BTrenchless Completes Major Colorado Tunnel Project Ahead of Schedule Words: Dan Kamys BTrenchless Completes Major Colorado Tunnel Project Ahead of Schedule BTrenchless, a Division of BT Construction, Inc., of Henderson, Colorado, just completed 4,200 linear feet of tunnels and bores for Aurora's Prairie Waters project. These tunnels were crucial to the completion of the $754,000,000 project. BTrenchless utilized various construction methods to account for the diverse ground conditions, including seven Microtunnels, four TBM's, two Hammer bores, and six Auger bores. Sizes of the installed tunnels ranged from 60" to 79" diameter. The Prairie Waters project for the City of Aurora, Colorado, is the first large-scale water re-use project in Colorado's history. Slated for completion in 2010, water will be pumped from the South Platte River, undergo a six-step treatment process, and ultimately replenish the diminishing drinking water supply.