The junior CFO sits on a board with exploration tenements spread across two or three states. On the balance sheet, line 2.3.1 shows a provision for rehabilitation costs. On the same page, the notes show state-held environmental bonds. The two numbers do not match, but nobody has asked why. Every Australian state mining act requires the licence holder to provide financial security to cover rehabilitation if the operator defaults — but the mechanism, the size and the re-evaluation cycle change at every border.
| State | Mechanism | Bond requirement | Re-evaluation |
|---|---|---|---|
| WA | Mining Rehabilitation Fund (MRF) levy | Annual levy (5-8% of annual spend) | Annual adjustment per DMIRS formula |
| QLD | Estimated Rehab Cost + Scheme levy | Varies by tenement. Levy 2-4% of annual budget | Mandatory at renewal. State issues top-up notice |
| NSW | Security Deposit under Mining Act | Cash or bank guarantee per Department schedule | At renewal. Can be significant increase |
| SA | Bonds under Mining Act and MARP conditions | Bonds required per MSA conditions. Typically cash | At state discretion when conditions change |
| VIC | No formal bond (exploration) | Not required for exploration licences | Not applicable |
| TAS | Bonds under Mineral Resources Development Act | On major operations only. Explorers rarely triggered | Discretionary with state |
AASB 137 Provisions, Contingent Liabilities and Contingent Assets requires a company to recognise a provision when there is a present obligation, it is probable the company will settle it, and a reliable estimate exists. For a company holding a mining licence, the obligation to rehabilitate at licence end is past, present, and probable. A provision is mandatory.
The provision unwinds each year at a discount rate, adding to P&L financing costs, largely invisible to the board unless explicitly monitored. Most junior miners underprovision because the impact of a realistic estimate is painful. A realistic rehabilitation estimate requires unit rates for drilling-pad remediation, pit stabilisation, access-track reinstatement, and water management. For tenements acquired years ago, the unit rates embedded in the provision may be stale. If the provision was copied from a 2020 due-diligence report, the rates may be 40-50 percent too low.
The bond is real money or a bank guarantee. The regulator holds it and will deploy it if the licence holder walks away. The bond is set by the regulator at grant or renewal. The regulator's calculation may rest on prior compliance history, cost schedules, and inflation margin. Some states re-evaluate bonds at renewal and demand top-ups. Others set them for the licence term. Either way, the bond is a compliance obligation, not an accounting estimate. It is a real cash outlay or bank guarantee the company must maintain for the licence life.
The blind spot emerges because the provision and the bond are calculated by different people for different purposes. The provision is the company's AASB estimate. The bond is the regulator's requirement. Three years after acquisition, a junior CFO can find the provision is AUD 2 million while the state bond is AUD 3.5 million. The divergence is rarely flagged because the provision is an accounting line while the bond lives in a tenement Excel sheet managed by the exploration team.
Junior CFOs face a choice: book a conservative provision and justify it, or use a modest estimate and flag it in the notes. Most choose modest. The cost is felt in subsequent years as the unwind adds to P&L. The risk is deferred to the relinquishment date, when the true cost becomes visible.
Provision is inherited. Bond is regulated. They rarely reconcile.
The CFO's blind spot
Patterns repeat across junior miners that find the gap late. Four are worth naming.
Provision is copied from old due diligence and never refreshed. Acquisition scope has changed. Ground conditions are different. The provision reflects 2020 reality, not 2025.
State issues a bond top-up from AUD 2.5 million to AUD 4 million. The provision stays at AUD 2 million. The balance sheet is now understated by AUD 2 million.
Provision was booked on 2020 rates. Current rehab costs are double. The regulator's bond, updated last year, reflects reality. The provision does not.
You hand back ground and the bond does not refund until completion sign-off. That takes 18-36 months. The state holds the bond pending inspection. If rehab does not meet criteria, the regulator retains it and the company funds rectification from cash.
A working CFO-ARC model brings three numbers into one view each quarter. For each tenement, a simple gap table shows provision vs bond vs current-cost. If the provision is significantly below the bond or the estimate, the ARC asks why. If the bond has moved due to state revaluation and the provision has not, a board paper explains the misalignment. This prevents the blind spot by making divergence visible at governance level.
Four moves. Done in one quarter, they take rehab liability from a footnote to a working ARC line.
Add rehab liability as a risk with owner, control, cadence, and duty link.
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Read article →Where the pollution carve-out bites when the bond is held against rehab.
Read article →Tuned for the junior miner operating rhythm: quarterly lodgement windows, AGM timing, tenement renewal cycles, and the regulatory news that actually matters.
30 minutes. Bring your tenement register and your AASB 137 line. We'll walk the gap, tenement by tenement.