Conundrum wins Highly Commended Award
Conundrum Holdings was awarded the Highly Commended CMPA Progressive Rehabilitation Award (Large quarries category), sponsored by Resources Victoria, at the CMPA Annual Dinner on 30 August 2025.
Jason Comben, Chairperson, CMPA Management Committee, presented the award to Brian Calovic, Manager, Conundrum Holdings.
Submissions were assessed on how well the nominee demonstrated delivery of effective progressive rehabilitation. Judges considered elements of planning, delivery and outcomes, including:
- Standard of rehabilitation delivered;
- Alignment with approved rehabilitation plan;
- Approach to monitoring, assessing and improving rehabilitation activities; and
- How operational decision-making reflected rehabilitation objectives
A family-orientated business, based in regional Victoria, spanning four generations in the extractive sector since the 1950’s, began as RF Kerr Quarries and in 1988, became Conundrum Holdings.
The Stawell Quarry was acquired in 1995 and has supplied Victoria’s western region for over two decades, particularly or infrastructure projects.
Planning
Conundrum Holdings developed a rolling rehabilitation schedule which was reviewed annually and detailed targeted areas aligned with their extraction plan.
The schedule identified specific timeframes for earthworks, topsoil spreading, ripping and seeding, ensuring rehabilitation kept pace with quarrying activities.
“Extraction sequencing was planned to facilitate early rehabilitation of completed benches, minimising disturbed footprints. Topsoil and subsoil were stockpiled close to future rehabilitation zones to reduce double-handling and compaction,” said Ron Kerr, Managing Director,
Conundrum Holdings.
Access roads were positioned to allow machinery to move efficiently for both extraction and rehabilitation works, minimising disturbance while optimising costs.
Delivery
A joint project with Project Platypus to the north of the extraction area, involved rehabilitating over 10 hectares including:
- Re-establishing erosion areas
- Completing Landcare trials
- Stabilising slopes
- Establishing native trees, grasses and shrubs
Ongoing monitoring of vegetation cover and species establishment was conducted, with survival rates of species tracked with supplementary planting to achieve target densities.
“Photo-point monitoring, weed management and inspection surveys documented progress and informed adjustments,” said Brian Calovic, HSW Manager.
All extraction zones were incorporated into the progressive rehabilitation program, ensuring obligations were met under the approved Work Plan.
Innovation
Conundrum Holdings demonstrated innovation through the following activities:
- Trialling seed and planting methods on steeper batters
- Placing tree trunks, branches and limbs to reduce erosion and increase habitat for insects and fauna
- Creating habitat for invertebrates, reptiles, birds and small animals to improve biodiversity
- Placing rocks, tree stumps and timber structures to reduce erosion and improve natural environment
- Blasting terminal faces at increased angles to improve long-term stability
Summary
The main objectives of the rehabilitation project included:
- Safe and stable landform
- Reaching terminal faces as soon as practicable
- Extensive earth works and placement of overburden to fill terminal faces
- Collection of topsoil prior to stripping and native replanting
- Stripping and hauling soil directly to area, avoiding double-handling
- Back-fill and water-flow redirection to reduce erosion
- Weed control program to protect indigenous plant species
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