JOINT COMMITTEE ON THE ENVIRONMENT, HERITAGE AND LOCAL GOVERNMENT díospóireacht -
Tuesday, 16 Feb 2010

Management of Severe Weather Events: Discussion.

Chairman

We move now to No. 3 on our agenda, a discussion on the management of severe weather events in Ireland. As part of our proposed report into the management of severe weather events in Ireland, we have invited a delegation from Met Éireann to discuss weather patterns and how an increased awareness of such might assist in our response to such events in the future. We have also invited an engineering surveyor to discuss the flooding in Cork.

I welcome the delegation from the Met Éireann: Mr. Liam Campbell, director; Mr. Gerald Fleming, head of the general forecasting division; Mr. Liam Keegan, head of climatology and observations division; and Mr. Ray McGrath, head of research and applications division. They are all very welcome. Before they begin, I draw their attention to the fact that members of this committee have absolute legal privilege, but the same does not apply to witnesses appearing before the committee. Members are reminded of the long-standing tradition that they should not comment on, criticise or make charges against a person outside of the Houses, or an official, by name or in such a way as to make him or her identifiable. We will begin with a presentation from our guests and this will be followed by a question and answer session.

Mr. Liam Campbell

I thank the Chairman and the members of the committee for the invitation to appear before the committee to consider some of the implications of the severe weather that affected the country in the past few months. Mr. Liam Keegan, who has studied the weather patterns over that period, will now make our opening presentation.

Mr. Liam Keegan

We have circulated two documents, one on the rainfall of November 2009 and the other on the cold spell of January 2010. I will give a brief overview and make some comments on these, as there is significant detail in the documents. The documents provide more information than I can provide in my brief summary.

I will begin with the rainfall of November 2009 and will deal with it in both a broad and specific context. The information I have provided in the documents is a draft of a report which was in preparation and which will, eventually, be published by Met Éireann, although perhaps in a slightly different format. The figures are sound, but I may just rephrase some of the facts. I ask members to please bear this in mind if they see a different version in the future. I also ask members to bear in mind that I will be speaking about rainfall. Sometimes in the media there is confusion when people talk about return periods and how rare events are, whether talking about a flooding event, a river flow event or a rainfall event. I would like to make it very clear that I will deal specifically with rainfall events.

To set the scene, let us look back about three years. It will not be news to anybody present that we have suffered three very wet years and particularly wet summers. To take 2009 itself, we had just come through a very wet summer. At Valentia Observatory near Cahirciveen, County Kerry, which is one of our top quality, long-standing stations with over 150 years of records, the summer rainfall record was not just broken but shattered, with close to 600 mm of rain in the summer compared with approximately 400 mm in the previous wettest summer. That is the broad context of the lead-up to the weather of November 2009.

Following that, there was a brief dry spell but coming into the middle of October it became wet again and that wet spell lasted into November 2009. The only word that can describe the rainfall of November in Ireland is "extraordinary", both in terms of the amount of rainfall and of the spatial extent — the area of the country — that was covered by very heavy or extreme rainfall events. It is often the case that these are of short duration and only cover a small area, perhaps a few square kilometres. However, for November 2009, we are talking about a rainfall event which lasted over most of the month and which had extensive geographic coverage, as I will show on the maps I have provided, particularly in the western part of the country, an area broadly delineated by the River Shannon, which was badly affected. This rainfall was extraordinary in many respects. While I will not read the document in detail, I would like to quote one figure, namely, that 79% of our rainfall stations recorded their highest ever November rainfall in 2009. This begins to give a flavour of the issue — records were being set and the effect was widespread.

Page 6 of the document contains two maps which give the broad picture of the November rainfall, with the one on the left giving the amount of rainfall in millimetres, ranging from 300 mm to 600 mm, which are large amounts of rainfall. The map gives an idea of where the heaviest rain fell. It is not unusual in a map that presents rainfall amounts that one can pick out the higher mountains — it is a fact of life that there is heavier rainfall high up in the mountains — and this is the case with this map, where such mountain areas can be identified in Kerry, Wicklow, west Galway, Mayo and Donegal.

The map on the right is a slightly more informative map, which gives the percentage of normal rainfall for November 2009. It shows many areas which received 250% more than normal and some nearly reached 400% more. Again, I would use the word "extraordinary" to describe it; this is an awful lot of rainfall, no matter how it is assessed.

To put rainfall of this nature in context, we often use the term "return period" and, as it is often misunderstood, I will take a moment to explain the term. It is a useful concept in expressing how rare or unusual an event is. If I say the rainfall return period for a particular event is, say, 100 years, I mean there is a probability of one in 100 of that happening in any given year. It does not mean that if it happened last year, one has 99 years in the clear; it is simply a probability. If the rainfall return period is 200 years, there is a probability in any given year of one in 200 of that happening.

The more important context begins on page 8 of the document, which deals with the duration of the rainfall from one to 25 days, spread over the entire country. Each grid square on each map contains information on the probability or return period, which tells us how rare or unusual the events are. The one-day duration is not particularly spectacular but, as we move to two-day duration, we begin to see the colours coming out and the more extreme events begin to happen. A map location on the Wexford border gives a good indication that even within a very large-scale event, there are still small-scale variations. The event in Wexford is for real, although it is quite localised. I simply point out it is not a mistake in the map — it is for real.

The next page deals with the four-day and eight-day durations. One begins to see widespread areas of the map shaded in colour, particularly in the west and broadly along the Shannon. This tells us that in some areas which experienced eight-day durations the event is rare beyond one in 100 years or even beyond one in 200 years. The next page deals with 16-day and 25-day durations. Talking on a broad scale, covering the whole country, the 25-day duration is where the event is peaking and where the worst picture is drawn. One can see swathes of the country affected by the 25-day duration.

One of the extraordinary points about the November rainfall was how much of the map of the country is covered by colours which represent a return period of 500 years plus — we do not go beyond 500 years to, say, a 739-year return period because accuracy is not possible. These are very rare, unusual and extreme events, covering a very large swathe of the country. Having seen the news reports, nobody will be surprised to see where the colours are located on the map and where the 500-year plus return periods occurred.

One event seemed to carry particular significance, namely, the event in Cork on 18-19 November, which has been mentioned at today's meeting. We have tried to shed some light on that event. Moving into a brief discussion of the Cork situation, members should keep in mind the context in which this is happening. It is not just two days; it is two days on top of all the other events which have already happened and all the rainfall that has already fallen. However, to take the two days in isolation, we have taken the opportunity to provide two charts, one giving the amount of rainfall in the millimetre amounts we believe fell in the various areas over those two days. We have tried to pin this down to the wettest 24-hour period. We have done the same exercise with the return periods to try to express how rare or extreme an event this was.

Members will see that the rain in the area was certainly heavy — we are not just talking about Cork city but about the catchment of the River Lee to the west and up into the mountains, which is the important area. However, taken in the context of what had been happening overall, particularly in November 2009, one could not say it was extraordinary — we are talking about return periods measured in decades, perhaps several decades and up to 50 years, but not hundreds of years in this case. Therefore, the way the events in the Cork area on 18-19 November must be understood is as a very wet couple of days by any standards, but against the background of the extraordinary amounts of rainfall which had been happening overall. The document shows there are some areas in the same catchment area in the mountains in the west of Cork, heading towards the Kerry border where, again, the return periods are measured in hundreds of years, although these are not as widespread or large scale as those further north. So, the story of 18-19 November is that while there was heavy rainfall, it is set against a backdrop of what had already happened leading up to that point.

At the back of this document, which I am not going to read out, members of the committee will find a table containing a selection of information for various specific point rainfall stations where we have actual measurements that we can contribute. They are grouped by county and show how much the maximum rainfall was over one, two, four, five, 16 and 25 days, along with the return period. That return period is a probability. Members should think of one over that number as being the probability of having that much rain over that number of days in any given year.

That is all I have to say in my initial introduction about the rainfall of November 2009. More information is contained in the document I referred to. If anybody has any questions I will be happy to try to answer them. Will I move on to the next item, Chairman?

Chairman

Yes, please complete the other one.

Mr. Liam Keegan

The second item on my agenda is what we will describe as the cold spell of January 2010. It is really the cold spell of December 2009, a couple of days when it was not quite freezing, and then moving into another cold spell in 2010. It is therefore, more or less, the same cold spell. I will try to do the same exercise of saying how bad it was and putting it in some sort of historical context to see how rare it was. I can go through this quite briefly.

December 2009 had been very cold, there is no question about that. We have given some figures here, including temperatures falling to -10o centigrade degrees some nights, along with snow falling in some areas. Then there was a brief interlude of only a couple of days. The cold spell continued into January 2010 and intensified with night-time temperatures again going below -10o. A temperature of -12.7o was recorded at Casement Aerodrome in Dublin, which set a new record. We also had some snow. This pair of cold spells is not particularly characterised by large amounts of snowfall; it is really that it was very cold and stayed thus for a considerable time so that whatever snow did fall was inclined to stay there. If some rain fell, that froze on top of it. We are not talking about an event that would stand out in terms of depths of snow; we have had higher depths of snow in the past. What is peculiar or extreme about this event is how cold it got in terms of temperatures and how long it lasted. I have given a weather diary, as I describe it, to flesh out a bit of detail on the day-to-day variations.

