Season 4, Episode 6: Tyler Antrup: Green Infrastructure and Climate Adaptation in Coastal Cities
Tyler Antrup, an urban planner and professor at the Tulane School of Architecture
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Tyler Antrup, an urban planner focused on climate adaptation and water management, a professor at Tulane School of Architecture, and a member of the Sewerage and Water Board, joins John to discuss the complex water challenges facing New Orleans. From green infrastructure to mitigate flooding to the creeping threat of saltwater intrusion into drinking water systems, Tyler shares insights on adapting urban environments to the realities of climate change. They explore the evolving dynamics between stormwater management, subsidence, and sea level rise, as well as the critical role of community-based organizations in driving innovation.
“Last year was a big scare. It was a wakeup call, but it’s not such an urgent challenge that we need to start taking big expensive swings. This is something that we can be very methodical about and very thoughtful, and actually take a very rational planned approach to how we want to address this challenge going forward.”
Key Topics
Saltwater Intrusion and Drinking Water: John and Tyler discuss the increasing threat of saltwater intrusion into New Orleans’ drinking water supply, driven by sea level rise and drought. Tyler shares insights on potential solutions, including upgrading water treatment systems, relocating intake points upriver, and fostering regional collaboration among water utilities.
Green Infrastructure for Flood Mitigation: Tyler explains how nature-based solutions, ranging from small, individual efforts to large, regional-scale stormwater storage systems, can address urban flooding in New Orleans, while delivering additional benefits like increased green space and reduced heat island effects.
Subsidence and Groundwater Management: Tyler sheds light on the challenge of land subsidence in New Orleans, caused by deltaic soils and historical water management practices. He emphasizes the role of groundwater recharging through green infrastructure in reducing subsidence and ensuring long-term urban adaptation.
Community Advocacy and Action: John and Tyler explore the critical role of grassroots organizations in driving community-based solutions, highlighting their leadership in building green stormwater infrastructure and addressing environmental inequities in underserved neighborhoods.
Links to Relevant Studies and Resources:
Learn more about Tyler Antrup
Learn more about the Sewerage and Water Board of New Orleans and their work on stormwater management.
Tyler highlights the contributions of Waterwise Gulf South in driving community-based solutions. Learn more about their work here.
Further Reading:
Tyler discusses the role of green infrastructure in mitigating urban flooding. Read about the benefits of green stormwater infrastructure in this EPA guide.
Saltwater intrusion poses growing challenges to coastal cities. Learn more in this USGS report on saltwater intrusion.
“There are so many ancillary benefits that come with [green infrastructure] because it’s solving this very sort of technical pollution related challenge, but oftentimes we can use these solutions to create neighborhood parks in places that are underserved by green space, and to plant trees to reduce the urban heat island effect.”
Transcript
START (AUDACIOUS WATER EPISODE 6, SEASON 4)
[MUSIC]
JOHN: Welcome to Audacious Water, the podcast about how to create a world of water abundance for everyone. I'm John Sabo, director of the ByWater Institute at Tulane University. On today's show we're diving into the complex water challenges facing New Orleans. My guest is Tyler Antrup, professor at Tulane School of Architecture and member of the New Orleans Sewage and Water Board. Tyler is an urban planner focused on climate adaptation and water management, and we discussed the growing threat of saltwater intrusion, the role of green infrastructure and mitigating urban flooding, and how New Orleans is adapting to subsidence and sea-level rise. Tyler, welcome to the show.
TYLER: Thank you. Good morning.
JOHN: Cool. Well, let's dive right in. Off the top, we both teach at Tulane University in New Orleans. What led you here?
TYLER: Yeah, I went to Tulane for grad school. I graduated in 2012 from the School of Architecture with a master's degree in sustainable real estate development, and I have an undergraduate degree in urban planning, and just kind of kept in touch with the school over the years in a number of different capacities, and started teaching as an adjunct in 2021, and full-time moved over in 2023.
JOHN: Great. So we're both new to the university more or less, at least in full-time capacity. Let's transition to another question that's also personal; it's one I like to start the show with, sort of background for the listeners. How did you get interested in water, green infrastructure, and urban planning?
