The Hickory Log Creek Dam is a new 188-foot-high, 975-foot-long roller compacted concrete (RCC) gravity dam. It is located in an 8.2-square-mile drainage basin and impounds a 411-acre reservoir. The dam and reservoir are part of a $100 million pumped storage water supply project. Raw water is pumped from the Etowah River.
Schnabel completed the geologic and geotechnical investigation in two stages. The first stage involved gathering site data to guide selection of the most cost-effective type of dam. The second stage was a more in-depth field and laboratory program specifically for the selected dam alternative. This included in situ pressuremeter testing of weathered rock, and water pressure testing of the foundation rock. From the data collected in the field, we designed a two-line grout curtain, seepage control cutoffs, and collection components.
Due to topographic constraints, the dam’s spillway narrows from 250 feet at the crest to 140 feet at the stilling basin. Schnabel, working with Utah State University, completed a 1:25 scale model study of the spillway and stilling basin to confirm the spillway rating curve and optimize the design of the stilling basin. This resulted in a substantial cost savings. The design and construction of the $46 million project were completed in 39 months. The project was awarded the ACEC Georgia Engineering Excellence Award, Honor Award in 2008.