Host Kristin Hayes talks with Dr. Denise Reed, an internationally recognized expert in coastal marsh sustainability and the role of human activities in modifying coastal systems. They discuss Louisiana's coastal master plan, on which Denise has be an adviser to state officials leading the plan development. This ambitious, long-term planning process has grown even more important in the face of rising sea levels.
The Full Transcript:
Kristin Hayes: Hello, and welcome to Resources Radio, a weekly podcast from Resources for the Future. I’m your host, Kristin Hayes.
Today we’re joined by Dr. Denise Reed, an internationally recognized expert in coastal marsh sustainability and the role of human activities in modifying coastal systems. Dr. Reed has spent much of her professional career in Louisiana, at both the University of New Orleans and the Water Institute of the Gulf in Baton Rouge. I’ll be talking to Dr. Reed about Louisiana's coastal master plan, on which Denise has been an adviser to state officials leading the plan development. This ambitious, long-term planning process has grown even more important in the face of rising sea levels.
Denise, thank you so much for joining us today on Resources Radio.
Denise Reed: Thanks.
Kristin Hayes: Yeah! It's great to be here in person with you as well. So, it's always nice to start with a little bit of an introduction to our guests. Can you tell us a little bit more about your background? How you got interested in natural resource issues and particularly in the coastal management side of things.
Denise Reed: Yeah, well, it's quite a long story. I'm from England originally. I was brought up in a kind of industrial manufacturing town just north of London. And I always liked landscapes. I've always been fascinated by ... not so much the biology, but just the shape of the earth and how it works. I did geography in college, and I always wanted to go to the Antarctic. So, here I am, this girl from north of London, really wanted to go to the Antarctic. And glaciers were always really fascinating for me, ice. And then, I discovered ... back then, that was quite a long time ago … that the British Antarctic Survey didn't actually take women to the Antarctic, so I was like, "What?"
So, I ended up working for my Ph.D. on coastal salt marshes. And one of the things I really liked about them was the way the tide came in and out every day. They were dynamic. They were always moving. There was always something. You can actually measure what was going on. As I scientist, you could really be understanding the dynamics at the scale of the dynamics. Not just measuring trends over really long periods of time. And so, I became very interested in coastal wetlands and how they worked. And that led me into this idea of how they respond to sea level rise and how they react and how does global warming, sea level rise, changes in human activities on the coast—how do they influence them?
So, just over 30 years ago, I came to coastal Louisiana to work, and just found myself in the midst of this massive expanse of coastal wetlands. Just like really kind of huge-
Kristin Hayes: Like the dream.
Denise Reed: ... and beautiful and wonderful things going on. But also, in the middle of a really serious environmental crisis, where the coastal wetlands were deteriorating very rapidly. We'd lost huge amounts of land to open water during the 20th century. And science, the kind of understanding that I was working on—what really happens, how does sediment move, how do they respond when a storm comes in—that was a really important part of that dynamic and so, I kind of found myself in this place where these things that I really was fascinated by were really relevant to this huge environmental issue and so, probably, the rest is history.
Kristin Hayes: That's fascinating. And, obviously, the change from a North London girl moving to Louisiana and then working in the coastal regions must have been very exciting, too. A whole new ecosystem to interact with.
Denise Reed: Yeah. A whole new ecosystem. And so, Louisiana is a really huge area of coastal wetlands. And I've also been really lucky in my career and being able to work in other areas as well. The early part of my career, my Ph.D. research in northwest Europe, where the marshes actually look quite different to how they look in the Chesapeake Bay, for instance. But I've also worked in California, San Francisco Bay area. A little bit in the Pacific Northwest, too. And so, when you see these different marshes, the plants are different, the tides are different, but some of the fundamentals are the same. That's what's really fascinating as a scientist is really trying to understand those basic processes that make these systems work, and how that changes from one place to another. And then, how the things that people do then also influence that change. And so, even though I have worked in coastal Louisiana for over 30 years now, I always say I get out a lot so it's okay.
Kristin Hayes: Excellent. Well, we're very pleased to have you on the podcast today, specifically focused on that expertise in Louisiana, and particularly, to talk a little bit about Louisiana's Coastal Master Plan. But before that, I do want to spend just one more minute asking you to give our listeners a flavor of why the Louisiana coast is so important for the state and for the country. So, can you tell us just a little bit about the values that it brings?
