Southeast Asia&rsquo s largest economy, Indonesia, is home to more than 270 million people. Its capital, Jakarta, is one of the fastest sinking megacities in the world. The main reason? People are extracting too much groundwater.

The rate of extraction of groundwater is faster than the rate of recharge, and this has lowered Jakarta&rsquo s foundations. Extracting groundwater is a common practice in Indonesia, with around 50% of Indonesian households still relying on groundwater for consumption (Figure 1). If this continues, parts of Jakarta will be underwater by 2050.