Cultural Heritage and Geothermal Development Collide at Mount Ungaran

A geothermal project at Mount Ungaran has drawn a petition signed by thousands of residents, opening a sharp dispute over the future of one of Central Java’s important cultural landscapes. The controversy pits the preservation of heritage and community living space against the national need for energy.

Nur Cholis, deputy director of Walhi Central Java, warned that geothermal extraction could put heavy pressure on the environment, particularly through water consumption and damage to springs. He pointed to the Dieng Plateau as a cautionary example, saying residents of Pawuhan hamlet have struggled to obtain clean water after a source was allegedly affected by nearby geothermal power activity and became salty.

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From an ecological perspective, geothermal extraction carries high risks for environmental carrying capacity, particularly in relation to water consumption and the preservation of springs.

The planned exploration area also lies close to Gedong Songo Temple. Nur said drilling, land clearing, heavy-equipment movements, possible releases of toxic gases such as hydrogen sulfide, and seismic vibrations could threaten the centuries-old structures. Changes to underground water flows could also cause land subsidence, he said.

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The potential impact is highly threatening and destructive. Gedong Songo Temple is not only a cultural heritage site and historic place that must be protected, but also supports the living space and economic lifeline of local residents through tourism.

“Gedong Songo Temple is not only a cultural heritage site and historic place that must be protected, but also supports the living space and economic lifeline of local residents through tourism,” Nur said. He added that continuing the project could sacrifice the ecosystem, historical and cultural heritage, and local livelihoods.

Walhi also questions whether the project is urgent. Citing 2025 electricity data from PLN’s Central Java and Yogyakarta unit, Nur said installed capacity stood at about 6,400 megawatts, compared with peak demand of roughly 4,200 megawatts. That left around 2,200 megawatts, or 44.94 percent, in reserve, he said, and weakened the case for adding a large plant in a landscape important to local communities.

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If this project continues, the government will not only sacrifice the ecosystem, but also destroy the historical and cultural heritage and the livelihoods of local residents.