Spatial Analysis of Groundwater Abstraction and Land Subsidence for Planning the Piped Water Supply in Jakarta, Indonesia

Although the special region of Jakarta Province (DKI Jakarta), Indonesia, has a large population of 10.9 million, piped water coverage remains at only 64%. Therefore, excessive groundwater abstraction has caused serious land subsidence over the last few decades. This study proposed the priority areas for piped water supply extension to alleviate the adverse effects of groundwater over-abstraction in DKI Jakarta. Water consumption and multilayer analyses (e.g., geology, groundwater abstraction, groundwater level, piped water coverage, and groundwater quality) were carried out to determine the priority areas for piped water development. Based on three parameters, namely the water demand-supply gap, land subsidence, and groundwater quality, the northern and western regions of Jakarta were selected as the priority areas for piped water development, followed by the southern and eastern regions. The demand for piped water by the population in the abovementioned priority areas is estimated to be 462,211 m(3)/d, while the total water demand of Jakarta is 1,878,899 m(3)/d, which is greater than the supply capacity of 1,747,440 m(3)/d from the existing water treatment plants. Therefore, the areas for controlled groundwater abstraction were also selected to augment the shortfall of the piped water supply capacity.