Assessing dam failure risk with WTW

You're listening to the Engineer's Collective, the podcast by New Civil Engineer. New Civil Engineer is the leading publication covering the Civil Engineering sector, a trusted and authoritative voice for over 50 years. The Engineer's Collective comes to you with monthly news analysis from our editorial team and in-depth interviews with industry experts and thought leaders. If you're a private sector organisation looking to reach tens of thousands of listeners, you can find out more about sponsoring an episode of the podcast by visiting newcivilengineer.com/podcast. Hello and welcome back to the Engineers Collective from New Civil Engineer. I'm your host and the Engineer's Editor, Rob Hackimian, and I'm joined by our Senior Reporter Tom Johnson. How are you T.J.? I'm good, thanks, how are you? Yeah, not too bad, not too bad. So, coming up in this episode, we have an interview with WTW Head of Flood and Water Risk Research Neil Gunn and WTW Climate Practice Associate Director, Dulce Periots Romero, and I chat to them about Dan Failure or the potential thereof. They work in a niche area where they speak to insurance brokers and asset managers about ensuring Dan's and the risk of flooding and what kind of liabilities they would be accountable for, should Dan break? Yeah, it's quite interesting as I'll let them explain more thoroughly how it all works in that interview portion, which is coming out, but ahead of that, I wanted to chat with T.J. about a couple of recent stories around mega projects, I suppose you could say one that is happening kind of, and one that is very pie in the sky. So, let's start with the pie in the sky one, which comes from three of our presidents, Chris Williams, who released this idea, because as we talked about on our last episode, who's been covered widely, Northern Powerhouse Rail is now back on the agenda, this mega rail plan to connect the cities of the North of England, but Reba Chief Chris Williams has gone a step further and said, "Why don't we connect all of the major cities?" So, there's a lot of major cities of England, North England, Scotland, Ireland, Northern Ireland and Wales in one massive superloop, which he's, I don't know, where he's got this figure from, but it says 130 billion pounds. Yeah, I mean, that seems like a low estimate to me, but I would love to see the math that's gone into getting to that figure. So, just the Northern Powerhouse Rail that's going to be 45 billion, this railway, which would have to cross seas either by bridge or by tunnel, and it's going to be a lot more than 130 billion. Well, a lot of the early designs seemed for it, a lot of it to be built on stone and viaducts as well, and these come CGI's they fit together. I mean, as incredible as it would be to build something like this, and it's a very futuristic vision, I myself, I'm a fan of ideas like this, but yeah, costing it at this stage when it's literally a pine sky idea with some CGI's is kind of crazy to me. Yeah, his idea is that it would put all of these cities, which are Glasgow, Edinburgh, Newcastle leads, Manchester, Liverpool, Bangor, Dublin and Belfast within 90 minutes of each other. So, that would be pretty fast, even faster than HS2, which is already centrally too fast. Exactly. And the trains would only be 50 meters long, this has been questionable. Yeah, so it almost run like a shuttle service. Yeah, in my eyes, I see it as like a cross country, cross border, cross city, almost like automatic people move, kind of thing, or like when you get on the shuttle at the airport, it stands to the getwik airport to take you to the to the right departure section. I imagine it being like one of those on steroids essentially. Yeah, he wants it. So, within pre these nine cities, within 90 minutes of each other, he describes it as a new global city dispersed but connected. I mean, like I said, coming forward with these crazy ideas, I don't want to say crazy actually, that's a bit unfair with these, you know, I don't want the right word is, I guess. Yeah, just, you know, futuristic, almost science fiction in a way. But I guess, you know, when you look at how other cities around the world are connected, you know, especially in places that are really far forward, far advanced with their sort of infrastructure tech like China and even Japan. And, you know, other places in Asia, you know, something like this wouldn't seem as far fetched to them. I don't think, but because we're in the UK still bumbling along with a lot of Victorian infrastructure. And also, it's going to cost, you know, over a hundred billion to build a train line from London to Birmingham. Yeah, it makes these things, yeah, exactly. It makes these things seem, you know, completely impossible and, yeah, very science fiction. Like when in reality, it's probably, you know, at the state that technology is advancing now in the world anyway, you know, it probably, you know, maybe in our lifetime towards the end of our lifetime, we might see projects like this being built in Europe. I'm not going to say the UK, but. Yeah, I mean, Williamson says that his plan was inspired by the scale and vision of Saudi Arabia's Neon, which is troubling for several reasons. But starting with the facts, Neon, the lion, he's spent the name check specifically, which is supposed to be this 170 kilometer long sit linear city in the desert, nearly 50 meter high, mirrored walls on either side. It looks pretty cool in CGI is kind of like the loop does, but the reality of building has been quite different. I mean, they. They wanted to have people in there by 2030 and at the moment it's still just a big line in the sand. And they've scaled it back quite a