The drought caused by El Niño has revealed the ruins of homes and a mosque years after their inhabitants were relocated due to the construction of the dam. Credit: Image Generated with AI
A prolonged drought has lowered water levels at Indonesia’s Karian Reservoir on the island of Java, about 100 kilometers (62 miles) southwest of Jakarta, exposing the remains of Somang, a village submerged during construction of the Karian Dam in Banten province. Homes, roads, foundations, and a mosque have reappeared as the reservoir receded in 2026.
The resurfacing is linked to declining reservoir levels during Indonesia’s dry season. Indonesia’s Meteorology, Climatology, and Geophysical Agency (BMKG) reported in July that El Niño had become active, and warned that the phenomenon could contribute to drier conditions. The event has renewed attention on climate change, although the available evidence does not establish that global warming caused this specific drought.
How Somang disappeared beneath the Karian Dam
Before the construction of Indonesia’s Karian Dam, Somang existed as a populated village in Banten’s Lebak Regency. The project aimed to increase water supplies, support irrigation and help control flooding across parts of Banten, Jakarta and West Java.
Construction began in 2015. The reservoir was designed to hold about 314.7 million cubic meters (11.1 billion cubic feet) of water and cover roughly 1,740 hectares (4,300 acres).
Indonesia designed Karian as a multipurpose water system. The reservoir can support irrigation for about 22,000 hectares (54,400 acres) of farmland and provide raw water to communities in surrounding areas.
Residents of Somang were relocated to new settlements before the reservoir became operational in 2023. The project became operational in 2023. President Joko Widodo officially inaugurated the completed dam on Jan. 8, 2024.
Indonesia’s submerged village has a parallel in Colombia. In 1967, authorities flooded the old town of Guatavita in Cundinamarca to create the Tomine Reservoir, relocating the population to a new town built nearby. The original settlement remains beneath the reservoir today.
El Niño drought exposes the submerged settlement
Parts of Somang became visible as the reservoir level fell during the 2026 dry season. Images from the exposed area show foundations, houses, roads and a mosque.
BMKG reported in July that El Niño had become active and could contribute to a prolonged dry season. The agency highlighted August as the peak of the dry season across much of Indonesia.
El Niño is a natural climate pattern involving changes in ocean temperatures and atmospheric circulation in the tropical Pacific. It can disrupt rainfall patterns across Indonesia, significantly increasing the risk of drought.
Indonesia’s Cidanau Ciujung Cidurian River Basin Authority said the reservoir had fallen about 80 centimeters (31.5 inches) below its normal level, reducing its volume by roughly 5 percent. The authority said the reservoir remained within safe operating levels.
The water shortage is also affecting nearby communities. Local reports said residents have used the exposed reservoir area for bathing, washing and sanitation as household water supplies have come under pressure. Visitors and anglers have also been drawn to the exposed settlement.
The available evidence links the resurfacing to reduced water levels during dry conditions. It does not establish that climate change caused the specific drought.
Climate change remains relevant to the broader water-supply question because changing rainfall patterns can affect reservoirs and other infrastructure designed to provide water during dry periods.
The Asian Infrastructure Investment Bank is considering a US$120 million project connected to the Karian Dam and Serpong Water Conveyance System. The proposed project would expand raw-water supply capacity across Jakarta, West Java, and Banten.
Karian Dam construction timeline
2015: Construction of the Karian Dam began in Lebak Regency, Banten.
2015–2023: The project transformed the area around Somang into a reservoir, requiring residents to relocate.
2023: The reservoir became operational, and water covered the former village.
Jan. 8, 2024: President Joko Widodo officially inaugurated the completed dam.
July 2026: Falling water levels exposed parts of Somang, including residential structures and a mosque.
For now, the exposed ruins of Somang remain a visible marker of the reservoir’s declining water level, drawing visitors even as dry conditions strain nearby water supplies. BMKG’s seasonal forecasts will determine how long the current dry conditions persist.