I will now try to put it in a historical context. Unlike rainfall where we can measure it, add it up and say there were so many hundred millimetres, deciding on how bad is a cold spell is somewhat arbitrary. Is it how low the temperature was, how long the cold spell lasted, or how much snow there was? It is a bit like trying to say how good a summer was — different people will react to more or less rain, or sunshine. Therefore one cannot really put a single figure on it, but we have done our best to try. We would characterise it as being the most severe cold spell since 1963. The last page of that document contains a graphical representation of the important cold spells that have occurred in our instrumental records. Starting at the bottom with 1946-47, it moves on to 1962-63, 1978-79, 1981-82 and our latest cold spell of 2009-10, which has just finished. The graphic contains day-by-day mean temperatures. The straight line, which the eye picks up running through — it is not quite straight because it goes up and down a bit as the months change — represents the average. The pink or red bits represent days with average temperatures above normal for the time of year. There are not too many of them in any of these episodes. Moving below the line we have what I would call light blue, which represents days where the temperature was below average. The sharper blue represents days when the average temperature was below freezing, that is, below zero degrees. An average temperature comprises the highest and lowest temperatures of the day added up and divided by two. Therefore to get an average temperature below zero in Ireland would be regarded as a very cold day. That is not a normal event and does not happen all that often.

These dark blue patches are severely cold days. One can judge that by seeing that the one at the top, which is the current one, goes down quite a lot into the dark blue. That tells us that on at least some days the minimum temperatures got well down, as I said, to -12o in Casement Aerodrome.

One will also see some of those in the 1981-82 cold spell. As one's eye moves down one will probably notice that in the 1979, 1963 and 1947 spells they are much longer. To characterise the recent cold spell, it was sharp, and certainly was a very cold spell. It belongs in this company. It is one of those four or five severe cold spells we have had down through this period of time. Whether it is a bit better or worse than 1982 is open to whether one prefers low temperatures and less snow, or whatever.

To put it in context, however, unlike the rainfall of November 2009, which I have been describing in terms of return periods measured in hundreds of years, these are episodes which have been happening over a timescale of two or three decades. That puts this particular cold spell in context. I hope that has been reasonably informative.

Chairman

I thank Mr. Keegan for the information he has provided so far. Before I call on other members of the committee, I wish to put some brief questions. Page 10 of the document refers to a return period of 25 days, which is the longest one. When did Met Éireann last have a chart, prior to this one, where some of them were almost up to 500-year events in terms of the return period? Is November normally the wettest month, or is the worst ahead of us in January and February? Can Mr. Keegan provide a chart showing the annual rainfall going back over a period? Has the annual rainfall in Ireland over the past three years been much higher than in previous decades? Has there been an accumulation of three wet years, which led to the ground being so saturated and which in turn led to the flooding? I know flooding is not Mr. Keegan's area, but rainfall is the biggest factor in causing it. He may not have the data to hand, but perhaps he can provide the committee later with figures for annual rainfall in a chart showing areas of heaviest precipitation going back over a period. We all believe we have had three wet years, but such a chart would prove it. I ask Mr. Keegan to provide some such statistical information as the committee wishes to produce a report.

Mr. Liam Keegan

I will do my best. The first question, as I recall it, was when I would last have seen a map like this. The answer is "Never" for two reasons, one of which is slightly pedantic. First, our ability to produce this sort of information has been quite newly developed. Twenty years ago we simply could not have produced this. Anecdotally, to put it in context, as to when I last saw numbers like 500 plus, members of the committee may recall the Newcastlewest flooding of 2008 for example. It was a different characteristic. It was a very short period of five hours rainfall I think. It was over a much more confined area, but the sort of rarity estimate was about the same: 500 plus years of a return period. We have certainly seen 500-year return periods happening before. It is not a contradiction to have a 500-year return period event happening from time to time; once it happens in different places it is still all right. The most interesting thing about this particular chart is the widespread nature of how many places were affected simultaneously. I do not know if that answers the Chairman's question

Chairman

Yes, it does.

Mr. Liam Keegan

It is the best I can do. I am glad the Chairman asked me about the wettest month, which I should know off the top of my head. I am pretty sure it is not November. I believe it is January or February; it is winter anyway. Although there is a tendency not so much for the long-term rainfall but for shorter-term bursts of rainfall to be more likely in the summer, including summer thunderstorms and that sort of thing.

It is certainly the case that the past three years have been very wet. I said that in my introduction. That is not going back too far. The past three years certainly have been quite wet.

Chairman

I ask Mr. Keegan to send us some statistical information to help us draft a report that is properly based.

Mr. Liam Keegan

We can certainly do that.

Deputy Phil Hogan

I thank the delegation from Met Éireann. They will get blamed for the rainfall and someone else will get blamed for the flooding. That is just the way it works.

The conclusion of the Met Éireann document on rainfall asks the rhetorical question which I do not believe was answered. It was whether the events of November 2009 and the heavy rainfall were related to climate change. The conclusion did not come down on one side or the other in stating that the fact rainfall displays such a high degree of variability, both temporally and spatially, makes it difficult to be definitive. We would like Met Éireann to be more definitive than that. Most of us wonder whether this trend is continuing. If Met Éireann does not know, how are mere mortals like us supposed to know?

When the rain fell in November to the extent it did, it was described by various people as a one in 100-year event. Am I right in saying that Met Éireann would not subscribe to that view? I ask for analysis of how many rainfall events have matched or exceeded the rainfall of 19 November in the past 100 years in places like Cork city? We need to establish whether it was a one in 100-year event. Were there specific issues relating to rainfall or did something else cause the city of Cork to be flooded? Are there other precedents for that level of rainfall? Does the delegation have a view on whether the major event in Cork city perhaps should not have happened? We have often had more rainfall previously and nothing like that happened.

Mr. Liam Campbell

I shall take the first question as to whether it is related to climate change. I ask Mr. Ray McGrath, who is head of research, to deal with that.

Mr. Ray McGrath

I appreciate that the Deputy would like a "Yes" or "No" answer, but unfortunately it is not possible. Rainfall tends to be a very noisy and chaotic element in it. There is a very small sample of data — three years of data. It is suggestive that the climate has shifted into a wetter spell. We would need a much fuller statistical analysis of the data before we would be able to come up with some kind of statement on it. Even then the Deputy would be unlikely to get a "Yes" or "No" answer. He would get something that might indicate a 75% probability of something.

Deputy Phil Hogan

Are there any examples of historical patterns of weather that would indicate the splurge of rainfall in the past three years might have happened 40 or 50 years ago to allow us to determine whether we should or should not get too excited about it?

Mr. Ray McGrath

We could compare it with the cold spell. We are reasonably happy that the cold spell was a statistical blip. It is the kind of event that would happen every few decades. The rainfall, particularly the November rainfall, as my colleague has pointed out, was exceptional. In the context of the past three years, during which we have also had some notable flooding events, taken together it is suggestive that the climate has got wetter. As I said it is easy to get a bunch of data, shove it into an Excel spreadsheet and get a trend suggesting a 25% wetter climate or whatever. However, it does not stand up to rigorous statistical analysis. As I said we are looking at the data in great detail. We are also running a climate model focusing on the period from 2010 to 2020 to see if we can get a better handle on climate change. The climate models in the past have suggested that winters are likely to become wetter and summers drier. That type of information tends to be rather course grained. One is looking at information that is averaged over a period of decades. We would like to sharpen that up a bit. At this point we have an extremely good climate model running in Met Éireann. We would hope that in 2010 or 2011 we will be able to come up with perhaps sharper estimates of how climate change may have impacted on the local climate.

Deputy Phil Hogan

I thank Mr. McGrath.

Mr. Liam Keegan

I shall address the second question. Again I shall need to come back to the Deputy with some numbers. If I have understood correctly he asked us to take past figures for the Cork area which might be comparable with what happened this year and give some summary of that. Obviously I cannot do that off the top of my head. It should not be difficult to do; we should be able to come back with that information quite quickly.

Deputy Phil Hogan

I am sure that Mr. Keegan would be aware that this has been spoken about in the community in Cork. I would have thought he might have had an opinion on it before he came in here today.

Mr. Liam Keegan

Yes, and this is how we chose to express the opinion. I might go into some more detail as to why we are presenting it in this fashion. We are certainly not attempting to avoid any other figures where the figures are available. There are two ways one can express the rarity of, for example, a rainfall event. One can look at the numbers from 40, 50 or 60 years of previous measurements and say that this is bigger than all of them, bigger than two thirds of them or whatever, and be happy with that. However, with reasonably extreme events one may not have that luxury and may not have any figures from the past which are quite as big or very few figures in the past that are quite as big as the numbers one has got. In that area we try to do a statistical analysis from extreme value theory. That takes the 50 years — or whatever is available — and attempts to glean from that more information as to the likelihood for figures which have not yet been recorded. This is the nature of the information we have presented here, which I thought would have been a more usable figure. However, we can certainly provide the others.

Deputy Phil Hogan

Figure 4(b) shows the return period estimates for two-day rainfall for 18 and 19 November. The Cork area on the map does not indicate any big deal suggesting this was an extraordinary level of rainfall that had not happened before.

