Semirara Mining and Power Corp. is scaling back operations at its Acacia mine as rising seawater inflows strain pumping capacity and threaten access to the mine’s remaining coal reserves.
SMPC said seawater entering Acacia has risen to about 30,000 cubic meters per hour, equivalent to roughly 12 Olympic-sized swimming pools every hour. The volume has exceeded the mine’s current pumping capacity despite continuing efforts to control the inflows, increasing the risk of flooding.
Addressing the problem over the longer term would require substantial spending on additional pumping equipment, power systems and related infrastructure. But uncertainty surrounding the government’s coal bid round has complicated SMPC’s planning for those investments.
The company said insufficient capital spending would increase the risk of flooding and potentially losing access to Acacia’s remaining coal reserves. The conditions have already disrupted operations, prompting a partial suspension of stripping activities needed to expose and access coal for future production.
With operating requirements reduced, SMPC is aligning its workforce through a supplemental redundancy program affecting 996 employees. The company said it recognizes the impact on affected workers and their families and would support them through the transition.
SMPC is maintaining its 2026 coal production target at 12 million metric tons. The disruption at Acacia, however, is expected to weigh on 2027 output because the mine had been expected to provide most of the group’s coal production next year.
The developments put a significant portion of SMPC’s near-term production outlook against the practical limits of keeping Acacia operational as seawater pressures intensify.
The Department of Energy conducted a site visit to Acacia from Sept. 24 to 26. SMPC said it continues to coordinate with the DOE on the mine’s immediate operating challenges and longer-term options.
The issue now for SMPC extends beyond managing water. It involves deciding how much capital to commit to preserving access to a mine whose future operating conditions remain uncertain.
