Indonesia's Dry Season Deepens Into Water Crisis as El Niño and Indian Ocean Dipole Combine

Friday, 4 September 2026

More than 7,100 households across Central Java, Yogyakarta, West Java and Maluku are now relying on emergency water deliveries as Indonesia's 2026 dry season, already forecast to be drier than the 30-year norm, peaks in the final weeks of August and September. Indonesia's meteorology agency, BMKG, has warned that El Niño conditions could persist into early 2027 and may strengthen further, while a positive Indian Ocean Dipole (IOD) event is expected to develop between September and December, a combination likely to deepen dry conditions across more than 80 percent of the archipelago.

Java, Bali and the Nusa Tenggara islands are considered especially vulnerable because of their sharply defined monsoonal seasons, which leave little buffer when rains arrive late. Districts including Cilacap, Klaten and Bantul have already reported clean water shortages, and crop failures are mounting as the dry season drags on, threatening food security in a country where a large share of the population depends on rain-fed and groundwater-supplied agriculture.

The Indonesian crisis is unfolding against a broader backdrop of water stress across South Asia. According to hydrological research covering the transboundary Indo-Gangetic Basin, India, Pakistan, Bangladesh and Nepal collectively withdraw more groundwater than any other region on Earth, with the basin accounting for roughly a quarter of global groundwater extraction. Around 69 percent of that extracted water goes to agriculture, and South Asia depends on groundwater for about 57 percent of its irrigated land. Satellite gravity measurements from NASA's GRACE mission have shown measurable declines in groundwater storage across northwest India, central Pakistan and southern Bangladesh, with some Bangladeshi districts recording annual declines of up to 12.5 millimeters. Researchers describe what was once considered drought insurance for farmers as having become a structural vulnerability in its own right.

The Asian Infrastructure Investment Bank has also pushed the issue up the regional agenda this year, arguing in its flagship Asian Infrastructure Finance report that the water cycle itself should be treated as critical infrastructure requiring sustained investment and stronger governance, rather than simply a resource to be extracted or a hazard to be managed after the fact. The bank points to chronic underinvestment and fragmented governance as key reasons the region's water systems are struggling to keep pace with climate volatility.

For now, the most immediate pressure point remains Indonesia, where local governments are trucking in emergency supplies while forecasters watch for signs of how strong this year's IOD event will become. Aid agencies and disaster-response officials say the coming weeks, as the dry season reaches its height, will determine how many additional communities need direct water assistance before rains are expected to return toward the end of the year.