Sea-level rise is accelerating. According to the National Oceanic and Atmospheric Administration, the global average sea level set a new record high in 2022 of four inches above 1993 levels. What do the effects of sea-level rise look like in real-time? To find out, The Washington Post installed a series of cameras in Carolina Beach, south of Wilmington. Brady Dennis is one of the reporters who worked on the story, and he joins me now.
Marshall Terry: So you set up these timelapse cameras last August, and you focused on a road in Carolina Beach called Canal Drive. Why there?
Brady Dennis: Researchers from UNC Chapel Hill and NC State, among others, had written about this. They set up their own camera system there. And in talking to them, (we) decided this would be a good place to look at this problem because it had all the elements of flooding that we see in so many coastal communities, and that are really increasing in a lot of coastal communities.
Terry: The story is broken into two days. One is clear and calm, the second is rainy. Let's start with that first clear and calm day. What did the cameras record?
Dennis: Yeah, one thing we really wanted to illustrate in this is that this type of flooding that's happening more and more in a lot of places is happening quite often on perfectly clear, sunny days. And to illustrate that, you know, we went when there was a particularly high tide known as a king tide. And you could see on a clear day the various ways that, you know, as the tide rises, water works its way onto this road that you referenced in Carolina Beach, which is kind of a main drag there.
One main way is that it covers the drainage pipes and kind of fills them up backwards. You've got seawater coming up the pipes and out drains that are on the street — instead of, you know, it should work in the opposite direction, obviously.
You have the groundwater, the water table itself is rising as sea levels rise — and it sort of pushes water up through cracks in the pavement, and sort of up through the land itself. And then the, sort of, more obvious way we might think about flooding, is it sort of overtops areas of the shoreline that maybe don't have a seawall. And you can see the water in real-time, sort of, come up over the land and onto the streets.
All three of these things were happening at once on this day, and by sunset you had a road that was completely underwater — more than a foot deep in some places. And we wanted to illustrate that, you know, through the timelapse, so that you could watch this happen in real-time.
Terry: Now, what about the second day, which was rainy?
Dennis: This is really important because scientists are very interested in and are studying what's known as compound flooding, which is when you have, you know, the sea at a high level and it combines with with rain. And that combination can really exacerbate flooding in many places and is expected to get worse as we have higher tides, as we have these stronger rainstorms that so many of us are familiar with now. As the sea levels get higher and the ground table gets higher and the drains fill up, as we talked about earlier, there's just less room to hold water that falls from the sky. There's just nowhere for it to go.
And, in fact, that was essentially what local officials told us in Carolina Beach, as well as the scientists who study this is, like, when the rain comes — the cause of all these other things that are happening with the higher sea level — there's nowhere for the water to go, and it backs up and it fills up like a bathtub, one of the city officials told us.
And that's exactly what we watched and recorded on the second day, was that it really didn't take long for the infrastructure there, and the drainage, the stormwater system, to really just get overwhelmed. The flooding was even deeper that second day, when this compound flooding happened with rain combining with a high tide.
Terry: Well, it sounds like these high-tide flooding events and compound floods are becoming more frequent, even routine. So aside from just them being inconvenient, I mean, what's the effect of all this?
Dennis: So you see this type of high tide flooding more and more often. Scientists at NOAA say it's happening about roughly five times as much as it did back in 1990. And that it's really going to accelerate, and we can expect these kind of floods to happen 15 times as often by 2050.
What does that mean? I think I think it changes everyday life in a lot of places. It's not as catastrophic, perhaps, or devastating as a hurricane, you know, all at once. But what you see in a lot of places is, you know, damage to cars from the saltwater, damage to homes and the infrastructure. You see people who either can't get to their home down their street, which is blocked. There are worries that, over time, as more and more roads fall below high-tide lines that, you know, certain people won't be able to get to the hospital when they need to or to the grocery store. So you have all these things that can really change everyday life for people, even if there's not flooding in their home.
Terry: What are officials in Carolina Beach doing about this?
Dennis: One of the main things they've done is to try to install what they call backflow preventers in their drainage pipes. And, essentially, that's to try to keep the seawater from coming up, you know, the pipes and through the drains, and putting water out onto the streets. Sometimes these work as intended, sometimes they don't.
There's talk about possibly raising roads in some places along the coast. There's talk about possibly doing buyouts in various places. I mean, all of that is very tricky — both from a cost perspective and, you know, when you're dealing with public property versus private property. I don't think it's a problem with an easy answer.
Terry: So the bigger series this story is a part of is called The Drowning South, which is very ominous sounding. What does this problem look like in other coastal communities throughout the South?
Dennis: You know, in places like Louisiana — wetlands, they're in a state of drowning essentially, They can't keep up with the sea-level rises happening. They're a buffer for hurricanes, and they're just really important.
Thousands of septic systems, which are obviously underground, are being compromised by the rising groundwater. And that's a really big deal in places like Florida and the Carolinas and Georgia.
You see worries about housing prices, and people's insurance rates obviously have gone up. Again, you've got more and more roads that are increasingly flooded at high tides and during heavy rains. We've been told by so many people we've talked to, so many people who study this, that this kind of flooding is likely going to be, you know, tougher to deal with and more expensive to deal with over time.
