in the most lurid detail the risks to which our great Metropolis is exposed. I find it, in a way, the most extraordinary document I have ever seen. There can never have been a time in history when a great natural disaster has been so plotted out in detail beforehand and described with such loving and academic precision.

The final conclusion of this document is: It is not possible to assess the indirect costs to business and industry, which would be very great, but it is probable that in the event of catastrophic flooding in London the damage would be of the order of at least £1.000 million. It goes on to say that Professor Bondi has said that in his view the flooding of Central London should not be allowed to happen. This of itself is helpful, for Mr. Bondi, whom I know well, is a great cosmologist, and he has described to me with very great precision the reasons why the sky is dark at night. But my own reaction on reading this document was to remind myself of a phrase that was used some many years ago in another place, and I hope your Lordships will allow me to quote it without thinking that I am offending against the traditions of this House. It is this: The Angel of Death is abroad in the land, and we may almost hear the beating of his wings". My Lords, may I be allowed to describe how this extraordinary situation has arisen? The defences of London against flood have been the responsibility, successively, of the L.C.C. and the G.L.C. and the statutory bodies concerned are required at all times to insist that the appropriate level of defences should be assured all along the river entrusted to their care. They have the same statutory responsibility for doing this as, let us say, they have for condemning meat which is found to be faulty at an abattoir. This is an inalienable responsibility of theirs which they have been expected to discharge for many years; and when the time came to build up the great sewers, the covers of which form the Embankment that we know so well, the authorities chose a level for the risk of flooding which in those days—that is. almost exactly 100 years ago—seemed to be adequate.

But it has been discovered—and it has in fact been known for many years—that the whole of this part of England is sinking slowly into the sea at the rate of perhaps a foot, or rather more, every 100 years. It has also been discovered that, apart from the sinking of the land, the level of high tides is rising by about 18 inches every 100 years; and it has also been discovered by examination that many of the barriers to the sea, the banks of the river, are sinking under their own weight into the London clay at perhaps 6 inches every 100 years. So the consequence of this is that the effective barrier we have in front of this House at this minute is lower, in proportion to the risks that it has to run, than it should be by an amount which would be 3 feet were it not for the fact that after the great flood of 1928 the level was raised by about one foot. So that outside here the barrier confronting the Thames is in effect 2 feet lower than it was 100 years ago.

After the disaster of 1953 the Dutch clearly understood the importance of raising their dykes, as I have said, and they have done so by about 6 feet. On the other hand (and here I speak, I am afraid, without any complete knowledge of events; but this is what I infer from documents I have read), after 1953 the G.L.C. contemplated the idea of raising its sea defences but were dissuaded from doing so by the Government on the grounds that there was a proposal to build in due course a barrier which would make everything safe. For this reason the G.L.C. did not in fact raise the barriers alongside the river over a period of 17 years, from 1953 to the present moment.

Two weeks ago the Minister announced the site for the barrage or barrier, or whatever it is to be called, and this, I suppose, will be built in something of the order of about six, seven or eight years. Until then, my Lords, nothing whatever that we can do will in any way minimise the danger we have to run from the possible (as I may call it) thousand-year flood against which the Dutch have protected themselves. But it is my belief that much could be done to protect us from the risk of other, smaller floods which in fact are far more likely to occur. I have said to your Lordships that there is a probability of a quite significant flood every 10, 20 or 30 years. There was one in 1928; there was another in 1953 and two or three times since then there have been alarm of floods which did not eventuate.

I think perhaps the best way to summarise the situation is to say that one might perhaps try to insure against the catastrophe which seems possible. Of course, no one can conceive of a market which would possibly cover a risk of the order of thousands of millions of pounds and the ultimate total destruction of our great city. But since it is so improbable, were a market to be found to insure against it the cost would undoubtedly be of the order of £1 million, £2 million or £3 million a year—not much more than that. On the other hand, the cost of insuring against what I might call a middling-sized flood of the kind which could probably occur once every 20, 30 or 40 years and which might do perhaps £100 million worth of damage, would probably be at least £10 million or as much as £20 million or £30 million.

