News
Medical District Drainage Tunnel Extension Project Receives Palmetto Award
During the American Council of Engineering Companies of South Carolina (ACEC-SC) 2025 Engineering Excellence Awards Gala, Davis & Floyd won the Palmetto Award for drainage improvements at Ehrhardt Street. The Palmetto Award is the highest achievement a firm can receive at the state level.
Needed Improvements
The Charleston Medical District, home to critical healthcare facilities including MUSC Health University Medical Center, Ralph H. Johnson VA Medical Center, and Roper St. Francis Healthcare Roper Hospital, serves the Charleston area and Lowcountry. However, 27 acres surrounding Ehrhardt Street frequently experienced severe flooding due to inadequate drainage infrastructure. This recurring issue of flooded roadways compromised accessibility and posed risks for emergency medical services. Patients, visitors, students, and staff faced stalled vehicles and impassable sidewalks.
To address these pressing concerns, the South Carolina Office of Resilience (SCOR) awarded $10 million in Community Development Block Grant-Mitigation (CDBG-MIT) funding, its largest project to date. The City of Charleston contracted with us and our team to design and implement innovative stormwater solutions aimed at mitigating flooding for uninterrupted access to critical-care facilities.
Project in Construction
The project consisted of three key components: extending the existing stormwater drainage tunnel by 900’ to Ehrhardt Street, constructing a 54” vertical drop shaft with a vortex structure, and developing a near-surface drainage collection system. The intricate design required tunneling through the Cooper Marl formation, a naturally stable clay layer, while carefully avoiding interference with nearby structural foundations.
Using advanced techniques, including a tunnel boring machine (TBM), we ensured the existing tunnel system remained operational during construction. We engineered the vertical drop shaft and vortex structure to channel stormwater runoff from horizontal flow into the tunnel below, minimizing air blockage and maximizing flow capacity. We designed the near-surface drainage system to manage runoff from the Ehrhardt Street watershed.
Project Results
The Medical District Drainage Tunnel Extension has reduced flooding, improved access to vital healthcare services, and improved the safety of those in the district.
As SCOR’s first successful initiative of this scale, this project showcases our expertise in delivering resilient, community-focused engineering solutions. Our collaboration with the City of Charleston has transformed the Medical District into a safer and more accessible hub for healthcare, protecting lives and fostering long-term community resilience.
