Schnabel is pleased to announce that the Deep Creek Watershed Dam 5D project was selected for a Grand Award at the ACEC NC Engineering Excellence Award (EEA) Ceremony held in Raleigh, North Carolina. The stated objective of the EEA award is “to recognize engineering and surveying firms for projects which demonstrate the highest degree of achievement, value and ingenuity.
Schnabel is the principal designer and engineer of record for the new Deep Creek Watershed Dam 5D constructed in Yadkin County, North Carolina. This exceptional project was made possible through joint cooperation and funding made available by the NRCS, the North Carolina State Conservation Commission, and the local sponsor, Yadkin County. Throughout the design, Schnabel collaborated closely with the owner and with the NRCS, who served as the technical review agency.
A composite dam design was selected to efficiently make use of the complex existing foundation conditions. The composite arrangement was selected as being the least costly of 12 alternatives evaluated by Schnabel and reviewed by Yadkin County and the NRCS. However, designing both a large high hazard roller compacted concrete (RCC) gravity dam and zoned earth embankment on a variable foundation presented a considerable challenge. Particular attention was needed at the connection between the two dam types where differential settlement and seepage may occur.
The Deep Creek project included the first use of grout enriched roller compacted concrete (GERCC) in the United States as the sole upstream barrier. This innovative process includes addition of a cement grout to the no-slump RCC at each lift along the upstream face and then mixing the grout and RCC using hand held vibrators to consolidate the material and provide a seamless lower permeability zone of concrete.
GERCC resulted in considerable savings to the project and its successful use at Deep Creek Dam has gained considerable attention from the engineering community in the United States. GERCC has been researched by several federal agencies including the US Army Corps of Engineers and has been the subject of numerous published articles in the United States. It is anticipated that GERCC will continue to be explored and used on future large RCC projects including dams and locks.
The Deep Creek 5D project will have a lasting benefit to the citizens of Yadkin County by providing additional safety for its residents and reduced flood damage to farms, homes and businesses downstream. The project also provides for future water supply needs of the County and surrounding community by including a raw water intake through the dam. Currently the County is in the process of planning and design for a new park around the reservoir area so that local residents can share in this public asset. This new park promises to be a centerpiece for future community activities.