Taking the other extreme, there is the possibility, almost the certainty, of every year a minor flood somewhere which may do damage. The cost of insuring against this might be perhaps £1 million. In other words, the really expensive insurance would be against what I may call the middle-term catastrophe, the Aberfan-sized disaster, and this might demand a premium of the order of at least the cost of the barrier itself. I may be wrong by a factor of 2; but no man can be sure either of the cost of the barrier or of the cost of the insurance. But it is true to say that the cost of insuring against disaster is so great (or would be were the Greater London Council to embark on it) that to double the price of the barrier would be worth while if one could have it one or two years earlier.

So I believe that, when the decision is taken to build it, the most important single parameter in the building programme is the speed with which this monstrous but essential device can be constructed. The problem of designing it is, of course, still to be faced. There are many problems concerned with the effect it will have on the water below the barrier and on the possibility of silting above it. These are all being studied. I have no doubt that some kind of scheme can be got under way, and I hope very much that the programme will be finished before long.

But the point I want to make is that, according to the G.L.C.'s own figures, the risk of a major flood (or even a minor or serious flood) is of the order of 1 in 20 in, say, the Isle of Dogs and the risk of the Tubes in some degree being inundated is, say, 1 in 34 in any given year. And we may have to wait six, seven or eight years before we are safe. It is fair to say that a risk of the inundation of the Isle of Dogs in the time which remains to us is of the order perhaps of 1 in 2 or 1 in 3; and the risk of the inundation of the tubes system is of the order of 1 in 5 or something like that.

It is my belief that although we cannot protect ourselves against a major calamitous disaster, we can do much to protect ourselves in the meantime against smaller-scale flooding, and it is this that I should like to urge the Government to do. I should like to suggest that since the G.L.C. figures have shown that a raising of the banks by something of the order of 2 feet reduces the risk of flooding by a factor of nearly 10, this is significant. I would therefore urge on the Government that they should, where possible, insist that the banks be raised by as high as can be, because although no protection is certain because some of the sand banks may prove to be unstable, nevertheless they would significantly reduce the risk to which so many people are at present exposed.

I should like furthermore to suggest that we could do far more than we have done to alert the people who live in these dangerous areas to the risks they run. It has been suggested, for example, that someone might paint the lamp posts at a point equivalent to the height to which the water would probably rise, let us say once in 100 years, or once in 1,000 years. I ask noble Lords to remember, if they feel that this is going to produce unnecessary public alarm, that there was a time in the Second World War when the general public was totally ill-informed and unaware of the risks they ran from bombing. It was when the Home Office abandoned its attempt to make the Home Office gas-proof room, which your Lordships will remember, in the privacy of Whitehall, and took the public into its confidence, that some steps were taken towards protecting the populace against the risks it ran from the Germans. I believe, my Lords, that the risk now facing many people in London is at least as great, if not greater, than anything to which they were subjected from the forces of the enemy.

There is much that can be done, and I should like to make a series of quite specific proposals for the Government to consider. The first is that it is extremely important that a decision should be made forthwith on the question of finance. Who is to pay for the barrage and who is to pay for any increasing of the height of the banks, if it were decided that this must be done as a matter of urgency? I do not believe that the Minister's Statement in the Commons, made about a week ago, gave any hint at all about the financial implications of building a barrage. He merely announced the site and, so far as I can make out, left the world in very considerable doubt. Although, of course, the matter may be well known to the authorities concerned, I have not found evidence that a decision has been made. I should like to ask whether it is the Government's view that the G.L.C.'s own desire to raise the statutory limits of the banks should be accepted, and that the statutory limits should be raised as soon as possible.

Finally, my Lords, I would ask whether the Minister can decide if appropriate arrangements have been made to rehearse the various schemes in preparation for safeguarding people in case of emergency. Your Lordships doubtless know that there is a complicated system involving the use of sirens; that people in Tower Hamlets, for example, have been circulated with documents describing the dangers to which they are exposed, and that it has been explained to them that the risk, although small, is nevertheless real; and that if flooding is thought to be imminent, a siren will be sounded and they will be asked to leave their homes, or to go to higher ground, or whatever may be thought best for them to do. I have the impression that much could be done to improve the efficiency of these arrangements; and that furthermore, much could be done to improve the efficiency of the protection for the Underground railways.

I have the impression that much of the difficulty which has prevented effective action from being taken hitherto has been due to arguments between the G.L.C., the Ministry of Housing and Local Government and the Ministry of Agriculture, Fisheries and Food, as to who is responsible—


No, my Lords; that is not so.