Mr. Liam Keegan

I refer the Deputy to figure 5(b) on page 11, which zooms in on the south west. We have tried to pick out the highest 24-hour rainfall for Cork. Looking at this figure, the Deputy might make the same comment. During my presentation I tried to suggest that while it was certainly heavy rain, one is not using words such as "extraordinary" to describe this. I suggested that it should be seen in the context of how much rain had already fallen in the time leading up to that. The event of the 18 and 19 November of itself does not stand out as being an extraordinarily rare event. Yes, it is certainly heavy rain.

Deputy Phil Hogan

It would probably need a committee to suggest it was the management of the rainfall. That is a separate issue. I would not ask Mr. Keegan to comment on that.

Deputy Christy O’Sullivan

I thank the delegation from Met Éireann for the presentations, which were very enlightening for somebody who does not know very much about the weather. Weather is always a very interesting topic, particularly for Irish people because every time we meet we seem to talk about it. How good have we become at predicting weather into the future? It is very important to get on top of that and get better at it. The key is being able to predict what weather is coming down the line. I am not sure whether that is possible. Perhaps one of the delegates could comment on that later.

I come from the area of Skibereen, Clonakilty and Bandon which was badly affected by the rainfall of 18 and 19 November. The delegation has suggested that what happened on 18 and 19 November was not that extraordinary. I take it from what was said earlier that what happened in the previous months leading to ground saturation etc. was the key factor in causing the flooding to a certain extent.

Mr. Liam Keegan

I shall answer the second question first and ask Mr. Gerald Fleming to comment on the forecasting. Lest we get carried away, the events of 18 and 19 November were not extraordinary in the context of the month of November that we are discussing. I again refer to figure 5(a) on page 11, which still indicates large amounts of rainfall, but just not as extreme as what we have been discussing in other areas. I completely agree with the Deputy's suggestion. That must be taken in context. I would not quite say the three very wet years is particularly relevant, but the summer which had just passed was, particularly in the south west where as I pointed out our station in Valentia observatory in Cahirciveen had shattered the previous record for rainfall. So there was a very large amount of rainfall in the preceding summer leading in to that time which would have completely saturated the ground. The weather of late October and November would have added to that. What happened on 18 and 19 November sat on top of that. I would agree that it needs to be viewed in that context.

Deputy Christy O’Sullivan

While it is not possible to be fully accurate, are there indicators to allow Met Éireann to predict long before flooding might come or the periods when we get most rain? Are there indicators it can be looking out for to put it on alert?

Mr. Liam Keegan

That is coming back to forecasting. I shall pass to my colleagues on the right on that one.

Mr. Liam Campbell

I will ask our head of forecasting to deal with that question.

Mr. Gerald Fleming

I shall try to put forecasting in context, and describe how we do it, where the technology is and where it is going. Scientific forecasting is based on first trying to find a very accurate picture or idea of what the atmosphere is doing at this instant in time and then using our knowledge of the physics of what happens in the atmosphere and between the atmosphere and the oceans and so on to represent that mathematically in equations and using those to apply mathematics, if one likes, to our current state to move forward in time to forward states of the atmosphere. This technique was pioneered in the 1950s or thereabouts. It is dependent on having good computer power because it is very hungry for computer power. It is a technique that has brought weather forecasting from in the middle of the 20th century predicting a day or two in advance to the present, when we can look six or seven days ahead. By and large the further ahead we look the less confidence we have. However, we can certainly have some idea.

It is a very scientifically complex enterprise and one which we as a country and certainly we as a meteorological service could not attempt to accomplish alone. So we join other European countries to have a combined research and operational effort in this area. There exists an organisation called the European Centre for Medium-Range Forecasts. Ireland has been a member since the start in the mid 1970s. Some 31 countries are members. At a centre in Reading in England the best brains from Europe in this area and the biggest computers are assembled together. Forecast guidance is developed, produced and disseminated, and each national meteorological service can draw on that in helping to formulate forecasts.

Using those sorts of scientific techniques we have now been able to get to a stage where forecasts up to five, six or seven days ahead are reasonable. We would hope to be quite accurate for two to three days ahead. The further ahead we go the less certain we are. With some particular weather situations we can look beyond that to nine or ten days ahead. That is one thrust of weather forecasting.

The other thrust is to try to get more localised information. This is about running different sorts of computer models. One of these we run in Met Éireann. It is a computer model that focuses on Ireland itself. It runs at quite a local level and tries to pick out the detail of rainfall, temperature and wind variations, which can vary considerably over short distances in space. We have both of these approaches. We have the short-range model looking at the detail of Ireland over the next two days and the longer-range model looking out six, seven or ten days ahead. That is what we call a global model because it needs to do calculations around the entire globe more or less simultaneously. Those techniques have brought us to where we are in weather forecasting.

Looking beyond that, if one likes, the Holy Grail of weather forecasting is trying to get beyond weekly forecasting to monthly and seasonal forecasts. Indeed in some parts of the world that has been attempted and achieved because there is a very strong correlation between the weather in that part of the world and what is happening in the oceans. We are not so fortunate — the Atlantic does not behave in quite as predictive a way as parts of the Pacific Ocean would. At this stage we cannot look beyond approximately seven, eight or nine days ahead. We do not have the ability to look forward into months or seasons ahead. Beyond that again one gets into climate change which is decades and centuries ahead which is another type of technology entirely. I am not sure if that answers the Deputy's question, but that is where we are at the moment.

Deputy Christy O’Sullivan

The answer certainly helps. A prediction with any degree of reliability five or six days ahead is a fair warning and is very helpful. Had Met Éireann given warnings about the recent floods?

Mr. Gerald Fleming

We had been giving warnings, in particular from the beginning of that week in November. As my colleague has pointed out, the whole of November was a very wet month anyway. We have various graduated levels of warnings. There are some individual concerns that get warnings from us at particular thresholds. If they know that 30 mm of rain will be a problem for them, we warn them of that. We have what we call public-service warnings which are set at a somewhat higher threshold and we were issuing them from Tuesday, 17 November. Normally for heavy rain we give warnings only up to approximately two days in advance. We can usually forecast in a general sense that the heavy rain is coming, but to give details of whether it will hit Galway, Clare or particular parts of the south or south west we need to be within a couple of days of the event. We normally issue weather warnings only out to a 48-hour period. However, having said that, for example, we issued a weather warning on Friday, 20 November that covered right through the weekend. People, particularly local authority staff and engineers who might want to make plans to deal with emergencies, need to be alerted three or four days in advance if we are covering a weekend or holiday period. We were issuing weather warnings throughout the week in question. We issued warnings on 17 November, 18 November, with specific warnings on 18 November to a number of different clients and we issued a warning on 20 November, which I believe was the last of the warnings in that series because the rainfall intensities decreased following that.

Deputy Ciarán Lynch

I thank the delegation from Met Éireann. It was interesting to see Mr. Gerard Fleming sitting in a chair rather than having a blue screen behind him giving us the weather.

Deputy Hogan referred to variables and locations. Page 3 shows the mid-Cork and western-Cork region with considerable areas of purple. They indicate areas with from 324 mm to 649 mm of rain. How accurate are the areas indicated? Is there a localised measurement? There is a 100% increase from the bottom to the top of that range. Can that be localised to a more specific sum in those areas?

Mr. Liam Keegan

Yes, certainly. I wish to explain what we have here. First the points refer to specific stations whereas the later maps try to cover entire areas. These are specific point locations where actual measurements of rainfall are taken.

Deputy Ciarán Lynch

It would not, therefore, be in the range, 324-649 mm of water, and that can be localised——

Mr. Liam Keegan

——to get an actual figure for each of these points. This is simply an attempt to show the geographic dispersion by dividing the total into four categories.

Deputy Ciarán Lynch

Could the committee be provided with the information for that region, if that is possible?

Mr. Liam Keegan

It could, absolutely.

Deputy Ciarán Lynch

The last big effluvial flood in Cork was on 6 August 1986. Can the committee be provided with Met. Éireann figures for that period as well with regard to rainfall for, perhaps, the ten days leading up to 6 August 1986? It would be interesting to see what the rainfall figures were for that period as against what they are at present. Significantly, at the time of the effluvial flood in Cork in 1986 there was no property damage. There was less of a release from the Iniscarra dam. I believe the release level was 300 cu. m. per second in August 1986 as opposed to 535 cu. m. on 19 November 2009.

On 16 November, Met Éireann issued a warning which indicated the wet weather would be ongoing, there was strong flooding potential and it said there were would be intermittent rainfall at different levels in that period. Most important it said there would be at least 50 millimetres of rain, but that the western third of the country could be more badly affected. Would the events that took place between 16-20 November more or less have borne out those predictions, or did Met Éireann fail to predict the weather during that period?

Mr. Gerald Fleming

We are quite happy that the predictions were reasonable in the context of what happened. When we give rainfall amounts within warnings, we intend them to be not peak rainfall amounts, but an average over a given area. If one looks at the warning, for example, that we issued on the morning of Wednesday, 18 November, we gave rainfall totals of 20-40 mm in many areas, with 50-60 mm likely in parts of the south-west and west, and some severe flooding likely. That 50-60 mm we would have interpreted as typical rainfall over that particular part of the country. We would not have intended to catch the peaks, as such, because as my colleague has explained, these often occur on the high mountains and are just specific to those areas of high altitude.

