Anisa Khalifa: The small mountain village Chimney Rock sits right on the Broad River in western North Carolina. Its main street is usually buzzing with tourists visiting Chimney Rock State Park, or locals enjoying their favorite restaurant, all while the steady rush of the river rolls by. But recently, Chimney Rock has looked much different. Hurricane Helene brought massive amounts of rain to western North Carolina last fall. The storm overwhelmed the river that runs through Chimney Rock.
[News Audio]Voice 1: Chimney Rock says much of the area is wiped out tonight by massive flooding from Helene鈥�
Voice 2:鈥� devastation we're dealing with here. Chimney Rock's gone.
Voice 3: But the storm's flood was so severe, it turned this thriving tourist spot into a desolate landscape.
Anisa Khalifa: Now, tourists have been replaced with trucks, tractors, and excavators. The village is ground zero in western North Carolina for a massive project in the wake of Hurricane Helene. Countless buildings and homes need to be rebuilt, as well as lots of roads. Helene wiped out hundreds of roadways. Now, engineers are working to fill in the holes it left behind. And in places like Chimney Rock
Nathan Moneyham: The whole thing's a big hole.
Anisa Khalifa: But how do you rebuild a road that's meant to last, in a climate that's changing quicker than we can keep up?
Lauren Sommer: The critical question right now is, what information are we using to plan for these disasters?
Anisa Khalifa: I'm Anisa Khalifa. This is The Broadside, where we tell stories from our home at the crossroads of the South. This week, producer Charlie Shelton Ormond goes to where the weather meets the road
Charlie Shelton-Ormond: [on the side of a road] Alright, so I'm standing where the original road was and looking down at the river. Nathan, can you hear me?
I'm standing on top of a ridge trying to talk to Nathan Moneyham. Where are you at right now? He works for North Carolina's Department of Transportation, DOT, as a division construction engineer.
[roadside] About how far down are you?
You probably can't hear him, but it's 80 feet.
[roadside]80 feet? I can't really hear you, but that's kind of the point.
Nathan's standing on a stretch of gravel that's winding along the river. It's part of the network of temporary roads DOT has built since Helene hit last fall. The storm wiped out Chimney Rock's narrow mountain highway, leaving a sea of rubble in its wake. Finding pavement now among the splintered streets is rare, but Nathan's showed me a small patch where the original road used to be, and carved into it is a big drop off diving right into the riverbed.
Nathan Moneyham: And in the height of the storm The water elevation had eroded into the slope all the way up to the existing road.
Charlie Shelton-Ormond: Wow, so the, so the water had risen, it was 80 feet from the river up to slice off this side of the road.
Nathan Moneyham: At its height, at least was washing away that existing slope you see here.
Charlie Shelton-Ormond: This slope is one of many along the highway that runs parallel to the river. Steep drop offs like this punctuate the valley.
Nathan Moneyham: For about two and a half miles, uh, the road was completely destroyed.
Charlie Shelton-Ormond: Have you ever seen anything like this in your time with DOT, in your time as an engineer? Have you ever seen any damage like this before?
Nathan Moneyham: No, and this is definitely something, this beyond any level of storm that, that Western North Carolina has seen and really above and beyond anything that's ever been seen in the state of North Carolina.
Charlie Shelton-Ormond: Now, DOT's big undertaking is set to begin: build back the miles of road that were washed away in Western North Carolina.
Nathan Moneyham: Pretty significant permanent repairs. A lot of new walls, a lot of that obviously has been washed away will need to be replaced.
Charlie Shelton-Ormond: It鈥檒l take a long time 鈥� years 鈥� to give everything the permanent fix it needs. Like that 80-foot hole鈥�
Nathan Moneyham: More than likely a pretty significant size retaining wall.
Charlie Shelton-Ormond: Okay so something like a retaining wall for this 80 foot drop off would be appropriate.
Nathan Moneyham: Yes, that's our expectation.
Charlie Shelton-Ormond: But with a climate that's getting more intense, the next big storm is only a matter of time. So how do you build it all back so it doesn't get washed away again? Like that retaining wall. Can DOT put in a wall for an 80 foot slope that'll hold for 80 plus years?