TYLER: Yeah. So as a kid I was in the Boy Scouts and my dad, and brother, and I would spend a lot of time backpacking and camping, and a lot of time outdoors. And I think that made me a bit of an environmentalist. And when I was in undergrad at the University of Missouri Kansas City they have the most expensive consent decree in the country for combined sewer overflowers. And so they pretty quickly identified the need for, you know, some smaller-scale nature-based solutions to their combined sewer overflow issue. And I just thought it was really compelling, this idea that you could solve these massive engineering challenges with sort of everyday solutions that people could take on at their own homes. And that really got me into green infrastructure and stormwater management, and I just have kind of continued pursuing that throughout my career.
JOHN: Okay, cool. You're spot-on to the theme of this series of podcasts, which is about the Mississippi River Basin. So let's unpack that a little bit. Let's start with the technical stuff. A consent decree--can you tell listeners what a "consent decree" is? And can you also tell us what a "combined sewer overflow" is?
TYLER: Yeah, absolutely. So a "consent decree" is obviously just a legal tool that the federal government often uses to force compliance with their regulations. So cities and counties around the country are required to limit their discharges of certain types of pollutants into waterways through the Clean Water Act. And so when they violate those requirements the federal government will place them under a consent decree to force them to make changes in order to come into compliance. And one of the major issues that cities are dealing with, particularly older cities, mostly cities in the north, are dealing with combined sewer overflows. And those are where their storm sewer and their sanitary sewer are combined. And so during a normal time when there's not rain or high demand on the system all the water in the system will flow to a water-treatment plant where it gets treated, the pollutants are removed and brought down a compliance level, and then are discharged into that body of water. But during a large rain event, or during, you know, large demand on the system the demand will overwhelm the water-treatment plants. And so the raw sewage essentially will discharge, untreated, into the receiving water body. Which is obviously both just generally undesirable, but also is a violation of the Clean Water Act. And so those cities are being forced to take a number of actions, like separating their sewers obviously, which is sort of the best guaranteed engineered solution, but it's also extremely expensive. And so cities are also just looking at ways to prevent stormwater from making it into the sanitary sewer system with solutions like green infrastructure so that they can reduce the amount that makes it into the system during rain events, and therefore limiting the amount of overflows that would occur.
JOHN: So yeah, that's super interesting. So it's kind of like an integration of built and natural infrastructure to create a solution that's less expensive and possibly aesthetic, too, right?
TYLER: Absolutely, yeah. Because there's so many ancillary benefits that come with it, because it's solving this very sort of technical pollution-related challenge. But oftentimes we can use these solutions to create neighborhood parks in places that are underserved by green space, and to plant trees to reduce the urban heat island effect, and... You know, there's a number of different benefits that are sort of co-benefits that come along with green stormwater infrastructure.
JOHN: And so how is that working in Kansas City?
TYLER: You know, I haven't kept up that much with their program. I know that they've really accelerated in, like, the last 10 years or so. I moved away 15 years ago, and I've seen a few of their projects when I've been back and visited, some large-scale sort of transit projects that they've built in a lot of green infrastructure. So they're creating these sort of - they're taking these corridors that are sort of historically, for lack of a better term, like, "traffic sewers" and turning them into these transit corridors with much better pedestrian infrastructure, and then a bunch of green stormwater infrastructure built in as well. So there are these sort of, like, really innovative corridors where, you know, people and the environment are really integrated in rather than cars, which is I think impressive.
JOHN: That sounds pretty big-scale.
TYLER: Yeah - yeah. I mean, that's where these programs have to end up going, right, is there's only so much you can do at the homeowner scale. You know, even if you have a really large rain garden at every single home in the city, that's not going to make up for the stormwater that's falling on the streets and on the large commercial buildings, the parking lots, these larger areas of impervious surface. And so most of the programs end up transitioning into these really large-scale detention projects where you can really start to get a lot more bang for your buck in terms of volume that you can hold of stormwater.
