Gentle Decline 2/31: Floods and Further
Looking at Ireland's rainfall, and what can be done to mitigate the effects of flooding.
Hello. This right-at-the-moment special-ish issue looks at flooding in Ireland, where we currently have soil moisture deficits (usually used to measure drought) of -10mm in places, and more water on the way. Media coverage and political commentary are beginning to understand that the future is rather more waterlogged than the past or present, and the present is pretty soggy. I’ve almost certainly written about this before, but there’ve been a lot of new subscribers since, so it bears repeating.
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(Flooded Boathouse, Charleville, Co. Offaly. Arguably, flooded is the proper nature of a boathouse.)
Floods & History
Ireland has a lot of floods. That’s always been the case; some of our coastal towns have a number per year, and that’s just how they are. Cork is the major example here; the city has had floods on average twice a year since the 1840s. However, the flooding in places already prone to it is getting worse, and places that have never really had to cope with flooding before are experiencing it for the first time.
This situation has been building for about two decades now. 2008 saw major flooding all across the country in August, 2009 had it in November. There was massive and indeed dramatic flooding in Dublin and other parts of Leinster in October 2011. 2012 had flooding right through the autumn and winter, with intermittent dry-ish periods. 2015 into 2016 had a “storm train” in December and January, which had flooding and high winds, including Storm Desmond. Storm Ciara in 2020 brought more floods and high winds, and now we have her 2023 counterpart Storm Ciarán which looks to wreak some havoc on the south coast this week, in the wake of heavy rain over the last ten days. That included Storm Babet, although it hit mainland Europe harder than Ireland.
Even before Ciarán’s arrival, Newry has been flooded, and a pretty solid looking old bridge in Louth has been taken out. The rail line (which is part of the route from Dublin to Belfast) is “closed until further notice” there. There’s been unprecedented flooding in Rosslare in Wexford (a coastal area with Ireland’s major port after Dublin). Cork, of course, has had floods three evenings in a row. There are a whole parcel of weather warnings around, amidst complaints that the warnings for Babet weren’t enough.
Personal & Housing Changes
In dealing with flooding, there are a few things people can do at an individual level.
The first question is whether your house has flooded before. If it has, it’s almost certainly going to do so again. The absolute best thing to do is move out, headed inland to places that have not flooded. If you stay put, the best you’ll ever manage is to mitigate the effects. Any place that has flooded before will flood again (I don’t know if this is true outside Ireland, to be fair, but it’s not a chance I’d take). The second best thing to do is to follow the other steps below.
First up, you need to assess how your immediate area is for floods. This isn’t easy. Look at maps (Google maps are pretty decent for this), and see if there are any watercourses nearby - even small streams. Canals are not so bad, because they’re built to let water out through locks; it takes a lot of rain for a canal to flood, assuming it’s in good repair. If there’s a stream, try to work out what will happen if it overflows its banks. In hilly areas, or places where the courses of rivers have been altered, it’s possible to be downhill from one quite a long way away, and if the slope is gradual, that may not be immediately evident. Otherwise, you need to look at the ground between your house (and if you’re in a housing estate, apartment block or even a rural house with a long driveway or access road, the approach to it from major traffic routes) and the watercourse. Basically, will the water come to your house, or cut you off? If it’s likely to reach the house, as above, move if you can. If it’ll just cut you off, you can make sure you have a few days of food and a heat source, and you’ll be ok.
If you can’t move, build some of your own flood defences. Flood barriers can be bought from a number of companies in Ireland, and certainly abroad. Amazon sell them, too. They’re essentially alumium planks that you drop into slots on posts fitted on either side of doors and windows, which form flood walls. Once water pressure comes on them, they more or less lock into place, and they’re waterproofed with sealants of various kinds. You can put in drainage ditches or channels to guide water away, or re-arrange so there are steps up to your outside doors, even if there have to be steps back down again inside. You can even do this with ramps if mobility is an issue, although I’d be even more keen on your moving to somewhere safer if that’s the case. At the very least, keep valuable items off the ground-level floors if there’s even the slightest chance of flooding, and have some sandbags you can place if need be. If you’re renting, try to persuade the landlord to install some of these for you - since it’s their property that’ll be damaged, it shouldn’t take too much persuasion.
Systemic Changes
More broadly, though, there’s a need for flood mitigation at a systemic level. County councils and the OPW need to be looking at building flood barriers, allowing for flood plains, un-straightening watercourses where that particular madness has been carried out, and planting trees by watercourses. The Netherlands has already done a lot of this work (that link is in Dutch; Google Translate renders it pretty well). The basic principles are to give rivers room to flood, and to have houses and infrastructure on mounds that do not block water flow. This does involve a good deal of capital investment, and honestly, I cannot see the Irish authorities taking this seriously enough in the short or even medium term. But we can hope.