Denise Reed: Well, one thing is, if your listeners have been down to Louisiana, they may have been to New Orleans or Baton Rouge or Lake Charles, probably one of the big cities, and they may have driven out down the bayou, as it were, and they'll have seen swamps and trees and a little bit of wetland and some birds and wonderful things like that, but they will really only have seen a very tiny part of it. It is a huge system. So, millions of acres of wetlands associated with the delta of the Mississippi River. The Mississippi River's like the sixth largest river in the world, this huge delta associated with it. And then, in the southwestern part of the state, over towards Texas, this area call the Chenier Plain, which is also associated with river, even though it's not really a delta.
And so, one of the things that's remarkable about it, when you think, you've got this world-class river, right? It's the heart of the United States, and commerce and all of those kinds of things. It's very much a world-class river, and the delta associated with that—if you think about other major deltas of the world, the big Chinese deltas, the Rhone or the Rhine, or even in the U.S, the Sacramento-San Joaquin Delta—those deltas have been heavily altered and largely converted to agriculture. That is not the case for the Mississippi. It's not in a pristine state, but we still have these vast extents, that are very inaccessible by road, of natural system. And so, there are millions of waterfowl that migrate up and down the Mississippi Flyway that spend important parts of their time there. Obviously, it’s a massive base for commercial seafood; shrimp, oysters, those kinds of things. People in Louisiana love to say how they export crabs to Chesapeake Bay, and all of those kinds of things. But the other thing—you've got this massive natural system that's really valuable ecologically, and you've also got this massive industry associated with it.
So, the Mississippi River is very much a commercial highway with huge goods coming in and out—coming in and out of the Midwest, goods coming in. And we've also got the oil and gas industry. So, we have a massive natural system and we have very much a working coast. And then, we superimpose on top of that things like sea level rise. And so, you've got this great kind of juxtaposition. It's really valuable ecologically. And it's really huge. It's very difficult to get a grasp on that when you come down to visit.
Kristin Hayes: Yeah. Well, I guess I'm just going to have to come down and visit then-
Denise Reed: You are.
Kristin Hayes: ... and see if I can grasp that for myself. So, my understanding is that the Master Plan is looking at the loss of this very important ecological system, as you mentioned. What are some of the drivers both historically of land loss in the region, but also what are some of the expected drivers in the future? Are they the same? Are they different?
Denise Reed: That's a very interesting question, really. Because it is a delta, a natural part of how large rivers work is they build land as sediment is deposited. It comes down the river and it hits the Gulf of Mexico, the water flow slows down and the sediment settles out and gradually accumulates and we get land and the river channels get longer and longer and longer, and eventually they find a more efficient route to the Gulf of Mexico and so, the river changes course. The river naturally changes course, we think, about every thousand years. And this happens in deltas all across the world, right? This is not just a Mississippi thing. So, gradually, over the last six to seven thousand years, you have this huge system that's built by the river. And we know then, from the geology of the system, that land loss has been a constant part of this evolution. Land loss and land gain. Loss in one area, gain in another area. That's just part of how the system works. It's a very dynamic system.
The story of the 20th century, however, is somewhat different. In the 20th century, several things happened. We channelized the Mississippi River in a big way in the 19th century for navigation, in the 20th century for flood control. Particularly after the 1927 flood, but even before then, there were levees on the Mississippi River. So, what that does is it isolates the river channel, with all that fresh water and sediment in, from this vast expanse of coastal wetlands. And so, that's one of the key things that really happens in the late 19th century, beginning of the 20th century.
Then, in the middle of the 20th century, we have a massive expansion of onshore, within the wetland area, exploration for oil and gas. And so, back in the 1950s, then, we could understand where we thought the oil was in the subsurface and we would just put a rig right on top of that spot and drill down and get it. And so, if that was in the wetlands, that meant we had to dredge the wetlands up and create a canal to get the rig onsite where we needed it. We're much better at doing that these days, but that's the way we used to have to do it. As the offshore oil and gas industry developed, kind of 50s and 60s, then, we needed to get that product onshore for processing, so we dredged a lot of pipeline canals. And so, all of these things together—these canals for different purposes, the management of the river for navigation and for flood control—what it did is it fundamentally altered the hydrology of large areas of the coast. And if you know anything about wetlands, you need to know that hydrology is the key. [They’re] very sensitive to changes in hydrology. And so, they're wetlands, right? So, they can tolerate being wet, but if the water stays too long, they can't. It's kind of like a Goldilocks zone where they do really well-
Kristin Hayes: It has to be just right.
