Dredge Economies

by Takuma Ono

2012

While there is an understanding that today’s patterns of consuming–producing–wasting are unsustainable, many networked societies founded on merchant shipping (an enabler of resource re-allocation) continue to rely upon it for elevating and sustaining its 'standard of living'. When perceived and treated as being independent of larger ecosystems, merchant shipping patterns (and related sea-floor dredging) distort and fracture many other interrelated patterns (fluid dynamics, biologic, vulnerability to storm surge, etc.)—slowly dwindling the resilient properties of our commons.

Dredge Economies takes Boston as a case study for imagining a more connected future—one that re-establishes relationships between global and local processes. By mapping the city's rich legacy of trade routes, underwater currents, and projected infrastructure developments, Dredge Economies seeks to build a paradigm for addressing these shared dilemmas.

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This research was made possible by the Maeder-York Family Fellowship in Landscape Studies at the Isabella Stewart Gardner Museum. Assisted by Ailyn Mendoza and Adam E. Anderson. The artist in residence fellowship, offered by the ISG Museum in Boston, recognizes emerging design talent across disciplines that engage in experimentation and research as it pertains to landscape. Biannually, a distinguished committee selects a single individual who has demonstrated high achievement in design.

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19th century

The 19th century in the United States set the stage for the massive proliferation of infrastructural projects.  By the 20th century, these projects set a precedent for practices that would alter the global ecosystem. A modern America, committed to the ideals of a free market economy, free enterprise, and individualism propelled opportunistic investments in industry and infrastructure. Wild floodplains and brimming estuaries, while a cornerstone of many Native American and early colonial settlements, required continuous transformation in order to urbanize in pace with increasing populations. In hindsight, the speed and scale of this growth left a collateral legacy of irreparable environmental depletion; a declaration that capital flows reinforced by economies of scale are unsustainable. The dystopias resulting from what is perhaps better described today as diseconomies of scale are encapsulated in the disappearance of the once inexhaustible and legendary abundance of America's natural resources.

21st century

Climate change will be one of the greatest challenges facing our generation. According to the Massachusetts Climate Change Adaptation Report, by 2050 even the low emission scenario for Climate Change is expected to significantly spike the frequency of climate-related disasters. Presently, Massachusetts has over 90 percent of its economy in an infilled estuary region, making it highly vulnerable to impacts of Sea Level Rise (SLR). However, the swarming sense of urgency surrounding impacts of climate change remains contained within the scientific community, stymied by the political will to re-ignite economies using reliable but myopic formulas for generating growth (i.e. oil, grey infrastructure, industrial agriculture). Finally, while study on climate science has helped uncover alarming details about potential impacts, the incomplete nature of this research is adding complexity to the problem by fragmenting decision-making. Meanwhile, populations continue to be supported by aging infrastructures and deteriorating conventions, which further highlights how a deadlocked global climate protocol poses a direct and imminent threat to the city and region. As such, the 21st century marks a period of great reconciliation, a time to re-think the way the assemblage of problems collide with the local and global systems that support life. In this renewed context, collaboration and coordination are becoming necessary for managing the vast array of human-altered ecologies.

Dredging Boston Harbor

In the British colonization of Shawmut Peninsula, the geologic and geographic converged in an idyllic coupling of economy and ecology; nautical charts document the ceaseless re-invention and re-definition of its shorelines, which occurred at different timescales and shaped the city over several generations. The geological framework of this landscape propagated one of nature's most productive, resource-rich environments and was a medium for growth. To expand trade-assisted development, the Corps's deepening of Boston's naturally shallow estuary was authorized in 1822.

By the 1960's, an environmental movement raised concerns over what it saw as a dig-and-dump activity.  As ensuing mitigative protocols and escalating energy prices became prohibitive, demand emerged in the 1990s for a national policy to restore economic incentives to dredge. President Clinton endorsed the National Dredging Policy in 1995 in recognition of a need to balance dredging practices with the need to conserve, protect, and restore the nation's coastal, ocean, and fresh water resources. Inability to dredge cost-effectively within a timely schedule fuels anxieties over the viability of sustaining economies dependent on international commerce. However, this dig-and-dump activity modifies the floor of the estuary, alters hydrodynamics and tidal patterns, and trickles down to alter patterns in biological systems. Still, the specific impacts of dredging on Boston Harbor remain mostly unknown as very few scientific studies on this subject extend beyond Environmental Impact Reports (EIR).

