Java's coast is sinking, and Indonesia bets $80 billion on a seawall

Indonesia is reviving a giant plan to wall off the sea along the north coast of Java, where the land is sinking and the ocean is swallowing villages. As Nikkei Asia reports, President Prabowo Subianto is pushing an US$80 billion seawall stretching some 500 kilometres, a project that could take 15 to 20 years to build, and Indonesia is reportedly seeking China's help to pay for it.

The need is stark. In one village near Demak, a fisherman named Ahmad Sarif watches the sea cover his land at every high tide. An area that spanned about 400 hectares in the 1980s is now mostly underwater, forcing its roughly 3,300 residents to keep raising their homes on stilts. The north-central coast of Java is sinking by 10 to 20 centimetres a year, among the fastest rates anywhere in the world, made worse by pumping too much groundwater and by rising seas.

A seawall could buy time, but it is hugely expensive and slow to build, and it does not fix the underlying causes. For the people already losing their homes, help cannot come fast enough, while for the government, the cost competes with every other pressing need.

Why it matters

For the millions who live along Java's crowded north coast, sinking land and rising seas threaten homes, farms, and livelihoods within a lifetime. A seawall is a costly bet that may not keep up with the water. Watch whether the project moves forward, who pays for it, and whether the government also tackles the groundwater pumping that makes the sinking worse.