Case Studies

Winyah Bay and Pee Dee River Basin Conservation and Resiliency Planning

As the third-largest estuarine drainage area on the U.S. Atlantic coast, the Winyah Bay, Pee Dee River Basin and Sewee to Santee drainage area supports an incredible variety of wildlife and habitats. The project area is divided into two neighboring focus areas — the Winyah Bay and Pee Dee River Basin Project and the Sewee to Santee Project — and spans approximately 1 million acres across six coastal counties in northern South Carolina. The project area encompasses the Waccamaw National Wildlife Refuge, the North Inlet Winyah National Estuarine Research Reserve, the Francis Marion Nationaparl Forest and the Cape Romain National Wildlife Refuge.

Since 1984, The Nature Conservancy of South Carolina has protected more than 111,000 acres of this vibrant ecosystem. In 2008, TNC SC integrated climate planning and adaptation into the project, launching the Winyah-Sewee Conservation and Resiliency Planning Project. The goal for this project is three-fold: safeguard habitat, protect and enhance biodiversity and increase the health of the natural system in order to maximize resiliency.

Value of the land and habitat

The Winyah-Sewee Conservation and Resiliency Planning project area encompasses approximately 1 million acres of freshwater and tidal wetlands, cypress-tupelo swamps, floodplain forests, pitcher plant bogs, multiple barrier islands and longleaf pine forests. This is the site of the largest isolated Carolina bay wetland in South Carolina, and is the third-largest estuarine drainage area along the U.S. Atlantic coast (only the Chesapeake Bay and the Pamlico Sound are larger).

The ecosystem offers vital habitat to several species of concern, including the federally endangered red-cockaded woodpecker, the endangered flatwood salamander and the federally endangered pondberry and American chaffseed. Additional species found here include 59 species of amphibians and reptiles — including the largest breeding population of loggerhead sea turtles outside of Florida — 66 species of songbirds, and nesting osprey. The ecosystem supports internationally renowned populations of migratory birds and waterfowl and American black bear rely on habitat corridors through the region to connect with populations in North Carolina.

Conservation concerns

Conservation concerns within the Winyah-Sewee Conservation and Resiliency Planning project area include:

  • Residential and commercial development, and the loss of rural land.
  • Greater restrictions surrounding the use of prescribed burns, as the nearby human population grows.
  • Diminished estuarine water quality due to dam operations, sea level rise and more violent storms.
  • Sea level rise and saltwater intrusion.
  • Water pollution in the form of stormwater runoff and soil erosion.
  • Increasing risks of invasive species.

Current protection status and management plan

Since 1974, TNC SC has been protecting habitat within the Winyah-Sewee Conservation and Resiliency Planning Project area. Approximately 10% — more than 111,000 acres — of the combined 1 million acres within the adjoining Winyah and Pee Dee River Basin project area and the Sewee to Santee project area have been protected by TNC SC primarily through land acquisitions. Many of these protected properties abut state and federal protected land, creating a network of approximately 330,000 protected acres across the entire project area. The protected properties include freshwater and tidal wetlands, cypress-tupelo swamps, floodplain forests, pitcher plant bogs, multiple barrier islands and longleaf pine forests.

Due to climate change and associated sea level rise changing the landscape within the Winyah-Sewee Conservation and Resiliency Planning Project area, TNC SC is now in the process of implementing land protection actions to mitigate the effects of sea level rise. Additionally, TNC SC is working with conservation partners to complete new modeling efforts that will improve the resolution of sea level rise predictions.

An adaptive management plan has been adopted for the project, which means that planning will be an ongoing part of the project. Several ongoing and pending modeling, research and monitoring projects will provide valuable guidance for the adaptive management plan, and will also be useful in gauging success.