Meanwhile, Climate Change continues on its long established trajectory and a sense of urgency seems to rise in sync with record-setting warming. While adapting is necessary, we are in an economic environment of escalating costs, dwindling finances, and a rising sense of desperation. Climate Change and ballooning costs of dredging are requiring the nation to re-conceptualize this globalized economy from the ground up. Throughout history, Boston's port played an important role in the development of New England and its global economy. Given this setting, the estuary emerges as the site for understanding systemic overlaps and scales at which solutions could be developed.

Mutualistic Dredging

Broadly speaking, Dredge Economies is an ecosystem-inspired design that imagines a mutualistic relationship between the process of dredging and natural systems; it does so by confronting containerized transport with acknowledgement of its centrality to sustaining present global economies. Sadly, even as the aggregated impacts of containerized commerce require us to re-think dredging, the greening of the container ship has been the focus of mitigative efforts, leading to the build-out of larger ships with expanded cargo capacities.

Instead, Dredge Economies begins by considering dredging as part of the ecosystem; the design reveres the industrial might of a conventional growth strategy (dredging) but acts opportunistically on this force. In theory, by re-thinking dredging as being integral to the ecosystem rather than an end goal, the progressive cultivation of this wilderness gains the potential to support a diversity of organisms. What happens when we begin to perceive dredged sediment as a valuable resource? What happens when we recognize that we are already active ecosystem shapers? Is it possible to cultivate the harbor – to create a net positive impact on natural systems?

As cultural perceptions of natural systems are dynamic and evolving, it can be expected that the current predominant version will eventually be displaced. In the short history of the United States the cultural perceptions of Nature have ranged from it being sacred, to something that must be tempered, to an exploitable and exploited resource, and finally, to something complex and precious. Within the sequence of these mainstream perceptions, to shift the paradigm to one of mutualistic understanding of industry and nature hinges on a evolution of the present conservative ideology. Hindered by the view that nature is complex and precious, research on the effects of dredging have primarily focused on mitigation and remediation even while resources are being consumed at an unsustainable rate. As a consequence, scientists know very little about what remains of wilderness and less information is available about the costs and effectiveness of adaptation measures than about mitigation measures. Despite this reality, it is becoming clear that the inertias of diseconomies are too destructive a force to be moderated through mitigation alone.

Adaptive Management

In the context of a weak global economy, the gathering inertia of human induced climate change is further compounded by political structures that are unfit for confronting this condition. In this cultural context, scientific uncertainties at the local scale are identified as primary barriers to decision-making at the institutional scale. In response to this barrier, both the U.S. Department of Interior (DOI) and the Intergovernmental Panel on Climate Change (IPCC) have endorsed the use of Adaptive Management, a strategy that focuses on learning and adapting to maintain sustainable ecosystems.

While risk-mitigating strategies such as conservation, restoration and energy efficiency have their own merits, taking the long-view, many scientists believe that dramatic transformations of operating systems are necessary to survive the impacts of climate change. , As the impacts of climate change are in themselves evolving, Dredge Economies envisions the adaptive strategy and its processes as integrated with and informed by the dynamic patterns of natural systems. To confront differences and divisions between mitigation, resistance and transformation, strategies that address near-term risk are synchronized with long-term agendas. In essence, adaptation is being recognized in this project as a process that is emergent from an orchestrated synchrony between dredging, dumping, and dynamic environmental forces.

Sediment Management as Living System

Applying the characteristics of living systems to the design of sediment management is a way of defining the problem in terms of feedbacks, efficiencies, redundancies, and dynamic interactions. The goal is to design a process that is self-organizing, that responds to externalities while maintaining an internal equilibrium.

Robustness

In Dredge Economies, Robustness is a desirable attribute emergent from a balanced expression of several key properties found in living systems (i.e. ability to react to stimuli, develop, evolve, metabolize, grow, and absorb). Coordinated through feedback, P A R T S work collaboratively in support of these properties and collectively confront a broad range of risks through adaptive management.

As a risk-mitigative strategy, the design is imagined as an assembly of repeating modular units. Not dissimilar from how amino acids combine to form proteins in biological systems, these units assemble incrementally into a range of permutations, forming evolving responses to evolving issues. As such, this graduated response has the effect of distributing risk over time and space. Furthermore, information obtained from the real-time monitoring of this design would feed back to the assembly line, creating a programmed flexibility, making it an ideal partner to adaptive management.