Deputy Ciarán Lynch

The Met Éireann summation is that its forecast for that area was more or less predicted.

Mr. Gerald Fleming

We are happy that our forecast was correct.

Deputy Ciarán Lynch

In periods when there is unpredictable weather or inordinately high rainfall, does Met Éireann notify the ESB, say, and the local authorities concerned before it gives the weather outlook to the general public on the 9 o'clock news bulletin?

Mr. Gerald Fleming

We have an established public service severe weather warning system in place. There are various thresholds for that rainfall, above a certain amount, temperatures higher than this, winds higher than that and so on. Those are issued to all the local authorities we believe might be affected. It could be all the local authorities, or a particular section of the country, the south west, the south or whatever. We contact various bodies such as the ESB, the AA, the Department of Defence and so on. There is a range of people to whom we send such warnings routinely. In fact, when I was surveying the warnings book, in which we record all this data, I found that this whole period was just one long litany of warnings. Apart from the heavy rains, there were strong winds and thunderstorms as well.

Deputy Ciarán Lynch

During that period, did Met Éireann issue any specific warnings to the ESB management for the Carrigadrohid and Iniscarra dams? Did it issue any specific warnings for Cork City and County Councils and were these warnings of an unusual nature?

Mr. Gerald Fleming

The warning which I just quoted as being issued on 18 November, would have been relayed to Cork County Council, giving 20-40 mm, with 50-60 mm likely in parts of the south west and west, which one assumes would include Cork. However, there was a specific warning issued to Kerry, Cork and the ESB which filled out that data somewhat, and referred to 40-60 mm of further flooding being possible, with some winds forecast as well, because we had expected strong winds for that afternoon, evening and the following day. Cork, Kerry and the ESB received a warning at 10 o'clock on Wednesday, 18 November for those rainfall levels.

Deputy Ciarán Lynch

Could Met Éireann provide the committee with that information, because it would be quite valuable for its report?

Chairman

What is the format for these warnings — is it e-mail?

Mr. Gerald Fleming

There is a variety of formats, depending on the recipients. Normally, the forecast is sent either as an e-mail or a fax and of course, these warnings also appear on our website, so that anybody can get them. At the moment each client, in the broad sense, may decide how it wants to receive the warnings. By and large, it is e-mail or fax, although sometimes we use the telephone.

Deputy Ciarán Lynch

Specifically, as regards the warning given to the council on 18 November, was that in the morning or evening?

Mr. Gerald Fleming

It was 10 a.m.

Deputy Ciarán Lynch

I understand that funding has been given to Met Éireann for these emergency warning systems. Perhaps Mr. Fleming might just explain what type of funding has been given and what the protocols are in that regard. Does Met Éireann telephone somebody specifically and give him or her a risk assessment or is it within the competency of the given organisation to assess the risk based on the information given?

Mr. Gerald Fleming

We do not get specific funding for this type of warning service. It is part of our public service remit. We only get funding for one particular aspect of weather warnings, namely, the icecast system which has been developed in conjunction with the National Roads Authority to provide road ice forecasts to local authority engineers throughout the winter months. That is a specific project in which we engage every year for which we receive a certain amount of funding.

These warnings would be covered within our normal public service remit.

Deputy Ciarán Lynch

The fact that flood risk will be ongoing is not something that occurs every 50 or 100 years. We have been told that much work has been done by the Department of the Environment, Heritage and Local Government as well as the OPW in recent years as regards emergency planning and specifically in regard to flood risk management and other aspects. Is Met Éireann tied in to that emergency structure, given that the water will fall out of the sky and it will be the agency to know about this first?

Mr. Liam Campbell

I should like to comment on that. There was an inquiry in 2002-03 which was set up by the then Minister of State, Tom Parlon, involving a flood policy review group, to examine all the arrangements for the management of flood events here in Ireland. That report was accepted by the Government and it envisaged a significant role for Met Éireann in flood forecasting methods. An interdepartmental co-ordinating was then established to bring the recommendations forward. I understand that at the moment the OPW is considering various options as regards how flood forecasts might best be done in Ireland. We are awaiting its conclusions as to how best it might be carried forward. Met Éireann will be happy to play its role in that regard, whatever is decided.

Deputy Ciarán Lynch

At present there are no structural mechanisms in place in this regard. There might be a code of practice or protocols that have been developed in practice over the years, but there is no regulation or formal protocol in place in any documentation as regards Met Éireann's engagement with the OPW in respect of flood risk management.

Mr. Liam Campbell

I do not believe there is any formal system. However, as well as effluvial flooding in the river catchment areas, which we are discussing now, there have also been problems with flooding in coastal areas caused by tide surges. We are working with the OPW to establish an operational system to handle that.

Deputy Ciarán Lynch

I wish to refer to the question of the probability of rainfall, and factors etc. Perhaps at the end of this the committee might be given a probability rating as to what actually happened in Cork between 16-20 November. The ESB's report is to the effect that it was discharging 535 cu. m. of water per second. It was being bandied about that this was a once in 800 years phenomenon, but the ESB's report indicated that the probability of such a discharge was once in every 150 years. What I am trying to grasp is that even it would maintain this would happen at most once every 150 years. Yet the probability rating the delegation gives of the amount of rain that fell in the Cork region is significantly less.

The reason there was so much water behind the Inniscarra dam and that there was a requirement to release this water is not a question for the delegation to answer this evening. However, the ESB probability rating of such a situation arising was at most once every 150 years while the delegation's probability rating of the weather that occurred during that period is a good deal less. Where does the delegation place the probability rating of the weather that took place during that time by comparison with previous years? Was it average compared to the weather for November in 2008, 2007 and 2006?

Mr. Liam Keegan

It is a complex question. As I pointed out at the outset, there is a significant difference between what took place down the river, the various mechanisms in place there and the rainfall which fell. They do not represent the same thing. Let us consider the matter of probability. I refer to two of the diagrams in the document before me. The diagram on page 11 depicts the Cork area 24 hour rainfall. This represents our assessment. The numbers that appear on the page are typically in the region of 30, 40 or 50, depending on which area one considers in the upper catchment. This is the probability we place on the one-day, 24 hour rainfall. I am not a hydrologist and I do not wish to get into that area but what comes down the river is not only what fell on the day in question, but what was backed up some distance and for some days leading up to then.

In this context I refer the committee to figure 4(e) on page 10 of the document. It is somewhat small and I have to squint through my glasses to see it but if one examines a similar area in west Cork, headed towards the Kerry border, it is possible to suggest that in what one might term a sub-set of that catchment area, not the entire catchment area by any means, one approaches a probability of one every several hundred years or a probability of one in several hundred of such an event happening in any given year. Our answer on this matter is very clear. For one-day rainfall, we have a clear picture in the grid map of what we believe the probabilities in question amounted to.

However, one must consider this in the context of the overall period in which this one day of rainfall was embedded. For that overall period, for some parts of west Cork, headed towards the Kerry border, there are areas where the probability reaches once every several hundred years or a probability of one in several hundred. For example, the probability is one in 500 in one particular location on the map. These are the rainfall probabilities or likelihoods.

Deputy Ciarán Lynch

I will attempt to summarise what Mr. Keegan has stated. In the western region of Cork there were probability factors that were in excess of one every 150 years but they were very localised. Is that correct?

Mr. Liam Keegan

Yes, they covered a relatively small area and the do not represent a one-day situation. They occurred during a 16 or 25 day duration where this took place.

Deputy Ciarán Lynch

I refer to flood risk assessment. I am familiar with that part of the country. There is high mountain land in that area and as a result there would be streams flowing off mountains into tributaries which, in turn, feed the main rivers. Flood risk assessment would be determined by where those tributaries flow. There are two dams in Cork, namely, the Inniscara and Carrigadrohid dams. The way in which they flow will determine water tables in those areas. The delegation maintains the 150 year factor was a rather localised phenomenon and does not reflect the broader basis of the western Cork region. That is my interpretation from examining the location of the red and blue spots on the map.

Mr. Liam Keegan

It may be open to question to use the term "very localised", but the committee is familiar with the area to which I refer. One could measure it and decide whether it is localised, regional or whatever, but it is clearly delineated.

Deputy Johnny Brady

I welcome the members of the delegation from Met Éireann. They are probably like the politicians in that when anything goes wrong they are blamed no matter what takes place. I can understand their predicament when there is severe rain, snow or frost. The delegation's graph refers to the period from 1947 to 2010. Since the period from 1979 to 1982 there appears to have been 20 years of a severe frost. I realise it was severe in 1982 but the snow and the drift that occurred was more serious and we are all aware of the consequences. It was not that it snowed excessively but that it came with a severe wind and there were severe drifts. I spoke with some very elderly people, some of whom are in their 80s and who happened to be out in a field of potatoes destroyed by frost at the end of January. An elderly man suggested he had not seen the likes of it since 1947, which is probably true.