lot. I think it's only going to be about 2.4 kilometers to start with. Exactly. And it's still going to cost several billion pounds dollars, whatever they won't really say how much because they have almost limit this money in Saudi Arabia to work on. Exactly. So in terms of the vision, you can see where he got that from. Yeah, definitely. And you know, I feel like he himself compared it to the lion or just, you know, Neon in general, because I'm pretty sure he was afraid or not afraid, but, you know, he thought, oh, if I put this, you know, vision out there, everyone's just going to say that I'm copying Saudi Arabia's. Kind of, you know, thinking or their vision, so he, you know, came straight out of there and was said, you know, I was inspired by the lion and the scale of the lion and the scale of Neon. And yeah, I mean, at the end of the day, like, I think there need there should be more effort to. Four visions to be brought forward on this scale and, you know, this, you know, seemingly so far, you know, so far out in terms of like reaching the point. It's just like the basis to scale something down and, you know, come up with an actual these more feasible idea, which, you know, you know, being able to connect all those cities in the north within. Even within two hours or, you know, not just the north in Wales and Scotland and Northern Ireland and Ireland as well, that would, you know, completely change so many people's lives and would open up so many opportunities for, you know, an area of the world which has been generally underfunded and especially in infrastructure terms, you know, been overlooked for, you know, a long time. And, you know, in England, London is a massive hub, you know, massive international hub and I think doing, you know, a project like this could make the whole country, put it on a par, maybe not on a par, but, you know, bring it closer to London's level of, you know, economic activity across the whole world, across the whole globe. And yeah, as I said, I don't think, you know, bringing forward these visions is a bad idea, it's more, you know, there needs to be some degree of understanding and I don't think we necessarily got that from everything that Chris Williams released that, you know, this is at the end of the day kind of a science fiction fever dream of what the UK's infrastructure could be if, yeah, if we were good at building these things. Yeah, the problem is, but yeah, bringing it back to the South Saudi Arabia comparison, obviously they have a lot more money than we do. So they can, like go ahead with plans like this, maybe one day we'll have the kind of reserves to do something like this, but find that hard to see where that will come from. But yeah, so they have no compunction about moving people out the way. Firstly, they've got a desert, but even that desert that they're building it, they had to move indigenous tribes out of the way illegally and brutally to make space for the line. And to do something like the loop, we would have to buy lots of land. That people are in the way of these bridges that are supposed to grow across the land. We're not just going to force them out at short notice. We'd have to go through the legal process. So that's going to add a lot of money and time to the project. Yeah, and it's, you know, what's going on in Saudi Arabia is, you know, essentially, no human rights violations. And also, in a lot of sense, it's very draconian and, you know, dystopian sort of indigenous people being moved for, you know, the progress of their, you know, civilization, not civilization. So, you know, their sort of economic society. So, you know, I guess the comparison, yeah, the money aspect is the main thing for me. I think, you know, if we really wanted to build something like this, I think that we could go through the legal process of acquiring all that land. For sure, many people would be displaced and I think we would have to do that very sensibly and very sensitively. And, you know, if a project like this ever took off and ever was being developed to the point where we could deliver it, this would be one of the main thing, apart from the money aspect, one of the main things holding it back would 100% be the displacement of people for where the infrastructure is being built. But at the same time, you know, we are a relatively developed country, you know, I think in a lot of sense, we are have a lot more, you know, widespread economic development and, you know, less, you know, I don't want to say less rural aspects, but, you know, for instance, somewhere like Saudi Arabia, you know, there are a lot of the people that were being displaced, like, you know, they weren't necessarily connected to any energy grid. They didn't have necessarily running tap water. Not that that is a reason to kick them out or anything like that, you know, I think what's happened there is horrendous and, you know, that should never happen anywhere ever. But at the same time, you know, in the UK, we do have a much more connected society in terms of the our infrastructure and part of me feels like that makes it more viable to be able to build these things because, you know, there is a lot more culpability with these people and a lot more accountability in terms of these people being, people being moved from there, you know, from where they live. Yeah. Anyway, that's one pie in the sky. Yeah, it's true. Let's move on to something that is actually happening, although it's still recently, which is the Hudson River tunnel between New York and New Jersey, which you've been following closely. Yeah. I mean, yeah. So this is an interesting case of, I don't want to use the word draconian again, but I guess an administration being