USA: Nature-based solutions in coastal Georgia
The protection and restoration of natural habitats can help communities adapt to the impacts of climate change.
Georgia’s coast is home to nearly 1/3 of the east coast’s salt marshes, totaling approximately 400,000 acres of this important and productive tidal habitat. It has 14 barrier islands, 300 square miles of open Atlantic Ocean, nine major estuaries 3,400 miles of tidal shoreline and expansive areas of freshwater tidal forests, maritime forests and longleaf pine forests.
It fronts cities of rich and complex history such as the coastal river cities of Savannah, Darien and St. Marys. Georgia’s coast is also home to many rare and endangered species from the gopher tortoise to the American bald eagle and West Indian manatee.
All of this is at risk as the growing reality of climate change threatens the Georgia coast—from rising sea levels to more frequent and intense storms and rainfall. That’s why we are investing in nature-based solutions across the coast.
Nature-based solutions are aimed at solving these climate challenges through the protection and restoration of natural habitats that can help communities adapt to and mitigate the impacts of coastal hazards, all the while supporting important biodiversity.
Nature can help us build a more resilient Georgia coast, all while supporting its growing population and the critical ecosystem services we know and value.
Living shorelines: The first line of defense
Our shorelines need protection—from erosion, pollution, tides, waves and storms. How do we tackle this daunting task? The answer is living shorelines, which combine human-made technology and engineering with oysters and native plants to stabilize shorelines.
Living shorelines are better for nature, help to restore oyster reefs, and combat climate change by storing carbon.
One square mile of living shoreline stores the equivalent of 76,000 gallons of gas.
“The Living Shoreline Project’s goals are to develop alternatives to conventional hardened shoreline erosion control methods and restore oyster reefs, which help filter the surrounding water and provide important habit for other marine species,” said Christi Lambert, Director of Coastal and Marine Conservation.
When hit with storms or strong waves, living shorelines are more resilient and more likely to protect the communities behind them. All this while supporting the biodiversity and natural habitats of species, like white and brown shrimp, blue crab, spotted sea trout, otter, alligator, and painted bunting.
TNC’s first two pilot living shoreline projects were constructed on Sapelo Island in 2008. To date, projects are underway or completed on Little St. Simons Island, Cannon’s Point Preserve, Little Cumberland Island, Tybee Island and Skidaway Island.
Scientists use a variety of techniques to monitor upland and estuarine areas to determine the rates of erosion and compare the results from before and after the living shoreline was constructed. They also collect finfish and crustaceans using seines and trawl nets to assess the impact of living shorelines on coastal ecosystems.
TNC isn’t alone in this work. Many partners have come together in collaboration, including the Georgia Department of Natural Resources Coastal Resources Division, Sapelo Island National Estuarine Research Reserve, Georgia Southern University, the University of Georgia Marine Extension Service, Coastal Wildscapes, and public and private landowners. Coastal Wildscapes members and volunteers also helped with bagging oyster shells, planting native plants on the shoreline and maintaining the native vegetation.
Helping communities prepare for and protect from floods
Much like other coastal Georgia counties, Camden County is a low-lying coastal community with wetlands comprising more than 50 percent of its land area. As a result, the county is susceptible to flooding from hurricane-induced storm surge and rising sea level, putting people, property and coastal habitat at risk. County officials are working with TNC and other partners to develop and pilot an online decision support tool to help citizens and community officials prepare for and respond to their flood risk.
The ultimate goals for the tool include helping citizens become aware of their flood risk, providing community officials with data to inform their decisions about future land use, and identifying critically important conservation targets that provide natural flood risk reduction.
Upon completion of the two-year pilot program and roll-out of the tool in Camden County, The Nature Conservancy will share this science-based approach and results with other coastal governments to demonstrate the benefits of conservation as a means of managing storm surge flooding.
“We hope to create a visual, easy to use digital tool that becomes a model for how coastal community officials can make science-based decisions to prepare for and mitigate the impact of storm surge flooding and help residents and business owners understand their personal flood risk,” says Ashby Worley, Coastal Resilience Manager.
Moving sediment and fighting coastal hazards
Georgia’s coastal waters are dredged routinely; usually for shipping channel maintenance near ports and the intracoastal waterway. The removed sediment is then placed at designated sediment disposal sites offshore or in upland dredge spoils.
But sediment is a limited resource on the Georgia coast due to dams along coastal rivers that limit the natural flow of sediment downstream. This leads to beach erosion and under-nourished salt marshes that can’t grow at a rate that keeps up with sea level rise.
A team comprised of The Nature Conservancy, U.S. Army Corp of Engineers, Georgia Department of Natural Resources Coastal Resources Division, and Jekyll Island Authority is exploring a sediment management technique called thin-layer placement in a marsh near Jekyll Creek in the St. Simons Sound. This work is part of a pilot project aimed at developing economically efficient and environmentally acceptable methods of managing dredge material.
Thin-layer placement deposits sediment in thin, uniform layers over vegetation such as marsh grass. In addition to its sustainable sediment management application, thin-layer placement can be used to nourish existing marsh or create new wetland.
In the Georgia pilot, approximately 5,000 cubic yards of sediment dredged from a portion of Jekyll Creek were sprayed onto a five-acre area that is susceptible to saltwater inundation due to its low elevation. The goal of this placement is to raise the elevation—by up to one foot in some places—to allow new marsh grass to grow at higher elevations. This pilot project will help us understand the potential of this technique for helping Georgia’s important marshes become resilient in the face of increasing sea levels.
Scientists will monitor the placement and control areas for two years to determine how the marsh is affected by the thin-layer placement. An elevated monitoring system is capturing images of the marsh throughout the project. The public can view up to a month’s worth of footage of the marsh from the camera feed.