I will not advert to rainfall for too long. We had very heavy rainfall throughout the county. Those of us in County Meath were lucky because we did not suffer to the same extent as those in Cork, Galway, Ennis and parts of Kildare. The severe frost did a great amount of damage. I will put a simple question to the delegation but I am sure they will not answer in kind. I have been listening to people discuss the matter in recent years. There were very mild winters as everyone is aware and very bad summers. People took the view that the reason for the bad summers was because of the mild winters. Is there a possibility we will have a very good summer this year, following the very severe winter and frost? Recently, I read an article in a newspaper in which a man from New Zealand predicted we would have a very hot summer. Can the delegation predict that or forecast it now?

Senator Jerry Buttimer

Let us get to the bookies first.

Mr. Gerald Fleming

One thing we also share with politicians is an inability to always bring good news when people want it. Unfortunately, there is no scientific correlation between severe winters and fine summers. It is quite possible we will get a good summer but we have no scientific basis on which to forecast it at present.

Deputy Deirdre Clune

I will be brief because a good deal of information has been extracted already.

Chairman

In fairness to Deputy Johnny Brady, he tried to extract some good news.

Deputy Deirdre Clune

I wish to put one point to Mr. Keegan. I have learned a lot in the past hour about weather forecasting. I refer to the diagrams on page 11, in particular diagram 5(b). Mr. Keegan described that as a return period that was not extraordinary. Could the same be said for the figures for the whole month of November 2009? I believe there was a very high level of rainfall but Mr. Keegan maintains it was not extraordinary.

Mr. Liam Keegan

At the outset I stated that the month of November 2009 was extraordinary. That is the word I chose to use to describe the various aspects. The month as a whole was extraordinary in terms of the amount of rainfall. Of that there is no question. This was the case even if one did not have spectacular return periods. There was still a great deal of rain. Approximately, 80% of our stations set new records in November and they have a reasonable history of records. As a whole, the month was extraordinary.

Deputy Deirdre Clune

What is the position in terms of the return period?

Mr. Liam Keegan

That is only for one day. The Deputy is referring to diagram 5(b), which is only for one day.

Deputy Deirdre Clune

Is that information available for month of November?

Mr. Liam Keegan

The 25-day diagram is an attempt to chose the worst 25 days. It almost amounts to one month. I suspect the monthly total would not look dramatically different from the pattern the Deputy can see on page 10 and the 25-day figure.

Deputy Deirdre Clune

I am keen to see the rainfall events for the past 100 years. Did a similar event take place in the Cork area previously? The delegation stated it would supply such figures to the committee.

Mr. Liam Keegan

On a note of caution, we do not have figures dating back 100 years, but whatever we have can be supplied. If I understand correctly, the Deputy wished to find out the figures we recorded this year and whether such levels occurred before or when something comparable took place previously. Is that correct? That can be supplied.

Deputy Deirdre Clune

That would help with the whole picture.

Senator Jerry Buttimer

I will be very brief. I thank Met Éireann for appearing before the committee and making the presentation. I compliment Mr. Fleming on his excellent interview on "Morning Ireland" during the period in question. It was very methodical and informative. He provided a very good service for the people. Although we and he get blamed, he did a very good interview on the day.

I have three questions, the first of which is on public service notifications and warnings. Could the warnings in Cork have been flagged more and could they have been taken more seriously by the relevant agencies? Did the agencies act appropriately?

Are we to assume that rainfall alone accounted for the flooding, particularly in Cork city? Does Mr. Fleming believe there was another factor that exacerbated the flooding in Cork? He has the documentation on the rainfall. Perhaps we could argue rain was not the sole cause of the flooding.

Given the remarks made at this meeting, is it not true that there are a number of agencies involved in forecasting, promulgating, etc., but that there is no anchor body and no co-ordination? Given the complexity of the issue and the different agencies that are either abdicating or accepting responsibility, should guidelines on management not be put on a statutory footing?

Mr. Fleming referred to forecasts two days before the event, six to seven days before the event and nine days before the event. Deputy Lynch referred to the imparting of information. UCC got a phone call early on the Thursday in question but no communication thereafter. The call was from the ESB. Did Met Éireann communicate with it directly? Mr. Fleming commented that Met Éireann picked up the phone. To whom in a local authority does Met Éireann impart information?

I appreciate one cannot be fully accurate scientifically. However, given that we have the ability to forecast potential rainfall and bad weather patterns, should the local authorities, and in Cork the ESB, not be more prepared with regard to the management of water?

Chairman

Mr. Fleming may not be able to answer all those questions.

Mr. Gerald Fleming

Much of it is beyond my competence. Each local authority nominates a number of persons to be contacted in the case of a severe weather warning. At the commencement of each winter season, we normally contact all the authorities and get them to update their lists. Generally, the lists include the senior engineer or a number of engineers, perhaps a couple of local engineers. The lists with which we are provided typically refer to three to five persons in each local authority who are to be contacted in the case of a severe weather warning. We contact them when we believe such a warning is justified.

The local authorities come within the public service statutory area, along with the Department of Defence and a number of agencies to which we have a statutory remit to provide a service. The ESB is in a slightly different area because it is almost a commercial client. It contacts us and asks us to provide it with warnings. It can set the thresholds for those warnings. If rainfall of 20 mm represents trouble to it, it asks us to warn it every time such rainfall is expected to occur. The same applies to 40 mm. We let the ESB set the threshold because it knows best what rainfall will cause it difficulties. We have similar contracts with purely commercial organisations, and the warnings pertain to wind or other phenomena. In north Dublin, where there is a lot of market gardening, wind can be a problem for glasshouses. We give warnings in that regard.

We have no say over what happens to the information once we pass it on. When we pass on a warning, sometimes the local authority nominee phones us to discuss it specifically. He or she may be concerned about a particular issue. That often happens with coastal flooding that involves a combination of wind, rain and low pressure. A number of different elements might combine to create a difficulty and the local authority staff might ring us to clarify aspects of the warning. We stick to the view that our role is just to give out weather information and that it is the role of the local authorities, with their local knowledge, to decide how best to use it. They have other considerations to take into account when applying the information. These might involve the closure of a particular road or the evacuation of a number of houses. The local authorities have information about which we know nothing and they must take it into account when applying a warning.

Senator Jerry Buttimer

Are those warnings coded? Are there red, green and amber warnings?

Mr. Gerald Fleming

That is an interesting question since we are actually on the way towards producing a coded series of warnings. We have two levels of warning at present, a weather warning and a severe weather warning. A pan-European approach is now being taken to warnings. We are part of a consortium behind the website www.meteoalarm.eu. It employs a four-level system using the colours green, yellow, orange and red. Green is normal so there is therefore a three-level classification system for severe weather. We are currently implementing this system but it will be a little while before we have it together in Ireland. If one looks at the front page of www.met.ie, one will see a link to www.meteoalarm.eu.

Deputy Ciarán Lynch

To expand upon that point, there are identifiable problem weather systems that may cause localised difficulties. A localised problem affecting Cork city, for instance, would involve a south-easterly storm with a high spring tide and heavy rainfall. This would lead to flooding in the eastern side of the city. If we get this weather forecast in Cork city, we know we have a problem. This has been the case for hundreds of years. Does Met Éireann have a map of Ireland that would suggest a particular formula coming into play would require its making contact with the authorities in Dundalk, Cork or Galway? Can a particular formula be identified?

Mr. Gerald Fleming

We do not have a database in that context. Various local authorities have made arrangements for us to alert them when certain combinations of conditions come into play. For example, if there is a wind above force 6 on the Irish Sea and low pressure, the local authority in Drogheda must be warned because it can cause flooding in the town. We depend on the local authorities to establish, in conversation with us, the weather criteria about which we can warn them.

Deputy Ciarán Lynch

Met Éireann notifies the local authorities when the established patterns are coming into play. The analysis and risk assessment are the responsibility of the local authority, not that of Met Éireann.

Mr. Gerald Fleming

Absolutely.

Deputy Ciarán Lynch

If there were a force 8, 9 or 10 wind blowing from the south east in Cork, a high tide and a given number of millimetres of rain, would protocol require Met Éireann to ring Cork City Council this afternoon?

Mr. Gerald Fleming

Yes.

Deputy Ciarán Lynch

On 19 or 20 November, was there any protocol that required Met Éireann to ring Cork City Council or Cork County Council to state there was a specific problem? The councils would have carried out the risk assessment and the analysis. What problem was identified on 18 or 19 November?

Mr. Gerald Fleming

We issued warnings.

Deputy Ciarán Lynch

Were they specific?

Mr. Gerald Fleming

There was a specific warning issued on 18 November to Cork and Kerry local authorities and the ESB for rainfall in the south west. It specified that rainfall of 40 mm to 60 mm was possible, in addition to further flooding and southerly winds gusting at 80 km/h to 110 km/h. This was issued at 10 a.m. on Wednesday, 18 November, for "this evening, tonight and tomorrow". It covered the latter half of 18 November and also 19 November.

Deputy Ciarán Lynch

Would the councils and ESB carry out a risk assessment based on that?

Mr. Gerald Fleming

They would use the information to do whatever they saw fit.

Deputy Ciarán Lynch

Will Mr. Fleming provide the committee with the information it gave the councils?

Mr. Gerald Fleming

Yes.

Deputy Phil Hogan

When does Met Éireann notify the ESB in advance of a problem in the Cork area? Are five or six days' notice given? When would Met Éireann have notified the ESB that it should have a reduced amount of water in its dams to allow for the rainfall forecast?