involved with some, you know, being involved. I guess it's hard to describe Trump's outlook on infrastructure in the US because, you know, by all accounts, he, every time he's come into power, he's been all about, you know, building business, you know, building America into even more of an economic powerhouse than it is. And, you know, at the moment, the rail system in the US is for lack of a better word lacking in a lot of places. You know, New York is actually one of the places which does have a subway and does have a very good metro system, but obviously the, yeah, the tunnel underneath the Hudson River at the moment, which takes trains from, is it Penn State in Penn State Station? Penn Station, yeah. Penn Station, sorry, in New York City. Yeah, in Manhattan, to New Jersey, was damaged by Hurricane Sandy and, you know, has routine problems, you know, costs a lot of money and maintenance, but due to the flow of traffic, they're not able to ever close it to properly fit it out. The Hudson tunnel project, also known as Gateway Development Project, has been put, you know, they started doing that to allow them, well, you know, building another tunnel under the Hudson River for those trains to essentially allow them to refurbish that old tunnel, creating excellent access capacity. And then, you know, this project is going to cost $16 billion, basically, and it's well underway at this point. Yeah, but what happened is, it was agreed that the funding would, well, majority of the funding would come from federal disbursements under the Biden-Harris administration, but since Trump came in, we've seen it with the high-speed rail in California, we've seen it with wind projects, and now with this one, because it's in a Democrat-led state, he doesn't want it to go ahead, he's decided he's stopped, he stopped the funding for it, which has caused, he did that in October when the government went into shutdown, and that caused, the project managed to continue on for a few months on credit that it had, but as of early February, it had to be drawn to a close because they ran out of money, putting a thousand workers out of jobs immediately, and potentially 11,000 more if it dragged on. Thankfully, a judge ruled in the favor of the state or the project, and said that the 205 million that was owed has to be paid, and they have now received that, so they're working to get the work back up and running again. But there's still a question about whether the rest of the billions that are owed are actually going to come forward when they're supposed to. No, exactly, and this was the point that I was trying to make, that there's no question that this project will very much advance the economic activity, and the crossover of money from New York to New Jersey, people aren't going to jobs, etc, etc, and Trump's. His viewpoint that this doesn't need to happen is solely based upon vicious intention towards democratic states. There's no other reason as to why he's never even come forward with a reason as to why he doesn't think that the tunnel should be built. I'm sure there's plenty of people that are placing a lot of disruption through the construction who might question the building of the tunnel, but I'm sure the millions of people that use that tunnel to travel from New York City to New Jersey every year. I don't think any of them would argue that the tunnel need, they need a new tunnel, and the tunnel that's already being used needs to be refurbished. No, he has, him and his administration have absolutely no objection to it in terms of the necessity. They just don't want it built because they want to piss off Democrats. Exactly. You got a comment from the White House, what did they say? Well, yeah, exactly. Their comment was, you know, it instantly instantly blamed Chuck Schumer, the, what is he, the Democrat lead in the Senate? Yeah. Yeah. So they, they, they, they're, they're comment on when I asked them why they were not going to continue to disperse the funding. They instantly launched into attack of Chuck Schumer and the Democrats. And then, you know, they literally said the Democrats are more interested in prioritizing interests of illegal aliens over Americans. When there's just absolutely no intelligence or no way that you could ever back up any of what they're saying, when these projects are literally being built to bring Americans from one place to another place to do everything they need to do, including work and including make money for the country of America, so it's just the whole situation is just completely baffling to me. And I think that's one of the reasons why I've been quite keen and wanted to talk to the White House as much as possible about it, because it just doesn't make any sense. And then when they responded to me saying, well, it would be nice if you gave us any reason as to why you don't want this project to go ahead to come back and say, yeah, their comment literally says, there is nothing stopping Democrats from prioritizing the interest of Americans over illegal aliens and getting this project back on track. So I mean, to refer, I guess from that they do want the, from that they do, it does make it seem like they do want the project to be built, but not by the Democrats who are apparently more interested in everything. Yeah. But like bringing illegal aliens and you know, this would, this like right wing rhetoric should never be brought into infrastructure, construction or, you know, the politics of, even the politics of infrastructure, you know, infrastructure. Yeah, I mean, we've seen this, we've seen the same problems over here with HS2, which obviously was an originally labor idea and then got cried with the chipped away under the