I'd now like to hand the conference over to Mr. Brendan Harris, Chief Executive Officer and Managing Director. Please go ahead.
Thank you, and good morning, everyone, and welcome to our quarterly call. As usual, our executive team is here with me today for the Q&A, which we'll get to very shortly. Before we start, I'd like to acknowledge again the traditional custodians of the land on which we stand, the Whadjuk people of the Noongar nation, as well as the First Nations peoples of the lands on which we conduct our business. We pay our respects to their elders and leaders past, present, and emerging. It's also particularly important that I acknowledge that we had our first-ever fatality when a 34-year-old male contractor tragically lost his life while installing a polyethylene paste distribution line in our Magdalena mine on February 25.
His loss of life is both tragic and completely unacceptable, and sadly, it reminds us of the risk that stored potential energy presents for employees and contractors in our industry. We're deeply saddened by these events, and our thoughts remain with the individual's family, friends, and colleagues. Following the incident, as you'd expect, we immediately activated emergency response protocols, notified the relevant authorities, and we continue to support their investigation. We've also engaged very closely with our workforce, contracting partners, and their unions to ensure impacted individuals are cared for and to reinforce the importance of well-designed work. In relation to our broader safety performance, our group TRIF increased slightly to 1.5 off a low base, and we recorded five high-potential incidents during the quarter. We are determined to learn from every incident, raising risk awareness and capability wherever we operate.
At Sandfire, we believe everyone is a leader, and we will only truly be successful when our culture has evolved such that everyone feels safe to speak up when they see something that isn't safe or just doesn't look right, irrespective of their title or level within the organization. Turning to operational performance. Group copper equivalent production for the March quarter was disclosed earlier this month as it fell short of expectations as both heavy rainfall and unplanned maintenance at MATSA and a further delay in the transition to high-grade ore at Motheo constrained performance. In MATSA's case, this led to the lowest level of quarterly throughput in a little more than three years and a 12% reduction in copper equivalent production to 21,700 tons. For year-to-date production of 68,000 tons, which somewhat ironically is within 1% of where we were at this time last year.
What's not obvious is that MATSA's performance in March improved strongly as annualized mining and processing rates recovered to 4.9 and 4.6 million tons respectively. Motheo's performance in the quarter presents a stark contrast to MATSA in so many ways as our team achieved record annualized mining and processing rates of 6.5 and 6.1 million tons respectively. Is too often the way in mining, despite such good operational performance, which included a strong improvement in mobile fleet availability and rates, it has taken longer to reestablish our face positions than we would have liked, such that higher grades are still ahead of us, with the average feed grade expected to rise toward 1.2% copper in the fourth quarter for copper equivalent production around the bottom end of our 58,000-64,000 ton guidance range for the year.
We pride ourselves on being consistent and predictable, and we're not shying away from our commitments in any respect. I can confirm that we remain on track to achieve group copper equivalent production within the lower half of our guidance range of 149,000-165,000 tons in FY 2026, which you'd recall was set at ±5% of the midpoint of 157,000 tons back in July of last year. While this requires us to maintain recent strong momentum across the remainder of the year, I can assure you that our assumptions are based upon robust bottom-up plans.
We simply need to run our business well, sustaining throughput rates at Motheo akin to those achieved in the third quarter, so we can reap the benefits of those higher grades, which I might add we are seeing now, and deliver a repeat performance at MATSA of the outcomes achieved in the fourth quarter of last year. More broadly, with no major maintenance and high rates of throughput planned in the run home, we currently expect underlying operating unit costs for both MATSA and Motheo to be materially consistent with prior guidance of AUD 86 and AUD 44 per ton of ore processed for FY 2026. As I'm sure you'd expect, there are more moving parts than usual.
