Location: Saint Ignatius, MT
Project Partner: N/A
Challenge: Dewatering, core drilling and void grouting from inside a limited access outlet tunnel for a dam in the middle of winter in Montana.
Overview: Condon-Johnson was contracted as the General Contractor to dewater over 400 million gallons of water from the Saint Mary’s Reservoir and perform void grouting from over 500 feet inside of a four foot wide by six foot tall tunnel.
Results: Condon-Johnson was able to successfully overcome temperatures as low as 30 degrees below zero while dewatering the reservoir to 6-feet below the invert of the tunnel. It was then a race against time to complete the drilling and void grouting while the reservoir inched closer to the mouth of the tunnel. All drilling and grouting was completed ahead of schedule and at a cost savings to the Owner.