JOHN: I have a colleague, Scott Collins, who is now the editor for Frontiers in Ecology and the Environment. And he often says about Phoenix, which is where I used to live, that Phoenix has been riparianized over time. And it sounds like it's kind of the goal for these larger-scale projects is to capture sort of the function of, you know, like, a floodplain as much as you can within a city. Is that accurate?
TYLER: Yeah, I think that's totally accurate. And in fact, in New Orleans a lot of times we talk about the urban delta. So we talk about the city as sort of an extension of the coastal delta. And it's the same riparian sort of functioning that we're trying to recreate, where you have different scales of sort of collection of water and ways in which the water is able to integrate back in with the environment rather than having this older model of sort of pathing and pumping, then sort of getting rid of water as quickly as possible, or trying to reintegrate those natural systems.
JOHN: So that's a good pivot point to New Orleans. So maybe before we go straight into that, talk to me about the challenges and how they might be different between a city like Kansas City and New Orleans.
TYLER: Yeah. I think that - obviously I think probably the biggest, most obvious difference is the coastal location. Obviously Kansas City has challenges with infrastructure (that are) causing their combined sewer overflow problem. I think they also have climate challenges in the form of, you know, drought, and more intense rain in periods, and more intense heat. But I would say that there are climate challenges that probably pale in comparison to New Orleans' climate challenges where we face, you know, extreme heat, we face more intense daily rain events, and then of course more intense tropical storm events like hurricanes, while also experiencing sea-level rise at a really high rate compared to really almost any other place on the planet. And then at the same time we have subsidence due to our sort of deltaic soils that are not super well-founded. And so we have water surrounding us that's rising, our ground itself is sinking, and all the time the weather is getting worse essentially.
JOHN: Some of our listeners may be familiar with some of these concepts. The point of this podcast is sea-level rise, this particular episode, and we'll get there in a little bit. But let's talk about some of those challenges. What's going on with subsidence and the soils? Unpack that a little bit for us. I don't think we've had a guest that's done that before.
JOHN: Yeah, I should caveat that I’m not a geologist or hydrogeologist, but I've certainly worked around a lot of them in my career in New Orleans. And so in very high-level summary, the soil in New Orleans is based off of deposits that were made by the Mississippi River over the last few-thousand years. This is - the land that we're on that, you know, I'm sitting on right now here in New Orleans is probably some of the newest land on the planet, in that, you know, it was formed relatively recently in terms of geological history. And since it was these deposits made by the river through the sort of flooding that would occur, or the changing course of the river over time, it's largely made up of clay, but then there are also areas where you had the sort of back-swamps from the river that have high content of organic material like peat, which requires moisture in order to maintain its sort of substance. It's like a sponge. And, you know, when a sponge dries out it gets smaller; when it gets wet it gets bigger. And so as we've developed the city over time and we started pumping, and preventing groundwater from maintaining its same level, or allowing, you know, water to sort of flood into the city and redeposit soils, the ground is essentially compacting and sinking. And so, you know, there are parts of the city - what people often say in New Orleans is a "city that's below sea level," and that's not technically true. Fifty percent of the city is below sea level, fifty percent is above, as it stands right now. But those areas that are 50% below were at one time relatively at sea level, just slightly above or slightly below. They were swamps, they were wetlands that, you know, depending on the time of year they may have been inundated. But there were times that they were drier. But when we came in and developed them and began to pump, essentially those areas subsided. And so there's areas that are now, you know, 10, 12, 15 feet below sea level. And those areas have largely reached a sort of stasis point in terms of their subsidence, but they do still continue to sink at a relatively high rate in comparison to subsidence in other places, talking in the range of, like, a centimeter a year.
JOHN: That's I think a great summary and consistent with, you know, things that I've heard from my colleagues, who are probably some of the same colleagues that you were talking about before. As you were talking about swamps I was thinking about the fact that I had the privilege to listen to our colleague, Rich (Campanella), sort of outlined the history of the development of New Orleans and what drove it, and kind of how it relates to where we are today. So one question about stasis, or reduced levels of subsidence--is there a connection between rebuilding green infrastructure on the surface and sort of restoring some of that function?