Mr. Gerald Fleming

We issue a forecast to the ESB every day. It is issued four and a half days in advance of the day to which it pertains.

Deputy Phil Hogan

Can Mr. Fleming supply the committee with what Met Éireann told the ESB on 12 or 13 November?

Mr. Gerald Fleming

We can supply the committee with what we told it on 12 and 13 November. In terms of 18 and 19 November, the earliest indication would have been in a forecast issued on approximately 14 or 15 November. Certainly, I can supply all that information if necessary.

Chairman

We have had a useful discussion. We will conclude this section of our meeting. I thank the delegation for their presentation. We found it informative. For us, it is a new area, which we had not any particular knowledge of or insight into. The delegation has definitely helped the committee in its work considering what happened overall in November last. The clerk to the committee will make direct contact with the delegation on the questions which involved supplying information to the committee and he can confirm what other information the committee requires.

As a vote has been called in the Dáil, the committee will suspend until the vote has concluded.

Sitting suspended at 5 p.m. and resumed at 5.25 p.m.

Chairman

We will resume in public session. We are still dealing with No. 3 on our agenda, the proposed joint committee report on the management of severe weather events in Ireland. This basically deals with the flooding events of last November. There is a second presentation today from Mr. Paudie Barry. He is very welcome to the meeting.

Before I invite him to address the members, I draw his attention to the fact that members of this committee have absolute legal privilege but the same legal privilege does not apply to any witnesses appearing before the committee. Members are reminded of the long-standing practice to the effect that members should not comment on, criticise or make charges against a person outside the House or an official by name or in such a way as to make him or her identifiable. I remind members that the ESB representatives will appear before the committee this time next week to discuss the two dams in Cork.

I invite Mr. Barry to proceed.

Mr. Paudie Barry

I found a 1986 flood report for the Lee valley. There are some very interesting similarities and disparities between the 1986 flood event and the November 2009 event. The next slide in the presentation looks at the rainfall. I will not delay for long on the rainfall as we have had about an hour and a half of discussion on it. I will focus on the rain for 1986 and for 2009 and show the members the figures we have. The average measured rainfall in August 1986 was 92 mm in the upper catchment. Cork Airport on 5 August 1986 measured 60.9 mm in that one day. On 19 November 2009, the ESB claims that 90 mm of rain fell in the Lee valley catchment and Cork Airport measured 51.2 mm of rain. It was mentioned in the earlier session that the ground was quite heavily saturated leading up to the November 2009 event. The August 1986 ESB flood report states that there was heavy rain a couple of days before the August event and in the months leading up to August the weather was broken and cold. This is the only information I have so far on August 1986. We have two sets of data — rainfall for August 1986 and rainfall for November 2009. Do members think it is similar?

The next slide looks at the discharge rates for August 1986. The maximum discharge at Inniscarra was 331 cu. m. per second. Compare it with November 2009, when the maximum discharge was 535 cu. m. per second. That is quite a difference in discharge. We read in the August 1986 report that the total discharge reached its maximum of 331 cu. m. per second and that this discharge has been exceeded on two occasions previously, in early December 1964 and December 1978. Discharge of 331 cu. m. per second is so rare from Inniscarra that it has only occurred three times up to 2009. In 2009 there was a discharge of 535 cu. m. per second.

I will compare the damage downstream from Inniscarra from the August 1986 flooding and the November 2009 flooding. An extract from the 1986 report states the main damage caused was to crops and market gardens, which refers to an area downstream of Inniscarra, and some houses were flooded but no structural damage was caused. The report also states many of the houses flooded had previously experienced flooding during heavy winter floods. In November 2009, the picture paints a million words. I have experience of all the flooding which occurred in 2009 because I surveyed many buildings, including UCC, factories and houses. The anecdotal evidence I heard when carrying out my engineering survey was that many of the people affected were flooded for the first time. Many people had lived in their houses for 60 years and had never experienced flooding, and suddenly had two feet of water in their living room. That was the experience of the damage caused by the 2009 downstream flooding.

In 1986, the ESB was very proud of how it handled the weather and the water through the dams. The report states it did a very good job. In 1986 there were unsung heroes but the report gives them praise. It states the regulation of the flood through Carrigadrohid and Inniscarra reservoirs prevented flooding of a more serious nature down stream to Cork city. It set out the distances from the foot of the dam along the centre line of the river in kilometres and cross-referenced this distance, otherwise known as a chainage, with a level. It levelled the maximum flood levels in August 1986 and charted them in the table contained in the presentation. The middle set of readings outlines the maximum flood level at a particular location of the river, that is, 2.7 m from the foot of the dam, 4 km and 5 km from it, and so on, to 13.1 km, which coincides with the position of the weir at the waterworks. The critical point is that when it set out this table, it set out a set of levels which it had calculated or predicted which the river level would reach if there were no dams. It made the assumption that there were no dams and calculated what the resulting river levels would have been with no dams. It shows an average difference in height of 700 mm or 800 mm between the two sets of readings.

The next three sets of slides describe the table. The first refers to August 1986. The river flood level is in blue. We are dealing with 92 mm of rain in the upper catchment. Cork Airport read 60.9 mm in 1986 and the flood was rated as a once in 250 years event. In other words, it had a return period of 250 years. If we examine the graph, it shows a reverse L-shape, which represents the dam wall. Behind the dam, to the left one can see the height of the reservoir. To the right of the dam a sign shows water spilling out. One can see the river level which has resulted from the control of the water in 1986. It is generally underneath the floor level of buildings, with 92 mm in the upper catchment and 60.9 mm in the lower catchment. The result was many buildings were not flooded.

If we examine the flood level prediction for August 1986, which assumes there are no dams for the same level of rainfall, one can see the resulting line is red and refers to results in buildings being flooded if there were no dams. On the right hand side, it states this shows at the waterworks weir, the water level would have been 0.7 m higher if there were no dams on the river. The red line refers to the ESB's calculation of the situation if there were no dams, with 92 mm of rain in the upper catchment and 60.9 mm in the lower catchment.

I carried out an accurate survey of the river using Robotic Total Station and RTK GPS. We built a lot of checks into our survey which is the most accurate survey of the flood levels currently available. The base line survey of 2009 flood level is represented in black. The survey will show the levels, on average, were higher than those which the ESB predicted in 1986, had there been no dams, with 92 mm of rain in the upper catchment and 60.9 mm in the lower catchment.

I will move onto the summary and recommendations. If we examine those from 1986, there were very good engineers and operators. I have a lot of admiration for what they did at the time. They stated the return period of the rainfall, which is 250 years. Their first recommendation, which is very important, was for legal and engineering reasons it was essential to monitor as accurately as possible large flood events on reservoir catchments, which is an extremely important point. I conducted such monitoring with my employee, off my own bat, on 21 and 22 of November until December and January. We have surveyed, as accurately as we could, the high water marks which resulted from the 2009 flood.

The next recommendation from 1986 states it is necessary to take advantage of large floods to build river rating curves by gauging high water levels. It is the same as the first recommendation. It is very important to take advantage of the situation. If there is a flood, one should run out and survey it as fast as one can, and record the information so one can have an historic record of such events. One can then do whatever one wants with such information. Another recommendation from the 1986 report which I have singled out is that a person should be assigned locally to ensure all automatic flow recorders and rain gauges are in good working order during the flood.

In 2010, these are my recommendations. If the storm in November 2009 is a 150 year or 250 year event, we need to know about it now so we can start working on it. I have said we carried out the most accurate survey of high water levels which is available. We also surveyed the melt water flood in January 2010, which produced some interesting results, on which we may do another presentation. As managing director of Baseline Surveys, with 20 years' experience in the industry, I propose to carry out an independent investigation to establish the root cause of the flooding, which can be completed, cost effectively, within six weeks. I thank the joint committee.

Chairman

I thank Mr. Barry for the presentation. Those of us who visited Cork previously also received a presentation from Mr. Barry, which was slightly different but on the same topic.

Deputy Phil Hogan

I am sorry I was not in Cork city to hear the previous presentation, but I am familiar with Mr. Barry's views on these matters. For the benefit of the committee, may I ask what is Mr. Barry's qualification?

Mr. Paudie Barry

I have an ordinary degree in civil engineering from the Cork Institute of Technology. I have spent 21 years working as an engineering surveyor. I am a professional member of the Institute of Surveyors, and of the Chartered Institute of Civil Engineering Surveyors.

Deputy Phil Hogan

Where does Mr. Barry live?

Mr. Paudie Barry

I live right at the edge of the river in the Lee Valley.

Deputy Phil Hogan

So Mr. Barry would be familiar with what was happening, on an hourly basis, on 18-19 November 2009?

Mr. Paudie Barry

Completely familiar with it, up to 4 or 5 o'clock in the morning. I watched the river rise from 4 p.m. to 4 a.m. I got a few hours' sleep and came down the next morning at 7 a.m. and saw that it had dissipated somewhat. Yes, I experienced the whole thing.

Deputy Phil Hogan

Mr. Barry is living in the Lee Valley?

Mr. Paudie Barry

Yes.

Deputy Phil Hogan

Was he warned about the possibility of the flooding?

Mr. Paudie Barry

Not officially. I got a warning from a friend who heard it on the radio. That was the telephone call I got.

