Coda Minerals Ltd
Coda Minerals Puts the Groundwork In: Hydrogeological Drilling Kicks Off at Elizabeth Creek
Coda Minerals Elizabeth Creek hydrogeological drilling underway marks a significant step in the company's development pathway, with Coda Minerals (ASX: COD) having mobilised a drill rig to its 100%-owned Elizabeth Creek Copper-Silver Project in South Australia. The company has commenced a six-bore hydrogeological programme across the Windabout and Emmie Bluff prospects. This work is a deliberate step in the Pre-Feasibility Study (PFS) process, designed to underpin mine dewatering design, environmental approvals, and water supply planning ahead of any move toward construction. Once the hydrogeological programme concludes, the rig will move directly to the Oakden prospect for exploration drilling, keeping the operational calendar active across multiple fronts.
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What's Actually Happening on the Ground?
The programme is structured around six bores totalling an estimated 1,400 metres of drilling, split across two prospects.
| Location | Production Bores | Monitoring Bores | Primary Purpose |
|---|---|---|---|
| Windabout (open pit) | 1 | 1 | Aquifer pump testing, groundwater response |
| Emmie Bluff (underground) | 2 | 2 | Dewatering, depressurisation, geotechnical data |
| Total | 3 | 3 | Regional hydrogeological model |
Production bores will support aquifer pump testing to measure water flow and recharge rates. Monitoring bores will track how the surrounding groundwater system responds to that testing.
Together, according to the company, the resulting datasets will feed directly into the regional hydrogeological model being built as part of the ongoing PFS.
Why Hydrogeology Matters More Than It Sounds
For investors less familiar with mine development, hydrogeology can appear to be a minor technical detail. In practice, however, it is one of the more consequential datasets a developing project generates.
What Is Hydrogeology?
Hydrogeology is the study of groundwater, covering where it sits, how it moves through rock formations, how much of it exists, and how it recharges over time. In a mining context, understanding the groundwater system beneath a project helps answer several important questions:
- How much water will need to be pumped out (dewatered) before and during mining?
- How stable are open-pit or underground walls once water pressure is removed?
- Is there enough water nearby to supply a processing plant?
- What are the potential impacts on neighbouring water users and ecosystems?
Why Does It Matter for Investors?
These are not abstract engineering questions. Regulators typically require hydrogeological assessments as part of a Mining Lease Application and environmental approvals process. Without credible groundwater data, approvals cannot progress, and without approvals, construction cannot commence.
Completing this work now, whilst other PFS studies run in parallel, is intended to prevent the project timeline from stalling at a later and potentially more costly stage.
"Hydrogeology underpins many of the major design decisions as Elizabeth Creek moves towards development. Understanding groundwater at Windabout and Emmie Bluff is essential for water supply, geotechnical design and confidence in how we will manage the project's environmental footprint," said Chris Stevens, Chief Executive Officer of Coda Minerals.
Stevens further added that the programme "reflects the progress of the PFS," noting the company has "moved beyond the core data-gathering phase and are now closing specific gaps while other studies advance in parallel."
A Secondary Opportunity in a Prospective Zone
One of the proposed Emmie Bluff bores is located approximately 300 metres north-west of diamond drillhole DD25EB0038, a hole in which Coda previously reported the first copper mineralisation identified in the Tapley Hill Formation outside the boundary of the existing Emmie Bluff Resource.
Whilst these bores are being drilled strictly for hydrogeological purposes and are not positioned as exploration holes, drill cuttings and any core recovered will be geologically logged. This creates an incidental opportunity to gather further geological information from an area Coda considers prospective for extensions of Tapley Hill Formation mineralisation.
Coda has been cautious in its disclosure. The mineralisation previously intersected in DD25EB0038 was reported as a sub-economic intercept of 0.76 metres at approximately 0.81% copper from 435.6 metres. Furthermore, the company has stated there is no assurance mineralisation will be encountered in the new bores. Nonetheless, the geological logging adds a layer of optionality to what is primarily an engineering programme, at no additional cost or delay.
The Elizabeth Creek Resource Base: Context for the Work Underway
The hydrogeological programme forms part of a broader development effort at a project that already hosts a substantial mineral resource base across four deposits.
Project-Wide Mineral Resources, Elizabeth Creek
| Deposit | Mining Method | Tonnage (Mt) | Cu Grade | Contained Cu | CuEq Grade |
|---|---|---|---|---|---|
| Emmie Bluff (Indicated) | Underground | 37.5 | 1.3% | 485,000t | 1.9% |
| Emmie Bluff (Inferred) | Underground | 2.7 | 0.9% | 26,000t | 1.3% |
| Windabout (Indicated) | Open Pit | 17.7 | 0.8% | 136,100t | 1.4% |
| MG14 (Indicated) | Open Pit | 1.8 | 1.2% | 22,700t | 1.7% |
| Cattle Grid South (Inferred) | Open Pit | 5.8 | 0.6% | 36,000t | n/a |
| Project Total | 65.5 Mt | ~705,800t Cu |
In addition to copper, the project contains an estimated 33,000 tonnes of contained cobalt, 28 million ounces of contained silver, and 75,000 tonnes of contained zinc across the combined resource base, according to Coda's disclosures. This polymetallic profile adds by-product value considerations to a development case centred primarily on copper.
What Comes Next: A Layered Programme of Work
Coda is running several workstreams at once, reflecting a project the company describes as advancing deliberately and in parallel rather than in strict sequence.
Near-Term Milestones
-
Hydrogeological drilling completion. The six-bore programme is expected to take several weeks. Production bores will progress to aquifer pump testing once drilling is complete.