My Lords, my noble friend Lord Kennet can explain it in more detail than I can, but that is the impression I have formed from reading the documents. Whatever the cause, I believe that the matter has now become urgent; that the general decline in safety of our great City—due to geological forces evidently totally beyond our control—has reached a point when action is essential, when the danger is great and when we can no longer pretend that if we forget it, it will be all right. The last time that the statutory level of the Embankment was raised was in 1930, nearly half a century ago. Since that time, as I have said, the effective height has risen by something like eighteen inches.

There are two other points that I should like to make, and they are both to be derived from this document which I hold in my hand and with which I am sure some noble Lords are familiar. This is, as I have described it, the G.L.C.s own account of the risks which they run. The first diagram shows that if another flood at the 1953 level occurred, it would overtop practically all the statutory defences by something of the order of one foot. This is in large part due to the fact that in 1953 London was saved because the banks at Canvey Island broke; the Island was flooded and so was some of the Essex marshes, and that saved London; it saved Kensington and may even have saved Westminster. These defences have been strengthened, so that relief is improbable in future.

The next diagram to which I must refer also is extremely important because it shows how it comes about that for every 2 feet more we raise the bank, the risk of a flood in any given year is diminished by a factor of 10. It shows furthermore—and this is terribly important—that by the year 2050, which is not so very long in terms of the time scale with which the G.L.C. has worked hitherto, the statutory flood level will be breached on an average every year. So that work done now to raise the banks will certainly not be wasted.

I have formed the impression—a layman's impression, I must admit—on reading these documents that the efficiency of the barrage is considerably in doubt. Although it is thought that it will usually work, there are considerable risks that there may be a sudden flood before the barrage can be closed—perhaps it may jam or a ship may get into it. So money spent on raising the banks above the barrage would not be wasted. This is the policy which the Dutch have followed for some time. They have raised the dykes and constructed an enormous series of barrages across the mouths of the Rhine and the Meuse.

I have spoken over long perhaps at this late hour, but in my view the problem is one of immense public concern. The risks are great. Our great metropolis is in peril. I believe that remedial action should be taken as a matter of urgency so as to reduce by a factor of perhaps 10 the risk to which the inhabitants of London are exposed. In my view, there is not a day or an hour to be lost.

9.22 p.m.


My Lords, at this time of night I shall not say very much. Indeed, after the complete exposition of this subject which the noble Lord, Lord Bowden has made, there is not a great deal more to be said. I must first express my apologies to the noble Lord, Lord Bowden, himself, to the noble Lord, Lord Kennet, who is to follow me and to my noble friend Lord Sandford, who is to reply for the Government, that I am so much already overdue for another engagement that I am afraid I shall not be able to hear the rest of the debate after I have said what I have to say. I shall read every word of it, I need hardly say, with extreme interest.

We must be grateful to the noble Lord, Lord Bowden, for bringing this matter to the attention of the House, for it is certainly one of extreme importance to the people of London and of Greater London. I have been familiar with Thames flood prevention from the time of the alarming surge in 1953 to which the noble Lord referred, when I was concerned as a member of both the London County Council and the Port of London Authority. On that occasion there was mercifully no loss of life and little damage, because although the surge that came from the North Sea, raising the level of the Thames by some eight feet, almost coincided with the top of a spring tide, there was at that time no great amount of water coming down from the upper reaches of the Thames. Had there been flood water coming down from the upper reaches, the water level in London, which lapped over the top of the river wall, might have been some five feet higher. If that had happened there would have been serious and extensive flooding, great damage and possibly loss of life, as there was in the disastrous flood of 1928 which was responsible for 14 deaths and, incidentally, for damage to a large proportion of the 20,000 or so water colours by Turner at that time housed in the basement of the Tate Gallery.

The flood defences were raised after the disaster of 1928 but, of course, the embanking of the river that is always going on up and down the Thames adds to its flow and to the height which the tide reaches. And the land level in South East England, as the noble Lord, Lord Bowden, said, is gradually sinking all the time, and in London this sinking is accentuated. These processes are slow. but they are enough in a half century to cancel out the raising of the river wall that was carried out after 1928. So although the probability of flooding is statistically no more than three times in a century, its incidence is all the time increasing. The risks are great and the matter is urgent.

