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ince 2000, groundwater levels in Yogyakarta province have dropped by an average 30 centimeters a year because of climate change, Gadjah Mada University hydro-geologist Heru Hendrayana says.

Speaking at a discussion on groundwater resources here on Thursday, Heru said there was a common misunderstanding among the local community who often associated water scarcities with uncontrolled usage of water resources.

"But it's not *caused by that*. It has more to do with prolonged droughts caused by climate change. This *kind of change* is affecting the whole world," said Heru, who is also an expert on groundwater resource management.

The phenomenon, he said, had been affecting Yogyakarta since late 1999 and the beginning of 2000. The depth of the water table in the province varied between four centimeters below ground in southern parts, to 25 centimeters below ground in the north.

The phenomenon, Heru said, had caused water surface levels in open wells to drop, adding that making the wells deeper and deeper would not stop the problem.

"This is just a temporary solution," Heru said.

Helping rainwater to get back into the soil was a better way to reverse the trend, he said.

Despite the groundwater surface level dropping, Yogyakarta has relatively secure water resources in terms of quantity, because it has one of the biggest groundwater shale in the country, Heru said.

In terms of the impacts of sand mining on the groundwater resources in the region, Heru said as long as reclamation and conservation measures were carried out by mining operations, they would not have severe impacts on groundwater.

"I just want to say that not all sand mining activities on the slopes of Mt. Merapi have negative impacts on the environment. Some former mining sites are even better after being restored following a sand mining," he said.

"What should be more of a concern is illegal sand mining operations, which there are many of on the slopes from Boyolali *Central Java* to Sleman *Yogyakarta*," he added.

Such illegal mining, he added, usually had detrimental impacts on the environment, because once they had finished in one area they would usually just abandon it.

"In this case, it is law enforcement that is important," he said.

On a national scale, Indonesia is regarded as having no problem with groundwater resources in terms of quantity, Heru said. However, in terms of quality, it was concerning that this had continued to decline for various reasons over the last few years, he said.

"To deal with this problem we need integrated programs involving all stakeholders," Heru said, welcoming several corporate social responsibility (CSR) programs aiming to address the problem.

Another speaker at the discussion, CSR coordinator Fainta Susilo Negoro, of drinking water company PT Aqua Danone Indonesia, said an integrated social responsibility program focussing on the Sigedang spring in Klaten, Central Java, had successfully controlling water loss in the region to less than 10 percent for the last three years.