Deputy Phil Hogan

Was that the same for most or all residents?

Mr. Paudie Barry

Some residents did get phone calls. I certainly did not.

Deputy Phil Hogan

What does Mr. Barry think happened with the management of the rainfall at Carrigadrohid and Inniscarra?

Mr. Paudie Barry

That is a loaded question with me here in the hot-spot.

Chairman

We will have the ESB representatives at the committee next week, but Mr. Barry might provide some background, to the extent that he can do so. We are not pushing him on that.

Deputy Phil Hogan

Mr. Barry might wish to elucidate on some of the issues he raised at City Hall in Cork.

Mr. Paudie Barry

It was a different presentation. However, given the information I have presented here, I can say that the rainfall is very similar. There are similar claims and it is a similar rainfall situation. One might argue about ground soakage, but I am not a hydrologist so I will not get into that. The discharge figures from Inniscarra in 1986 and 2009 are miles apart. There is a huge difference in the discharge. The downstream damage in 1986 was minimal, while in 2009 it was absolutely and utterly catastrophic. According to the data I surveyed in 2009, the level the river came to is higher, on average, than what the ESB predicted the river would have come to in 1986 had there been no dams. All that data is factual, as I see it. The Deputy is an intelligent man and I am sure he can infer what may have happened.

Deputy Phil Hogan

I will put the question in a general way. The management of rainfall as regards the dams was completely at variance with what happened in 1986.

Mr. Paudie Barry

Completely and utterly.

Deputy Phil Hogan

Mr. Barry's figures indicate that.

Mr. Paudie Barry

Yes.

Deputy Ciarán Lynch

I thank Mr. Barry for attending the committee. I know that parliamentary privilege is not extended to him, although he would probably like to say a lot more at this meeting. I wish to take him through some of the points he made in the presentation. The first one concerns the discharges that took place in 1964 and 1978. Does Mr. Barry have figures for the volumes coming out at that time?

Mr. Paudie Barry

No, I do not have those figures. However, the 1986 report states that the discharge had been exceeded on two occasions. I do not know what the discharge figures were, but it would be interesting to find out.

Deputy Ciarán Lynch

Above 300?

Mr. Paudie Barry

It says that the discharge had been exceeded on two occasions, which would have been more than 331.

Deputy Ciarán Lynch

That is the 1986 volume.

Mr. Paudie Barry

That is the 1986 one, yes. It would be interesting to see the discharge figures, as well as the downstream effect and the rainfall for those two dates.

Chairman

Is that an ESB report?

Mr. Paudie Barry

It is.

Chairman

Was Mr. Barry able to obtain that publicly?

Mr. Paudie Barry

Yes, on the Internet.

Chairman

Okay. I just wanted to be sure. I did not know where it was from.

Deputy Ciarán Lynch

Maybe Mr. Barry can explain table 2 of the 1986 report, because we are not engineers. To a certain extent we need this data transposed into layperson's language. As I understand it, the ESB had two basins and were transferring water to another location. The ESB examined the size of the basins behind and in front of the dam, stretched over 13 km. It concluded that if water was transposed from one location to another, such and such would be the level the water will reach. Is that the case?

Mr. Paudie Barry

That would be a simplified way of looking at it, yes.

Deputy Ciarán Lynch

It is similar to when the man came into the engine room of the Titanic, saw the breached bulkheads and said, or words to the effect, “There’s so much water coming in here per minute, so many bulk heads have to be breached, so the ship is going to sink in two and a half hours”. This is an engineering examination — quantifying the volume of a substance and how it actually travels.

Mr. Paudie Barry

It would have been an engineering, hydrological or hydrometric analysis.

Deputy Ciarán Lynch

The engineering analysis at that time was that the weir, which is 13 km away from County Hall, is just at the point where Cork city reaches its tidal mark.

Mr. Paudie Barry

That is correct.

Deputy Ciarán Lynch

As I understand it, the tidal mark is at——

Mr. Paudie Barry

The foot of the weir.

Deputy Ciarán Lynch

——the bridge. This is a non-tidal area.

Mr. Paudie Barry

It is non-tidal, yes.

Deputy Ciarán Lynch

The maximum elevation during the flood in 1986 was 7.4 m.

Mr. Paudie Barry

It would have reached 7.4 m at the waterworks weir. I would like to make another point, which is probably one for the committee's report. The ESB levels refer to Poolbeg, but that datum was disbanded years ago. Cork County Council's datum is Malin Head, which is the modern datum. We should all be singing from the same hymn-sheet, so the ESB data should also be based on Malin Head. I had to convert my GPS readings from Malin Head to Poolbeg, so I could make this presentation. I am going back a few years therefore. Basically everyone, including the ESB, Cork County Council, myself and the OPW, should be singing off the same hymn-sheet in terms of datum. However, the ESB is on Poolbeg, while Cork County Council and the rest of Ireland are on Malin Head. It is time for the ESB to move to Malin Head, otherwise it will cause confusion somewhere.

Deputy Ciarán Lynch

As regards the 1986 report, was the ESB in Malin Head?

Mr. Paudie Barry

Poolbeg. I got a recent sheet which showed a graph of the Inniscarra dam filling and that is on Poolbeg. That is dated 20 November 2009.

Deputy Ciarán Lynch

With no dams, the assumption is that the weir would have been at 8.1 m of water.

Mr. Paudie Barry

Yes.

Deputy Ciarán Lynch

How far above that water line is the weir?

Mr. Paudie Barry

In terms of distance or height?

Deputy Ciarán Lynch

Height. So at what water level would the weir be breached?

Chairman

Please give Mr. Barry an opportunity to resume his seat, otherwise the microphone will not record him.

Mr. Paudie Barry

I will look at my documents, including some data I got from Cork County Council. I called into the waterworks this morning on my way to the train station. I met an engineer there and asked him what level did the water come to at their pump-house. Everybody knows that the pump-house was well under water. I took a level at the pump-house when I was going around with my GPS equipment, and I assumed that other people were doing it as well. I assumed correctly because the waterworks engineer had a separate reading to mine concerning the waterworks level. I must again convert back to Malin Head. The level I recorded at the waterworks was, from memory, 5.45 m.

The Chairman asked me previously at City Hall about how I could corroborate this information. How do I know it is right? The engineer's level at the waterworks is 5.516 m. There is a difference of 2 inches. I can possibly explain that because we use GPS and I did not use Malin Head data or Poolbeg data.

Chairman

It is approximate. We can live with 2 inches of a difference.

Mr. Paudie Barry

Two inches is approximate. I would say my level is more accurate.

Chairman

When we are dealing with more than 5 m then 2 inches is not much.

Mr. Paudie Barry

I am within 2 inches of the engineer's reading.

Chairman

The readings are close enough.

Mr. Paudie Barry

He carried out his survey completely independently of mine. I will do a calculation based on the engineer's level. I have a slightly different conversion because I tied my GPS survey in to the gauge at the back of the dam. Ignoring my slightly different adjustments and the slight variance that the ESB would have on Poolbeg at the dam, let us take the engineer's level and do a straight conversion. The result is 8.23 m at Poolbeg. That is according to Cork County Council, not me. If we look at the figures in table two, we see 7.4 m for the actual flood level and 8.1 m for the predicted flood level with no dams. The engineer got 8.23 m for the same position. I would more or less agree with his level.

Deputy Ciarán Lynch

My question was whether a level of 8.1 m would breach the weir. If there was no dam in place, would the weirs be flooded?

Mr. Paudie Barry

If the weir overflows then it does not behave like a weir anymore.

Deputy Ciarán Lynch

I am sorry, I should have said pump station. Would the pump station have been flooded at 8.23 m?

Mr. Paudie Barry

The pump houses would have been flooded at 8.1 m. It would possibly have been flooded at 7.4 m as well if it there was 600 ml or 700 ml of rainfall because there was a good depth of flood there. It might not have been flooded to the depth that it was and it might not have done the damage because as I understand the damage was a bent manifold, which would have been due to water pressure.

Deputy Ciarán Lynch

It would have flooded anyway.

Mr. Paudie Barry

It would have been flooded anyway, but a hell of a lot of the houses around Cork would not have been.

Deputy Ciarán Lynch

A recommendation was contained in the 1986 report that it is essential to monitor as accurately as possible large flood events on reservoir catchments. Does that refer to monitoring floods in real time or post-flood?

Mr. Paudie Barry

It is monitoring after the flood.

Deputy Ciarán Lynch

So it is not in real time. Was the examination Mr. Barry carried out in real time?

Mr. Paudie Barry

No, I did it after. One could not really do it during the flood because one could imagine the practical difficulties if one is trying to get the water at its maximum height while the water is flowing. When water starts dropping off or peeling back on its level, it leaves a mark at its highest point. If one has the skills, knowledge and attitude then one will pick that point up. I would imagine that is what they did in 1986.

Deputy Ciarán Lynch

I have two final questions for Mr. Barry. I believe he surveyed above the Inniscarra dam.

Mr. Paudie Barry

Yes.

