Final Independent External Peer Review Report Supplemental Major Rehabilitation Evaluation Report for Center Hill Dam, Caney Fork River, DeKalb County, Tennessee.

摘要

Center Hill Dam is currently a U.S. Army Corps of Engineers (USACE) Dam Safety Action Classification I (DSAC I) dam, in DeKalb County, Tennessee. A Major Rehabilitation Evaluation Report (MRER) for Center Hill Dam was approved in 2006, and construction began in 2008. A baseline risk assessment was done in 2010 through 2012 to document postconstruction risks for elements already completed or in construction. The risk assessment incorporates both new data (subsurface exploration obtained during construction) and riskinformed policies and procedures implemented after the original report was approved. Resulting changes to the scope of the rehabilitation effort include a reduction in barrier wall and grouting and the construction of a roller compacted concrete (RCC) reinforcing berm at the saddle dam (in lieu of a barrier wall and grout curtain). A Supplemental MRER, published in June 2013, includes the risk assessment and documents the changes to the project scope, including National Environmental Policy Act (NEPA) documentation and a real estate plan. The Supplemental MRER was conducted in accordance with USACE Engineer Regulation (ER) 1110-2-1156, Dam Safety Policy and Procedures. Because Center Hill is a DSAC I dam (categorized as Urgent and Compelling ), the Nashville District, in coordination with the USACE s Lakes and Rivers Division, USACE Headquarters, and the Risk Management Center Director, has continued design of the RCC berm at the saddle dam concurrent with processing and approval of the Supplemental MRER. This will hasten the construction of the final protective measures and minimize project cost increases and schedule delays. Since the saddle dam RCC berm is already in the design phase, a Type II Independent External Peer Review (IEPR) (Safety Assurance Review [SAR]) is also under way. Center Hill Reservoir is about 50 miles east of Nashville, Tennessee, and about 7 miles south of Interstate 40. The dam is in north-central DeKalb County, Tennessee.