# OKD ČSM mine closure advances > Live situation record from CLSTR: https://clstr.news/situations/okd-sm-mine-closure-in-czechia > Updated: 2026-07-30T05:18:42.000Z. Sources: 7. Developments: 3. In late July 2026, Czech mining firm OKD began the first phase of sealing the ČSM‑Jih ventilation shaft at the ČSM mine in Stonava, using around 45,000 m³ of certified stone slurry. The operation followed the completion of 87 explosion‑resistant dams and was reported to be ahead of schedule and under budget, supported by a CZK 3.3 billion financial reserve. The company confirmed continuous 24‑hour filling of the southern shaft and outlined the full closure programme: a similar fill of the northern shaft planned for September, cement‑fly‑ash work on the initial shaft in December, and final sealing of all chambers by the fourth quarter of 2028. The plan also includes demolition of surface structures, removal of back‑fill, landscape covering, installation of degassing pipelines for future methane extraction, and the winding down of a workforce that has seen over 1,500 layoffs in the past 18 months. By the end of July, OKD announced an accelerated timetable, aiming to backfill the main shaft with a cement‑ash mixture by early 2027 and complete closure of all four shafts by Q4 2028. In contrast, state enterprise Diamo, responsible for liquidating former mines in the Karviná region, proceeds on a longer schedule. Diamo has secured the closure of eleven of the eighteen shafts it inherited, three of which are already backfilled to ground level. The remaining four shafts – two at the former ČSA mine and two at Darkov – are slated for completion by the end of 2029, contingent on additional state budget allocations. ## Timeline ### 2026-07-30: OKD Accelerates Mine Closure While Diamo Extends Timeline in Czech Republic OKD is fast‑tracking the closure of the ČSM mine, targeting full shutdown by Q4 2028, while state firm Diamo follows a longer plan, aiming to finish remaining shafts by end‑2029. 2 sources. https://clstr.news/cluster/okd-accelerates-mine-closure-while-diamo-extends-timeline-in-czech-republic ### 2026-07-24: OKD Begins Closure and Reclamation of ČSM Mine in the Czech Republic OKD completed dam construction at ČSM Mine, began slurry fill of the southern shaft, plans further fills, demolition and methane degassing; closure backed by CZK 3.3 bn reserve and affects over 1,500 workers. 2 sources. https://clstr.news/cluster/okd-begins-closure-and-reclamation-of-sm-mine-in-the-czech-republic ### 2026-07-21: OKD starts filling ventilation shaft at ČSM mine in Stonava, Czechia OKD began filling the 900‑m ventilation shaft at the ČSM mine in Stonava, using 45,000 m³ of stone, with work set to last 11 days and full mine closure aimed for Q4 2028. 3 sources. https://clstr.news/cluster/okd-starts-filling-ventilation-shaft-at-sm-mine-in-stonava-czechia --- Cite as: OKD ČSM mine closure advances. CLSTR, https://clstr.news/situations/okd-sm-mine-closure-in-czechia