conservatives. Yeah. Anyway, yeah, politics and infrastructure, sadly, they have to mix, but they don't mix well. Anyway, I think we're just shattered enough for now. Good news is that they've got their 205 million for the Hudson Tunnel. Work is about to restart, but we'll have to keep an eye on whether that actually continues. Enjoy my chat with WTW coming up after this. You're listening to the Engineers Collective, the podcast by New Civil Engineer. The Engineers Collective comes to you with monthly news analysis from our editorial team and in-depth interviews with industry experts and thought leaders. If you're a private sector organization looking to reach tens of thousands of listeners, you can find out more about sponsoring an episode of the podcast by visiting newcivilengineer.com forward slash podcast. Alright, welcome back to the Engineers Collective from New Civil Engineer. I am now joined by my two esteemed guests. We have WTW Head of Flood and Water Research Neil Gunn, Hello Neil, I'm there up, and we also have WTW Climate Practice Associate Director, Dulce Perez-Ramera, Hello Dulce. So thank you both for joining me. We're here today to discuss an interesting topic, Dan Failia, and hopefully avoiding Dan Failia mainly. But before we jump into that topic, why don't you both introduce yourselves and your background and then we'll go on to what WTW does exactly, because it's kind of an interesting position in the sector. So I'm Neil Gunn, I've said that already. I've worked for WTW for coming up to four years. Before that, I worked for the Environment Agency in Floodless Management for 25 years. Little bit of time before that in agriculture and some other aspects of youth. I'm a chartered engineer and a chartered Water and Environment Manager 3, so that's me, nice. And Dulce? Yes, so my name is Dulce Perez, I'm also a part of WTW for, I've been there for, for and a half years, and part of risk and analytics. And before coming, becoming a risk consultant, I was working as a break engineer for more than a decade in engineering fields in the UK and Spain, mainly on maritime engineering projects. And I'm also a charter member of the institution of civil engineers. Very nice. So WTW might not be, I don't know, it might not be recognized by everyone in the sector, so I'm going to give us an introduction to what it does. So WTW, that stands for Willis Tower's Watson, it's a massive global corporation, 48,000 people, just over 48,000 people work for us, we're in 140 countries around the world, we're better known, half of our company is better known as Willis, we're based in the city of London, as they offer so many people in the UK might be familiar with, we do a number of things, insurance, health, wealth and career and employee advisory and consulting. And also, for the most part, 99%, we're in the insurance, the risk and the risk and the broken side of Willis and so we're dealing with helping insurance brokers understand risk and giving risk management advisory, so that's how big is my risk and what can I do about it before I go and buy insurance. There's an easy parallel here, which is that after the fire of London, people started to sell property insurance, within a couple of years of that, a fabricate was set up to put the fires out to reduce the size of the claim, so that risk management advisory is a means of getting rid of risk through your behaviours rather than transferring them all through insurance, that's what Willis do, interesting. And I believe that you cover a few trillion dollars worth of assets, but people might not or people who listen to this who are a bit new to the sector might not know how an engineer ends up in insurance, I don't know, why don't you tell us about what the crossover is? Yeah, that's actually a very good question, so as Nielik explained, we are like the consulting arm for our corporate risk and broken business, so we have different practices within this consulting arm and one of them is the climate practice and what we do is we help our clients and our brokers to understand physical risk due to climate barriers and natural catastrophes. And then we have a very diverse team and we need to have engineers that understand design, how things are designed, how the failure of the probability of failure of a certain structure given a certain hazard, so we have a very diverse team, we have engineers, we have hazard specialists, we have actuaries and all of us have our own skills to contribute to provide solutions to clients and analyzing risk, so that's like I would say the bridge. Interesting, so we're here to talk about dams, are you both focused on dams entirely or do you cover other assets as well? Sure, we cover all type of assets and dams are one of the very unique challenges, I would say that the offering we have is very bespoke, but we cover buildings, industrial sites and any type of asset. I was the lead officer for reservoir safety in England for the environment agency and before I found my way into the insurance industry, I was on the verge of becoming reservoir supervising engineer on the panel in the UK, in England. But you took a different fork in the road? Absolutely, but Neil maybe you're the best person then to give us a bit of history of dams. I mean where did they start? They've been around for a long time, which is kind of part of the issue with them aging now, but let's go back to the very start, what were the original dams like? So there are dams through history, some of those are very old and they've been around for a long time, there's a famous dam and collapse, the whole civilization was built on in the Yemen, when the dam collapsed, it swept the civilization away and it never got going again. But