This new tunnel construction project established a canal irrigation water conveyance from the Tulloch Reservoir to bypass over a mile of existing canal that was subject to seismic and slope failures on steep mountain slopes. Drill Tech performed preconstruction environmental assessment of this project including SWPPP plans and grading. Variable ground conditions were encountered and required multiple different support types. Excavation proceeded from both ends by roadheaders powered by a complex electrical system of generators, high voltage transmission cables, and transformers.  

Both portals involved Drill Tech value engineering redesign to optimize the portal geometry and integrate Drill Tech’s means and methods for subsequent excavation at no cost add to the owner. Tunnel construction was completed with shotcrete and concrete liner to support future irrigation water flow.