TL;DR: A volumetric survey in Mackay measures the run-of-mine and product coal stockpiles, waste dumps, reject piles and terminal yards that move billions of dollars of metallurgical coal out of the Bowen Basin each year. Industrial Spatial Solutions flies CASA-certified drones and deploys 3D laser scanners across mine ROM pads, CHPP product yards and the Hay Point and Dalrymple Bay export terminals, delivering surveyed volumes to 2-3% accuracy with reports tied into your reconciliation and inventory systems.
Key takeaways
- A drone-based volumetric survey in Mackay measures ROM, product and reject coal stockpiles to 2-3% accuracy, the precision needed for month-end inventory valuation and production reconciliation across Bowen Basin operations such as Goonyella Riverside, Saraji, Blackwater and Moranbah North.
- Stockpile inventory feeds straight into financial reporting: a 5% error on a 500,000 m³ ROM coal stockpile worth $15-30 million misstates inventory by well over $1 million, which is why operators here demand surveyed volumes, not estimates.
- ISS captures volumes by UAV photogrammetry (2-3%), terrestrial 3D laser scanning (1-2% for covered or complex yards) and GPS or total station where drones cannot fly, all referenced to MGA2020 and ground control under the AS/NZS guidelines and ICSM standards.
- Drone volumetrics across a full mine site's stockpiles typically complete in under two hours and deliver within 24 hours; an indicative single-site survey runs $4,000-$10,000, with discounted rates on monthly reconciliation contracts.
- Volumetric reconciliation also underpins Queensland rehabilitation and waste-dump compliance under the Mineral Resources Act and the Environmental Protection Act, where dump volumes and progressive rehabilitation earthworks must be measured against approved plans.
Volumetric surveying in the Bowen Basin
Volume is money in the Bowen Basin, and nowhere is that more literal than in Mackay. The region feeds the world's largest metallurgical coal export chain — mine ROM pad, coal handling and preparation plant (CHPP), rail, then the Hay Point and Dalrymple Bay terminals — and every link in that chain holds stockpiles that have to be counted. A volumetric survey is the measurement that turns a coal pile into a number on a balance sheet, a reconciliation report and a royalty calculation.
The scale is significant. BMA's Bowen Basin mines alone produce over 50 million tonnes of metallurgical coal a year, and the Hay Point and Dalrymple Bay terminals have combined export capacity exceeding 180 million tonnes per annum. Coal does not move in a continuous flow — it accumulates in ROM stockpiles ahead of the CHPP, in product yards awaiting rail, in reject and tailings cells, and in vast terminal stockyards waiting for the next Capesize vessel. At any moment, a single Bowen Basin operation may be holding hundreds of thousands of tonnes of inventory, and the value of that inventory has to be measured accurately enough to satisfy auditors, financiers and the Queensland regulator.
A "volumetric survey mackay" enquiry almost always means one of three things: a stockpile inventory survey for month-end reporting, a waste-dump or pre-strip volume for contractor payment, or a rehabilitation and landform volume for compliance. ISS handles all three, with the equipment and the local knowledge to do it inside the operational windows that coal mining allows.
Key point: In coal, the stockpile is the ledger. A volumetric survey that is 5% out is not a rounding error — it is a material misstatement of inventory, a reconciliation gap that hides ore loss or theft, and a compliance risk all at once.
Where volumetric surveys are needed around Mackay
Volumetric work in the Mackay catchment falls across the mines of the Isaac region, the coal handling infrastructure, and the export terminals on the coast.
Mine stockpiles and dumps
The Bowen Basin's open-cut and underground mines all hold coal in motion. ROM coal accumulates on the pad before processing; washed product coal stockpiles before rail; reject and coarse tailings build in dedicated cells.
| Operation | Operator | Volumetric requirement |
|---|---|---|
| Goonyella Riverside | BMA | ROM and product stockpile inventory, overburden and pre-strip volumes |
| Peak Downs / Saraji | BMA | Large-scale pit and dump progression, monthly stockpile reconciliation |
| Blackwater | BMA | Product coal stockpile volumetrics, waste-dump tracking |
| Moranbah North / Grosvenor | Anglo American | ROM stockpile inventory, CHPP feed pads, rejects |
| Isaac Plains / Isaac Downs | Stanmore | Pit and dump topographic volumes, rehabilitation landform measurement |
| South Walker Creek | Stanmore | Overburden and waste-dump volumes for contractor payment |
For active open cuts, overburden and pre-strip volumes drive contractor payment and mine planning — a single month's overburden movement of around 1,000,000 m³ can represent $2-5 million in diesel and equipment, and that figure is only as defensible as the survey behind it.
Coal handling and preparation plants
Every Bowen Basin mine runs a CHPP, and each plant has feed pads, product yards and reject areas that need regular measurement. ROM feed pads are surveyed to verify what is queued ahead of the plant; product yards are surveyed for the inventory that links mine output to rail despatch; reject and tailings volumes are tracked for both reconciliation and environmental compliance.
Hay Point and Dalrymple Bay terminals
Twenty kilometres north of Mackay, the export terminals hold the largest single coal stockpiles in the chain. Terminal stockyards are surveyed for stocktake and demurrage management, and the same flights frequently capture stacker-reclaimer reach and yard geometry. Volumetric survey of terminal yards demands careful edge definition where machine-built piles meet hardstand, and is often combined with control work supporting the broader survey services across Mackay and the Bowen Basin.
Method and equipment
ISS selects the volumetric method to suit the pile, the access and the accuracy required.
UAV drone photogrammetry is the standard for open coal stockpiles and dumps. A drone captures overlapping imagery, which is processed into a dense point cloud and digital surface model; volume is then computed against the defined base surface. With well-distributed ground control, drone volumetrics achieve 2-3% accuracy and can survey an entire site's stockpiles in under two hours. ISS operates under CASA Remote Operator Certification, with licensed pilots and the airspace approvals needed to fly across live mine sites and near terminal infrastructure.