the Romans have been building dams in and around their empire, I'd believe that one of the dams that they built in the third century AD is still standing still operational in Spain, and there are dams in the UK, the rise out of monastic works on the summer set levels, so they're very old, not very high and very interesting for the people who manage them to take care of, because they're made of so many different ways. materials. So we've had dams around for a long, long time, and there's new materials have come online. The dams have changed a fair bit and the understanding of how dams work. And importantly, the lessons you learn from the times when they fail have really taken through out the engineering business. That's really interesting. I didn't realize there were so many old ones still around. I've heard of the heavens and levels, but I didn't realize that they were considered dams. Sorry, some are set levels. Sorry. And they are registered under the reservoirs at 1975. So that was basically the Somerset Levels of John Paddyfield with steps of reservoirs marching down towards the sea by no means always full. Nice. But I suspect when people hear dams today, they think of more modern, big walls to be crude about it. But how have they changed in the last, I know, 50, 100 years? So I think the biggest changes that got bigger by a long way. I think if you look at the UK and you look at a lot of the class of dams called paneling dams, which tend to be quite, well, then made out of earth and might have stone pitching on various different elements of them. But key is a clay core there. That's moved on in many instances to let's not say that's a dated design, but the safety of those designs and the more use of things like rather compacted concrete and concrete dams that are much higher, much bigger, you're kind of hoovered dams as one dams and things like that are really important. And there was a boom in the '60s and '70s, I believe. So I think that there's an era called the Great Acceleration, which followed World War II, through the '50s. And there was a major booming construction, as you say, through the '60s and '70s, with a lot of dams being built, the world over, often funded by organisations like World Bank or IMF, as well as national investment plans going ahead in different countries. And this became more of a world-wide thing. And there was subsequently a rash of failures, which followed that, that happened then, because one of the most perilous times in the life of a dam is the first time you put water in it. You tend to find the places that are weak in it, so that there was a rash of failures then, through kind of construction errors and things like that. And maybe because some of those places where they were building them were unfamiliar with the techniques, so quite a lot of that going. And I suppose the maintenance regime has been developed as well, maybe they didn't. I don't know what is the maintenance regime of a dam. I would say perhaps the first thing that you decide when you're doing a maintenance wave here is to take a base approach. So how often am I going to look at this? You should be thinking about the maintenance regime when you design a structure as well. So the higher the risk, the more often that you need to look at it, and as when you spot defects that you're relatively quick to get on top of them, obviously you could get a defect greater than hazard. The sooner you need to get on top of even minor defects. Interesting. So if you're thinking about dam failure, which is hopefully something that we'll see less and less of, but how much risk is there? I mean, I guess the starting question is how many are there in the world? Do you have any idea? Well, I'm going to say there's probably hundreds of thousands. But there's a useful definition from I-Cold, which is a large dam. They're 15 meters high or contain more than 3 million cubic meters of water. Of those there are about 50,000 around the world. Probably according to I-Cold, about 200,000 dams in number. But it's difficult to do that because once you start getting down to farm reservoirs and things like that, people aren't going to be counting them, but they are around and some of them might be a cause for concern. And would you say that the majority they were made in the last century? No. I don't know exactly. I would say the majority of the large dams are likely made since the turn of the 19th and 20th century. Not the majority of dams necessarily. That would depend upon which constant you're on. And my view might be biased by the fact that I'm from Britain, despite the fact that I take a global view of this product. So you mentioned the great acceleration and that I suppose also we have to think about climate changes as a main risk factor for dams. I mean, how affect how much impact is it having on dams? Well done. Okay, so we've been talked to answer any question by dam safety trainers. First of all, saying that depends. So is flooding your primary risk factor that's going to dry failure? That's the first question you have to ask yourself. In some places in the world, it might be earthquake. So you might not be so worried about climate change. But I think that another common mode of failure is a piping failure, where water just finds its way through the core of the dam flows through the dam and through internal erosion eventually causes its catastrophic failure. But then the other way is an overtoppy failure where on any dam, there's a we call the spillway, which is designed to pass flood flows. And the spillway either fails because of engineering defects or because the flood that's overtopped the dam is bigger than the spillway was designed to pass, which then