this material and if a large empty cavity collapses it could take the dam with it To relieve pressure during the repairs the core has lowered the lake by 40 feet
There have been impact to the recreation users with the lake drawn down but it’s important to note the driver for that decision is the life and safety of downstream community and that’s why we’re spending a little over three hundred million dollars at this project to get a timely fix in place.
For the core the first step in making the dam safe is to fill the holes in the rock, a simple idea but an expensive process.
The work that you see going right now is the first stage of the fix and it’s grouting and that’s pumping submit slurry down into the foundation to plug any openings.
It’s not the first time the rock underneath the dam has needed repairs. the place limestone was first addressed in the nineteen sixties . A decade later wall was installed to reinforce the dam and control seepage and now a new concrete wall is being built behind the old one.
Will be much deeper and much wider than the existing barriers and the purpose of that will be to block the opening in the rock that are allowing the flow of water from the lake to come under the dam.
The potential for water from the lake eroding material under the dam requires constant monitoring.
We have inspections going on 24 hours a day seven days a week. People walking the embankment with the checklist and looking at the critical areas and critical indicators for signs of something that may be going on an increase in wet areas downstream of the dam depressions in the downstream slope at the crest of the dam mud flow into the river