With the conflict in the Middle East fueling higher energy prices, which is also feeding into freight rates and other input costs and contributing to a slight correction in certain foreign exchange rate markets such as the euro, which is providing some relief at MATSA. I'm sure Megan will be very much looking forward to talking to you about costs in the Q&A. To give you a flavor for the uncertainty inherent in any forecast that we make today, I remind you that 90% or more of MATSA's costs are typically euro-denominated. While diesel alone accounted for around 3% and 15% of MATSA and Motheo's costs in our FY 2026 plan. With the price up something like 50% in recent weeks.
Of course, it would be bold to suggest markets aren't efficient, and it would seem to us that commodity prices have proven to be resilient, perhaps because of the inevitable steepening of cost curves and the increasing risk to supply itself. While cost sensitivities are understandably of interest to people on this call, we're particularly focused on securing our supply chains for those key consumables as we generate very strong free cash flow, as you've seen at these prices. Within this context, we are well-positioned at MATSA, given its primary resilience or reliance on the grid in Spain and the country's industrial heartland, and we have relatively good visibility in Botswana out toward the end of this financial year. I would, however, caution that it's unlikely we fully understand all of the second and third order effects of the current conflict, which may take some time to manifest.
From a strategic perspective, we now have the bit between our teeth in South Australia, where we're gearing up for a significant drilling campaign which could exceed 130,000 m over the next 12 to 24 months. The associated TFS work streams that could amount to a collective investment of AUD 100 million, all of which is designed to unlock the secrets of the Kalkaroo copper and gold project, which we believe has the potential to underpin a 10 million ton+ per annum, low-cost, long life, open-cut mine, ideally located in a preferred jurisdiction to become the next major catalyst for the continuing transformation of our company. Jason and Ian Kerr are onboarding key personnel as we speak. Camp facilities are being prepared and two drilling contractors have been secured and are preparing to mobilize.
Within the Kalahari Copper and Iberian Pyrite Belt, we're really starting to see the benefit of bringing exploration together as our talented, centralized team of geoscientists are better placed to support and challenge our teams on the ground, ensuring our targeting approach is continually learning, capturing fresh ideas, and constantly being rejuvenated. We'll have an increasing emphasis on the drill bit next year as we leverage our depth of knowledge and take a real swing in the Motheo hub and in the shadow of MATSA's processing facility, where we have been encouraged by early indications but have much more work to do.
Pulling this together, we generated record financial outcomes in the quarter on the back of buoyant commodity markets, particularly in relation to our by-products, such as silver, with unaudited group sales revenue of $408 million, translating into underlying EBITDA of $220 million for an underlying margin of 54% to finish the period with net cash of $76 million. Having paid, I might add, AUD 46.5 million to Havilah for our initial entry into South Australia and $26.1 million to the tax authorities in Botswana as Motheo made its first two installments. Motheo's rapid transition to a tax-paying position, having paid back its capital base in as little as three years, is yet another marker of its success and a further indication of the potential that can be realized in the Kalahari when the right company takes the lead and the ingredients are right.
As you might expect, we are proud of Sandfire's growing economic contribution to Botswana and the broader local community. We're also proud of the way we've set our company up for success. I've said it before, we have the right team, we have the right balance sheet, we have the right operations, producing the right commodities at the right time with the right by-products. We're incredibly cost competitive with two operations that had a C1 cost below AUD 1 per pound in the quarter. With that, let's go to questions. Thank you.
Thank you. First question today comes from Kate McCutcheon at Bank of America. Please go ahead.
Hi, good morning, Brendan and Megan. If I can just drill down on Motheo in March quarter. That operation has been milling and mining a record, which seems to be running well ahead of the budget for the FY. If you're ahead on tons, can you just help me understand the grade piece? Is grade reconciling well from A4? Is this just a case where the mine plan had to change because of wet weather? I guess there's no underlying grade reconciliation issue. It's just what I'm trying to understand there.