TYLER: Absolutely, yeah. The sort of running hypothesis I would say amongst the experts that we've worked with are that subsidence can be mitigated by reintroducing water into the soil. And so green infrastructure is one way that we can attempt to recharge the groundwater and bring it up to a higher level, which seems to be the longer-term solution to reducing subsidence in New Orleans. We find that obviously in the environment we're in groundwater is much higher than it would be in most other places. You know, an average groundwater lever here is only a few feet below the surface. But in many cases it actually needs to be a bit higher even in order to reduce subsidence. And the way that the system is functioning now is that the sewer pipes and the drainage pipes are essentially acting as drains inside the soil. And so generally the groundwater level throughout the city when we measure it is at the level of the bottom of the closest drainage pipe or sewage pipe. And so getting water in that layer between the pipe and the top of the soil in order to keep those soils sort of, you know, saturated and at their form can be achieved through recharging that groundwater with green infrastructure.
JOHN: So this is way more dynamic than I thought, which is pretty interesting. How does the city manage the aquifer in conjunction with surface-water flooding? Tell me about that.
TYLER: Yeah. Unfortunately--and this is a conversation that comes up all the time--there really is no entity that is charged with managing the aquifer. There are sort of state-level permitting with regards to building wells and extracting groundwater. But there really has been no effort to set up any kind of authority or agency that tracks the groundwater levels or actively manages them. By default, based on the, you know, the idea that your groundwater level is sort of being managed by the sewage and drainage pipes, so by default that means that essentially the sewage and water board of New Orleans is managing the groundwater for the city. But it's really, again, like, the word "default" is sort of critical there. It's not a part of their mission to do it, and so therefore they don't actively take steps to monitor it or manage it in any specific way. It's a very passive management process.
JOHN: And now back to the connection with managing just stormwater. Is the aquifer used to manage stormwater? I've heard a lot about this, and I'm just sort of fact-checking in some ways because I'm also new to New Orleans. The strategy that I understood was groundwater levels are managed in a way to absorb when we have these more intense rainfall events that are non-tropical-storm-related. So it's kind of dynamically managed. Is that accurate, or is it just that it fluctuates because we're doing maybe the best we can in a non-strategic-management way? It's ad hoc?
TYLER: Yeah. I would say that calling it "dynamic" is pretty generous. I think there is a certain amount of that in that you're right, oftentimes sort of before a large rain event perhaps the Sewage and Water Board will, for instance, pump down canals in order to allow, you know, more space for runoff as a large event is approaching the city. And so that in a way will lead to some reduction in groundwater levels as well in those areas. But again, the purpose of them doing that is to create more space within the system to store stormwater. And so the effect on groundwater is really just sort of ancillary at that point for them.
JOHN: Interesting. So let's kind of move towards the saltwater questions. What's the relationship - this topic that we're talking about, green infrastructure, stormwater management, and sea-level rise, what are the relationships between those? And I'm thinking in particular saltwater intrusion and things like that. How do we couple these things to get better outcomes?
TYLER: Yeah. I think that that relationship we're still exploring. We know that in New Orleans obviously and other coastal cities that are vulnerable to sea-level rise, we're starting to see intrusion of saltwater in the groundwater of these places. So in New Orleans, you know, we're not directly on the Gulf. We're not, you know, directly coastal, but we do have Lake Pontchartrain, which is an estuary that leads to the Gulf of Mexico and is brackish. And so we have started to find - are monitoring that. We're getting some salt intrusion along the lakefront in the groundwater there. At this point I think that a lot more research needs to be done to understand both the impacts of what that - effect that could have on our systems, our infrastructure, and also our natural infrastructure. But also I think we need to do some more work on modeling or forecasting what that could look like under various sea-level-rise scenarios--if we'll see, you know, either just higher concentrations in a small area, or whether the salt will continue to migrate further and further inland through the groundwater. And the concern - I think the biggest concerns about that would be corrosion of underground infrastructure. So waterlines and sewer lines that are made of steel, we could see faster rates of corrosion on the outside of those pipes that would obviously lead to a faster degradation of their condition, and perhaps failure. And then from a natural point of view, obviously thinking about things like trees that can't survive in a higher-salinity environment. And so thinking about, you know, in these areas where we know that we're already getting some level of intrusion, but then also where we could see more intrusion in the future is perhaps changing our choices in terms of things that we're planting, starting to replace species as they die out. And in terms of the connection with green infrastructure, I think that there are people that I've heard, you know, discuss the concept of utilizing green infrastructure to essentially recharge freshwater that would sort of push out saltwater. But I think it's very understudied at this point and probably needs a lot more research in order to determine if that's a viable solution or not.
