Healthy Port Futures: Making Cases for Adaptive Sediment Management
Kids playing among the shells, animals, and large woody material on a mudflat. South shore of Lake Cayuga, Lake Ontario Basin, Winter 2019. The mudflat is exposed in periods of low water and protects the shoreline of the historic Stewart Park when submerged during periods of high water. This muddy landscape has long acted as an extension of the parkland and rich habitat for shorebirds.
The Value of Mud, and Ports
It is possible to protect the Great Lakes by revaluing its mud.
Mud—the fine-grained silts and clays together with sands and gravels that make up the sediments of the Lakes—stands alongside water itself as the most basic of materials in the Great Lakes region. In varying concentrations and contexts it forms the wetlands and mudflats, the beaches and dunes, the islands and riverbanks that healthy ecosystems, communities, and anglers rely on. If we have taken this material for granted in the past, it is only because it is so fundamental that we cannot imagine our favorite places without it.
Today many nearshore environments in the Lakes are sediment-starved, while others have far too much, or the sediments are contaminated. This is because human-induced processes have created hydrological and nutrient cycles that are out of sync.
Ports are an unusual human environment: they produce sediment through the need to maintain navigation. Situated at some of the most sensitive and productive ecological areas in the Basin—river mouths—ports have long been economic and cultural drivers for communities throughout the Great Lakes. In this context, the Healthy Port Futures project is motivated by the simple question:
What if ports could also become ecological drivers in the protection and restoration of the Great Lakes?
The importance of sediment in terrestrial and aquatic ecosystems in the Great Lakes has been a subject of tremendous interest in the last twenty years, and the beneficial use of sediment is a widely recognized effort and area of innovation. In some ways sediment is a resource out of place: while it is often beneficial in nearshore or wetland environments, in the open lake or navigation channels it becomes a problem.
In the absence of outside funds, many port communities still rely on open lake placement as the cheapest available method of managing sediments. To move away from this practice, there is a need to reduce the capital costs, as well as the complexity of the design, construction and permitting process of beneficial sediment use projects, particularly for small and mid-size harbors which find these barriers prohibitive. The primary way our team aims to approach all of this is through a strategy we call passive sediment management (PSM).
Passive Sediment Management
Through this concept we propose to leverage natural coastal and fluvial forces such as winds, waves, and currents to achieve desirable sedimentary outcomes including shoreline protection, maintenance of navigation, habitat creation, and wetland restoration.
Our team is developing work flows and technologies that will allow for conditions to be quickly characterized, analyzed, and modeled, and employ design research that can leverage these insights. These adaptive approaches will minimize costs and maximize value creation in sediment projects.
In some places PSM may be deployed for wetland creation, in other places to protect upland habitat and maintain navigation, or several objectives together. Because PSM requires a grounded understanding of the local conditions affecting sedimentary processes, it acknowledges that not all management strategies are deployable at all locations.
Building on best practices established by state and federal agencies, we are working with input from local residents and agency stakeholders to ensure all the potential values of the process are captured effectively. PSM requires engagement—not only the characterization of natural systems and analysis of conditions but also drawing from local knowledge. This engagement is motivated by landscape thinking that sees natural and cultural systems as equal partners. Lead by local partners across the basin, this approach guides the Healthy Port Futures project.
While Healthy Port Futures has several aims, pilot projects are key as they offer a specific, achievable means to establish precedents and to verify the multiple benefits of this adaptive approach to sediment design.
The team has placed considerable attention on ports in Ohio for a variety of reasons. The Ohio EPA and DNR have actively pursued new ideas in sediment management, and the US Army Corps of Engineers (USACE) Buffalo District is a proving grounds of the Engineering with Nature Program. Moreover, the local communities are engaged and invested in their coastline, local habitat and fisheries, and the continued viability of their ports.
We have been working with partners in the development of a set of wetland habitats with dredged sediment. Our team has demonstrated the potential of more open systems that work with the waves, winds, and currents to create complexity in the constructed wetlands while still ensuring the persistence of biological integrity and shoreline protection over time.
In Ashtabula, OH a potential pilot project is about to move into the design phase, where the agreed-upon schematic will be refined for construction by the USACE Buffalo District. The proposed wetland concept will demonstrate that the habitat can be enhanced over time by interaction between waves in the harbor and placed sediment utilizing a dynamic and cost-effective design. We are now working on the design of contemporary containment methods to enhance vegetation establishment and habitat creation.
In Lorain, OH the pilot is still in the feasibility phase, where sites are being identified and evaluated. We have been instrumental in advocating for pilot sites that offer the highest habitat value, the most potential for PSM, and can position sediment as a long-term coastal resource in the area. By designing and modeling scenarios that demonstrate the above qualities, we have successfully advocated for a range of longshore sites and several of them are presently receiving additional funding to be studied further by the USACE as possible pilot locations.
Going forward, Healthy Port Futures will be identifying project partners outside of Ohio that will allow us to work in different environmental and social conditions and demonstrate the potential of PSM. Presently we are engaged in discussions in Illinois, Michigan and New York.
Healthy Port Futures envisions a new coast for the Lakes, one neither sediment-starved and hardened nor cloudy and polluted with harmful algal blooms, but rich with wetlands, spits, bluffs, shoals, and functioning harbors in communities of all sizes. Passive sediment management may be a new tool in this effort to bring innovation to port communities of all sizes and means by revaluing their mud.
–GLPF wishes to thank Sean Burkholder and Brian Davis, leaders of the Healthy Port Futures project, for this post.
Sean Burkholder is an Assistant Professor of Landscape Architecture at the University of Pennsylvania. He is also the director of the Landscape Affairs Group, a Landscape Research and Design consultancy focused on the human-entangled freshwater ecosystems of postindustrial regions.
Brian Davis is an Assistant Professor of Landscape Architecture at Cornell University. He is also the director of the Borderlands Research Group. His background and current work center on the overlap of urban design, water infrastructure, and public space.
- GLPF Projects