Yeah. Look, Kate, I love your attention to the detail. Look, first and foremost, I'll pass to Jason. I'll just make a couple of comments. Very simple ones. If we had a grade reconciliation, we'd tell you. If there was an issue with grade reconciliation, we'd tell you. We're very transparent. You're right. Throughput, processing rates, mining rates have been picking up and are running incredibly well. I know Jason will tell you that it's an operation. When things are going well and you don't have your large shutdowns and so on, it's hard to hold it back. It likes to run at a rate in excess of our 5.6 million tons per annum. Again, it's really timing. Maybe Jason, I think it's probably worth you digging into some of this because it is important.
Also to just really, I guess, build confidence of the grade profile that we should see over the remainder of this year, but also how it sets it up into next year. Because again, I think we're really transitioning from a risk perspective, into a different phase of mining at Motheo.
Absolutely. Thanks, Kate. Firstly, just to reiterate, we do not have any reconciliation issues at all. Both ore bodies are reconciling extremely well. We're seeing, particularly at A4, because we're coming down on the top of the ore body and we are now into it. We are seeing that it's in place. The tonnages are reconciling well. We're seeing the grades, and we're also seeing that transition through some of the oxidation that we plan to see of copper mineralogy up the top. As we stand at the moment, we've been reacting by making sure that that A4 blend into the feed has been capped to manage that, and we've already started to increase that percentage of A4 in the blend as we're seeing that ore freshen up as expected. Just on Brendan's point there, and I might step back and talk about the year.
If you cast your mind back to the start of this financial year, we provided guidance in terms of what the production profile would look like throughout the year. That was driven by basically where we're at in the mine plan with Motheo, transitioning from the end of stage two in Q3, right, to transitioning from the ore feed being at the top of stage three. That's what we've seen, and we were expecting to see lower grade ore, and certainly in Q1 and Q2, with it ramping up towards the end of Q3 and into Q4. Now, the issues we've seen with grade so far solely relate to phase position. We've had challenges there with our overall mining fleet availability, which has meant that we haven't achieved the phase position that we required, particularly in Q3.
We've got a mine plan in place now to pick that up and make sure we take that into this quarter and also beyond, as Brendan was talking about. Certainly from our point of view, when we look at the life of mine, this was one of the higher risk production years in Motheo's life. As we move into FY 2027 and 2028, we very much are right into the main part of T3 stage three. We're getting right into the body of A4 stage one and stage two, and we transition into T3 stage four. All of which we have more than ample ore supply at a higher grade throughout that period.
Okay, crystal clear. Thank you. You're moving into drilling at Kalkaroo this quarter, so you have a new country per se. Is there an update on the strategic review at Black Butte? Or what timeframe are we working towards for an update there?
Yeah. Look, again, thank you. I think I mentioned previously that once we entered the process, the formal process of, I guess, reviewing the asset fit within our portfolio, that I wouldn't actually expand too much further until it was concluded. That's where we're at now. We do expect still, to be able to provide you with an update, a robust update around the time, if not, in conjunction with our full year results in August. There's probably not a lot more I'd like to add at this stage, Kate, but I certainly appreciate the interest.
Thank you.
Thank you. Your next question comes from Kaan Peker at RBC. Please go ahead.
Good morning. Good morning, Brendan, Jason, Megan, and team. I have one on MATSA, or maybe two. Just looking at Cu volumes for the quarter, great to see that the volumes have increased, but obviously grades are lower than reserves. Maybe if you can talk to when you've started to mine above that 1.1% or 1.2% material. I think Jason mentioned that moving deeper into the ore body. Is there any metallurgical variability risk, as you move deeper? Is recovery purely a function of the ore type? Thanks.
Yeah. Look, thank you for that. Yeah, going back to Motheo and particularly A4. I think the point that we would stress is obviously our plans are not only based and premised on good evidence in terms of the capacity of our mill and broader processing circuit, but also on our block models and as we get obviously closer to extraction, detailed blast and grade control results. Again, it gives us a great degree of confidence. I think what Jason was particularly referring to, as is the case at T3 and often is the way in any similar base metals project, as you're moving through into the surficial parts of the ore body, particularly where they're relatively shallow, there is that potential for a level of oxidized material to come into the mix that you've got to manage and deal with.
