Results
Increased spillway resilience to extreme rainfall events, bringing the dam into compliance with modern engineering standards.
Enhanced protection for downstream communities by reducing the risk of embankment overtopping and failure.
Maintained excellent safety record throughout delivery, with up to three drilling crews operating simultaneously at peak periods.
Delivered works within timeframe despite harsh weather and logistical challenges, securing additional works on the dam.
Improved long-term functionality and security of the dam through upgraded spillway and drainage systems.
Project
Solution
Deployed a 160t crane to position A-frame wagon drills along the spillway, reducing manual relocation time and improving productivity.
Utilised a fully bunded grout station, mobile water systems, and continuous grout intake per anchor to ensure technical compliance and protect the waterway.
Combined rope access techniques with crane operations for safe and efficient positioning of crews and equipment.
Installed 86 vertical DCP anchors, 16 rock bolts, and 15 sub-horizontal drains, along with anchor water testing and catch fence installation on the dam embankment.
Collaborated with designers to adapt specifications in response to access, equipment, and ground condition constraints.
Project
Challenges
Remote, isolated location with no permanent communications and highly variable weather conditions, requiring careful planning and contingencies.
Live spillway environment with the potential for rapid water level rises, demanding strict compliance with the Dam Safety Emergency Plan, early-warning systems, and rapid evacuation protocols.
Rockfall hazards and unstable slopes above and adjacent to the worksite, necessitating additional scaling and temporary catch fences.
Complex drilling conditions through variable man-made fill and fractured natural geology, requiring multiple techniques and casing systems to achieve design depths.
Working at height in restricted access areas with environmental controls for grouting and anchor installation.
Project
Overview
Murchison Dam, a 93-metre-high concrete-faced rockfill embankment in northwest Tasmania, required critical safety upgrades to meet modern flood capacity standards. Originally designed over 40 years ago, new hydrological modelling showed the existing spillway capacity could be exceeded during extreme rainfall, risking overtopping and potential embankment failure.
To mitigate this, the project scope focused on raising the spillway chute wall with a passive anchor solution, installing new anchors, drainage, and reinforcement systems while maintaining strict environmental and safety standards in a live water asset