Taken from the TVA Site

Blue Ridge Dam Rehabilitation
July 2010

Project managers
Samantha Godsey
Jeff Brown

Phone Safety is the number one job at TVA: the safety for the public surrounding TVA lands and lakes, and the safety of TVA employees. To help ensure the safety of the people of Blue Ridge and in downstream areas and to meet more rigorous dam safety standards, TVA is performing a rehabilitation project expected to last from mid-July 2010 to 2012.

The rehabilitation project at Blue Ridge Dam consists of three components:

The penstock, the underwater pipe that carries water from the reservoir to the turbines in the powerhouse, was damaged when the reservoir was refilled after construction in 1931.
TVA will install a new liner in the penstock to repair it. The intake tower will be stabilized at its base.
The upstream and downstream faces of the dam will be stabilized.
To safely install the lining in the penstock, TVA will draw down the level of the lake beginning in mid-July 2010 and will hold the elevation about 68 feet lower than the usual summer elevation for about six months. Following completion of the penstock repair, the refilling of the reservoir will be contingent on the Spring rains in 2011. Completing the penstock repair should do away with the deep drawdowns currently required every five years for inspection of the penstock.

Drawdown timeline