As we get into the heart of the ore body, not only do we have good visibility on grade, but we also have very good visibility on metallurgy. Obviously we have a good understanding of how that performs and behaves in our processing facility. Perhaps as frustrating as it may be, it's a fairly simple story that as you get into those primary bornites and chalcopyrite and as you know, the very coarse minerals in Botswana, you tend to see them float very, very well. You get very, very, very strong rates of recovery. That really is the relationship that we're talking about here. Jason, anything else there?
Thanks, Kaan. Just building on Brendan's comments. If we look at last quarter, we are already mining 1.2% material. If you look at we report an overall average grade, which includes, we differentiate different ore types in our grade control, which is a high-grade run and also a lower grade stockpile ore. We are already consistently seeing +1, +1.2% material that's already been mined, and we know that's coming. That percentage of our mining will increase going into Q4 and beyond. If we look at metallurgical recovery and risk, we know at A4 and very similar to Q3, we start off at the very tip of the ore body where we do see some oxidation of the copper mineralogy. We know at A4 because it's slightly deeper, we actually make that transition quicker than we did in Q2 2023.
I kind of touched on it there with Kate's question. We're already seeing that transition and that mineralogy improved just over a couple of benches already. That's as we expect, and particularly going into Q4, we've now grade controlled pretty much 100% of our ore to be mined out of A4 in this quarter. We've got a very good handle on that grade and that metallurgy going out to the end of the year. Look, building on Brendan's final point there, the mineralogy, copper mineralogy at A4 is dominated by chalcopyrite and bornite, both of which we know liberate extremely well and float extremely well to produce a high-grade con. Overall metallurgical risk at A4 is very low and it decreases with depth, if that answers your question.
Maybe, Jason, at risk of repeating ourselves, just to be really clear. We are three weeks into April. We've effectively got a week to run. Obviously, we're getting very close to the end of the year. Motheo is currently running ahead of plan for April. Now we've got to sustain that. We've got to continue to deliver. We've got to do all the things that we've said, particularly in relation to maintaining our face positions, our fleet availability, getting the rate that we need, and we obviously need to ensure that the processing facility continues to run. As we mentioned, there's no major shuts planned for the remainder of this year. There are your typical routine maintenance programs in place that very rarely go over 24 hours. That's built into the plan.
As I've said, we are ahead of where we need to be right now.
Absolutely.
No, great. Very detailed and appreciate it. Second one's on MATSA. You've pointed to improvement into March and April. Where are you actually running today versus nameplate? Is there anything that needs to be done to get back to full throughput?
That's great. Look, I'll take it up front. Again, we highlighted that as we came out of March, the business was running very well in the month. That momentum is continuing. One thing that I look at, and it's just an interesting marker. You'll notice I said that we're within 1% of where we were last year. Last year, we ended up producing 94,000 tons of copper equivalent on a comparable basis. If you look at the throughput rates, the recoveries, the grades, again, in effect, what we need to do is effectively replicate the performance of that fourth quarter of last year. There's nothing built into our plan, if you like, that we haven't done before. Maybe Jason, if you can expand on that.
No, I think you've hit the nail on the head. If you look at our processing rates, pretty much in line with what we've done in prior quarters. If you look at it, we probably quarter-over-quarter have a slight increase in processing of copper only ore, as part of that increase and a slight increase in grade, which is driven by the mine plan. Overall, our polymetallic ore is pretty much consistent with last quarter in terms of grade and also expected recovery.
Thank you.
Thanks, Kaan.
Thank you once again. Your next question comes from Ben Lyons at Jarden. Please go ahead.
Thank you. Good morning, Brendan and team. Just a couple of quick ones on the detail, please. Probably the first one for Megan, and apologies for leading with a question on tax, but appreciate the additional steer that you've given us on the effective group tax rate for FY 2026 and a reminder of that Botswana calculation in the footnotes. Given that you've now appeared to have largely used up your CapEx tax shield in Bots, if we were to assume that elevated copper and silver prices prevail through FY 2027 and beyond, should we expect an effective tax rate for Bots towards the top of that sliding scale? Unless you were to undertake more meaningful CapEx programs like using the opening up of A1 CapEx as a bit of a tax shield. Thanks.
