Island Restoration Study to Evaluate ‘Triple-Win’ EWN Objectives
The coastal islands and marshes of Chesapeake Bay USA, are disappearing along with the ecosystem services and infrastructure/shoreline protection they provide. Within the last half century, cumulative effects of shoreline erosion, subsidence, inadequate sediment supply and sea level rise, have accelerated the rate of island submergence. To counter such losses, island construction and/or restoration has been pursued. Islands constitute an important natural and nature-based feature (NNBF) that meet the ‘triple win outcomes’ of USACE’s Engineering With Nature® (EWN®) initiative, by providing economic, social and environmental benefits. For example, the Smith Island complex has been experiencing erosion at rates of up to 3 m per year over the past 75 yrs. To protect against further losses, the USACE Baltimore District is restoring historic island footprints using dredged sediments. Here we highlight the restoration and monitoring of Swan Island using 55,000 cubic yards of dredged sediment. The creation/expansion of Swan Island, which is part of the an island complex in the Chesapeake Bay, is expected to produce significant benefits in terms of ecosystem services, increased resilience to future sea level rise, and abatement of erosive losses to an adjacent coastal community. The pre- and post-restoration monitoring and model development by project partners (NOAA’s National Centers for Coastal Ocean Science, US Army Corps of Engineers – Baltimore District, US Army Engineer Research and Development Center, US Fish and Wildlife Service, and Maryland Department of Natural Resources) will serve to quantify the benefits and efficacy of the island restoration thereby facilitating island restoration as a viable NNBF option in the future.
Swan Island, Chesapeake Bay (View PDF)