Hydrogeology of the coastal region of Jakarta, Indonesia

Rapid urbanization and industrial growth of Jakarta since the 1970s has led to mining of groundwater as surface water supplies are inadequate to meet the municipal and industrial demands. Groundwater withdrawal in the Jakarta area has resulted in changes of the recharge-discharge system. Water levels in deep wells have declined by up to 50 metres since the early 1900s. The geological setting is conducive to groundwater withdrawal-induced subsidence due to natural compaction and surface loading. Surface elevations have declined by up to 100 cm but can not be uniquely related to withdrawals. Prediction of groundwater withdrawal-induced subsidence is hampered by the complex setting, uncertainties in the distribution and withdrawals from wells, the lack of data on geotechnical properties for depths greater than 50 m, and the absence of subsidence measurements. The distribution and concentration of chlorides is due to the geological setting and history and not to classical seawater intrusion.