Nathan Moneyham: As much as we can. to incorporate resiliency and our current standards into these designs.
Charlie Shelton-Ormdon: And in the meantime, as they gear up for this big rebuild, DOT has all those temporary roads they just finished. If all that's going to be there for years, those roads are going to see some storms of their own.
Nathan Moneyham: We'll be looking to pave this in the coming months so that they can function for the next several years.
Charlie Shelton-Ormond: So, what this road needs, what this area needs, is a new road that is going to be, uh, stronger. So if I wanted to learn more about how to design a road like this
Nathan Moneyham: Yeah, hydraulics is a major player in these areas of damage with the storm that are along the river. And Chimney Rock's a good example of that.
Charlie Shelton-Ormond: Alright, hydraulics. They're the engineers who make sure roads can handle water, whether that's rivers, rainfall, flooding. So I knocked on their door. and met up with DOT's main hydraulics guy, Matt Lauffer.
Matt Lauffer: Just oversee all the water management requirements for the department, basically.
Charlie Shelton-Ormond: And as far as water management goes, Matt says Helene in much of Western Carolina was unreal.
Matt Lauffer: I mean, from a rainfall perspective, you know, it's off the charts, it was greater than a thousand-year event.
Charlie Shelton-Ormond: A 1,000 year event. Let's break that down. That means the chance of rainfall from a storm like Helene happening in any given year is one in a thousand. It's not that this much rain happens once every thousand years. It's a percentage -- one in a thousand, a 0. 1% chance. So, very rare. Matt says trying to safeguard against a storm like that is nearly impossible.
Matt Lauffer: The magnitude of this event is something, you know, you can't really design for. But you can definitely look at ways to build stronger, better.
Charlie Shelton-Ormond: In order to do that, let's check out some of what's in Matt's tool belt. Some of the things he uses when drawing up plans for a road. To get a good sense of how much water a highway, a bridge, or drainpipe is going to see, Matt relies on two big resources. One of them comes from the U. S. Geological Survey. It's where Matt can find data on streamflow.
Matt Lauffer: You want to know what the flow in the river is, right, and the streams that you're crossing.
Charlie Shelton-Ormond: So when Matt's drawing up plans for something like a bridge, this data helps him get a feel for the volume of water that's likely to flow underneath that bridge.
Matt Lauffer: Then you have, for rainfall, there's Atlas 14.
Charlie Shelton-Ormond: Atlas 14. This is a data set from NOAA on rainfall records. It's where Matt can look at a specific place, like Chimney Rock, and see how much rain amounts to a 1,000-year event. Or a 500-year event, a 100-year. The data goes all the way down to a one-year event.
Matt Lauffer: And they go through a complicated analysis of all the rainfall gauges for different regions of the country.
Charlie Shelton-Ormond: For example, if a rainstorm lasts for three days, like Helene, a 1, 000-year event in Chimney Rock would be nearly 12 inches of water. But like Matt said, Helene brought rain to the region that was off the charts.
Matt Lauffer: We've got reported rainfall amounts as much as 11 inches per hour. That's just a significant amount of rain, right? It's unprecedented.
[News Audio]Voice1: I want to get a look at some of those rainfall totals for you. Busick, North Carolina saw over 30 inches of rain from Wednesday to Friday. That's over in Yancey County.
Voice 2: Look at this -- to the east of Asheville, North Carolina, an estimated 14. 1 inches of rain.
Charlie Shelton-Ormond: The intensity of Helene was rare, but the rainfall it dumped is just a warning for what's to come. Matt put it like this.
Matt Lauffer: Like today's 500-year will be 2100's 100-year.
Charlie Shelton-Ormond: Today's 500-year storm is set to be a 100-year event by the end of this century.
Matt Lauffer: Well how do we build this back so that it can withstand those forces in the future?
Charlie Shelton-Ormond: It can be hard sometimes to think about what life will really be like in 2100. A lot of us probably won't be around by then. But if DOT is putting in the work, and money, to build a new highway, they certainly want it to still be here at the end of the century. So it's crucial for them to know.
Lauren Sommer: Okay, what should we plan for in the future? And that's where rainfall records come in.
Charlie Shelton-Ormond: That's Lauren Summer. She's a climate correspondent for NPR.