After the flood of 1953 a committee was set up under the chairmanship of Lord Waverley to go into the whole question and to make recommendations. It consulted, among others, the Dutch engineers who have a great knowledge and experience of flood prevention, and it reported with commendable speed. It recommended two things. The first was the setting up of a system to give warning of the surges that come down into the North Sea, which are produced apparently by winds of hurricane force in the region of the Arotic Circle. It recommended, secondly, the construction of a tidal barrier that could be lowered to take the top off the tide when there was an exceptional surge and an expectation of flooding.

The Waverley Committee reported; the warning system was brought into being, and it exists. It cannot, in the nature of the case, be perfect, but it is, in my belief, well-conceived and about as good as a warning system of this kind can be. But for the last 16 years the barrier has been bandied to and fro between expert consultants; the question of who should pay for it has been argued between the Government and local government, and nothing has been done to provide the vital safeguard for London of a tidal barrier. We must all be grateful to my noble friend (I use the word in a personal and not in a political sense) Lord Greenwood of Rossendale, who, as I understand, before leaving office took the decision that a barrier of the drop-gate type should be created in Woolwich Reach. That is probably the wrong place: almost certainly it should be further down the river, in Long Reach. There it would, indeed, be more costly, and would take longer to build, but, on technical grounds, as was confirmed by the expert consultants, it would be better placed there and would also have the advantage of protecting the 60,000 inhabitants of the great development on which the Greater London Council are embarking at Thamesmead.

But we should be thankful that a decision has been made in this matter. A second best decision is better than no decision. Even so, it will, I understand, be at least two years before a start can be made on the building of the barrier, because of the purchase of land, the investigation of the soil conditions and all the rest of it that is necessary. I should like to join with the noble Lord, Lord Bowden, in urging the Government and the G.L.C. to press forward with it as a matter of the most vital urgency. I should like to ask whether the possibility of an inflated barrier on the river bed, as a short-term interim measure of protection, suggested, I think, by Professor Schofield, has been examined, and whether, if it is feasible, it cannot be put in there without the delays that are inevitable in the major project. The risk of a disaster may not be statistically very great at any one moment, but it might happen—I was going to say to-morrow, but if not to-morrow, by the time of the next new moon, the next full moon or the next spring tides. It might happen in six or twelve months' time. The protection of London is a matter of most vital urgency, and I hope that my noble friend Lord Sandford will be able to tell us, when he replies for the Government, that the barrier will now be at long last built, and built with all possible speed.

9.31 p.m.


My Lords, we are indeed a phlegmatic race. Yesterday, at an hour a little earlier than this, when we were discussing matters of great moment, but not of life and death, there were some 330 Peers present. There are now three noble Lords opposite and four or five on this side I do not know whether the Government intended it to be this way, and, if so, whether they think Parliament is unimportant, or London is unimportant—I am not sure how this goes. I did not expect to find so thin an attendance in the House—and the Government Benches in particular so thinly covered—on a matter of intense and tormenting; magnitude.

Almost all of what my noble friend Lord Bowden said I should like specifically to endorse out of an experience which I will mention to your Lordships in a moment. I must make three exemptions from that blank endorsement. He said that he believed that there might be 100,000, 200,000 or 300,000 dead in the event of a major flood in London. I do not believe that; I believe that the warning system we have is such as to ensure that if dead there were—and there might well be dead—it would be a small number. It would be possible to get people out, or to the tops of the tower blocks, in time. We are talking about catastrophic damage, and £1,000 million may well be right, with another £1,000 million derivative damage., with the Underground system out of action for a year and the cessation of the functions of London as the capital of the country. This is what we are talking about, not a very great loss of life.

I also know that the noble Lord is wrong in having said that delays, and the time it has taken to reach a decision, were due to disagreement between Departments about which should do what. This is not so. There have been no disagreements in this field, although they are common enough in less important ones. The gravity of this matter has been sufficient to avoid departmental squabbles. The time has been taken in research, which was necessary, and in composing honest differences—differences which were maddening, dangerous and, in some cases, irresponsible—about what should be done. There has been no buck-passing until now. I do not believe that when the barrier is built there will be any appreciable danger of a flood coming up so fast that there is no warning to enable the barrier to be brought into operation in time. That is not the way the warning system has been set up, and we need not worry about that. But that still leaves enough for us to worry about.