Yeah, great question, Ben. You'll notice that we've really, I guess, further emphasized what's happening in Botswana this period. We think it is important people understand it. I think it's also important that the questions like yours give us a chance to even build upon that. You're right, a key component of this is ongoing capital that is deductible, and then of course, any specific larger point of a better frame, lump of capital and how that plays through. I know Megan's always reviewing the models and updating them. Over to you for the detail, Megan.
Thanks, Brendan. Thanks for the question, Ben, and very happy to elaborate on that a little bit further. As you're aware, the Botswana tax rate uses a sliding scale, and that takes into account taxable profitability divided by gross revenue, essentially. Now, our capital spend in any given year is a really key component of that, as Brendan touched on. In periods where there is higher capital spend, that comes through in the calculation. During H1 FY 2026, we actually utilized all of our carry forward tax losses in Botswana, and they were in connection with the construction of Motheo. That purely reflects the profitability of the asset and the reality that effectively we've achieved payback within sort of a circa three year period.
Now what we've tried to provide some guidance around in the quarterly is where we think our effective tax rate is going to land at June for FY 2026, and that's really based on what we know today and taking into account the strengths in commodity prices that we've seen play out in recent months. We provide some numbers around that with the rate within the range of 34%-37% anticipated for FY 2026. Now, Ben, what I would say beyond FY 2026, what I expect to happen based on what I can see in front of me today, and obviously metal prices is the biggest swing factor here, together with the level of capital spend. I expect beyond FY 2026 that we should see the effective tax rate for Motheo start to approximate around the Australian statutory rate. Not exactly.
It'll be a little bit higher, but it's going to level out back to that sort of level. What we're seeing in FY 2026 is it is going to elevate, and that's really a function of the accounting requirement that we have at the end of the period to revalue our deferred tax liabilities to reflect the rates that we expect will apply when those deferred tax liabilities effectively reverse in future. That's why we have an elevation in this next quarter. In terms of your comment on the upper end of the range, the 55%, that is probably not a realistic upper end in a practical sense, because you would only ever get to 55% if there was zero deductions, if you know what I mean.
Probably I think the key thing to come back on is over the life of the mine, based on what we know today, we expect it to sort of approximate what we see in Australia, albeit a few percentage points higher.
It is complicated, because obviously we've got various capital plans built into there. I think, Megan, we assume A1 is constructed in our life of mine. I've said many times, it's not going to be a large pit. There are certain elements in there. What I would say over and above that is obviously David Wilson, who you all know well, as a chemical engineer, he's rapidly becoming a tax expert. He would be very happy to sit down with any of you on the call to the degree that he can and try and help you work through and understand some of the nuances that are at play. Megan, anything else?
Probably just to highlight, Ben, I'm sure you're aware it's in the footnotes. That's based on the current tax legislation. As some of you would be aware, there's proposed changes that are currently under consideration in Botswana. The most significant change, if it goes through, would see a change from moving away from upfront deduction of capital to effectively a minimum 10-year period to take that capital deduction over. The numbers I've been talking around and the guidance we've provided in the quarterly is based on the current tax legislation, not the proposed amendments that are currently under consideration with the government.
Yep. Cool.
Does that help, Ben?
Thanks very much. Sure. Yeah. No, it's very helpful, very detailed, and a very kind offer to follow it up with Dave. The less we talk about tax, I think the better. No, it was very reassuring that a 55% outcome, which would be extremely egregious in terms of a fiscal take, seems to be an incredibly low probability event and an outcome closer to the Australian corporate tax rate, 30%, is a much better outcome. I appreciate you stepping through that. Thank you.
Thanks.
Maybe just one more from me.
Yeah.