The Irish Times discusses river management in the context of the Liffey. In particular, there’s this choice quote:
“Sea level rise and storm surges are a risk to Dublin city, but not the only risk. Heavy rainfall is also a significant risk. If there was significant downpours of rain over an extended period of time and this combined with very high tides, would create a flooding risk to the city along the Liffey,” a DCC spokeswoman said.
I’ve seen rainfall and high tide causing issues myself; The Liffey came very close to overtopping its walls in October 2011, and there were a number of flooded streets, leading to two deaths, as storm drains backed up. That was from 85mm of rain in 3 hours, which is certainly a lot, but is also very likely to re-occur in the next decade or so. Indeed, it’s extremely likely that this will be overtopped, and that 85mm was falling onto soil that could still absorb some of it, unlike the current situation where it’ll essentially run straight off the saturated de-forested mountains and into the watershed.
“Flood meadows” - the same idea as the Dutch giving the river room - are mentioned in that article, and in another, talking about water supplies for the city, there’s this quote:
“One of the tragedies is the uplands – where the water comes from – is destroyed,” says ecologist Pádraic Fogarty. It has been burned, overgrazed by sheep and covered in conifer plantations. “The fact that it supplies the water for the city and yet has been allowed to degrade to such a point is atrocious.”
Conversely, he adds, restoring the uplands would be an amazing thing to do, “because it would hit so many boxes. It would improve the water quality; it would help to mitigate the flooding and regulate water flow. It would improve the biodiversity... and be a fantastic amenity.”
The restoration here would be replanting with trees, which is a drum I’ve been banging for a few years now. It would be fantastic if it actually happened, and turned our accursed bald mountains back into tree-covered ones. That would prevent a huge amount of flooding downstream, not to mention all the other environmental and biodiversity benefits.
Population and Urban Changes
The major thing that needs to change, though - and which will have to over the next 40-50 years - is that people, businesses, and infrastructure need to be moved out of flood-vulnerable areas. Dublin’s city centre, in places well under the 1.7m-above-sea-level mark (a figure determined by climate intelligence company Cervest) still has major building investment going on.
That needs to stop, realistically, and those areas of the city need to be closed out, buildings demolished, and the area given over to Dutch-style room-for-the-river. Parkland, say, with running tracks and playing fields than can be used when it’s dry, and which nobody needs to use when it’s under a metre of brackish water. It can be a gradual process, certainly. But anyone committing to long-term leases or building ownership in those areas (or their equivalents in any other coastal city with a river, which is most of them) is acting stupidly.
Infrastructure also needs to be moved, and this can’t happen quickly, so it needs to start soon. Dublin Port will need to make changes. In the short term, just building the port upward will work, as long as there are bridges that go to the higher and drier areas. The port tunnel - which was a huge and expensive project - will need to be protected, because if water ever gets in there, pumping it back out will be difficult. Rail lines will need to be rebuilt further inland or at least higher up; there are already problems in stormy weather with the parts of the line closest to the coast. And buildings in the commercial centres of Dublin - O’Connell Street and the shopping streets off it, Westmoreland Street and the areas north of Trinity College, and anywhere along the quays right up to Heuston Station - will need to have flood defences that can be deployed at short notice.
Weather Warnings
Meantime, there’s the concern with weather warnings. From the article above,
“Senior meteorologist with Met Éireann, Eoin Sherlock has acknowledged that the methods by which they categorise extreme weather situations will have to change because of climate change. Future weather warnings will be about what the weather will do rather than what the weather will be.”
Better weather warnings are good, for sure. But people also have to understand what they’re looking at. If you have county-level warnings - as we currently do in Ireland - then some parts of the county are going to experience different conditions. Cork is a huge county, for instance. Some parts of Galway are coastal, but the inland side of the county is 60km or more from the sea. So a county-wide warning has be actually looked at and some judgement used.
In particular, if there’s an orange warning county-wide, then it has to be understood that that’s an average. There will be parts of the county where a red warning would have been merited, and parts where it barely rated a yellow. Weather is localised, and flooding is extremely localised. And at the same time, we can’t have a forecast that lists off 83 townslands as red warnings, several hundred as orange, and a few more as yellow or none for each county; it’s too much information and too confusing. People are going to have to understand forecasts.
Closing
In the interests of getting this out while it’s still current, I’ve left out the Positive Things component I’ve been otherwise trying to include. If you have things that could be included in this section in future, please do send them to me! I’ll try to head back towards my current broader line of thinking in the next issue, although given how the weather is looking, it might yet turn into a flooding retrospective.
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