Restoring Crabtree Swamp

EQL Projects

Restoring Crabtree Swamp

Since the 1960s, the US Army Corps of Engineers has dredged an eight-mile canal through Crabtree Swamp to prevent and control flooding. The dredge materials were piled onto the adjacent banks, creating a very steep, unstable levee system with failing banks and an unstable channel bottom that isolated the remaining floodplain, increased water velocities, and eliminated habitat and fish spawning grounds. 

In 2008, Horry County and the city of Conway signed a Memorandum of Understanding with the Horry Soil and Water Conservation District and Crabtree Swamp Watershed Conservation District to undertake an initiative to restore Crabtree Swamp to a more natural state. In 2009, the group completed the first phase of a floodplain restoration project with help from project partners that included Coastal Carolina University, Clemson University, the US Fish and Wildlife Servicee, USDA/NRCS, SC DHEC, and US EPA. The project was designed to increase flood storage capacity, stabilize canal banks, filter pollutants from water with native plantings, and provide wildlife habitat. 

crabtree swamp before

Before restoration, incised channel

crabtree swamp excavation

During excavation

crabtree swamp planting

Young native plantings

Thepaut Crabtree fieldwork

Monitoring native plantings

In 2013, Horry County Stormwater installed a low-head rock weir in Crabtree Swamp for the purpose of controlling channel and bank erosion. The project is permitted by the US Army Corps of Engineers and used a design prepared by the US Department of Agriculture's Natural Resources Conservation Service. If the project is a success, additional weirs will likely be installed. The weir is designed to slow the water down and collect sediment in an attempt to build up the channel bottom. The weir was placed just downstream from a small bridge in hopes of arresting the undercutting that was occurring there.

Project monitoring and assessment is ongoing. 

You can see additional pictures and learn more in the Crabtree Swamp restoration brochure (pdf).

To learn about plant survival in this project, see Plant Survival in the Floodplain Restoration of Crabtree Swamp (pdf).