Barnard Construction Co., Inc.

Owner:

Manitoba Hydro

Scope Of Work

Wedging a 1.5-mile-long, 208-foot-high RCC dam between an earthen dam and an active powerhouse on an expedited schedule resulted in the country’s largest ongoing dam construction project during all three years Barnard spent building the Saluda backup dam. Seismic stability tests showed that the original 1930s-era earthen Saluda Dam needed bolstering to protect South Carolina’s capital, Columbia, and its 125,000 residents, just 10 miles downstream. Yet draining the upstream lake to strengthen the dam would deflate the economy built along 600 miles of shoreline and reduce the utility’s hydropower source. So, SCE&G hired Barnard to build a backup dam immediately downstream on a site that required working around two active power plants, five penstocks, two circulation pipelines, high-voltage transmission lines, and a high-pressure gas line, all bisected by a river.

Over three years, we achieved an excellent safety record and met or beat all milestones. Unforeseen foundation conditions meant our excavations below the dam would need extensive dewatering and be limited in size at any given time. A lowered Lake Murray was refilled a full year ahead of schedule as a result of Barnard’s value engineering ideas. Our Team designed, implemented and patented a filter placement method that’s since become an industry standard. We also designed an RCC truck placement method that allowed for a separate simultaneous RCC placement with the all-conveyor system. And then we ran these methods in tandem around the clock. Partnering brought all stakeholders on board. The hard work of more than 650 employees putting in over 1.2 million hours secured Columbia’s safety.