The barrier has been talked about since the mid-19th century. It was the 1953 flood which brought it to be a practical possibility. The Waverley Committee reported and said that there should be a barrier or barrage; then there were 14 or 15 years of muddle; technical reports were submitted; two firms of consultants who were brought in contradicted each other, and the Government did not know quite what to do. And by the time the last Labour Government came into office the subject was lying in pieces all over the floor. We therefore commissioned Professor Hermann Bondi (and I should like to join my tribute to that which has been paid by my noble friend to a very remarkable man) to report on the matter. He did so, and said that we had not looked widely enough at all the possibilities, and, above all, that we should stop worrying about the magnitude of a disaster; we should stop trying to put a price on it, and stop trying to calculate the exact number of people who would be homeless. The disaster would be so terrible that it must not happen: action must be taken by the Government, and that action should be the building of a barrier in a place which should be determined according to wider views and criteria than any that had yet been used. As a result, in 1967 or 1968 the Government took two steps. They commissioned the G.L.C. to carry out a detailed study on the right site and type of barrier that should be built. Then my noble friend Lord Greenwood of Rossendale set up a Policy Committee on this whole matter, as Chairman of which he was rash enough and confiding enough to place me. It was, of course, by far the greatest and most alarming responsibility I have ever faced in my life, or that I think I ever shall face in my life, to bring the correct policy out of this matter over the two-year period. This Policy Committee represented all the public bodies concerned. We kept finding more public bodies which were not represented on it and should have been. It became very large and it was a difficult but an absolutely necessary, life-and-death task to drive it forward to its conclusion.

The G.L.C. reported in the document my noble friend referred to. This Report came out in January of this year, and in May of this year my noble friend Lord Greenwood of Rossendale was able to announce that he had that day asked the Greater London Council to proceed with the studies necessary to enable them to recommend a precise site for a drop-gate barrage. He asked them to choose the precise site and he named the type. Those are the two great questions: where and what. That went forward, and we came to the Written Answer by the present Secretary of State for the Environment, Mr. Peter Walker, on November 4 of this year, in which he said that he agreed with the view of the Greater London Council that the right site is at Silvertown in Woolwich Reach."—[OFFICIAL REPORT, Commons, 4/11/70; col. 352.] Good! The site is chosen. In my view it is the right site, and in the view of the overwhelming majority who have studied this matter for so long it is the right site.

I wish one could confine oneself to cheering. But in the next paragraph Mr. Walker said: Detailed design work will begin as soon as a decision can be taken on the type of barrier."—[col. 352.] A decision had been taken by the last Government on the type; it was to be a drop-gate. Unfortunately, the present Government have gone back on this decision and so the question is open again. They have taken one step forward in choosing the site, and one step backward in unchoosing the type.

I come now to the Adjournment Debate in the other place on November 9, when Mr. Eldon Griffiths, speaking for the Department of the Environment, said one or two things which I hope the House will bear with me if I take up, because it was not possible for anybody to take them up in the other place at that time. He said: … it would have been so easy to postpone a decision as our predecessors did."—[OFFICIAL REPORT, Commons, 9/11/70; col. 169.] My Lords, I must utterly reject that: his predecessors postponed no decision. They went forward a great deal faster than had ever been done before towards a decision, and I hope that the noble Lord who is to reply to this Question will accept from me that it is right for me not to allow those words to stand uncorrected on the Record of either House.

Mr. Griffiths also went to to say: All I can say in answer to his question is that the type of barrier constructed, depending on what is chosen, will certainly not exclude the possibility of tide control in the future"— which was one of the matters looked into— but for the time being I think this is a matter for consultation with the G.L.C. and the Port of London Authority."—[col. 169.] We are right back, still consulting between two public bodies. I thought we had reached a decision on that. His last words were: Further investigation will be required in respect of a site. More discussions are needed in respect of the money. Full consultations will be required at all stages, but nevertheless the decision has been made and the action can now begin."—[col. 171.] Well, it has been made on the site, and that is good. It is in my view a great pity that it has been unmade on the type.