[MUSIC]
JOHN: Up next Tyler explores the growing threat of saltwater intrusion in New Orleans' drinking water and what needs to happen to adapt to this hidden threat.
JOHN: I think that sounds super promising.
TYLER: Yeah.
JOHN: I think it would probably require scaling in the way that we discussed for Kansas City, right?
TYLER: Yep.
JOHN: And how do you think we would do that in New Orleans? Is it like making major thoroughfares like down Esplanade, you know, like, a riparian area? Or is it even bigger than that?
TYLER: Yeah, I think that the challenges that we face in terms of - well, it certainly depends on the driver that you're trying to address. There are a number of different reasons that we pursue green infrastructure. You know, in the Kansas City example their primary driver is regulatory. They're trying to meet their permit requirements under the Clean Water Act. And then the other driver is (inaudible) around water quality, and beautification, and things like that are sort of bonuses to them. Here our primary driver, we do have regulatory requirements, we don't have a combined sewer though, and so we're not under a consent decree for our stormwater system. And so our primary driver is actually reducing surface flooding. And so it's more of a volume question in a different way, where we're trying to keep the water from accumulating on the surface and causing damage to property and to life, rather than trying to keep water from getting into a pipe. And the reason that obviously we get flooding is because we have these rain events that exceed the capacity of our pipes, and so then the water has to go somewhere, it flows to the surface and causes flooding. And so in creating green infrastructure there's obviously, again, a huge benefit that comes from the smaller-scale solutions that everyday folks can take on their own properties. But in a city like New Orleans that receives 64 inches of rain a year, sometimes, you know, rain and events of 6 to 9 inches in an hour in the summertime, there's only so much you can collect in your little rain garden at home. And so when you have those really, really large events that overwhelm the system you really need these massive storage systems to hold that much stormwater to prevent flooding. And so in terms of addressing some of those challenges like, you know, saltwater intrusion and groundwater, I think smaller-scale solutions probably actually make a lot more sense of having a lot of distributed infrastructure that can sort of push a lot of fresh water into the ground. But when it comes to addressing the driver of flooding, you know, we're talking about, you know, massive systems that hold millions of gallons of stormwater that are required to really start to make an impact on flooding in New Orleans for these really big rain events.
JOHN: Are we on a good path for that?
TYLER: I think that the last decade or so we've made an incredible amount of progress. And I think that a lot of people in the field who are the sort of evangelists of using these nature-based green-infrastructure solutions for flooding, a lot of them are sort of down on our progress because they wanted to see implementation happen much more quickly. I tend to be more congratulatory about it. Because I think - when I look back to ten years ago when we were really starting these conversations, that was a time when--like, back in my day [LAUGHTER]--that was a time when, you know, you'd sit at these tables with engineers from the Sewage and Water Board or from the City, or consulting engineers, and you'd talk about green stormwater infrastructure. And their immediate response would be, "Absolutely not. That will never work here," and they'd give you a million reasons why it would never work. And we're at a point now where the City and the Sewage and Water Board have invested millions of dollars and these pilot projects have really proved the concept. And when I go to these sort of larger gatherings of professionals working in the space now, a lot of those same engineers are there now and they've become the evangelists because they've seen it actually work. And so I think that while it means that we had ten years of building some stuff but not enough, I think that we've also created a really durable coalition of people who are passionate and are committed to solving the challenge. And I think that will pay off over time.
JOHN: I love that. One thing that I've learned in all these years is that there are also activists and "evangelists," as you called them, on the ground that lead community-based organizations in various neighborhoods and various communities in New Orleans. Is there a big push from the grassroots for this as well?
