HDR Assessment of Flood-Damaged Dams Advances to National Engineering Competition

HDR’s assessment of flood-ravaged dams for the South Carolina Department of Transportation earned honors from the American Council of Engineering Companies of South Carolina and will advance to the organization’s national competition, held in April.

South Carolina’s worst weather event since Hurricane Hugo in 1989 took a tremendous toll on the state and its residents. Record rainfall meant that some areas received more than two feet of rain in four days at the start of October 2015. Catastrophic flooding, coupled with high winds, stranded motorists and residents, forced hundreds of rescues. Nineteen people lost their lives, numerous homes and businesses were destroyed, and many roads and bridges throughout South Carolina were severely damaged. Infrastructure damage included 50 breached dams. Roads traversing privately owned, earthen dams were closed as a result of flood damage.

Faced with many unknowns, SCDOT sought assistance from HDR to perform site assessments and field studies to determine dam failure risk. The HDR team assessed 10 dams in Lexington, Calhoun, Clarendon and Richland Counties with extensive embankment erosion, breaching, slope distress, pavement collapse, debris accumulation, utility damage, and culvert damage. Each dam required unique analysis and professional expertise.

HDR performed site inspections, topographic surveys, limited geotechnical evaluations, wetland delineations, and closed-circuit TV camera inspections of culverts connected to dam spillway pipes and structures.

The first repaired road in the project was a primary thoroughfare for residents of the Springdale and West Congaree communities. Its closure had created significant increases in commuting and emergency response times. The team was able to reopen the road less than 90 days after assessment.

Completion of the repairs to the first site marked a rapid response to disastrous flooding with safety, efficiency and client needs in mind. The project — $152,000 under budget and on schedule — provides guidance to the rest of the country on how to manage unprecedented flood events.

About HDR

For more than a century, HDR has partnered with clients to shape communities and push the boundaries of what’s possible. Our expertise spans nearly 10,000 employees, in more than 225 locations around the world — and counting. Our engineering, architecture, environmental and construction services bring an impressive breadth of knowledge to every project. Our optimistic approach to finding innovative solutions defined our past and drives our future.