All sorts of ideas are floating around. There is the idea of a great nylon bag downstream which can be hoisted up to keep the water out. There is the idea of the so-called rising gate, where air is allowed into a great drum at the bottom of the river and it comes up and holds itself there by flotation. There is the idea of bank-raising upstream of the frontal side of the barrier to give interim protection, or even indeed to give us belt and braces once the barrier is built. It would not be right for me to urge the Government either to do, or not to do, any of these alternatives by supplementary means; but this I will urge them not to do. I beg them—and I think that everybody who knows the facts could only beg them—not to allow investigation of these possibilities, not to allow any further research, not to allow any further discussion, to delay the building of the barrier at the site chosen. And I would add, not to allow these discussions and researches and possibilities to delay the building of a barrier of a type that we know will work, namely, the drop-gate, and not to risk fiddling around with untried technologies of a sort which exist nowhere in the world and which may or may not work. If they did not work one would then have to start on the long, slow task of building the known type of certain protective barrier, namely, a drop-gate.

9.41 p.m.


My Lords, I am sure that the whole House, or such Members of it as are here, will be grateful to the noble Lord, Lord Bowden, for his initiative in raising this important matter. I think the whole House would want to acknowledge the responsible and valuable part that the noble Lord, Lord Kennet, has played in bringing this matter to the point at which it now stands.

Perhaps I ought to start by spelling out more precisely than has been done so far the dangers to be apprehended and to be met by these measures. They arise from a combination of high tides, strong gales in the North Sea, a spate in the Thames and this rather mysterious Rossiter factor which the noble Lord, Lord Cottesloe, enlarged upon, which has the effect of raising the high tides in relation to the land by about two and a half feet a century. It is the combination of these four factors with which we have: to contend. Facing those, and in the light of the disasters that occurred in 1928 and 1953, it has been agreed, as the noble Lord, Lord Kennet, said, that the building of a movable barrier was urgently necessary and that it should be built at Silvertown. That was a decision taken by our predecessors and announced by the Secretary of State for the Environment in another place on November 4.

The G.L.C. have been asked to press ahead with the detailed site investigation and also with the completion of the remaining studies which, as the noble Lord, Lord Kennet, said, include confirming the choice of the barrier to be used. The detailed design work will begin as soon as that decision has been taken. The G.L.C. are therefore now proceeding to carry out the work necessary to enable them to decide on the precise site and on the particular type of barrier to be used.


Will the noble Lord give way for a moment? He is not, of course, disputing the fact that Mr. Greenwood's announcement in another place in fact chose a type of barrier, namely the drop-gate, and therefore this is a step backwards?


I am not disputing that for a moment, my Lords. I am just setting out precisely what the position now is. When the design has been chosen, the barrier will take about two years to design and about five or six years to construct. Therefore, if a decision on the precise type of barrier were to be reached early in 1971, and if authorisation to build the barrier followed immediately upon completion of the design it would be completed in the late 1970s.

The choice about which the noble Lord, Lord Kennet, spoke is between a drop-gate (or a guillotine) type of barrier with a single opening 450 feet wide, and a rising sector type of gate (with submerged gates between the piers of the river) with several openings, each 200 feet wide. The issue is a navigational one and hinges upon whether the navigational interests will be content with 200 feet openings. The rising sector gate will be cheaper by £9 million and will take about a year less to complete, but the navigational interests may feel compelled to insist on 450 feet in the interests of the safety of shipping. This is among the many issues which the G.L.C. are at present investigating.

In considering the whole question of a barrier siting and the difficulties of London in the downstream area, it is important to bear in mind that it would be necessary not only to construct a barrier but also to carry out a complete survey of the riparian banks and walls downstream and to raise them where necessary. A major effect of damming a flood tide by means of a barrier will be, of course, to raise the high tide level downstream, and this will have to be contained. This work will be programmed and carried out in conjunction with the construction of the barrier, by the G.L.C. and the Essex and Kent river authorities as flood protection authorities for their respective areas.