Denise Reed: ... and it doesn't take much to disrupt that. And so, for many areas of the coast, those disruptions resulted in conversion of what were previously vegetated wetlands to open water. So, when we talk about wetland loss in Louisiana, it's quite interesting. A lot of the discussion, perhaps in the 90s in the US, about wetland loss was about development. Like converting a wetland to a golf course or grocery store or something like that. That's not the kind of wetland loss we have in Louisiana. We convert something that is a vegetated wetland—it's not solid land. You can walk on it, it's a bit squidgy and sinky, right, but it's there, you can see something. Convert that to open water. And so, it's almost like the Gulf of Mexico is kind of encroaching, but it's not just the kind of edge of the system eroding. It's almost like a Swiss cheese effect where it kind of deteriorates from the inside out. It's really—if you do go down to Louisiana, you really need to get in a small plane or make sure you fly in the right direction and get a window seat and you'll be able to see these patterns.
So, that's really the 20th century story of wetland loss. Superimposed on that, we have hurricanes. I think we've always had hurricanes in Louisiana and so, they're just another natural factor, if you like, superimposed on it. The good thing is when we look forward into the 21st century, then, it's unlikely that this big period of canal dredging and all of that kind of thing is continued. There are some legacy effects of that which still continue, but we don't expect that to be repeated. So, we now kind of understand some of the mistakes we made in the past, if you like. But the idea of the land sinking gradually and the lack of sediment to replenish it and keep its head above the water ... That's a problem. And obviously, as sea level rise increases a pace into the 21st century, then that becomes more of a problem. So, the result, if you like, is the same. We're still talking about wetlands converting to open water, but the causes, we think, change a little bit over time.
Sorry that was so long, but there's such a complexity to this issue. You know what I often say is that trying to work out why a particular piece of wetland converted to open water, it's like doing an autopsy without the body.
Kristin Hayes: You know what the end result is.
Denise Reed: You know what the end result is, right, but you weren't actually there to see it.
Kristin Hayes: That's fascinating to understand the differences there, too. Given all this, it seems like Louisiana has really been on the front edge of planning for these changes, whether from historical causes or future causes, and that's where the master plan comes in. So, I took a quick look at the master plan. It's actually a very readable document. It seems like it was designed not just for the people implementing the plan, but for those who might have a broader interest in the coastline. But the executive summary notes, what I thought was a good overview of what the plan is all about, they say, "The master plan, in its purest sense, is a list of projects that build or maintain land and reduce risk to our communities. Because the funding for all of these projects is not available now, the master plan identifies a long-term program of construction, operations, and maintenance, and adaptive management that is guided by a robust and continuous planning process." So, there's a lot in there, but clearly, there's a big vision and part of it is about priority setting. They recognize that not all of these things are gonna be feasible just at this moment. Either for financial reasons or otherwise.
So, just to start off. Can you tell us a little bit about how the authors of the plan think about prioritization of these different projects that they've listed?
Denise Reed: So, the plan is very much a State of Louisiana plan. The agency that is the lead on putting that plan together is called the Coastal Protection and Restoration Authority. And that is a part of state government that emerged from Hurricane Katrina in 2005. When I was discussing the land loss processes and those issues with the wetlands previously, that's been ongoing for a while. And before Katrina, up until the early 2000s, we thought about restoration of wetlands as one thing and we thought about the protection of communities as a different thing. And they were tied together in this government agency after Katrina. And so, we now try to think about them together.
So, the priorities for the state folks in putting together the plan, particularly the 2017 Coastal Master Plan, are restoration—Coastal Protection and Restoration Authority—and that is about how much land we have. That's a fundamental decision driver, the highest priority is land. And that's wetland, Mulberry Island, it’s natural land area. And then, on the other side, on the protection side, it's how much we can reduce the expected annual damages from storm effects. So, the priorities for the Coastal Master Plan are storm surge-based flooding, and reducing damages, and sustaining the greatest extent of coastal land area.
So, projects, and as you say, the 2017 plan is really a list of projects in its purest sense. Those are selected on how they are expected to contribute either to building or maintaining land, or to reducing damages in coastal communities. So, it's a pretty set of priorities there even though we know that the coastal ecosystem and the great wetland area is important for commercial fisheries and for waterfowl and things like that. I think the folks decided that the best way to reflect that was just in land. Because if we don't have any wetlands, we don't have any of those things, right? And so, rather than going into the minutiae of brown shrimp versus a speckled trout versus an alligator versus a muddled duck or whatever it might be that have slightly different habitat requirements ... they're all gonna need wetlands.