Lauren Sommer: You know, you don't want to build for the climate of the past.
Charlie Shelton-Ormond: But here's the problem. Atlas 14, the rainfall data that's a key part to the building process, is solely based on the past. It's historical data.
Lauren Sommer: That doesn't capture how much more extreme storms are already today, and it definitely doesn't capture how much more extreme storms are going to get in the future.
Matt Lauffer: When we look backwards, we can't really, that's not a good indicator of what's going to happen in the future now, right?
Charlie Shelton-Ormond: If an engineer is using old, outdated tools, that road is going to quickly turn into a dead end. And then what? That's coming up after a quick break.
[ADVERTISEMENT]
Charlie Shelton-Ormond: Alright, we're rebuilding a road that was wiped out from massive flooding. And we want to make it strong enough to withstand more storms in the future. So what do we have? We have the tried-and-true research at our disposal.
Matt Lauffer: Right now, we have our traditional methods that we're still using.
Charlie Shelton-Ormond: With lots of climate data from the past. But how helpful is data that's decades old when we're looking at the road ahead, literally. Well, the good news is--
Matt Lauffer: There's a lot of research and thought going into how we can design for the future.
Lauren Sommer: There's been a big push to get those rainfall records updated.
Charlie Shelton-Ormond: Climate reporter Lauren Sommer again.
Lauren Sommer: And NOAA is now in the process of updating rainfall records for the entire country. Before it was kind of piecemeal, where it would be one region would get some, the states would have to help pay for it. It was a very tricky process. So now it's going to be done nationwide, and it's going to be done in a way that takes climate change into account.
Charlie Shelton-Ormond: This new data set, the one replacing Atlas 14, will be called鈥� any guesses? Atlas 15.
Matt Lauffer: When Atlas 15 comes out, you're going to see a shift, I think, in how we look at some of our design criteria for future conditions. And what I mean by that is if it's like an interstate highway that's going to be in place for 100 years, you're going to be looking at what is the rainfall going to be in 2100.
Charlie Shelton-Ormond: Atlas 15 is going to be a game changer for engineers like Matt 鈥� when it comes out, NOAA is set to release most of Atlas 15 next year in 2026. But meanwhile, places like Chimney Rock need to be rebuilt now. The people who call it home had their lives upended and they're ready to see their town repaired as soon as possible. Because of that, North Carolina's Department of Transportation sees a lot of potential in Atlas 15, but its engineers aren't exactly waiting around for it.
Jared Bowden: I just got this call from Matt Lauffer, and almost like a cold call to some degree, where it was like, we鈥檙e concerned.
Charlie Shelton-Ormond: Enter Jared Bowden. He's the Associate Director for the North Carolina State Climate Office.
Jared Bowden: I've been running climate models for decades now, almost over 20 years.
Charlie Shelton-Ormond: A few years ago, Jared and Matt got to chatting and quickly realized it was high time for a climate scientist and an engineer to join forces.
Matt Lauffer: And the partnership with climate scientists is really important for us engineers, civil engineers as we go forward. Historically, we haven't had to have that because everything's been based on, okay, well, we're assuming a constant climate. It's not the case anymore, right?
Charlie Shelton-Ormond: So, Jared and his team got to work sifting through a bunch of historical data on North Carolina's climate, and turned the past into a prediction.
Jared Bowden: What we did in our project, we took it a step further. We were able to look at the frequency of rainfall events and how the intensity may change.
Charlie Shelton-Ormond: The result? One word. RaInDROP.
Jared Bowden: We created this tool called RaInDROP, and I can't remember what the acronym stands for.
Charlie Shelton-Ormond: Oh wow, that鈥檚 a lot of letters for an acronym.
Jared Bowden: Yeah, yeah.
Charlie Shelton-Ormond: I thought it was just a cool word.
Jared Bowden: Yeah, no, it's an acronym.
Charlie Shelton-Ormond: That'd be impressive if he could remember all that.
Charlie Shelton-Ormond: RaInDROP is kind of like a North Carolina specific version of Atlas 15. It's an interactive map that predicts rainfall levels in the future. Jared actually gave me a little tutorial of it in action.
Jared Bowden: Yeah, so you can start making these comparisons, right?
