What is involved in the remedial repair work and how much will it cost?
A12. An intensive grouting program designed to fill voids in the rock will begin before construction of a cutoff wall proceeds. Grout is a fluid form of concrete that can be pumped into the foundation voids under pressure. This grouting program will reduce seepage under the cutoff wall. The concrete cutoff wall will be installed through the embankment and the problem foundation rock to provide additional seepage control. The wall thickness will be a minimum of three feet and be installed as deep as 275 feet. The wall will be placed on the upstream slope of the dam and will extend the full length of the embankment and a portion of the end concrete dam monoliths. The fully funded estimated cost of this work is $317.1 million. Remedial construction is currently scheduled to be completed in 2014; however, an accelerated schedule will be aggressively pursued to complete construction by 2012.
