The U.S. Army Corps of Engineers Charleston District and Horry County partnered to study flood risk reduction measures for flood impact areas along the Waccamaw River and its tributaries.
Charleston District and Horry County signed a Feasibility Cost Share Agreement in August 2022 to kick-off the Waccamaw River Flood Risk Management Study. The purpose of the study was to address flood and life safety risk to communities and transportation routes specifically within Horry County, and to recommend a plan to reduce this risk. Primary flood impact areas identified in Horry County based on historical flooding information included Bucksport, Socastee, City of Conway, Red Bluff, and Longs.
The study evaluated both structural and nonstructural measures to reduce flood risks. Examples included flood barriers, floodwater diversions, flood water retention, and water conveyance measures using a range of hardened structures such as flood walls to nature-based structures such as floodplain benching. Nonstructural measures studied included elevating, floodproofing, and acquiring structures in the floodplain.
The Study Objectives
• Reduce the risk of flood damages to structures, critical infrastructure, and roads
• Increase the accessibility and resilience of ingress/egress and supply routes
• Reduce the risk of flooding on human life and safety
Study Process
Input provided by the public, and by state and federal agencies, was used to develop an array of action alternatives to address flood risks in the four flood impact areas. The Corps and Horry County evaluated and modeled the actions in relation to existing and future conditions, and assessed community characteristics to identify which actions, if any, would be effective at reducing flood risks. The effective actions that were most beneficial in reducing flood risks to the communities that met federal interest requirements were in Conway and Socastee and have been recommended for implementation. The results of the evaluation have been written up in an integrated Feasibility Report and Environmental Assessment.