To dredge simply means to scoop up sediment, often underwater, and move it to another location. While this process is often associated with moving contaminated soils to a place where they can be safely capped, today, dredging is also increasingly about harnessing natural processes to create new landforms and ecological systems. New "dredge landscapes," designed places, offer opportunities for ecological restoration, said Brett Milligan, Dredge Research Collaborative, at 2014 meeting of the American Society of Landscape Architects (ASLA) in Denver.

Sediment is dynamic and dramatically differs from place to place. Studying the natural flow of sediment in rivers and deltas, we can begin to understand how the movement of sediment can be "choreographed" to achieve ecological goals. However, given sediment flow happens within complex ecosystems impacted by human activities, like the deepening of channels for large ships, using dredge to create new landscapes is a highly complicated process.

As an example, Milligan pointed to efforts to dredge sediment into new landforms that can support wetlands in Jamaica Bay in New York. At current rates, "the wetlands will totally disappear in 10 years. Water regimes have changed due to stormwater runoff and deeper shipping channels." While efforts are underway to rebuild the low-lying islands that can support wetlands in the bay, he asked how dredge can be used to restore a natural environment "where everything has changed?"

In the Mississippi River delta, Roberts has been working on the White Delta diversion project, which aims to create the most efficient interventions for spreading out sediment in the widest possible fan from the river into the delta. Flow paths are dredged to enable the reconstitution of sediment far into the delta plains. All of this is part of an effort to undo the built system of containing the river, which looks like "a plumbing diagram," in favor of letting the river flow and deposit sediment where it's most needed, ecologically.

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