TYLER: Absolutely. I'm really glad you asked that, because I think that the progress that we've made is probably almost exclusively to the credit of the community-based activists that we have working in New Orleans. You know, you have organizations like Water Wise Gulf South, which is a coalition of many different small neighborhood groups almost exclusively led by women of color, who are - I think "evangelists of green infrastructure" is probably a not-sufficient way of describing these ladies' zeal for advocating for green stormwater infrastructure. But, you know, these are folks who are just, like, trying to get it done. And so they have decided, like, they're just going to build it. They're just going to do what they need to do to impact their communities, and have been incredibly successful at attracting national and international funding and attention to build projects in their neighborhoods largely with their own labor. And that has, again, really led to a proof-of-concept for not only the ability for the solutions to work, but I think have also been eye-opening in terms of the sort of "constructability" I guess I should say of these solutions. And that I think a big consulting engineer might say, "Oh no, you know, that's a $30 million project. It's going to take, you know, years." And these ladies are, like, "I can just dig a hole and, you know, and build it myself, and it will cost me, you know, $100 of materials." And of course the scale is different, but I think the idea that green-stormwater infrastructure is something that every person who can use a shovel can build is super powerful.
JOHN: Talk to me, too, about gaps in that. Like, you know, the fact that these solutions are being pushed, evangelized, and implemented by grassroots suggests that there's enormous need for it. And that need, you know, might be in disadvantaged communities. Tell me more about that.
JOHN: Yeah, absolutely. And I think these groups, especially the groups I was talking about from Water Wise, you know, they're folks who are accustomed to being sort of ignored by the institutions that would be charged with solving these challenges. And so I think that really sort of drives them to say, you know, "We're just going to solve our own problems because we can't rely on the government, or the utility, or whoever, to come in and solve those problems. And I Think that there's an incredible amount of value in the work that they're doing. I also think though that in New Orleans I've observed over time that there is this idea of because the institutions are not going to solve the problems we can only rely on ourselves, which leads to a sort of institutional decline of the institutions. And so what I mean by that is, you know, largely a lot of the challenge around solving these problems is a lack of resources at the institutional level. And so while I’m certainly not going to deny that there are historical patterns of disinvestment in different neighborhoods based on the types of people that live there, I think what we're experiencing in this current era is a sort of wholesale disinvestment in infrastructure in all communities in the city, because of a lack of resources in order to address those challenges. And so sometimes in saying, you know, we can't rely on the government to solve our problems, and so we're going to solve them ourselves, I think leads people to then think that when perhaps a new funding request comes up for the government, or some opportunity presents itself, that there's not a lot of support for that. Because the government is seen as being unable to be trusted to deliver solutions, sometimes rightly so. And that means that, you know, again, there's only so much that an individual can do in terms of scale when the challenge is this big. And it's really only the utility or the government that can achieve the sort of large scale that we'd need in order to, you know, address the bigger challenges that we have.
JOHN: Got it, cool. Let's shift for a little bit towards drinking water and salinity. In 2023 we had saltwater encroaching on drinking-water infrastructure in New Orleans. Talk to me about this. And, you know, before that I think, too, in 2022 it was also an issue, but it didn’t quite make it as far upstream as it did in 2023. So it didn't make national news, but still clearly two drought years in a row that had effects on shipping traffic and drinking water. Tell me about where we get our water and how it's challenged by sea-level rise, which is happening on a near-daily basis.
