Weekend Weather Word #7 – Atlantis-on-Lee

Well, Cork is finally getting its flood defences, after I don’t know how many years of political wrangling. And what is the first thing people do? They whine and complain about how these crucial defences will in effect destroy Cork. Seriously, is no one EVER satisified in this country, and especially in this city? Seriously, a group called Save Cork City has already been set up on Facebook, Twitter and Instagram to “fight back” against these “destructive” flood defences. In fact, on Thursday, Jan 19th, they managed to get their “concerns” published in the Evening Echo. However, I haven’t seen any counterproposals from these individuals yet, which of course is par for the course for these groups. Interestingly, the article in the Echo sparked mostly negative reactions, something not usually the case with these organisations. But let’s take this step by step, shall we. Why does Cork even need flood defences?

Well, to make the answer short, the city centre stands on a floodplain and former swamp. Maybe that’s the reason city politics often descends into mudslinging, but I disgress. Cork is situated in a basin on the lower reaches of the River Lee, just below the point where the Lee stops being influenced by tides. It is also joined here by the Kiln or Bride river, running down from the suburb of Blackpool, and flowing into the Lee underneath the Christy Ring bridge, and the Curraheen River, which empties into the Lee near the Western Gateway building and the UCC campus. And, as everyone knows, where there are rivers, there’s water. Lots of it usually. That goes for Cork as well, and the clue is in the name. Cork is derived from the Irish term Corcach Mór Mumhan, or the great marsh of Munster. The entire city centre is built on a swamp. In fact, many of the streets in the city centre are former channels of the Lee, most obviously the undulating Patrick Street, part of the commercial heart of the city. Building a city on such a terrain means that there will always be a risk of flooding. One only needs to look at some of the images in the windows of the Irish Examiner office on Oliver Plunkett Street to see proof of this, indeed proof that flooding used to be much more commonplace than it is today. 

Things have of course changed since the 1920 and 1930s. As far as flooding is concerned, the biggest change are the two large dams at Inniscarra and Carrigadrohid on the upper reaches of the the Lee, both built in the 1950s and 1960s, primarily as hydroelectric power stations. Smaller tributaries, like the Kiln or Curraheen I mentioned above, or the River Shournagh are completely unregulated. Plus, there’s the issue of water coming into the city from downstream. Cork may be several kilometres from the open ocean, still much of the city is within the tidal influence of the Atlantic Ocean, indeed the difference between high tide and low tide can easily be 3-4 meters at the right time of the month. In the right weather conditions, southeasterly winds can prevent water from flowing out of Cork Harbour after high tide, or indeed push it further upstream. If you then take into consideration that these southeasterly winds usually go hand in hand with significant amounts of rainfall, getting a kayak to do your city centre shopping suddenly doesn’t seem so far-fetched anymore, does it?

Now how can Cork get out of this quagmire (No pun intended, or is there?)? Lets take this step by step, starting with the Lee river system. The events of 2009 have shown that the Inniscarra and Carrigadrohid dams can only hold back limited amounts of water, and of course the structural integrity of these dams needs to always take top priority. To prevent or at least minimise the damage of future floods, the first step must be to immediately stop all housing or commercial development in the remaining floodplains in the Lee Valley and the valleys of its tributaries. Existing but vacant housing estates should not be finished or repaired, but instead be torn down. The next step would be considerably more unpleasant. A series of low barrages should be built across the Lee valley, with floodgates large enough to allow the Lee to retain its usual rate of flow, or even higher rates of flow. Under normal circumstances, the artificial lakebeds created by these barrages will be dry, meaning they can be used for grazing, recreation, or indeed sports pitches given that any buildings associated with these pitches are located outside the basin. Similar structures should be built along the tributaries of the Lee as well. The main aim of these structures will be to hold back flood waters until they can be safely discharged through the river system. If this is not possible due to urban/suburban encroachment into rhe floodplains of the river, flood embankments should be built to protect these developments. This kind of work, which from the plans I’ve seen so far is already part of the Lower Lee Flood Relief Scheme, is definitely something that should be undertaken by the State, and yes, it should be started ASAP!