I turn to the question of cost, on which the noble Lord, Lord Bowden, asked me a particular question. The cost of the barrier and the related works will be borne by the Greater London Council with financial assistance from Exchequer funds. The rate of grant will be calculated in accordance with the method normally used for flood protection works carried out under the Land Drainage Act, which takes account of the burden placed by any project upon a local authority's financial resources. The Government recognise that works of improvement may also be necessary on riparian defences, banks and walls, downstream of the barrier site in the areas of the Kent and Essex river authorities, and to the extent that such works can be regarded as associated with measures to protect London, the Government are prepared to pay grant. Broadly, the terms will be those applicable to flood protection schemes undertaken by river authorities under the Land Drainage Acts. Details of these grant offers are about to be discussed with the river authorities concerned. I hope that that is a satisfactory answer to Lord Bowden's question of who pays.

The noble Lord also asked me about warnings. Since 1953, when the tidal floods caused widespread damage and loss of life along the eastern seaboard, the Ministry of Agriculture, Fisheries and Food have administered a flood warning system for the whole of the East coast including the Thames estuary. This system, known as the Storm Tide Warning Service, is operated by the Hydro-grapher of the Navy on behalf of the Ministry. Officers of the service stationed at the Meteorological Office in Bracknell are equipped with repeater tide gauges which continually reproduce the analogue record from gauges at Stornoway, Wick, Aberdeen, Tynemouth, Immingham, Lowestoft, Walton-on-Naze and Southend. The information is transmitted to Bracknell by direct private telephone lines. Warning information is sent by the Bracknell unit jointly to the river authorities, who are the local bodies directly responsible for the sea defences, and the police in their areas. But because not all river authorities are on the telex network, messages go directly from Bracknell to county police headquarters, and the police pass them to river authorities by the quickest means, usually telephone.

From this stage the river authorities monitor the situation locally by means of their own gauges, and the police, acting on their advice, give warnings to the public. The 12-hour warning, the alert, is a warning that meteorological conditions are such that tidal flooding could occur. To distinguish between marginal and more dangerous situations, the four hour warning is in two classes. "Alert confirmed" means that the tide is expected to be within plus or minus six inches of danger level, and "Danger", the second class of the four hour alert, is when the next tide is expected to be a certain number of feet above prediction.

Now I come to the London flood warning system superimposed over that. In 1968, a special flood warning system for London was devised and introduced by the Minister of Agriculture, Fisheries and Food. This is in effect a more elaborate local system grafted on to the system I have just described. The nerve centre is the Ministry's flood room, which is manned jointly by their engineers and engineers of the Greater London Council. The flood room is equipped with a continuous tide gauge repeater for Southend, backed up by repeaters for Tilbury and Tower Pier. It is also connected by direct telephone lines to the hydro-graphers at Bracknell, the Metropolitan Police, the control room of London Transport and the B.B.C. The primary function of the flood room is to warn the general public in the flood vulnerable area. This is done by sounding 80 or so strategically selected air raid sirens, 30 seconds on and 15 seconds off alternately for two minutes about one hour before flooding is likely to occur. The later a warning is given, the more accurate will be the forecast on which it is based. It is important not to alert the public unnecessarily, and one hour is regarded as sufficient time for the necessary action to be taken by them.

The public have already been advised through regular Press, radio and television publicity what to do when the flood warning sirens sound; an important instruction is to listen to B.B.C. Radio 1 for announcements on the situation given by the flood room over its direct telephone line to the B.B.C. Certain organisations require a longer period in which to make preparations—for instance, the Underground; and local authorities who need to safeguard elderly or handicapped people living in basements. Arrangements have been made to give them earlier warnings according to the period of notice they require. These early warnings are given through the Metropolitan Police communications network on the advice of the flood room.

Each riverside London borough council has prepared its own plan to meet local circumstances in a flood emergency. In general, these plans provide for key personnel to be alerted on receipt of a warning four hours in advance of likely flooding. If the risk continues, a three-hour warning is issued on which operational teams and equipment are mustered. The one-hour public warning is the signal to evacuate elderly and handicapped people to prearranged places of safety and to move people from extremely low lying areas.

So much for the warning. Now for the practical preparations. Emergency accommodation in public halls, schools and so on, with supplies of blankets and feeding arrangements, have been made by the borough welfare organisations. The Underground has a scheme—the noble Lord asked me if the scheme had been tested, and the answer is that this one has—which can evacuate everyone within one hour.