-
Aquifer pump testing. This will determine water flow and recharge rates, feeding into a full site water balance. The balance will inform decisions on whether additional field programmes are required to define a production bore field, or whether that work can be deferred to the Definitive Feasibility Study (DFS).
-
Oakden exploration drilling. The rig will relocate from Elizabeth Creek to the Oakden prospect once the hydrogeological programme is complete. That follow-up programme is expected to comprise approximately 5 to 6 RC drillholes for up to 400 metres of drilling. Coda has indicated it will release a separate announcement outlining the targeting rationale before drilling begins.
-
Ongoing PFS studies. Hydrogeological results will be integrated into the broader PFS alongside geotechnical, metallurgical and environmental studies progressing in parallel.
Possible Follow-On Work Later in 2026
- Should the water balance identify meaningful water supply constraints, a small additional field programme may be undertaken later in the year to outline available resources and plan a production bore field.
- If water risk is assessed as low following completion of the balance, this work may instead be deferred to the DFS stage.
| Workstream | Status | Timing |
|---|---|---|
| Hydrogeological drilling (6 bores, ~1,400m) | Underway | Several weeks |
| Aquifer pump testing | Planned (post drilling) | Following bore completion |
| Full site water balance | Planned | Following pump testing |
| Oakden exploration (5-6 RC holes, ~400m) | Announced | Following hydrogeological programme |
| PFS completion | Ongoing | Advancing in parallel |
Why Investors Should Keep Elizabeth Creek on Their Radar
With Coda Minerals Elizabeth Creek hydrogeological drilling underway, several features of this announcement stand out from an investor perspective, reflecting a company progressing through the mine development pathway in a systematic manner.
This is gap-closing work, not delay. The hydrogeological programme was not triggered by a setback. It reflects the PFS reaching the point where specific datasets are now needed to close out design decisions, which suggests the project continuing to progress rather than stalling.
The resource base is substantial. At 65.5 Mt containing approximately 705,800 tonnes of copper, Elizabeth Creek is not a small target. The Emmie Bluff underground deposit alone, at 40.2 Mt grading 1.9% copper equivalent (CuEq), carries grade and scale that warrants continued development attention.
Multiple prospects, multiple catalysts. The Oakden exploration programme following immediately after this work means newsflow is unlikely to pause once hydrogeological results are in. The targeting rationale for Oakden, to be released separately, adds a near-term exploration catalyst to an already active development calendar.
The environmental pathway is being addressed early. By tackling hydrogeology, groundwater impact assessment, and site water balance ahead of the Mining Lease Application, Coda is consequently managing regulatory considerations at the front end of the approvals process rather than later in the development timeline.
Polymetallic optionality remains a feature. With silver, cobalt and zinc alongside copper, Elizabeth Creek carries diversified metal exposure that may hold relevance as commodity markets evolve between now and any future production decision.
"Coda Minerals is executing a sequenced development programme at Elizabeth Creek, using the current hydrogeological campaign to close specific PFS data gaps while positioning the project for environmental approvals and geotechnical design. With Oakden exploration drilling to follow, the company maintains active newsflow across both development and exploration fronts. Investors tracking copper development projects in Australia may wish to follow Elizabeth Creek's progress closely."
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Key Terms Explained
What Is a Production Bore?
A production bore is a drill hole designed to extract groundwater for pump testing and, potentially, future water supply for operations.
What Is a Monitoring Bore?
A monitoring bore is a drill hole used to observe how groundwater levels and pressure respond to pumping from nearby production bores.
What Is Aquifer Pump Testing?
Aquifer pump testing is a field test in which water is pumped from a bore at a controlled rate whilst nearby monitoring bores track the groundwater response, used to calculate permeability and sustainable yield.
What Do Dewatering and Depressurisation Mean?
Dewatering is the process of removing groundwater from an open pit or underground mine to allow safe working conditions. Depressurisation, however, refers to reducing groundwater pressure in rock formations around underground workings to improve wall stability and reduce inflow risk.
What Are PFS and DFS?
A PFS (Pre-Feasibility Study) is an intermediate engineering and economic study that refines the technical and financial parameters of a mining project ahead of a full DFS. A DFS (Definitive Feasibility Study) is, furthermore, a detailed engineering study used to support a final investment decision on project development.
What Is CuEq?
CuEq (Copper Equivalent) is a single grade metric combining the value of multiple metals — such as copper, cobalt, silver and zinc — into a copper-equivalent percentage for comparison purposes.
What Is RC Drilling?
RC drilling (Reverse Circulation) is a drilling method that uses air pressure to return drill chips to surface, commonly used for exploration targeting due to its speed and relative cost efficiency.
What Is the Tapley Hill Formation?
The Tapley Hill Formation is the geological unit hosting copper mineralisation at Emmie Bluff, which Coda is seeking to understand further and potentially extend.
What Is JORC?
JORC is the Australasian code governing the reporting of mineral exploration results, mineral resources and ore reserves, setting the standard for public reporting of geological data.
Want to Follow Elizabeth Creek's Progress Towards Development?
Coda Minerals (ASX: COD) is advancing its 100%-owned Elizabeth Creek Copper-Silver Project through a structured Pre-Feasibility Study process, with hydrogeological drilling now underway and Oakden exploration drilling to follow. With a 65.5 Mt resource base containing approximately 705,800 tonnes of copper alongside silver, cobalt, and zinc, this is a project worth watching closely. Investors seeking to learn more about Coda Minerals and the Elizabeth Creek development programme can visit www.codaminerals.com for the latest updates.