causes a similar kind of failure. Have we seen anything like that in the UK at all? We've had a couple of near-admisses this this century once 2007 on the early reservoir up in Yorkshire and the other one much more recent was Toddbrook Reservoir Failure. Sorry, that was not a failure, a near-miss. The Toddbrook one was an overtoppy problem, but there were already some pre-existing problems. And the early reservoir was some design defects in the spillway, which were then remediated after the dam had been drawn down. In both cases, the reservoir was drawn down. The causes were found and largely agreed upon, and then remedial action was taken to put the reservoirs back into action. And interestingly, reservoir legislation in the UK marched in lagged previous preceding failures. So the different acts that you have that govern reservoir safety tended to be brought into place after a disaster had happened. And we have a new reservoirs act, been worked on at the moment, that worked, been led by the environment agents in the ICE. That's come as a result of the near-miss at Toddbrook, and there probably going to be a number of changes in reservoir safety legislation in the UK. Yeah, I went to visit Toddbrook maybe a year or so after that happened to see how they were remediating it. It was quite an interesting project, but it was quite dramatic at the time. I remember they had an army helicopter flying over and dropping sandbags to stop the leaks and stuff. Was that something that should have been noticed before it happened? I think that's controversial. I think as, so let's go back to that risk-based approach to dam safety and the role of visual inspections in assuring ourselves as to whether a dam's in good condition or not. I think there's other types of ways that you can monitor the condition of a dam through the use of technology, whether that's things like, let's say, ground penetrating radar or LiDAR to measure defamation and embankment. You could do that from space [BLANK_AUDIO] synthetic aperture radar, all using fiber optic cables to measure defamation in a structure. So those are just a few examples, but I think as those technologies move on, your more likely to find defects at an early stage, rather than when it becomes a critical safety issue. So I wouldn't want to put myself in a situation where I would say that any inspecting or supervising engineer on a reservoir is at fault because you can overlook things inadvertently with that sort of thing, but there are multiple layers in the Swiss cheese model of assurance. Which means that if they're in place, properly, proper engineering assurance going on, that you should be able to catch those issues before you have a problem. And I think with people learning lessons and reporting honestly, those defects are, you know, with those ways in which we've struggled to manage reservoirs are less likely to happen if people are attempting. Interesting. So let's talk about where WTW comes in and how it works with the asset managers. What's the relationship? We help clients to fully understand the risk, and so we begin to look at the different failure modes that they can experience, and this is together with the client and also their engineering team or the appointed engineer. And as Neil said, the thumbs can fail in many ways, so you can have an overflow or overtopping, they can develop internal leaks. So it's important to understand what could happen because that will then drive how the water will get released and how fast it will reach the downstream areas and population. So it's about understanding, you know, all of these steps, so how the thumbs can fail, how fast, and quickly the wave of the water could be released, and then what's the population, and then infrastructure downstream that could be affected. And then you use all of that data, you kind of combine it to find the broker, is that right? Well, our work is directly either with the client or the broker, so our work is mainly helping them understand the risk and translate. So what we really start working is when we already have from from either the client or the engineering team, the flood pad, or the flood footprint of the down bridge, then we overlay that with all the downstream receptors. So for that, we need to characterize all the assets that we have downstream, if they are commercial, residential, the population that is at risk, the type of industries, the infrastructure, because then we need to assess or quantify the financial loss. Sorry, it didn't mean or did mean to interrupt, but I didn't think I thought you finished. So the workflow, we are a broker, so the workflow is that with a client's need is identified, whether it's through conversation with us or from themselves. And they're likely going to have a reservoir failure assessment, but we may work with a subcontractor to do that, because assessing how quickly the dam fails and how that propagates and the depth and velocity and the debris factors within the flow, it is very specialized to us, equally specialized, though, is the loss modeling, which is Duluthay's forte. Of course, he brought the Duluthay now. Yeah, that's where we really add value here. I mean, it's through what I'm nearly saying that for assessing the how the dam bridge develops, you really need engineering expertise. Where we start our work is downstream assessing and the losses, and understanding how the flow in terms of flood depth and velocity will impact the assets downstream and translating that into a financial loss, that then the client can use for risk management and also for risk transfers strategy. So they can assess how to transfer that risk to the insurers. Do you ever show your client all the modeling