Hickory Log Creek Dam- Why did the engineer make those decisions?

The proposed Hickory Log Creek Dam will be a 180-foot high roller compacted concrete (RCC) gravity dam impounding a 411-acre reservoir. This dam and reservoir is the central feature of a pump storage system for the City of Canton, Georgia and the Cobb-County-Marietta Water Authority. Schnabel Engineering was faced with a fast track time line to have the project impounding water within three years. Many design and contractual decisions had to be made and scrutinized by multiple review agencies and an internal review committee. The design team's goal was to utilize state of the art RCC dam design, including the many lessons learned from the over 50 existing RCC dams in the United States. In addition, the contract documents were developed to allow the contractor flexibility and minimize, as much as possible, his risks, which he has little control over. This paper will walk the reader through the entire process of designing a $41 million RCC gravity dam and the sequent construction management process. The alternative analysis, which led to the selection of an RCC dam, will be discussed in detail explaining why RCC was chosen over an earthen embankment. The RCC design features, including spillway section, seepage control and collection, facing systems, RCC mix design, and dam section stability will be presented. Construction of the dam is well underway with a projected October 2007 completion date. The paper will also cover the means and methods employed by the contractor, the intensive quality control program, and field decisions made to overcome obstacles. 11 pp., 6 photos.