OceanaGold (Philippines), Inc. has achieved a breakthrough in mine rehabilitation through its pioneering “Harmony in Diversity (HiD) Effect” — a method that reduces rehabilitation costs by more than half while accelerating forest regeneration from 15 years to just 3–5 years.
Under traditional methods, mine rehabilitation costs around ₱3.5 million per hectare. By 2025, OGP has cut this to just ₱1.3 million per hectare by replacing hydroseeding and imported mulch with a locally adapted approach that supports natural ecosystem recovery. The savings are being redirected to other environmental programs, reinforcing OGP’s broader sustainability commitments.
Mimicking Nature, Restoring Ecosystems
The HiD Effect combines four techniques: Japan’s Miyawaki Method, Burkina Faso’s Zai Pit Technique, the introduction of mycorrhiza fungi for soil enrichment, and the use of decomposing biomass to create mini-ecosystems. Together, these approaches mimic natural forest succession, allowing native species and wildlife to return much faster.
“Through the HiD Effect, we can transform a disturbed mining area into a self-sustaining forest in just three to five years, compared to at least 15 years under conventional methods,” said Donna Del Moro, OGP Acting Superintendent for Environment.
Already, native plants are naturally regenerating, and endemic bird species such as pacific swallows, swiftlets, wagtails, and scaly-breasted munias have been spotted in rehabilitated areas — a sign of a thriving ecosystem.
Collaboration with DENR Research Arm
The success of the HiD Effect has caught the attention of the Ecosystem Research and Development Bureau (ERDB) of the DENR. ERDB and the Mines and Geosciences Bureau (MGB) visited the Didipio Mine in April 2025 to assess the approach as part of a nationwide evaluation of progressive rehabilitation practices.
“We value the opportunity to collaborate with DENR’s principal research arm, combining their institutional knowledge with our on-the-ground innovation,” said Nericel Langres-Daulayan, OGP Mine Environmental Protection and Enhancement Office Manager.
A Model for Responsible Mining
Since 2013, OGP has invested US$2.5 million in progressive rehabilitation, successfully regenerating 55 hectares, or 16% of its disturbed 345-hectare area. With its faster timelines, richer biodiversity, and natural defenses against erosion and landslides, the HiD Effect is positioned to become a model for responsible mining nationwide.
“OceanaGold is committed to leaving a positive legacy by proving that responsible mining includes not just resource development but also regenerative ecosystem renewal,” Langres-Daulayan added. “The HiD Effect ensures that post-mining areas can thrive and sustain communities for generations to come.”