So, let's focus on the wetlands. We've got a really big area. We know all these wetlands are going to be slightly different because they're on different parts of the coast. They'll have different salinities and different water depths and all of those kinds of things. And that mosaic of change will provide habitat for all those different organisms, but let's just focus on wetlands. On the risk side, on the protection side, the expected annual damages pulls together lots of different factors of the way in which damage can be prevented and the way in which damage is expressed economically. So, they're kind of summary priorities, if you like, that are umbrellas over lots of different issues.
Kristin Hayes: So, can you ... I'm curious for more specifics. Can you give us just one example, perhaps, of what a restoration project or a protection project might look like?
Denise Reed: Yeah. So, let's deal with protection first. I live in a coastal community down there in Louisiana, and my house is ten feet off the ground. Fortunately, I haven't been flooded yet by a hurricane, but I'm not behind a big levee like New Orleans is. And so, on the protection side, there are basically two kinds of projects. One is what we call structural protection. And these are systems of earthen levees, flood walls, and structures that basically keep the water out when the storm comes. I think a lot of people are familiar with the levee system that was rebuilt around New Orleans after Katrina. So, something like that, but for other parts of the coast. So, we call that structural protection.
But there are also lots of smaller communities across the coast where building big levee systems is just really not feasible or perhaps not even desirable. And so, in that instance, it's called non-structural protection. And so, what happens is you protect the asset from flooding, but you don't necessarily alter the water movement. And so, this could be flood-proofing. So, if the water's not expected to be very deep, we might flood-proof a grocery store or a commercial structure or something like that. We might elevate a house. Or we might get involved in voluntary acquisition, buying people out and actually helping them move out of the way of the water. So, those are the two kind of sides on the protection.
There are a number of different approaches on the restoration side, but two that really characterize them are the idea that we can use dredging. We can dredge sediment and we can rebuild wetlands. We've lost a huge amount of wetlands in the 20th century in coastal Louisiana and we can physically rebuild them. We can dredge material, place it ... We're actually very good at that in Louisiana. We do it well, we don't even have to plant grass on it afterwards. It just grows. We have to wait a little bit. So, we call that marsh creation, where we're dredging solely for the purpose of creating the marsh. This isn't like beneficial use that you sometimes do in navigation channels. It's the same principle of making it, but we are dredging just to create the marshes.
The other thing ... and we are lucky because we have the Mississippi River right there. It's still a world-class river. Not quite a natural river, maybe, but it's still a world-class river with lots of freshwater and lots of sediment in it. And so, we do have the ability to, without compromising the flood control system on the river, to let water and sediment back out from the river into the wetlands to kickstart that delta building process again. Which has pretty much been eliminated by river management. And so, we call that sediment diversions, where we're gonna make ... There's a big levee along the side of the river that prevents people being flooded when the river is high, and we put a structure in that levee, big, huge structure in that levee, and then, have a channel that lets water out and it just spreads out into the wetland and nurtures the wetlands that are there, fills in the open water, and just kind of does the same thing that we could do with a dredge, but does it kind of naturally.
So, what happens there ... They work slightly differently. What happens when we dredge sediment and create marshes that way, we build a platform quickly, but then we have to make sure that it stays. Remember the wetlands in Louisiana are degrading, so we build it, why is it going to stay there when all the others around it are degrading? With the sediment diversion approach, we're trying to address the process side of things. So, one's about structure, if you like. Let's get that wetland platform back that we've lost. And the other one is about process. Let's get those processes that originally built the wetlands back working again. It takes a little longer to build wetlands that way, but-
Kristin Hayes: But probably more sustainable.
Denise Reed: ... it keeps going into the future. That's the idea. Yes.
Kristin Hayes: Yeah, interesting.
Denise Reed: The reality of this, though, for both the protection side and the restoration side is ... It's not about, do we need marsh creation or do we need sediment diversions? Do we need levees or do we need non-structural? We need everything. And the problem is so massive and so severe when you think about the higher rates of sea level rise that we might be experiencing in the future. It's not about very nuanced choices between this or that. It's like, what have we got that can actually make a difference, and how can we play that out over time to make a difference in the coast? And that's what the master plan does.
Kristin Hayes: Well, I'm also curious ... I'm always curious, just on a personal level, about the process of putting plans like this together. It clearly, as you noted at the very outset—this area touches both communities and thriving industries and has a long history. And so, I imagine there are a lot of stakeholders that are interested in the future of this area and therefore, a lot of stakeholders who would want to engage in the plans for its future. So, can you tell us just a little bit about that process of engagement? How the plan was put together? And then, are there lessons that were learned in between putting together the 2007 plan and the 2017 plan that might be interesting for our listeners too?
