The more than 200-acre project aims to shield mainland communities by enhancing barrier island resiliency and building and protecting back-barrier habitats
Leading global design firm Stantec has begun the next phase of design support and hydrodynamic modeling for the Cedar Island Marsh creation project, in collaboration with the Virginia Institute of Marine Science (VIMS). The project aims to improve barrier-island and marsh resilience on a 216-acre site to protect against coastal erosion and island breaching, while expanding wildlife habitat and ecosystem services. This will help protect underserved coastal communities against the impacts of coastal flooding and damage from storm surge.
Virginia’s Eastern Shore is fronted by 13 barrier islands which, along with their marshes and shallow lagoons, play a vital role in protecting mainland communities by providing a buffer from coastal storms and sea level rise. They also serve as centers of commerce for agriculture, aquaculture, tourism, and recreation. Of the 13 Islands, Cedar Island was selected for the project because it is one of the most dynamic in the region. The rapid deterioration of its southern shore poses multiple threats, including flood risks for the Town of Wachapreague, disruption to navigation routes, and reduced economic vitality of the central eastern shore, which relies heavily on the ecosystem services of the marshes and bays.
Using an innovative, science-based design, the restoration plan consists completely of natural and nature-based features, including the construction of more than 200 acres of new tidal marsh, which will be planted with native, desirable marsh grasses. The result will lead to a complete, contiguous back-barrier marsh habitat for the most vulnerable areas of southern Cedar Island that allow for natural barrier-island rollover and enhanced resilience against storm events and continued sea level rise. Additionally, the design team expects the new marsh will increase the value of carbon storage benefits.
“As sea level rise and the frequency of severe weather events continue to increase, so do the threats to our shoreline communities and ecosystems,” said Daniel Proctor, principal and water resources engineer at Stantec. “Using a nature-based approach allows our team to create a solution that will help protect the mainland coastline while restoring critical habitat and mitigating negative environmental impacts.”
Stantec is a leader in environmental engineering and restoration, having supported a variety of large-scale projects worldwide. This includes designing the Prime Hook National Wildlife Refuge Restoration in Delaware, which restored two miles of shoreline, restored acres of threatened salt marsh, and protects vital natural habitats from severe storms. Stantec also supported the Terrebonne Basin Barrier Islands and Beach Nourishment project, which restored critical beach, dune, and marsh habitat to protect fragile inland marshes. Just as Prime Hook serves as a worldwide template for shoreline resiliency and salt marsh restoration, Cedar Island has the potential to be a model for back-barrier habitat creation and the slowing of barrier migration through reduced breaching risks.
An article on the Cedar Island project entitled “Leveraging the Interdependencies Between Barrier Islands and Backbarrier Saltmarshes to Enhance Resilience to Sea-Level Rise” was recently published in the journal Frontiers of Marine Science. The article was written in partnership by researchers at the Virginia Institute of Marine Science, Randolph-Macon College, George Washington University, and Stantec senior coastal engineers, Jeff Tabar and Todd DeMunda.
Hydrodynamic modeling for the Cedar Island Marsh project is expected to be completed in 2022. Subsequent final designs and permitting efforts are awaiting additional funding.