and they go, wow, I never realized how much was it risk? Yeah, well, for this type of analysis, the losses are in the billions. Well, it depends on the exposure downstream, but if we're talking about that dam, it's outside mediums ICT, it can be very catastrophic, because it impacts, well, there is the component of the loss of life, then all the properties that are impacted. If we're talking about industries or commercial sites, we're talking also about not only damage to the shops or to the buildings, but also the interruption of their business, which is also something that the dam operator may be liable for, then there's also the component of the cost of the emergency response, there's also the component of the impact on the vehicles that maybe dropped on the floor, on the flow, any contamination if there are impacting sites that may have a storage tank of any contaminant, so there's a lot of things that can go wrong and our work is to analyze that scenario to be as realistic as possible. Do they ever push back and say, "I believe that it's going to be that bad?" Well, they always trust what you'll work. Well, there is a price when they see the figures, but we always are clear and transparent in the way we assess these things, it's very important to note that there's a lot of uncertainty. So we analyze scenarios that look also at what will happen if, for example, we are assessing loss of life, what will happen if the failure happens at night or at midday, so you need to make assumptions of where the population will be concentrated, and that help understands the uncertainty on these things, just testing different scenarios. But yeah, we need to understand that it's a very complicated thing to model, and the more accurate you are, the better, but it's very difficult to predict these things. And how often do you reassess for a client? I think there's several reasons why you might do it, has there been development upstream with the dam? Does that change anything? Has there been new development downstream with the dam in the area that would receive the water, if it failed? On your last key inspection of the dam, did anything change at the site? When you reviewed your hydrology, did something else change? So really, a periodic assessment of risk is a good behaviour to have just as a part of your dam site's de-assessment and your whole operational program, but revisiting it when everything changes is also another good reason. But those regular assessments should be tracking the hydrology as well, and whether climate change is making the likelihood of failure more or less likely. And I forgot to ask for the modeling, how do you collect all that data? Where does it come from? You talk about the dam, or the dam failure, or all the data about what's upstream and everything else, where do you collect a little from? There'll be mountains of data on the dam safety, on the dam size, the baslimitry, and therefore the stored volume of water. You also have have catchment data, so you'll be looking for some kind of digital terrain model, more likely that you're in a western setting where you've got LIDAR, high density, good quality DTMs, it kind of puts together how much water you're going to have with the hydrology that you've got, and then that feeds into Duluthase side of things where you're looking at the loss data, so I'll let her take the lead with where you get that information from. Yeah, well, for the lost data, well, we use some open sources, it depends on the region, sometimes there's a lot of information, so because we need to build a model downstream, so we need to use open street map, there's a lot of GIS work involved on that and characterizing the assets, then we need to assign value to each asset, replacement value, and that means that we need information on the valuation of assets, if that's not available, then we need to do some research, then in terms of also the population, sometimes we get granular information as age of all the population, because elderly people may struggle more to have acquired, etc., so it's important also to know that, and in terms of one key important thing is that the models that we use to assess the damage to the assets, and in the industry these are called vulnerability curves or damage curves, which is the relationship between the intensity of the hazard and the potential damage to the asset, and for that, I would say there needs to be also research, because it depends on the region, so the core of each vulnerability curve is the engineering response of a particular asset or a building to an intensity, but then there are a lot of other components that also play a role, for example, if we are in a country that with advanced building codes, and then we know that they are stringent and the application of those building codes is done, or how prepare the country maybe, because that will influence the damage that you would expect, and so for that, we need to look for the vulnerability models that with a degree, they replicate the damage that we would expect, and it will be different in each region. So, just to finish off then, maybe a big question or not, how worried about Damfailure should we be? You should definitely be concerned, you shouldn't take it lightly, that's what I mean by being concerned, so you should be prudent, how worried should we be about Damfailure now? Well, the rate of Damfailure is ticking up just a little bit, particularly in North America at the moment. There would be an average of, say, one major Damfailing a year, telling storage facilities with special case, but there are rate of failures ticking up a bit as well, we won't dwell on them for long. I think if you, let's look at the US just for