Of course, that can only go so far, and even such a system can be overwhelmed given the right weather conditions. So, the city centre, and low lying properties must be defended, and while I don’t like to borrow ANY idea from Donald Trump, in this case walls really are the best solution, or at least part of the best solution. I can truly speak from experience here. I was born near Hamburg, and have seen the effects of storm surges and related flooding first hand, ever since I was a kid. What’s more, my parents and grandparents both witnessed the horrific flood of January, 1962, which cost more than 300 people their lives. Following this catastrophe, the flood defences in Hamburg, and indeed in all of Northern Germany were massively beefed up, to such a degree that when the “Capella” storm and the accompanying flood , the most powerful such storm of the 20th century. hit Northern Germany on January 20th, 1976, none of the flood defences along the Elbe estuary were breached. This is despite the fact that the storm surge was almost a meter higher than during the great flood of Febrary 1962. In fact, they haven’t been breached since that fateful flood of 1962. So, walls do work, something that I myself witnessed during the great floods of 1990, 1993, and 1994, all of which exceeded the 1962 flood in height, shortly before my family moved to Prague.

Now, I agree that walls aren’t the prettiest solution, and can affect the aesthetic appeal of a place, however, the protection of residents, infrastructure, and property must always take precedence over aesthetics. That isn’t to say that there is no room for improvement with the concrete barriers proposed by the Office of Public Works, the flood defences along the Baumwall street in Hamburg are an example of how such an impact can be minimised by turning them into a viewing platform, for example. However, any decoration, etc. must not be allowed to interfere with the rapid shutting of flood gates in the case of an approaching flood. Therefore, they must to a certain degree be unattractive, so they don’t turn into sleeping places for homeless people, or get blocked with trash. They must also be robust, because make no mistake, there will be a lot of strain on those barriers once the river starts to flood, which is one of the reasons why I’m not a fan of glass barriers. Concrete is also far less susceptible to vandalism, which is unfortunately always a risk in this city. It may not be the prettiest of solutions, but it will work. And, let’s be honest, Cork is no Paris, no Amsterdam, or no Bristol, it isn’t the prettiest city, so those flood defences likely won’t have too much of an impact.

That is not to say that I am completely on board with the new flood protection scheme, or that it will be plain sailing from here. There are a few issues that I haven’t found answers to yet, maybe I need to recheck the plans. One crucial issue is water being pushed up through storm drains and culverts during a flood. This regularly happens along stretches of Oliver Plunkett Street, Grand Parade, Winthrop Street, or Grand Parade. I did not see anything in the plans that adresses this, no non-return valves, shutters, or sluices to prevent this. This is something that urgently needs to be addressed, as uncontrolled flooding through the storm drains could undermine the entire system.

Another Issue I have not been able to get a straight answer to is the height of the flood defences. The issue here is whether these walls are all built to a certain height above ground, or to a certain height above either average water level, or high tide. The problem is that the embankments along both channels of the River Lee vary quite drastically in height. If the flood barriers are only designed with a certain height above the existing embankment, the barriers along the lower stretches of the river embankment will simply be a liability in severe flooding scenarios. That brings me to another point. What level of flooding is planned for in the Lower Lee Flood Relief scheme? I haven’t been able to find any information on this in the documentation.

Regardless of these details, the fact remains that the flood barriers are vital to the safety of Cork and its citizens. Practically the entire city centre, as well as significant parts of Blackpool and the South Side are currently completely unprotected and at risk of flooding. Trying to stoke up opposition to this much needed scheme on the basis of “aesthetic” reasons, or to be more bluntly, plain old NIMBY-ism ist not only disingenuous, it is dangerous. It puts the lives and livelihoods of those at risk who live or work in vulnerable areas. I find it interesting that the Twitter, Facebook, and Instagram accounts run by “Save Cork City”just link to each other, without providing any further contact details. It appears that whoever operates those sites is aware that they are toying with other people’s existences and do not want to be found out. It is equally telling that they are not offering any alternatives to the existing plans. This kind of blind obstructionism must under no circumstances allowed to go unopposed, the lives and livelihoods of far too many people are at stake. I for one welcome the new scheme and will do everything I possibly can to ensure it moves along as quickly as possible.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s