TYLER: Yeah, absolutely. So in New Orleans all of the communities here along the river in southeast Louisiana, for the most part downriver of Baton Rouge, get their drinking water from the Mississippi River, which obviously is generally probably a very desirable source in that it's, you know, one of the largest rivers in the world. And so it's a very plentiful source of water. I'm sure it's the envy of water utilities in the western United States. But, you know, there's the sort of converse side of that that we're at the end of the watershed, meaning we're closer to the Gulf, and so with sea levels rising there is of course the risk of saltwater intrusion in the source. And largely that's caused when, like you mentioned, during drought years where there's just less fresh water moving down the river from up north, which means that there's less sort of outward pressure in terms of water towards the Gulf. And then with the sea level rising, you know, you get more pressure of the saltwater coming up the river from the Gulf. And so when you have those two things that meet you end up - the saltwater tends to sort of win because of its higher viscosity. It creeps up in sort of, like, a toe or a wedge up the river. And so, yeah, last summer we experienced a pretty scary close call where it was looking for a while like our intakes for the City of New Orleans would be impacted by higher salinity. I think it was the question that always existed of to what level of salinity we might have seen during that event, and if it would've actually caused a problem. Because obviously there's a level of salinity in the water that we can withstand before it becomes undrinkable. And that's - there's a pretty large gap between, you know, the current level of salinity in our drinking water on a daily basis and where that sort of "action level," the EPA would call it, exists. But so the advantage of last year's event in sort of not causing a catastrophic problem for our drinking-water system though has been that it's really driven a lot of research and thought around how we can address this challenge going forward. And so there's a lot of effort going into understanding the dynamics of the potential for future saltwater intrusion in the river, both during drought events but also just generally with sea-level rise over time, looking at our water-treatment processes and seeing how we could potentially shift those treatment processes to address higher salinity in the watershed, and then also studying the impacts of higher salinity on our infrastructure, like our drinking water service lines, like, for instance lead service lines and galvanized service lines, to understand the tolerance of those lines to salinity, to ensure that the water supply can remain safe to drink.
JOHN: Okay. Just a follow-up question on saltwater intrusion. In my experience--and again, I've only been in New Orleans for three years--but my experience with the 2023 event was that for all the solutions all fingers were pointing to things that are short-term. On the other hand, drought is something that happens and probably will happen more frequently with climate change and aridification in the Basin, but it doesn't happen every year. Of course there was a lot of discussion about the sill, and whether the sill would work, and whether it would continue to work. But when I was interviewed, oftentimes on national media, I described the situation just like you did. I said it's a battle between saltwater and fresh water, and we're losing, and that's why the battle line is so close to New Orleans right now. But in my view the sea-level rise is the key issue, right? Like it's going to continue to come and come some more, and make every drought like 2023 worse and worse. So talk to me about how that conversation is playing out in New Orleans, in the general public or in the government. You know, what are people talking about? Because eventually we're going to need a permanent solution, because it's going to be a permanent challenge, right?
TYLER: Yeah, absolutely. I mean, I think the other thing that I'm sort of grateful for about last summer's scare, if there's anything to be grateful for about it, is that I think it really created a conversation in New Orleans about our drinking-water system, which I think was long overdue. I think for the past 20 years or so, since Katrina, the conversation has really been focused on stormwater management and flooding as the only sort of critical water issue that we face. But we also have an aging drinking-water system that really needs to be addressed. And so this was sort of a good entry point for people to enter that conversation. I think that there's a lot of fear in the community. I think the event last year was really eye-opening for I know folks at the utility level about just the level of dis- and misinformation that was being spread in the community about the water system, and I think was a really good learning lesson for them on how to maybe communicate more, communicate more directly, and communicate sooner to keep that from happening in the future. But I think that it's also created a lot of sort of institutional response certainly at the water utility level, and also coordination between the various water utilities that operate in greater New Orleans, to an extent that has not existed, to my knowledge, in a very long time. And so it means that these folks are really - they're talking to each other about what they're experiencing, they're sharing data, and then they're also discussing potential solutions. And I know at the sewage and water board for the utility that serves the City of New Orleans, you know, that utility was already--sort of by happenstance luckily I think right around the same time as the saltwater wedge issue--had put out a request for proposals for a new water treatment master plan to look at the quality of our drinking water over the next 30 to 50 years, that had a significant component included in the scope about saltwater intrusion and climate change as something that, you know, the utility had anticipated being a challenge in the future. And so it was just sort of serendipitous that it all kind of converged at that same time. And so what they're really focused on now is, you know, really understanding their treatment process that they currently use, and looking at the range of options that exist on the market today in terms of their cost, in terms of their effectiveness with the source water that we have, and also looking at, you know, the potential to remove salt from the water during either these sort of seasonal events, or perhaps a more regular longer-term basis. I think there's also been discussion, albeit very high-level and conceptual at this point, about perhaps, you know, moving our treatment plants further upriver. There have been discussions about perhaps building some sort of, like, a regional water treatment plant that could be located much farther upriver and we could essentially pipe our drinking water for the whole region down, so that you'd be receiving your source water at a location that's well outside of the forecasted range of saltwater intrusion, even under an absolute worst-case sea-level rise scenario. But all of this is very preliminary where, you know, I think luckily the experts, we seem to think that this is a challenge that we're beginning to experience. Last year was a big scare, was a wakeup call, but it's not such an urgent challenge that we need to start taking, you know, big expensive swings. This is something that we can be very methodical about it and very thoughtful, and actually take a very rational planned approach to how we want to address this challenge going forward.