He asked me particularly about the statutory defence levels. The concept of statutory defence levels is, for all practical purposes, somewhat obsolescent now. After the floods of 1928, in which lives were lost, the L.C.C., pursuant to their powers under the Thames Flooding Acts, prescribed various levels for the riparian defences in their area. In some places frontagers were required to raise defences to comply with these levels, while elsewhere the L.C.C. themselves raised the defences. But after the emergency of 1953 it became quite clear that these levels were no longer adequate. However, fresh levels have not been prescribed since: if there is to be a flood barrier at Silver-town, the whole nature of the defensive system will be altered and conditioned by it. The G.L.C. are therefore at present carrying out a separate investigation into the possibilities of providing different interim protection.

There is, of course, a strong case for providing such interim protection, either generally, by means of the temporary raising of existing walls, or selectively for areas or installations particularly at risk—for example, Underground access points. The provision of such protection is attended with considerable difficulty—for example, the extent of the work that may be necessary to ensure the stability of higher walls; the detriment to amenity likely to be caused by raising the height of embankments in central London, and the complications involved in access to a great deal of private land in different ownerships. There is also the question of how much cost it would be reasonable to incur to give protection for a few years when we are simultaneously incurring a total cost of over £80 million on permanent defences operative in the late 1970s. But all the views expressed to-night—


My Lords, before the noble Lord leaves that point, he says that there is a strong case for increasing the height of walls. After what has been said, I should have thought that to be something of a understatement. Can the noble Lord not say when a start is to be made on increasing the height of these defences?


NO. I said that there was a strong case for providing different interim protections from the simple one of raising the statutory defence level; and this is a matter which the G.L.C. are investigating.


My Lords, my question now is when is this work going to start.


My Lords, as soon as the G.L.C. have reported on the precise nature of these different interim protections and their report has been considered and accepted.


My Lords, has the noble Lord set, or is he going to set, some sort of time limit for these considerations?


My Lords, as the noble Lord will know—and in fact his noble friend explained—the G.L.C. were asked in 1968 to start studying this problem. The first phase of their considerations, as I understand it, was directed to coming to decisions about the flood barrier, which they have done. That major decision having been taken, there is now the subsidiary question to which the Question of the noble Lord, Lord Bowden, was primarily directed, to establish whether or not the interim protection consists of just raising the statutory defence level, or whether the whole question needs to be looked at afresh and a different form of interim protection provided.


My Lords, I am sorry to interrupt, but what I was trying to get at is this: I believe that something could be done by starting work somewhere to-morrow morning. We have been told of delays and delays, discussions and discussions, and arguments and differences of opinion between firms of consultants, and heaven knows what! The fact is that all this time London has been sinking, the Dutch have been improving their very much more complicated defences, yet we have done nothing. My plea is that something can be done, starting almost to-morrow morning. I do not mind where, and I do not think it matters very much. It may even turn out that the work which is first done is totally useless. Nevertheless, something could be done quickly, I am quite sure. What I am so anxious about is this interminable delay while a final definitive solution is produced—a solution which may come too late to save London from catastrophe.


My Lords, we have had, and we are very grateful for it, a clear recommendation about the Thames Barrier, and the general site for this has been selected. That is a firm, constructive decision. In the light of that—and only in the light of that—it is now possible to go on to the further question of the interim protection. It is quite impossible to do things until it is clear, from the recommendations of the G.L.C., what they consider to be the priorities. What is now becoming quite apparent is that it will not be sensible just to raise the statutory defence levels.

I am almost at the end, and I hope that by the Answer I have given I have made it clear that, following the main basic decision to defend London from flood by means of a barrier in the Thames, Her Majesty's Government, and the G.L.C. in particular, are now pressing forward to the next stage of implementing that decision. The site at Silvertown having been chosen, the design of the barrier has to be considered. The noble Lord, Lord Kennet, believes it is quite straightforward to take that decision, and I hope it will not be long before a decision—if not the one that our predecessors arrived at, at any rate another decision—will be taken. The design of the barrier has to be settled; and, meanwhile, the floodwarning system, which I have described at some length because I think it is important, is being kept up to date and is in full working order. The G.L.C. are investigating what further interim and different defence protection is best in all the circumstances until the barrier is completed. We expect their report, after which action can be taken very shortly.


My Lords, when is this report now expected?


My Lords, very shortly.