Charlie Shelton-Ormond: We're looking at two maps. One up top, the data set is Atlas 14, so that's looking at observational historical data, that's rooted in the past. And then the map on the bottom, the second map, is the one that uses the predictive modeling that y'all put together.
Jared Bowden: Yeah, so you, you can come here and let's say that the large differences are at end century.
Charlie Shelton-Ormond: It's a lot of red and orange鈥�
Charlie Shelton-Ormond: RaInDROP also lets you tweak the map according to different levels of greenhouse gas emissions.
Jared Bowden: These different options mean high emissions, like high greenhouse gases, or kind of like a middle of the road greenhouse gases.
Charlie Shelton-Ormond: And the map confirms. that if higher levels of greenhouse gas emissions continue, the really intense storms will become more common down the road.
Jared Bowden: On top is the today's 100-year storm. The bottom is a future 50-year storm. You'll see that these look very similar.
Charlie Shelton-Ormond: Like Jared said, he's been running these kind of climate models for decades. But it's one thing to put all this data into a tool like RaInDROp. It's a whole other thing to get that tool into the right hands.
Jared Bowden: North Carolina Department of Transportation is on the cutting edge of, of this DOT invested in, for instance, doing climate model simulations themselves. I don't think that a lot of other state dots are thinking of doing those type of things as actively as DOT here, North Carolina DOT
Charlie Shelton-Ormond: This dynamic duo between DOT and climate scientists means taking the public data that's available, things like Atlas 14, and making it even more southern. For example, much like the engineers rebuilding the roads, Jared's crew spotted a big hole in the data and decided to fill it.
Jared Bowden: A fundamental problem is precipitation from hurricanes. We recognized early on that this was a weakness in some of the data sets we have. And so we then created a data set that was looking at future hurricanes. We not only have tools in the data that DOT can use to think about resilience. But they have different flavors of the data.
Charlie Shelton-Ormond: So, what do these tools and data mean for a place like Chimney Rock? Well, if Matt's drawing up plans for that retaining wall, he wants to make sure it's built to last for a long time.
Matt Lauffer: What can we expect maybe in 2100 or 2050 from a precipitation standpoint? How do we do a better job for future conditions?
Charlie Shelton-Ormond: North Carolina DOT is looking decades down the road. But data isn't the only thing you need to rebuild. There's one final piece.
Matt Lauffer: It also costs a lot of money.
Charlie Shelton-Ormond: Yeah, about five billion dollars. That's how much DOT estimates it'll cost to repair all the damaged infrastructure. They have some relief money to start the job. But getting all five billion that's needed will take time. So how does DOT decide how to best use those funds? Well, not every road is built the same. Matt says each road design is case by case according to where it is and what it needs.
Matt Lauffer: Is it a primary road? Is it a U. S. route? Is it an NC route? Or is it just a secondary route, right? Those also drive the decision-making process.
Charlie Shelton-Ormond: For example, an interstate highway isn't getting the same treatment as something like a back road, a secondary road, as Matt says.
Matt Lauffer: I mean, you're not building a secondary road to a hundred-year design storm, right? Economically, it doesn't make sense.
Charlie Shelton-Ormond: So what's the recipe for rebuilding? Well, each road has its own unique concoction fused into its concrete. Engineers develop a specific equation that looks at the data available and balances resiliency with cost. And now they have some new tools in the shed, ready to be used. But the real work? The designing and actual rebuilding is only just getting started.
Matt Lauffer: And we don't have all the answers yet. There's just a lot that needs to be done. So, it's going to take some time.
Charlie Shelton-Ormond: And in that time as the rebuild unfolds, here's to hoping another Helene, another thousand-year storm, doesn't come through again anytime soon.
Anisa: This episode of The Broadside was produced by Charlie Shelton Ormond. It was edited by Jared Walker. Wilson Sayre is our executive producer. Special thanks to Kenny Malone for his help on this episode. The Broadside is a production of 吉彩网网站 North Carolina Public Radio and is part of the NPR Network. You can email us at at broadside@wunc.org. If you enjoyed the show, leave us a rating, a review, or share it with a friend. I'm Anisa Khalifa. Thanks for listening. Y'all we'll be back next week.