Hydroelectric Dam

Clark Fork, Idaho



    DFS was contacted regarding a high risk bore with unknown geology, and the ground to be drilled was blast fill from the original dam construction in 1951. The project was replacing the original sewer line which had corroded. Although a small job, its technical aspects were intense. The bore was 588 feet in length, but involved a 212 foot elevation difference to drill down and inside the hydro electric dam. To pull back a HDPE sewer line which was to be fed in through the dam to be pulled to surface. When drilling was almost complete, some ingenuity was needed to find a way to capture the drilling fluid once the bit had made it through the concrete wall, without flooding out the entire operating capabilities of the dam This was successfully accomplished and the project was completed on time and schedule.  


  • The mud program was adjusted on the fly to counter unknown geology.
  • No frac outs were to be tolerated. 
  • Project experienced zero downtime related to the drilling fluids.
  • The project was completed efficiently, although it took longer than anticipated, it did not hinder the project schedule.