Just on the regional exploration program in Bots. I know you haven't hit the meters that you were planning on, just given those safety interventions with the drilling contractor earlier in the fiscal year. Just given the overall importance of that program and noting that you're hitting up seven of your high priority targets, anything that you're seeing coming out early doors that gives you indications you're on the right track, whether it's actual decent intercepts or even pathfinder mineralization? Thank you.
Yeah, look, it's a difficult one. I'll be honest with you. At times, I wonder from a regulatory perspective, what we can and can't actually say in this day and age with regards to exploration. I think it is a vexed issue, and I actually don't think it's overly helpful to investors because I think investors deserve to understand progressive trends and progress more broadly. I'll give it a go, Ben. Look, we've said that for a period of time, we spent a lot of effort building that deep geological and geophysical knowledge base, both in the Iberian Pyrite Belt and obviously, in the Kalahari.
On the back of that and then the learnings, and I think the critical piece we've talked about many times, the learnings that we've garnered by actually opening up two ore bodies and really getting a much more tangible understanding of the genesis of these ore bodies and the drivers for economic mineralization. Bringing all of that together has been, obviously, a particularly important piece for us. Then bringing all of exploration together under Jason's guidance, I think has been critical because it means that we're really making sure that all of those learnings and elements that come from our mine geological teams through to our centralized teams, through our regional teams, are all being brought together and then being built into, as I said, a process of exploration, which is continually learning, and if you like, upgrading targets.
Now, that's all great, but as we often say here, the rubber hits the road when you actually put a drill in the ground. We were somewhat delayed for reasons that we've mentioned in Botswana. We're past that. We're working primarily with new drilling contractors. We're starting to make big inroads now. I've talked about an area that's proximal to the A1 area that we will expect to declare a reserve for towards the back end of this year, and most likely with our results or around that timing. I've said before, we think it's somewhere between a half a year and a year. That's sort of broadly unchanged. We expect it to be economic and to make its way blended into the mine plan in the 2030s. That's important.
Proximal to that, but not included in that area, we have had some very encouraging intercepts. We've been drilling around that with a number of holes where we're seeing a continuation of those, call it encouraging intercepts. The question now is, how continuous or contiguous is it? What is the strike length? What are the thicknesses? How much is the volume? What would the strip ratio be? And could it become an economic lode? We don't know the answer to that, and it is absolutely way too early. Beyond that, we are, as you said, targeting those broader structures in and around primarily the Motheo hub, and you'll see us focus even more so in that area over the next 12 months. We have had other similar, and one specifically recently, very interesting intercept, that all I can say is precisely what we're looking for.
It's in a different structure. What we don't know is whether we'll see repeats of that. What we don't know is the scale or potential. Again, what it highlights, and I think the message I'd want to leave you with, is that all the things we see continue to encourage us that being in the Kalahari Copper Belt is the right place, and that it is geostatistically highly unlikely that we found that the only three ore bodies in that district, almost within a millisecond of each other, and there isn't more to be found and more to be mined. That's what we've got to prove to ourselves, and we've got to prove to all of you over the coming two and three or four years.
That's the sort of timeframe we've got before I think we're going to be in a position where we need to find that discovery hole, so to speak, and then repeat that somewhere in that sort of timeframe. Does that help, Ben?
Yeah. No, that's awesome. Very encouraging outcomes there. Look forward to hearing how they're followed up in the future. Good luck. Thank you.
No, thanks, mate. I think I said to Jason the other day, exploration, it's always that story. It happens quickly, but it took me a decade. It took me many years. That's the reality here, that there's so much work and so much time put into this. When you make the discovery hole, it always feels like it happened easily and quickly. Again, we're going to stay the course. We're very focused. We're putting the dollars in the ground, and what's really important for me is that latter point. It's all only good to do all the, call it, the academia around exploration. The critical thing is actually drilling holes. Jason, as I've said, he's literally got the bit between his teeth. Both in Spain and Botswana.
Yep. Copy that. Thank you. I'll pass it on. Thank you.
Thank you. Your next question comes from Daniel Morgan at Barrenjoey. Please go ahead.
