GROUNDWATER CONTROL DURING SALUDA DAM REMEDIATION CONSTRUCTION

Project Location: Nebo, NC

Owner: SCE&G

Engineer: Paul C. Rizzo Associates

Project Revenue: $16,000,000.00

Project Start and End Date: 2005

THE CHALLENGE

The Saluda Dam needed repair to meet modern seismic safety requirements. The earthen Dam is 200 ft. high, over a mile long, and has a storage capacity of more than 2,100,000 ac-ft of water.

The project began when SCE&G officials discovered that the earthen Dam at their Saluda Hydroelectric Project could liquefy during a seismic event equal in intensity to the quake that struck Charleston in 1886.

The project was a significant undertaking. In addition to keeping the 48,000-acre reservoir nearly full, and keeping the hydroelectric plant and coal-fired steam plant operational, the project also required that the safety of the 120,000 residents living in the flood plain be ensured while also addressing the environmental concerns regarding the wetlands surrounding the Dam.

THE SOLUTION

The required excavation for repair on the downstream toe drain was 80 ft. deep. Griffin designed a dewatering system using deep wells, eductors, and wellpoints to control groundwater and allow construction on the dam to be conducted safely and efficiently. Eductors were used for dewatering the embankment fill and foundation soil beneath the excavation — eductors on the project ranged in depth from 30 to 70 ft. More than a mile and a half of eductor lines were in operation. Installation methods included: sonic , dual rotary, & wash rotary drilling.

THE GRIFFIN DIFFERENCE

Griffin’s extensive experience and knowledge in dam and levee remediation and installation of eductor dewatering systems facilitated the successful repair of the dam.

The ASCE recognized Griffin Dewatering for their contribution and work, along with SCE&G, Paul C. Rizzo & Assoc., Barnard Construction Co., Inc., and Kleinfelder, on the Saluda Dam Remediation Project in Columbia South Carolina with the American Society of Civil Engineers’ OPAL (Outstanding Projects and Leaders) award.

Thanks to the combined efforts of top engineering and construction firms that expertly executed this engineering and construction feat, which spanned a decade!