After weeks of rain and difficult working conditions, the City of Libby successfully completed construction of the access road and crane pad at Flower Creek Dam on the afternoon of June 11, 2012. A 175-ton hydraulic crane from Rhodes Crane and Rigging was mobilized to the site on June 12, and CRUX Subsurface (the specialty drillers for the project) arrived on June 13 to begin drilling operations. City personnel assisted the project during the drilling by clearing trees from the hillsides at and adjacent to the proposed drill sites. By the end of the drilling tasks on June 24, 2012, seven holes had been cored on the project to depths of 75 feet. The drill sites ranged from relatively flat to steep hillside sites where the drillers and engineers used high-angle climbing and rappelling techniques to safely access the drill sites. Drilling equipment was moved to the drill sites by the crane, which reached over 200 feet across the Flower Creek coulee lifting loads of about 1,500 pounds. All of the holes were also packer tested (pressure tested with water) as the basis for grouting on the new dam foundation area. In addition to the drilling and packer testing, NTL Engineering performed additional geologic mapping to support development of the final dam design report. Following completion of the drilling tasks, the drilling equipment and crane were demobilized on June 25th.
July 24, 2012