Process of achieving protection and resilience to climate change

Climate change, sea level rise and worsening storm damage are all of concern within the Winyah-Sewee Conservation and Resiliency Planning Project area, with changes already being seen on the landscape. Some parts of the project area may lose approximately half of their beach habitat, and saltwater intrusion will shift some freshwater habitats to brackish or tidal communities. By planning with these changes in mind, TNC-SC seeks to enhance resiliency and increase the options for animals and plants to migrate as local conditions change. To take a closer look at these issues, the National Oceanic and Atmospheric Administration (NOAA), TNC SC, and US Fish and Wildlife Service (USFWS) conducted a Sea Level Affecting Marshes Model (SLAMM) analysis with high-resolution and localized data sources for portions of the project area. Using NOAA’s Habitat Priority Planner (HPP), other spatial data was incorporated with the SLAMM predictions such as parcel size, swallow-tailed kite nesting and observation points, protected lands layer, refuge boundary, and habitat. The results showed that approximately 14,000 acres of currently protected freshwater wetlands within the Waccamaw National Wildlife Refuge (NWR) are at risk of converting to brackish marsh over the next 50 years, and that the Cape Romain NWR may experience a 47% loss of beach, dune and salt marsh by 2100. New and unusual tidal creek formations have already been observed in the Cape Romain NWR, and erosion and vegetation loss both are accelerating.

Current climate change response recommendations include the expansion and connection of protected areas, allowing for the creation of habitat corridors across the topography of the ecosystem. This approach — often referred to as conserve the stage — allows habitats and natural communities to shift their ranges as climate conditions continue to change.

Several species are especially vulnerable to sea level rise and storm erosion. Sea level rise scenarios predict that the ecosystem’s freshwater forested wetlands — core swallow-tailed kite nesting habitat — may convert to brackish marsh due to saltwater intrusion. Those same forested wetlands used by breeding kites are also vital corridors for coastal black bears and help connect the populations between North and South Carolina.

Sea level rise is already taking a toll for some species. For example, up to 1,500 loggerhead sea turtles nest on the beaches of Cape Romain NWR every year. In 2011, more than half of these nests were relocated by volunteers due to vanishing shoreline and high rates of erosion.

Plans for the future

Objectives for the next five years include implementing large-scale oyster restoration projects, leading efforts to guide public policy as it relates to estuary restoration and climate adaptation, and identifying, prioritizing, and conserving lands that advance climate adaptation in coastal SC.

TNC SC is currently seeking funding to deploy water quality monitoring stations through a contract with the US Geological Survey (USGS). These stations will provide continuous monitoring of water quality indicators such as tidal range, salinity and sedimentation. These results will be used to develop an oyster habitat suitability index model and a more refined sea level habitat conversion model.

Ongoing partner research includes:

  • Monitoring of habitat conversion in wetland communities.
  • Ground-truth predictions of increasing freshwater tidal reach.
  • Species specific projects focusing on black bear, swallow-tailed kites, red cockaded woodpeckers and bobwhite quail.

All work related to climate change is expected to be ongoing.

Engaging Stakeholders

Stakeholders and local citizens have been kept informed through regional and local workshops, including a series of round-table discussions with coastal resource and water managers to discuss the impact of sea level rise and salinity intrusion into coastal communities and protected areas.  TNC SC is also actively engaged with the landowner community in the Black River and Mingo Creek Conservation Area, and joined with local land trust partners in 2012 to host the first “gathering of neighbors” to discuss the future of the conservation area and the role that private landowners can play in a long-term vision for the landscape. TNC SC also uses newsletters, email alerts, its website, and an international magazine to communicate its work.

Key Partners

Partners in research and planning:

    • NOAA Coastal Services Center
    • North Inlet and Winyah Bay National Estuarine Research Reserve
    • University of South Carolina
    • US Fish and Wildlife Service
    • US Geological Survey
    • Waccamaw National Wildlife Refuge

Partners in land protection:

    • American Rivers
    • Ducks Unlimited
    • Lowcountry Open Land Trust
    • North Inlet Winyah Bay National Estuarine Research Reserve
    • Pee Dee Land Trust
    • South Carolina Department of Natural Resources
    • Waccamaw National Wildlife Refuge
    • Waccamaw Riverkeeper

Lessons learned

  • Scale matters. Consider the resolution of the models and/or predictive analysis when determining the appropriate scale at which to apply conservation actions for climate adaptation.
  • Be alert for multiple benefits. Many climate adaptation conservation strategies also provide benefits for human and natural communities.
  • It is helpful to communicate benefits of land protection and restoration to stakeholders. For example, the restoration of wetland habitats will improve drinking water resources, flood control, wildlife habitat and public/private recreational opportunities.
  • Do not let perfection stand in the way of progress. Climate models and other methods of predictive analysis are not perfect, and cannot answer every question. However, it is important to use whatever information and technology is available to make informed decisions about where and how to direct conservation funding.