Terrestrial 3D laser scanning is used where accuracy must reach 1-2%, where piles sit under cover or in sheds, or where geometry is too complex for clean photogrammetry. Leica scanners capture millions of points per setup, producing a point cloud that resolves fine surface detail and tight edges. Scanning is slower than drone flight but unbeatable for covered product bins and confined reclaim areas.
GPS and total station methods remain valid where drones cannot fly — restricted airspace, persistent wind, or small confined piles — capturing surface points for cross-section or surface-model volume calculation at 3-5% accuracy.
The base surface is everything. ISS defines it explicitly for every job: a surveyed base plane beneath the pile, a previous survey surface for change-over-time, or a design surface for cut-to-go. Processing runs through Propeller Aero, Pix4D, 12d Model or Trimble Business Center, and results are reconciled to MGA2020 with ground control held to two to three times the required survey accuracy.
Key point: A volume figure without a stated base surface and bulk density is not a result — it is a guess. ISS reports the method, the base surface, the density applied and the estimated accuracy on every survey, so the number stands up in an audit.
Standards and compliance
Volumetric surveying in Queensland coal sits inside a clear regulatory and technical framework, and ISS delivers to it.
- Mineral Resources Act 1989 and the Mining and Quarrying Safety and Health Regulation require accurate mine plans and survey records; stockpile, pit and dump volumes form part of the operational and statutory record.
- Environmental Protection Act 1994 governs waste dumps, tailings storage and progressive rehabilitation. Volume-based limits and rehabilitation landform measurement against approved plans depend on defensible volumetric survey.
- ICSM and AS/NZS survey guidelines govern datum, control and accuracy. ISS references all volumetric work to MGA2020 and the GDA2020 datum, with control established to survey grade before any drone leaves the ground.
- CASA Part 101 and Remote Operator Certification govern the UAV operations themselves — pilot licensing, airspace approval and maintenance — which matters when flying within the controlled and restricted environments around active mines and the Hay Point terminals.
Reported accuracies are not aspirational: drone photogrammetry at 2-3%, laser scanning at 1-2%, and a documented bulk-density conversion where tonnes are required, with the density source stated so the volume-to-weight step is transparent.
Why ISS for volumetric survey in Mackay
ISS works the Bowen Basin the way coal mines actually run. Our surveyors hold current Queensland site inductions and underground certifications for major operations, so a volumetric crew can be on a ROM pad without burning a day on access. We schedule around despatch and reconciliation cycles, flying product yards ahead of month-end and turning surveyed volumes around within 24 hours so they land before the books close.
We bring both halves of the job: the control network and the capture technology. Drone and scanning data only reach engineering accuracy when anchored to surveyed ground control, and ISS establishes that control rather than relying on assumed coordinates. Data is delivered in the formats your planning and asset systems already use — DWG, DXF, 12d Model, Surpac, Deswik or Propeller deliverables — so a volumetric survey feeds straight into your reconciliation workflow rather than sitting in a PDF.
Queensland carries the most severe surveyor shortage in the country against a $61.6 billion resources sector. For Bowen Basin operators that means specialist volumetric capacity is scarce, and a contractor who already knows your stockyards, your terminals and your reporting cycle is worth more than a generalist mobilising cold.
Frequently asked questions
How accurate is a drone volumetric survey on Bowen Basin coal stockpiles?
With well-distributed ground control, ISS drone photogrammetry achieves 2-3% volume accuracy on ROM, product and reject stockpiles — the standard for month-end inventory and reconciliation. Where you need tighter, terrestrial 3D laser scanning reaches 1-2%, and is the method of choice for covered product bins and confined reclaim areas where drones cannot capture the full surface.
How quickly can ISS turn around a stockpile survey before month-end?
A full mine site's stockpiles can usually be flown in under two hours once on site, with processed volumes and a report delivered within 24 hours. We schedule flights ahead of your reconciliation cut-off so the surveyed inventory lands before the books close. For recurring work, monthly contracts lock in preferential scheduling and established control.
Can you measure coal stockpiles under cover or at the Hay Point terminals?
Yes. Covered product bins and shed stockpiles are surveyed by terrestrial 3D laser scanning from multiple positions, which captures the pile surface without needing drone access overhead. At the Hay Point and Dalrymple Bay terminals we coordinate airspace and site access for yard volumetrics, and combine drone and scan methods where machine-built piles and tight edges demand it.
Does a volumetric survey give me tonnes or cubic metres?
A volumetric survey measures volume in cubic metres directly. Converting to tonnes requires a bulk density, which varies with coal type, moisture, compaction and segregation. ISS states the bulk density applied and its source on every report, so the volume-to-weight conversion is transparent and auditable rather than a hidden assumption.
Request a quote
If you need a defensible volumetric survey on Bowen Basin stockpiles, dumps or terminal yards, talk to a surveyor who knows Mackay coal operations.
- Call us on 0407 057 015 — describe your stockpiles, pads or dump volumes and we will recommend the right method and accuracy.
- Receive a fixed-price proposal — scoped to your site, your reconciliation cycle and your deliverable formats.
- Mobilise to site — inductions, control and capture coordinated around your despatch and month-end windows.
For operators surveying stockpiles on a regular cycle, ISS offers monthly volumetric reconciliation contracts with preferential scheduling and consolidated reporting across multiple Bowen Basin sites.
Industrial Spatial Solutions — volume measured, inventory accurate, reconciliation ready across Mackay and the Bowen Basin.
Related reading: Survey services in Mackay and the Bowen Basin, Volumetric surveying methods and accuracy