Natural Infrastructures: Sediment, Science, and the Future of Southeast Louisiana

Excited to share this piece I just wrote up for the anthropology and environment society. Check it out here on their Engagements blog.

Natural Infrastructures: Sediment, Science, and the Future of Southeast Louisiana

“Losing a football field an hour”

1_historic+future land loss
“Historical and projected coastal Louisiana land changes: 1978-2050” (

Losing land at an average rate of approximately a football field an hour, Louisiana is disintegrating into the sea. Since the 1930s, the state has lost over 2,000 square miles of its coast to the Gulf of Mexico due to accelerating rates of coastal erosion and the channeling, damming, and leveeing of the Mississippi River that has cut the river off from its surrounding wetlands (Couvillon et al 2011; Barras et al 2003). Efforts to abate land loss and protect the sensitive environments of the coast reveal a host of contradictions in knowledge about the coastal landscape and its biophysical characteristics, as well as contests over how to define and design the future of this place. My current research focuses on those contradictions by examining the science and politics surrounding coastal restoration practices.

Graphic depiction of solid land compared to wetland in Louisiana included in the popular online article ‘Louisiana Losing its Boot’, 2014. This graphic is a dramatized version of a study by Blum and Roberts (2009) that estimates that 10,00-13,500 square kilometers of coastal Louisiana will be drowned by lack of sediment and sea-level rise by 2100.

Not long after arriving in Louisiana, I realized that a key site for understanding these issues were the sediment diversion infrastructures themselves. Like the urban infrastructures associated with the modern city (e.g., Joyce 2003), sediment diversions are conduits that connect disparate actors and entities to one another, configuring new relationships between people and their environments. In the realm of environmental change, a focus on infrastructures and the ideas and materials that circulate through them highlights struggles over knowledge and science that are at the heart of debates about the creation and validity of climate change, and the application of technoscience to confront the increasingly ‘unruly earth’ (e.g. Braun and Whatmore 2010; Clark 2011; Latour 2009). It also prompts us to question how the biophysical and chemical work of non-human entities such as sediment, marsh, and saltwater might enable or disable particular human-environmental configurations and futures.

Nature-based infrastructures

Sediment is the key to saving the coast. An expanse of wetlands, once vast, is slipping away and taking plant and animal habitats, and coastal cultures and livelihoods with it. Dredging and pumping sediment from the river where it is deposited off the continental shelf (the “Bird’s Foot Delta) has historically been the primary means of sustaining Louisiana’s wetlands against coastal erosion. It is prohibitively expensive, however, and the state hopes to rely upon less. One promising alternative – Louisiana’s “moon shot”[1] – is to construct sediment diversions.

Long distance sediment pipeline and marsh creation project. Monica Barra, 2015
Long distance sediment pipeline and marsh creation project. Monica Barra, 2015

Emerging out of decades of research on wetlands ecology and geomorphology (see Reed & Wilson 2004 for a review), sediment diversions – essentially outlets cut into existing river levees designed to move sediment from the river to the wetlands – were included in the state’s 2007 and 2012 Master Plan for coastal protection and restoration. It is seen as a radical idea and one that, some say, might just abate land subsidence – and potentially even outpace it.

Sheet 15 of Harold Fisk’s geological investigation of the Mississippi River alluvial valley, “Ancient courses Mississippi Meander Belt,” 1944.
Sheet 15 of Harold Fisk’s geological investigation of the Mississippi River alluvial valley, “Ancient courses Mississippi Meander Belt,” 1944.

The argument in support of using sediment diversion structures draws on the geological history of the Mississippi River and its engineering history. This is perhaps best visually captured by looking at Harold Fisk’s 1944 “Mississippi Meanders” maps depicting the various routes the river has taken on it journey to the Gulf of Mexico alongside the US Army Corps of Engineers diagram of flood control, “Project Design Flood” that depicts the general framework and infrastructures designed to control river flows and keep it more or less in place.

“Project Design Flood Diagram,” US Army Corps of Engineers. 1958.
“Project Design Flood Diagram,” US Army Corps of Engineers. 1958.

The diversions are ideally designed to mimic the natural land building function of river deltas by allowing the sediment-rich water of the Mississippi to flow unencumbered into adjacent wetlands where sediment can accumulate (accrete), vegetate, and become sustained wetlands. Despite their nature-based design, however, sediment diversions are the most controversial project in the state’s toolbox for saving coastal Louisiana. They are the first of their kind to be built anywhere in the world and, as such, they are “an experiment, as one civil engineer described it to me, and many residents critical of the project are quick to point this out.

Science experimenting with the future

Future land loss (red) and land gain (green) with four sediment diversions, Coastal Protection and Restoration Authority, 2015.
Future land loss (red) and land gain (green) with four sediment diversions, Coastal Protection and Restoration Authority, 2015.

In public meetings where sediment diversions are discussed, two struggles between the state and coastal groups, particularly commercial fishing, tend to emerge. On the one hand, residents invested in the local seafood industry question what impacts on inshore estuaries influxes of freshwater from the river might have on current brackish and saline ecosystems. This is a question their livelihoods and futures depend upon. Some are also concerned that diversions could increase flood risk to communities residing outside of local and federal levee systems. On the other hand, the state supports its decision to build diversion infrastructures by drawing upon the expertise of natural scientists and engineers modeling river hydrology, future wetland building scenarios, and their ecological impacts with and without sediment diversions.

Future land loss (red) and land gain (green) without restoration projects, Coastal Protection and Restoration Authority, 2015.
Future land loss (red) and land gain (green) without restoration projects, Coastal Protection and Restoration Authority, 2015.