Hi, Brendan and Team. A lot of encouraging, I guess, chatter about Motheo and just how the mine is set up. For FY 2027, 2028, you're saying it's basically very de-risked in terms of the face positions. What does that mean for managing that operation through there? You're going to have a lot of ore at good grades. How will you manage that? Does this mean that we might see some other production upside through FY 2027 and 2028?
Good question, Dan. I think, and I'll throw it to Jason. I think what we're saying is that the plans we've provided you in previous iterations, site tours and other things where we said, we expect that we'll hold sort of FY 2026 plus or minus guided production rates out to the end of this decade at a minimum. That what we're saying is we expect to do so, but into next year it's a lower risk plan, touch wood, all else being equal than as we went into this year. Jason?
That's it. Brendan, you've hit the nail on the head again. If we look at it, we'll see a much more even production profile over each of the quarters going into FY 2027. Where we are, we've got access to more ore in both A4 and T3 over the next two years. At the same time, we do need to make sure that we are doing our waste stripping, which will set us up for FY 2029 and beyond that as well. That's very important that we maintain, particularly those total material movement rates from open pit mining.
Because once again, we can introduce risk if we don't maintain the rate and keep moving those high throughput or those high mining rates through this period as well. But short answer, yes. In terms of ore supply, we have de-risked the plan. We've got ready access to good quality ore over the next two years.
I guess a similar question at MATSA. Obviously, the June quarter, you're going to benefit from a lot better grade, but how are the leading indicators of performance beyond this quarter looking like in terms of development and advance? How is the mine set up to deliver? I'm not looking for quantitative guidance, but just is it set up well for next year?
Yeah. Look, I think, in many ways we have provided an indication on the quantitative side where we said similarly that we expect to retain or maintain similar levels of, call it copper equivalent production again out to the end of the decade at MATSA. Very, very simply, it's a similar story. Jason will expand upon it. We've talked a lot about Olivo and San Pedro. We've talked a lot about the amount of work we've put in investing heavily in underground development. We've talked about the importance of creating additional degrees of freedom. As we go into next year, that is probably the most important delta for us, is we start to see those additional degrees of freedom open up, because effectively of the level of development we're getting into some of those areas. Jason?
Dan, if you look at it the last couple of years, and if I start with Aguas Teñidas. We've invested a lot of capital development in opening up the Western extension, which is the main part of the higher grade ore body that's remaining there at Aguas Teñidas. We've now opened that up and we've set up, particularly our ventilation, our capital development, and all the infrastructure that we need to maintain a higher mining rate through those areas. Firstly, that set us up well, particularly over the next year to two. At Magdalena, we've established that underhand mining there in MATSA too, and that's working very well for us at the moment. If I look out beyond and really just to reiterate Brendan's themes there, we've provided prior outlook for the next three years.
Everything I'm looking at the moment is that we've got quite a stable mine plan covering that period going forward. Consistent with what we've given to the market previously.
Thank you. Very clear. Just last question on Kalkaroo. I appreciate you're only just starting on the Kalkaroo journey. How are you going to interact with your joint venture partner, Havilah, with regard to the release of results over time as they come in for that big drilling program?
Thanks, Dan. In terms of how we're going to interact more broadly, we're really building a, I'd say, an incredibly fruitful and productive relationship. I met with them only, I think two Fridays ago. Very, very good discussion. Strong alignment. I know they're excited about the level of commitment we're putting in. The fact that we committed to a minimum 20,000 m drilling program. As I've said to you, we think it could be as much as 130,000, assuming we continue to see the results that at least we're anticipating. Obviously what goes hand in hand with that, and the drilling is the biggest piece, is that expectation of a total spend moving towards the conclusion of a PFS of around AUD 100 million. I know they're very pleased with that. In terms of results, it's still obviously early.