Deputy Ciarán Lynch

A CPO had to be carried out as part of the 1946 Act that acquired the land base for the ESB to put its dam in place. Was the CPO line, the high watermark, breached at any time during——

Mr. Paudie Barry

I do not know if the CPO line was breached at Inniscarra. I surmised what the property contour was. It is very close to 50.9 m. I know what the property contour is in Carrigadrohid and I know how it lays itself out there. I will not quote figures off my head. An educated estimate of the property contour was that at 50.9 m the high watermarks were extremely close to their property line.

Chairman

However, there was no major breach of the property contour.

Mr. Paudie Barry

There would not have been a breach of the property.

Deputy Ciarán Lynch

From Mr. Barry's estimations around 18 and 19 November——

Mr. Paudie Barry

What we need is for the ESB to tell us its property contour.

Deputy Ciarán Lynch

The ESB will be before us next week. The information Mr. Barry is providing to us today will inform us in our questioning of the ESB. According to Mr. Barry's estimation, were the water levels behind the Inniscarra dam in approximation to the compulsory purchase order line?

Mr. Paudie Barry

They would have been very close.

Deputy Ciarán Lynch

In his presentation Mr. Barry noted that one of the outcomes from the flooding is the possibility that an independent investigation will be carried out. What would Mr. Barry consider to be an independent investigation?

Mr. Paudie Barry

I do not think it could be done by Cork County Council or the OPW because they work with the ESB. It is very difficult to get people who work together and collaborate with each other through the work environment to investigate what happened. What the situation requires is someone from outside who does not have much of a connection with the ESB, Cork County Council and the OPW to rigorously find out what happened.

Deputy Ciarán Lynch

Something similar to the 1986 investigation.

Mr. Paudie Barry

Something similar, but the ESB carried out its own investigation in 1986. I do not think it should carry out this one.

Senator Jerry Buttimer

I thank Mr. Barry for being here today. In fairness to him he has given tremendous time and commitment to the committee. I suggest that the presentation he gave us in City Hall could be compiled and added to the committee's record. That presentation was very interesting. Mr. Barry expressed strong views and collated much information. On the previous day he attended the committee he referred to the management of the Inniscarra and Carrigadrohid dams by the ESB. Will he elaborate on that?

Mr. Paudie Barry

What does Senator Buttimer mean?

Senator Jerry Buttimer

Mr. Barry made particularly strident comments regarding the Carrigadrohid dam. He suggested there was a question mark over water management. Why does Mr. Barry think the ESB or the local authorities did not inform all or some of the residents? Mr. Barry is living on the Lee Road which is part of the catchment area. In part 8.1 of the summary of the 1986 report, it was suggested that the flood had an estimated return period of 250 years. That was 1986 and the next flood was in 2009.

Mr. Paudie Barry

Twenty three years on.

Senator Jerry Buttimer

From Mr. Barry's presentation it appears that far more extensive damage was done to property on this occasion than in 1986 and it was in different locations. Does Mr. Barry think lessons have been learnt? What would he recommend to the committee in terms of averting this type of flooding in as far as that is humanly possible?

Following on from Deputy Ciarán Lynch's question, the final slide in Mr. Barry's presentation referred to an independent investigation. I would like to hear his views on that. He said he proposes to carry out his own investigation. Does he consider an independent investigation to be necessary? If that is the case, what would it achieve that is not evident from the 1986 report and that the ESB or the OPW could not provide to us? The OPW has just published a CFRAM study for Cork. Has that a direct role to play in further averting the problem? I thank Mr. Barry for his tremendous presentation.

Mr. Paudie Barry

The Senator has asked me four or five convoluted questions. I will ask the Senator to repeat them one by one and I will write them down and answer them one by one. They are all very pertinent and interesting questions.

Senator Jerry Buttimer

Why is the independent investigation necessary?

Chairman

We will deal with one question at a time. Mr. Barry has partly answered that in that he believes all the public bodies work in unison in any event.

Mr. Paudie Barry

It is not fair to ask two people who relate to each other, have meetings together and work together, although they do not work for the same company, to investigate each other. It is very difficult for somebody who is working with somebody else to investigate what that person did. However, if one had a person who was very familiar with the matter to come in and ask all the correct questions, one would get the answers.

Senator Jerry Buttimer

My second question was about management at Carrigadrohid dam. Mr. Barry has very strong views on it and a very good slide of City Hall. I am sorry he does not have it today.

Mr. Paudie Barry

I will not comment on Carrigadrohid until I get information from the ESB showing the head levels.

Chairman

The ESB will be here next week and we will ask all these questions directly to its representatives.

Mr. Paudie Barry

There are two items of information that will complete the jigsaw. I am carrying out an investigation and have been doing so unofficially since 19 November. I have been on the case all the time, thinking, talking, working, analysing and surveying.

Chairman

I suspect the second item of information concerns the levels in Carrigadrohid dam. We will ask for this information.

Mr. Paudie Barry

What I require to finish my jigsaw are the two hydrometric reports for 19 November and 20 November, and perhaps for a week theretofore and thereafter. While I can confirm everything in theory and while my information is bearing true and dovetailing with other information I am receiving, I will not be able to confirm everything completely until these reports are received.

Members will see an example of what I am referring to in the 1986 report, which was e-mailed to them. In 1986, the ESB was proud of what it did. It gave us the hydrometric reports, from which one can see head levels, an hour-by-hour breakdown with information on rainfall, inflow, outflow, discharge and the volume going through the tail. Everything is listed in the hour-by-hour breakdown for Carrigadrohid and everything will be given for Inniscarra. The two documents I await will answer every single question, including those on the hydrological breakdown pertaining to how much water was entering the catchment. All the measurements will be available and we will not need anything else. Once we have the information, the case will be closed and we will be able to draw our conclusions.

Senator Buttimer asked the very important question as to why I believe it important to know what happened. It is very important to know what happened because the phenomenon is like a roundabout. If — God help us – one's child had a heroin problem, one had cancer or one's wife were an alcoholic, one would really need to focus on it and find out what happened. It is a painful process. People naturally go into denial and do not want to know what happened for many reasons. Once one knows and can recognise what one is dealing with, one can move forward.

I live in the valley. I do not know whether what occurred in November 2009 was a freak rain event or a mismanagement issue associated with the dam. If we knew it was the former, and that it could recur, we could take the proper steps to counteract it. If we knew it was a case of mismanagement at the dam, we could take steps to correct it. If the problem is mismanagement at the dam, we will not need to spend €100 million building walls 2 m high up and down the Lee Valley to protect the city. This is why we need to find out what happened. To do so we need to immerse ourselves in pain and embarrassment and, having done so, come out of the ashes and create a solution that will prevent the problem from recurring. It is vital to learn from our mistake.

Senator Dan Boyle

I will be brief. I was speaking in the Seanad during the earlier contributions but tried to catch what I could on the monitor. Reference was made to the report carried out on behalf of the OPW. Its projections relate only to the risk of tidal flooding, the traditional type of flooding in Cork. Mr. Barry may have questions about that. The report does not deal with the type of flooding experienced in November.

Mr. Barry said he cannot give a full account of the influence of Carrigadrohid dam and its management until further data are supplied to him. We will have an opportunity to talk to the ESB directly. Is it fair to say Mr. Barry's concern over the dam relates to the fact that, since everyone on the night in question was preoccupied with Inniscarra dam and the fact that the water rose to within ten feet of the top, less concern was paid to the management of Carrigadrohid dam and that the higher capacity in the basin area could have been relieved through better management thereof? He needs further data to confirm this.

Mr. Paudie Barry

We need the data to confirm that. My theory points to Carrigadrohid dam as being the root of the problem. This needs to be borne out with more data.

Chairman

We will obtain a view from the ESB on whether the dam has 50% more capacity than Inniscarra. I refer to the bigger one upstream.

Mr. Paudie Barry

It is 9 sq. km., compared with 6 sq. km.

Deputy Ciarán Lynch

Slide 8 states the flood level for November 2009 was higher than that referred to in the 1986 report of the ESB.

Mr. Paudie Barry

It is higher than its predicted level based on there being no dams.

Deputy Ciarán Lynch

It appears significantly higher.

Mr. Paudie Barry

It is not significantly higher.

Deputy Ciarán Lynch

It appears so on the basis of the slide.

Mr. Paudie Barry

No. I will speak in loose terms. There is a difference between the red and blue levels of approximately 800 mm. This should give one a scale as to how much higher the black line is above the red line. It is marginally over the line; I would not say it is very much over it. While I know how far above it is in terms of numbers, I am not prepared to give out those numbers at this point.

Chairman

We could speculate it is 200 mm to 300 mm.

Mr. Paudie Barry

One could speculate on that basis.

Chairman

We hope a delegation from the ESB will be able to answer our questions at our next meeting. That is the main issue. We will ensure we get the answers from it in public session next week. The background information supplied by Mr. Barry, both in Cork and at this meeting, will help us in formulating our questions. There are questions we would not have known could be put to the ESB had we not been given the background information. Mr. Barry has not given us critical data because they depend on the ESB's information. He has given us an understanding of how we can deal with the ESB better. We would possibly be like lambs to the slaughter without it, depending on what information the ESB supplies. We are better prepared for the main meeting next week. I thank Mr. Barry for attending and the members for remaining with us. The meeting was very informative and will be helpful to us in our work.

The joint committee adjourned at 6.10 p.m. until 3.45 p.m. on Tuesday, 23 February 2010.