JOHN: I like that a lot, especially given the conversation during the wedge, which I think was not really methodical or careful, right? It was like a Band-Aid, a very expensive Band-Aid, that would've had to be replaced again at some point in the near future.
TYLER: Yeah. I mean, it was panic. It was, you know, how do we address this? You know, get a bunch of engineers in the room. What's the easiest thing we can do to make sure that we, you know, keep things safe? And, yeah, those are usually your most expensive and probably your least sustainable solutions. And so we want to make sure that we're doing this right and finding solutions that address not just this challenge but many of the challenges that we face with drinking water going forward in a way that, you know, is very resource-conscious.
JOHN: Interesting. Okay. One last question. What should we be talking about in relationship to sea-level rise or drinking water? The relationship between those two I think is really important, and it's really not getting that much attention.
TYLER: I'm trying to think of how I want to put this together. I guess I would say I would like for there to be more of a thoughtful conversation about the sort of dynamic relationship that we have with water in New Orleans. And I think it has changed a little bit over the last decade, but I think there's a lot more work that needs to be done. And when I say that what I mean is I think a lot of times people get siloed in one type of water versus another, meaning they're really focused on flooding and stormwater management, and they're not really thinking about drinking water. No one's really thinking about sewage. No one cares about wastewater in New Orleans, but it's also a challenge that all cities face. And so I think the same thing extends to sea-level rise and our coastal water issues, is that a lot of times people who work in the water space in New Orleans sort of think about our levees as walls and they don't think about what's happening on the outside of them. And obviously this, you know, event where we have potential saltwater intrusion in the water supply was a sort of mental breaking down of those walls for a lot of folks. And so I guess I would just like to see, yeah, a much more dynamic conversation happening about all the different various pressures and challenges we face and how they're interrelated, and how we can find solutions that address multiple challenges at once in order to create efficiency in a system that's much more effective at managing the different sort of levels of water that we are surrounded by and use on a daily basis.
JOHN: So in a sense kind of applying the One Water concept to New Orleans?
TYLER: Absolutely, One Water, yeah. Because it is, it's just - it's one water. It's all the same.
JOHN: Okay, that's fantastic. I really appreciate your time, Tyler. Thanks for joining us on the show.
TYLER: Yeah, it's been a lot of fun.
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JOHN: Okay, so that's a wrap on this complex topic that connects sea-level rise, urban natural infrastructure, stormwater management, and the sustainability of drinking water in New Orleans and cities in the Gulf south in general. This is a complex topic in climate adaptation. One clear theme that emerges is that there is a solution for stormwater management. This is green infrastructure. But the scale of deployment of nature-based solutions has to be on par with the challenge: big. A second theme that emerges is that the saltwater wedge conundrum of 2023 is something that New Orleans will probably see many more times in the coming years as a result of sea-level rise and drought in the Mississippi River. Connecting these two symptoms of climate change is essential, but more essential is thinking through long-range rather than Band-Aid solutions. Finally, communities are important. Community-based organizations in New Orleans have a long-standing history of evangelizing scalable solutions to problems. Maybe we need to listen more.
JOHN: That's it for this episode of Audacious Water. If you like the show please rate and review us, and tell your colleagues and friends. For more information about Audacious Water, and to find in-depth show notes from this episode, visit our website at AudaciousWater.org. Until next time I'm John Sabo.
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