LAKE SINGKARAK, Indonesia — Mardianis recalls reading the Quran with his parents and two children here on the western shore of Lake Singkarak before the desperate cries of galodoh.

A dark wall of rock barreled down the hillside as the family rushed to higher ground. Mardianis remembers the flood careening into the family’s small food store, and the totality of destruction to the community mosque. Dozens died here in Guguak Malalo ward, Tanah Datar district, in the Indonesian province of West Sumatra, during the flash flood, known locally as galodoh.

That disaster occurred 25 years ago, but a layer of trauma lies beneath the surface of this lakeside community.

“If there’s heavy rain and it lasts a while, I won’t dare spend the evening at the food stall,” Mardianis told Mongabay Indonesia.

Many here blame the flash flood on blast explosives used to cut 17 kilometers (10 miles) of tunnels to channel water from the lake to a hydroelectric power plant.

Malin, a young resident of Guguak Malalo, said the intake for the hydropower plant had introduced new currents that made fishing more difficult.

“Many of the water sources were lost because of the tunnel that was built from Singkarak to Lubuk Alung,” Ardinis Arbain, a hydrologist at West Sumatra’s Andalas University, told Mongabay Indonesia, referring to a town to the west of the lake.

A development plan prepared by the Japan International Cooperation Agency (JICA), the country’s overseas development aid agency, showed only one in five homes in the region that includes West Sumatra province had electricity prior to the hydropower construction.

The Singkarak hydroelectric plant has a capacity of 175 megawatts and was built to power hundreds of thousands of homes in West Sumatra province.

Today, few communities in Indonesia lack access to electricity, although most of it is generated by polluting coal-fired power plants.

This year the government is preparing a new 10-year energy plan that could see around 70% of an additional 71 gigawatts of new capacity brought online over the next decade powered by renewables.

Indonesia has repeatedly fallen behind neighboring economies’ progress with clean energy. The country of 280 million has similarly failed to meet its own renewable energy goals. If successful, the new target would imply renewables accounting for around a third of the grid by 2035, up from just 12% at present.

Panel show

The collective memory of tragedy among the Indigenous community on Lake Singkarak has complicated efforts to construct the largest field of solar panels in Sumatra to date, a joint venture between Indonesian state-owned electricity utility PLN and Saudi Arabia’s ACWA Power. As with the hydropower plant, the solar installation will also be centered on the lake: It will be a floating solar array generating up to 50 MW.

“This floating solar farm will be a revolution in the development of domestic renewable energy, and we hope that this project will contribute significantly to the development of the renewable energy business in Indonesia,” PLN chief executive Darmawan Prasodjo said in a statement in December 2023.

However, many on Lake Singkarak say they worry construction will eradicate the bilih fish (Mystacoleucus padangensis) that many in the community rely on to sustain their families.

“We will ensure that the presence of the Lake Singkarak Floating PLTS [solar farm] will not interfere with the natural habitat of the bilih fish,” Helmi Kautsar, chief executive of AWCA’s local subsidiary, PT Indo Acwa Tenaga Singkarak, told state news agency Antara.

But the reassurance has so far proved a tough sell in a community that remains antagonistic toward the hydropower plant built more than two decades ago.

“They said it would have no impact,” said Ardinis, who was involved in an environmental audit of the Singkarak hydropower plant. “But that, in fact, was not the case.”

Ardinis said structural leaks had appeared in the tunnel wall, allowing water to accumulate unregulated in the landscape and depriving some rice fields of natural irrigation.

Researchers are increasingly documenting the extent to which land use for low-carbon energy projects is disproportionately affecting the poorest in low- and middle-income countries.

Mongabay’s reporting has documented the extent to which the environmental and health costs of some energy transition projects in Indonesia are already being paid by local communities, from those displaced by a solar factory in Riau Islands province to the pollution threatening the health and livelihoods of those living near nickel mining sites.

“If policymakers do not effectively center human rights in the just energy transition, they may inadvertently cause widespread harm to Indigenous peoples and local communities,” the Columbia Center on Sustainable Investment, a branch of Columbia University in New York, wrote in a 2023 policy briefing.

Sunlight the best disinfectant

Fabby Tumiwa, executive director of the Jakarta-based Institute for Essential Services Reform and a proponent of solar energy development in Indonesia, said the developers should ensure full transparency to help ease minds among the local population in Lake Singkarak.

“Release the Amdal study,” Fabby said, referring to the Indonesian name for an environmental impact assessment. “That way, the community will know what impact the installation of the solar farm will have on the community.”

Solar regulations mean no more than 15% of the lake area can be covered by photovoltaic panels, Fabby added. The Singkarak solar farm plans to use 49 hectares (121 acres) of the lake, which is less than 1% of its surface area.

Andre Rosiade, a parliamentarian from the ruling party who represents West Sumatra, has traveled to the site with officials from PLN to mediate between the utility and local residents.

“I guarantee that every investment in West Sumatra will have to benefit the community,” Andre said as quoted by state media.

However, anecdotal testimony indicates local people remain concerned about risks of damage to the lake ecosystem.

“It’s entirely possible that the endemic aquatic creatures and those that depend on the surrounding areas will be disturbed, or even disappear,” said Beyrra Triasdian, renewable energy lead at Trend Asia, a Jakarta-based civil society organization.

“It will also affect the lives of the Indigenous people in Lake Singkarak, which is a traditional area that has been inhabited for generations and needs protecting.”

Banner image: A small boat on Lake Singkarak. Image by Jaka Hendra Baittri/Mongabay Indonesia.

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This story was first published here in Indonesian on March 1, 2025.