We haven't actually got drill rigs on site yet. As I mentioned, they're preparing to mobilize. My current thinking, but to be tested, is that we will provide, most likely, the results on a quarterly basis for the drilling program. The reason for that is at different points, undoubtedly, there may be material outcomes relative to, if you like, Havilah's disclosure thresholds as opposed to ours. As a result of that, I think, if you look at York, you can't release discrete drill holes. You have to release the broader, if you like, suite of information. I think one way to manage that is actually to be, as we like to be transparent and release the information as it comes to hand. Again, Dan, one for us to work through, but that's probably the current thinking that we have.
In other words, I think there should be a very, very strong level of information flow coming out of Kalkaroo over the next 12 months. Because just to be clear, the sort of 24 months we talk about, our expectation barring something unforeseen with regards to weather, frankly, fuel availability, is that the vast majority of the planned drilling will actually be done within around 12-15 months. Again, with that information, not only will we have a good understanding of where it's headed. My sense is if you do the work, you will too.
Thank you so much for your perspectives, Brendan and team.
Thank you. Your next question comes from David Radclyffe at Global Mining Research. Please go ahead.
Hi, good afternoon, Brendan and team. My question is really a follow-up to Dan's on Kalkaroo. Now the deal's done and you're starting to spend not an insignificant amount of cash on the project. Really the question's to the point of scale that you see in the asset or what you would hope to define to make the asset worth the squeeze, if I use the terminology you've used before. Because it would seem that if you look back at, say, even the BHP 2023 concept scale size, it wouldn't quite be to the scale of your existing operations on a copper equivalent basis. There's obviously other benefits to location and mine life, and let's see what the studies show.
Given the timeframe and the scale here, is it fair to assume that there's room for you guys to continue to look to enhance the portfolio with other growth options?
Thank you for that. I really appreciate it. I think the way I think about the latter part of that question, it's beholden on any management team to always be looking for opportunities to create value. If we can generate like ideas, translate them into action where there's asymmetry of returns well in excess of the cost of capital, I think that's what shareholders want us to do. I think if you look at the Kalkaroo transaction, there's a win-win. What we do will benefit Havilah substantially, but it leaves us in a position where there is really strong asymmetry in return for our shareholders. I don't think that's been common in deals of this nature. We're very, very pleased with that. As you mentioned, there is a lot of work to do.
I think Havilah talked about historically a mineral inventory, for want of a better term, which I think was a way of trying to understand the opportunity of around 184 million tons, well in excess of the current reserve. Now, our program is designed to test whether that scale is also significantly undercooked relative to the potential of the geology that we see. On that basis, I think if you work through the numbers, you can start to see an ore body that has the potential to support throughput rates which, when combined, could match our two operations today. If you think about the grade profile, it's not dissimilar to Motheo. It's slightly less. Got more by-product than copper. Or if you like, it's got a greater ratio of by-product to copper than Motheo. The strip ratio, from what we can tell, is probably about half as much.
It's also at that scale amenable. Because of the geometry of the ore body and the thickness, it's amenable, we believe, to much larger mining equipment, higher productivity rates, and so on. When we look at all of that, we think it has the potential to be a very significant operation for Sandfire, but one that also has the potential to run for decades. That's what this program of work is designed to test. That's why the spend is what it is. It's why the number of meters is as high as it is. Of course, if we're not seeing what we expect, we will throttle back those plans. I guess that's the first point. As I said, right at the outset, we're very excited about the potential of Kalkaroo.
That doesn't mean we don't look around the world for opportunities that could match the potential of Kalkaroo, where we see similar asymmetry in returns that can benefit our shareholders. We're never going to try and grow the company for the sake of growth.
Okay. Thank you. That's very clear.
Thank you. That does conclude our question and answer session. I'd like to hand the call back for some closing remarks. Thank you.
Look, again, I know hopefully a slightly less busy day than usual, and hence really appreciated and enjoyed the depth of questioning. As I mentioned, Dave and Tom are really eager to help through the course of the day as you try and work through some of these things. We know they're complicated. We appreciate your time. We look forward to seeing you all in person again soon. Thanks again.