a second, the American static civil engineers produces a health assessment of their infrastructure every year, and in 2021, where dams go to D, and 2025, the dams go to D minus. At the moment, they've only got 20 billion allocated out of 185 billion that they should spend, and that number has risen quite significantly beyond the rate of inflation between 2021 and 2025, and their own count from the American down safety officials have 90,000 aging dams. So there's been under investment, so where there isn't sufficient investment, where there's perhaps political instability or conflict, you're more likely to see the failure of the infrastructure. That sounds like a no-brainer, but when you're in a global insurance broker working with clients who might have hydropower resources in Latin America or sub-Saharan Africa or things like that, you have to have a view to how things unfold in those nation-states, and with individual assets, because one asset in one country could be managed completely differently to the whole of the rest of the country, so you can't tie everyone with the same brush. But I think the other thing to keep an eye on, as we did touch on the principle causes of failure, if not all of them, they're a many, that was the earthquake, the internal erosion, and the over-topping failure of the spillway. There's some two drivers which are increasing the likelihood of spillway exceedance and damage. The first is just as the world warms. The atmosphere can hold more moisture and therefore the intensity and amount of rainfall that can fall in a single event is increasing. The second one is a little more subtle, but I've been noticing that as a flood manager when I was at the Environment Agency is something that's referred to a sequencing. It's been picked up by National Hydrological Institutions globally. There are scientific papers on it which are coming out of most countries, so you see the EAS Hydrology team that Claire Waller was leading, I'm picking up on this, but so the Swedish Meteorological and Hydrological Institute and the USPR. They've noticed that where the patterns get locked in and you get these atmospheric rivers or things like this where you have a sequence of events come. You then have very, very wet anti-seeding conditions and then a more moderate rainfall than your design rainfall event might come, but it gives you an exceedance flow. Furthermore, you're getting these exceedance flows more frequently because of this feature. What this means is that, yeah, sure, first couple of times, the spillways up to it, but a small defect emerges and more to get under somewhere and then the end time that that sequence plays itself out, you start to see dam failures. There have been a couple of instances. There was one sequencing event in Appalachian North Carolina where I believe as many as 35 dams failed in one sequence of storm events because of this multiple loading effect. I would say be more attentive or be my takeaway from this. If I could just put in a little bit of a plug for Willis here, I work in a team called Willis Research Network. We don't have a sales role. Our job is to understand and unpack risk to advise colleagues like Dulfay or to advise insurance brokers. We've got to clear our understanding of the risks that we're facing. To use that understanding to give better risk management advice to clients, and while many of us are subject matter experts working on either risk caused by humans like cyber or natural catastrophes like tropical cyclones or heavy rainfall, we can't know everything, so we commission outside organisations to do that research for us. For example, we're working up something with Imperial at the moment, looking at the mobilisation of debris and floods. With Newcastle, we've developed in particular a surface water flood model to help us understand pluvial risks better because insurance models don't do pluvial risks so well, they do it, but they could do it better. We're working on the modelling of non-Newtonian fluids so that we can understand the failure of tailing storage facilities better and carry that into our mining clients who are very concerned to improve the safety of large tailing storage facilities. So don't be worried because there are professionals out there doing their jobs for us. But are there enough of them? Well, that's a really good question, Rob, because I've read the Spanish Parliamentary investigation into the supply of dam safety engineers. I've looked at the one from England because that's why I got onto the list to become a dam safety engineer, and there's an insufficiency of people from the industry taking an interest in this facet of engineering. And it's one of the sexy ones to be fair. You know, bridges, nuclear power, dams, they're the kind of open heart surgery of civil engineering, aren't they? If you say so. I don't know, I think people like Railways and tunnels, but hopefully some people will listen to this and be inspired then to pursue a career into dam safety. Anyway, thank you both Neil and Duluth for joining me and explaining to me all about dam safety and the risks. Yeah, it's been really interesting. Awesome. Thanks very much for having us. Thanks for the opportunity. I have a problem. Yeah, thank you very much. And to the listeners, we will see you next time on The Engineers Collective. The Engineers Collective comes to you with monthly news analysis from our editorial team, and in-depth interviews with industry experts and thought leaders. If you're a private sector organisation looking to reach tens of thousands of listeners, you can find out more about sponsoring an episode of the podcast by visiting newcivilengineer.com forward slash podcast. (upbeat music)