Thank you, Tim.
We are Australia's newest silver and zinc producer, with production that's just recently commenced from our Endeavour Silver Zinc Mine, just some six weeks ago. For those that don't know us, we are Polymetals . We're an East Coast- domiciled precious and base metals company. We pride ourselves on our cost-efficient management and our owner-operator approach to things. We do all our own internal engineering, construction, and build. We also operate our own mine ourselves. The team i tself, the core team, has been working together for decades, developing a number of projects across Australia in both gold, silver, and base metals. The board itself, as with any good growth company, we're very committed and we've all put serious money into making this venture work. The past year has been quite defining for our business.
Just a year ago, 12 months ago, we acquired the Endeavour Silver Zinc Mine. Shortly after, we secured finance. We then began redevelopment of the project in November last year. We secured our own mining fleet. Mining production commenced in May of this year. Mill commissioning started in June, and we've just received our first cash flow in July. We operate in the Cobar Basin. The Cobar Basin has had a century and a half of continuous underground mining. Currently, there are five active copper, gold, and silver zinc operations. Endeavour itself is located 30 km North of the CSA Copper Mine, 40 km North of the township of Cobar by sealed road. The project itself, it was discovered in 1974 by Electrolytic Zinc, which morphed into Pasminco.
The project was built by Fluor Daniel in 1982 and ran continuously until it was placed on care and maintenance in December 2019. The reason it was placed on care and maintenance is that there was a 100% silver streaming royalty attached to this project, which eventually made it uneconomic. Prior to our acquiring this project, we restructured that royalty to a 4% NSR. The net effect of that is basically bringing back around 25% of previously lost revenues. We're not doing anything majorly different. We're producing zinc and silver lead concentrates through a plant that's done it for the last 40 years. We just have the benefit now of getting revenue from silver. The project, there's a 1.2 million-ton processing plant. There's an underground mine, Twin Deak mine. It's shaft haulage from 300 m below surface.
The mine is serviced by a water pipeline, grid power, sealed road, and railway to site. Additionally, it comes with quite a large real estate portfolio, which we're housing our employees in at the moment. The project itself, what we know to date is that the Endeavour ore body is a 50 million-ton polymetallic ore body. Over its history, there were 32 million tons of ore mined, recovering and producing 92 million ounces of silver, 2.6 million tons of zinc, and 1.6 million tons of lead. Today, we still have 16 million tons of joint resources. We think that this operation will certainly extend past the 10-year mine plan we have today as we convert further of those resources to reserves. In our initial 10-year mine plan, we're looking at various areas in the mine.
The pink-purple area at the top is a very high-grade silver area left behind because of that silver streaming royalty, which I spoke about earlier. In the main ore body itself, we have a lot of primary stopes. Most of these primary stopes were left behind because they were more silver-rich than lead zinc, as well as some remnant mining, which we're doing later in our mine plan. Down the bottom there, you can see the deep zinc lode. This is an area that was only drilled out in 2016. It's open to the North-south and at depth, and that's a virgin ore body down to the base. The mine itself is fully developed. It's fully serviced. During its current maintenance, four years of current maintenance, it was kept dewatered. It was kept ventilated. This mine is in very good condition, and there's great ground conditions here for Cobar.
We're down at 1 km depth. Our mine plan goes down to 1.4 km. Excuse me. In comparison to our friends down the road at CSA , they got mine plan down to 2 km . What we're really excited about is the high-grade silver area. We've only got 270,000 tons of ore reserve, which we put together in our mine plan released last year. Since then, we've done geotechnical drilling. In our mine plan, we have assumed a cut-and-fill mining method, which is very slow and costly. Since then, the geotechnical drilling suggests that we can potentially stope this area, giving us more tons faster at lower costs. We're really excited about that aspect of things. Also, in this area, historically, it contains quite a lot of dendritic native silver.
We're unable to quantify how much silver is there in its native form, but we do know that it does exist. We're hoping we can get some more upside from this area, not only in tonnes from changing our mining method, but also the grade that we may get through that native silver component. Our mining commenced in May, shaft haulage, we've got an underground crusher, began in May. Mill commissioning during June, we actually started processing ore on June 6 and then produced our first concentrates later in June. We now have processed, well, we have around 7,000 dry metric tonnes of concentrate in our concentrate shed, and we'll start transporting that concentrate through Adelaide for export over the next two weeks. In essence, we've been operating for six weeks. The month of July was our first month of production.
During that month, we've met our operating costs, which is great. We're now stockpiling ore. We're still ramping up. We're only running at about 60% of our steady-state capacity. Last month, we produced a bit over 5,000 dry metric tonnes of silver, lead, and zinc concentrate. We've got drilling programs to continue extending our mine life whilst we ramp up production, aiming to hit steady-state capacity around October of this year. Over the last month and a half, we've generated $15.5 million of cash flow, which is great. We're now meeting our operating costs. We've got $22 million in the bank. In parallel with our redevelopment of the Endeavour , we've been drilling. There's been a drill rig turning on the surface since January of this year. There's no plan to stop that.
There hasn't been that much exploration done over the last 20 years where the vendor, a Japanese smelting company, was just chasing lead and zinc concentrates. We're really bullish on our exploration across the project, not only near mine under the mining leases, but through our regional portfolio as well. The areas we're targeting at the moment are a southern extension to the main ore body. This area was never drilled, and we've been drilling there for the last three months. It's looking interesting. We're vectoring in these Cobar-style deposits. They're very high grade, narrow, but have deep depth persistence. It makes exploration quite difficult, but we think with persistence, we should get a good outcome at the end of the day. Also, in the mine itself, the ore body is open, certainly in the deeps north-south and at depth, and also the northwestern mineralization is open.
We should be getting an underground drill rig in there probably later in the year to extend out our resources and reserves in this area. Likewise, we control 100% of the Northern basin. It's over 70 km of strike. It starts immediately West of the CSA Mine and runs 70 km to the North. We have many targets throughout this portfolio. There's 50 years' worth of data from explorers from Getty Oil to Delta Gold to Newmont. We're excited to follow up some of these targets. We've now resourced up our exploration team to be able to go execute our r egional programs, probably starting in the next two months. For us, we think the next project will come from our existing portfolio, either by discovery, additional resources from in the mine itself, or also metallurgical solutions. We have a proven asset that operated for 40 years.
The infrastructure is all in place. We've refurbished it so it lasts at least another 10, if not longer. We have resources of scale, and we do have a real exploration opportunity in the hands of an effective management team. We've returned Endeavour to production. We are now onto our second goal, which is optimizing our existing assets. We're currently only running at about 60% of our nameplate capacity, and we're aiming to fill that with either our own additional ore or by external ore feed. We do have an agreement in place to mill some of CSA' s silver lead zinc ore, which is 30 km to the South. We'll continue to convert more resources to reserves. Our drilling and our exploration is continuing. We're looking to spend about $7.5 million a year on exploration.
That will ramp up as we get into free cash flow. As a business, we're aiming to be Australia's lowest cost zinc producer. That's our aim. If we get there, we should be able to ride the waves over the next 10 years. We're also looking to establish an efficient and sustainable capital management policy, whether that's through dividends or continued exploration. What we've achieved in the last 12 months from getting a project from current maintenance financed into production and now meeting our operating costs, it's a big effort. Who knows, given what we've achieved over the last 12 months, I might be here next year with a second project. That would be nice. Just in closing, I'd like to thank our team on site. It's been a huge effort to pull this project together.
We spent $30 million in capital, which was just an exceptional outcome for the business. Thank you, and thank you to Diggers and.