YOGYAKARTA, Indonesia - The rapid exploitation of groundwater in Yogyakarta has caused the water table to fall by between 20 and 30 centimeters annually, an official has warned.
Edi Indrajaya, the head of the mineral resources and energy division at the Yogyakarta Provincial Public Works, Housing, Mineral Resources and Energy Agency (PUP-ESDM), said that the phenomenon had begun in 2011.
"This is a warning for us. If this goes on for another 50 years the decreasing groundwater levels could cause land subsidence," he told The Jakarta Post recently.
He said that based on current mapping, the level of water in the underground pockets averaged 100 meters. These pockets were located over 50 meters under the surface.
The increased exploitation of groundwater is in line with the increasing population and economic activity.
The agency said the number of licenses to exploit groundwater issued by the Yogyakarta municipal administration had risen from eight last year to 13 this year.
Edi said that conversion of open spaces in urban areas into high-rise buildings, including large hotels, had also reduced the water catchment area in the region, thus decreasing the volume of rainwater that entered into the underground pockets.
"Big hotel developments need to be limited," he said, adding that the development of a basement of between 10 and 15 meters deep also had the potential of cutting off the groundwater flow that later could influence the water supply in people's wells.
Geologist Eko Teguh Paripurno of the National Development University (UPN), "Veteran", Yogyakarta suggested that residents would have to collect rainwater, for example by digging bio-pore wells, in an effort to conserve ground water.
"Unfortunately, residents are still reluctant to harvest rainwater for this purpose," he said.
Concern over the increase in the number of hotel and mall developments in Yogyakarta has also been expressed by the street-art community as shown by graffiti and posters on the Kewek Bridge.
Taking "Jogja Asat" (Yogya runs out of water) as the theme, local artists painted slogans and posters on the bridge earlier this month criticising the municipal administration.