Denise Reed: Yeah, I think so. I have been involved—I work as a scientist, I don't work for the state—but I've worked very closely with them over all three of these plans. My observation would be in 2007, the suggestions were coming from the stakeholders and they weren't massively vetted and were kind of accumulated in the plan. For the 2012 plan, the state folks came to a bunch of us in the scientific community and said, "Everybody's kind of knocking on my door saying, 'I want money to build this. Look, it's in the master plan. Give me some money to build this.'" And so, at that point, the state invested in a very large, detailed scientific effort to pull together some analytical tools that could be used to sift through all these different ideas that had been put forth on what to do for the coast, and they built a set of models.
I think the key thing for the 2012 plan and the 2017 plan, and I say this as a scientist who's worked on it, is that we have developed trust in the analytical tools. And so, as the state folks go out to the public, in all kinds of different ways in the 2017 plan—going out to church halls and community meetings, not just the standard kind of scoping meeting with the microphone in the front of the room—really trying to engage with folks. Talking with local governments, focus groups for different industries. They really were explaining the process of project selection. How are we going to do this? How can we help you understand how these tools work and what options we have for exercising them to pick the projects?
And so, there's this process that has been developed which is quite complex, but I think has engendered trust in the development of the master plan. People rarely come and say, "Your models are wrong." That might be because they're too complex to understand, but I think we have also, for the 2017 plan, done a good job. I was pleased to hear you say that you felt the plan was very accessible to a wide audience. Obviously, the state folks put a lot of time into that. But there's also a massive amount of appendices that really describe in lots of detail-
Kristin Hayes: Technical detail, sure.
Denise Reed: ... of how the analysis was done. So, that too, I think, engenders trust. The scientific community can look at these reports and really see how the calculations were done and what assumptions were made. So, I think that, as a scientist working on this, I like to think that the science has been a really important part of it, but I also always want to give credit to the state folks for actually recognizing that you can develop a master plan in a politically charged environment like coastal Louisiana, with a lot at stake for a lot of people, and do it on the basis of a solid analytical platform. And so, I always try to give them credit for that. I just hope we can continue in that way.
Kristin Hayes: That's great. Yeah, that's fascinating to hear that. And I feel like you've already answered this question a little bit with your last response, but I am very curious; based on your history with this process in Louisiana, I'm sure there are other places in the country—my understanding is that Miami and New York and North Carolina, a number of cities and states, are actually figuring out what their own long-term planning processes will look like. If you had to give those folks one piece of advice, based on your experience in Louisiana, what would it be?
Denise Reed: I think it would be to be really honest about the problems that are coming and to really think about what the future's going to be like and try to plan for it. And don't try to keep the system the way it is now. You need to have somebody with the leadership on the state who's ready to invest in the planning process. The planning process in and of itself takes a lot of time and a lot of resources, but I think you find that it's paid off for the folks in Louisiana.
Kristin Hayes: Fascinating. Well, I have really enjoyed this conversation. This is territory... no pun intended, but territory that I'm not too familiar with, and thank you for your explanation of both the ecosystem itself and the process of hopefully maintaining it for a long time to come. So, I do want to close with our regular feature called Top of the Stack where we ask our guest to recommend something to our listeners that they either have read or listened to. It could be on this topic, it could be something a little bit different, related to natural resource management. But is there anything that you would recommend? What's on the top of your stack?
Denise Reed: Well, I think there are some great books about the development of New Orleans, about how we gradually progressed out from the historic settlement of New Orleans and reclaimed the swamps, and all those kinds of things that trace that kind of history, and the lessons learned from that. And I'd say some of the books by Richard Campanella, for instance, about New Orleans are great reading for people. They're about history, about what we did. And we all know that we don't want to repeat those mistakes again or do those things again, but it doesn't hurt to be reminded.
Kristin Hayes: That's great. Okay. Apparently, I also get to offer what's on the top of my stack. One of things that I have been paying attention to this week is a new paper on, it's actually on renewable portfolio standards, and how states are evaluating whether or not their renewable portfolio standards are in fact working and at what cost. So, there's a paper by Michael Greenstone and Richard McDowell and Ishan Nath and it's gotten some interesting commentary from the world of energy academia, including some significant pushback. And frankly, one of the best responses I saw was this—this is so 21st century, but a series of tweets from Jesse Jenkins at MIT, helping the rest of us understand what that paper is looking at, what it's allowed to say, and perhaps, what it's not allowed to say. So, yeah. That's been an interesting commentary. I've learned a lot this week. But really, not as much as I have learned from this conversation. So, it's been a pleasure, and thank you for joining us.
Denise Reed: Well, thank you very much.
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