A key point of contention between groups is knowing the biophysical nature of the delta through years spent living and working in the wetlands, and knowing it through analyzing computer modeling programs that use field data (land, water, sediment samples) from the past to make projections about ecological impacts and future land building capacity of sediment diversions. For residents, the significance of knowing the wetlands from laboring and living in them versus through technoscientific tools and models is best captured in the words of one coastal resident from a recent public meeting: “How much of the land is theoretical? It’s all theoretical land.” The “hypothetical” futures scientific models produce are often not enough to convince coastal publics that sediment diversions will produce tangible, physical results that will build and sustain new land, protecting their homes, businesses, and futures.

“Stop Diversions Now” sign put up by an anti-diversion group in southeast Louisiana. Monica Barra, 2015

As the comment about ‘theoretical’ land building suggests, discussions about sediment diversions indicate the role science itself plays as an actor and contested concept in determining the future of human-environment relations in south Louisiana. To elaborate, during the above-mentioned meeting members of the state coastal protection authority implored parish elected representatives and residents to “attack the science” in their critique of the state’s decision to move forward with designing and building the diversions, instead of attacking them and the institution they work for. Compared to scientists and engineers who use virtual simulations (hydrological models) to understand the region’s future geomorphology, groups like fishermen, one parish council member pointed out, are the ‘best scientists in the world’ because they have worked and lived in the Mississippi River’s bays and backwaters for generations.

Through infrastructures, expertise is politicized, delimiting the possible relationships between people and the environment. Technoscientific expertise about delta geomorphology and infrastructural design becomes a veritable shield the state thrusts between itself and a skeptical public. It is an example of how infrastructures are circuits through which experts and expertise participate in the production of political rule (c.f. Mitchell 2002). But these encounters also demonstrate how the “rule of experts” is contested. Furthermore, it is illustrative of how different ways of knowing the biophysical environment circulate through discussions about the material and virtual qualities of infrastructures: How they are made, controlled, and integrated into social and physical environments. As such, the case of sediment diversions in southeastern Louisiana speaks to the role of technoscience and infrastructures in shaping the possible relationships between people and environments in flux.

Parish (county) council meeting where the state announces its decision to move sediment diversions into the design and engineering phase. Monica Barra, 2015.
Parish (county) council meeting where the state announces its decision to move sediment diversions into the design and engineering phase. Monica Barra, 2015.

Bringing infrastructures to bear on environmental anthropology

My research shows that sediment diversions are more-than-environmental and more-than-technoscientific affairs. Pulsing through questions about research, design, and debates are ethical and cultural values suffuse within decisions about whether and how to alter the lower delta landscape, and what guiding optic – geology, culture, economics, protection – to follow. To some, sediment diversions signal hope for a particular future of Louisiana to become an exemplar of coastal restoration practices for the world. To others, it rings the potential death knell to a way of life that is uniquely woven into the delta environment as it exists today. While everyone knows if nothing is done everything will be lost, it is a struggle between different kinds of knowledges about the lower delta landscape and different cultural values that ultimately play out in casual conversation at the boat docks and heated debates in public meetings about the use of diversions to save the coast.

Works cited
Anderson, B. 2014. Louisiana Loses its Boot. Medium. Published September 8, 2014:
Barras, J., Beville, S., Britsch, D., Hartley, S., Hawes, S., Johnston, J., … & Reed, D. (2003). Historical and projected coastal Louisiana land changes: 1978-2050. US Department of the Interior, US Geological Survey.
Benjamin, W. 1999. The Arcades Project, trans. Howard Eiland and Kevin McLaughlin. Cambridge: Harvard University Press.
Blum, M. D., & Roberts, H. H. 2009. Drowning of the Mississippi Delta due to insufficient sediment supply and global sea-level rise. Nature Geoscience, 2(7): 488-491.
Braun, B., Whatmore, S. J. 2010. Political matter: Technoscience, democracy, and public life. Minneapolis: Univ. of Minnesota Press.
Carse, A. 2014. Beyond the Big Ditch: Politics, Ecology, and Infrastructure at the Panama Canal. Cambridge: MIT Press.
Clark, N. 2011. Inhuman nature: sociable life on a dynamic planet. Sage Publications.
Coastal Protection and Restoration Authority. 2012. Louisiana’s Comprehensive Plan for a Sustainable Coast. Baton Rouge, LA.
Couvillon, B. et al. 2011. Land area change in coastal Louisiana (1932 to 2010). US Department of the Interior, US Geological Survey.
Joyce, P. 2003. The rule of freedom: liberalism and the modern city. New York: Verso.
Larkin, B. 2013. The politics and poetics of infrastructure. Annual Review of Anthropology, 42: 327-343.
Latour, B. 2009. Politics of nature. Cambridge: Harvard University Press.
McPhee, J. 1989. The control of nature. New York: Macmillan.
Marshall, B., Shaw, A. and Jacobs, B. Louisiana’s Moon Shot. The Lens/ProPublica. Published December 8, 2014:
Mitchell, T. 2002. Rule of experts: Egypt, techno-politics, modernity. Los Angeles: Univ. of California Press.
Reed, D. J., & Wilson, L. 2004. Coast 2050: A new approach to restoration of Louisiana coastal wetlands. Physical Geography, 25(1): 4-21.

[1] Bob Marshall, Al Shaw, and Brian Jacobs. The Lens and ProPublica. Louisiana’s Moon Shot. Published December 8. 2014:

Monica Barra is a PhD candidate in Cultural Anthropology at the Graduate Center, City University of New York. She is currently conducting research for her dissertation on the science and politics of coastal restoration practices, land loss, and their relationship to social change in southeast Louisiana. Her research is funded by the Wenner Gren Foundation.

This post is part of our thematic series: The Nature of Infrastructure.


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