Erosive Structures

Containers are built with dredge...for holding dredge. Some of these containers are designed to be porous, allowing water to flow through and gradually erode the pile. Strategic placment of these polymeric rings work with natural systems (wind, water) to reinforce desirable directional flows. New tidal habitats emerge from, and evolve with this process.

Coordinating P. A. R. T. S.

(Portable, Adaptable, Renewable, Transposable, Scalable)

Portable

According to the U.S. Commission on Ocean Policy, dredging is possibly the most direct and prominent way humans affect sediments in marine waters. In Boston, a planned "improvement" of an existing navigation channel is expected to generate 13 million cubic yards of sediment and rock. As such, the ability to rapidly dispose dredge is being recognized as an important part of a beneficial-use program. Containers for holding dredge (opposite page) are manufactured – in proximity to the dredge site and in pace with the dredging operation – to allow most of this sediment to be retained in the system. These containers create an environment where the dredge can be freely ported, ultimately enabling the integration of broad-scale beneficial use with small-scale projects.

Adaptable

Dredge Economies proposes using Soft Infrastructure to systematically reduce Boston's exposure to short and long-term climate-related vulnerabilities. 

While the planning and design for  soft infrastructure requires ongoing collaboration and coordination between managers, agencies, and policies, it is superior in its capacity to stay in sync with the temporal and spatial dynamics of exposure and vulnerability.

While Nantasket and Deer Island Peninsulas are the primary headlands that define the outer limits of this harbor, this semi-enclosed water body is further sub-divided by secondary headlands, tombolos, causeways, salients, islands, flats, rivers, and human disturbances that comprise this estuarine system. Over the past two centuries, a flattening and homogenizing of this aqueous landscape (through dredging, damming, filling, ploughing and poisoning [,,,,] ) have reduced the diversity of spatial typologies and tempered the rates of fluid exchange between the river, harbor, bay, and ocean.[,] While facilitating rapid human settlement, past modifications had deleterious effects on the estuary. Dredge Economies proposes articulating the site in ways that: support the self-organization of variegated seascapes, strengthen flows and networks between distinct seascapes, and provide selective barriers to storm surge.

Renewable

Coupling the operations of dredging with the purposeful redistribution of the dredged sediment can be seen as the basis of a new opportunistic approach to large-scale mitigation, remediation, and nutrient cycling.

The Port of New York and New Jersey recently succeeded in coupling its deep draft navigation dredging (to -50ft) with a skillfully planned construction of estuaries. Although ecological benefits from the newly built estuaries have yet to be fully realized, the project is already successful in terms of the quantity of dredged sediment used (60 million cubic yards). It demonstrates that large-scale dredging and an estuary-building process can be coordinated both financially and logistically.

In Dredge Economies, a sustainable regeneration is envisioned as being emergent from a balance between evolvability and resilience. Stated in another way, renewability is seen as arising from the programmed flexibility of a sediment management plan – measured against the effectiveness of a climate adaptation strategy.

Transposable

While being informed by the rhythmic patterns of the environment, Dredge Economies envisions making alterations to it that would further guide and support adaptation to the rapidly changing climate.

move sediments = move flow patterns; move flow patterns = move sediments; flow patterns = conduits and settlement areas for nutrients and organisms

Shaped like large ‘jacks’, these tetrapoidal units possess the minimum number of legs required to stand on it's own. Some of the dredged sediment (sand and gravel) are used to construct these structures. The flexible, multipurpose quality of these units create myriads of opportunities.

Scalable

For nearly a century, concrete units like these have been used along coastlines to dissipate erosive wave energies - for one, they are easily scaled - as a monomer and as a polymer. Stacked, it armors the urban shoreline from damaging waves;  arranged in a circular formation, it becomes a container for holding large quantities of dredge.

Scenario 1: Tetrapods align the Inner Harbor, creating a layer of defense from wave energy. The same tetrapods arranged differently define the entry to the Inner Harbor and influence the directional flow of currents.

Scenario 2: Drifting mounds of dredge enhance and promote a variegated landscape between existing harbor islands. As a whole, this porous barrier acts selectively to drown wave energies generated by Nor'easter and hurricane winds.

Under typical conditions the thickened barrier of islands guide the flow to move around it. Consequently, this concentrated flow invigorates the exchange of water between the river, harbor and bay.

This dredge-enhanced landscape also functions as spawning and feeding grounds for pelagic species. Juvenile fish and shellfish are carried by tidal currents from this porous hatchery to other parts of the harbor and bay.