Yogyakarta (ANTARA News) - Japan will help Jakarta in dealing with land subsidence that has been reaching 18 centimeters per year, and is suspected to be the main cause of annual flooding.

"We have conveyed this idea to the Indonesian Ministry of Public Works and are preparing a grand plan to normalize the ground level in Jakarta," Water Resources Policy Advisor to the Ministry of Public Works of Japanese donor agency JICA, Kunihiro Moriyasu, said here on Wednesday.

According to Moriyasu, the main cause of land subsidence in Jakarta is the excessive use of ground water by industries and households.

With good management of groundwater usage, Moriyasu said the land subsidence, which causes flooding and is estimated to result in 10 percent of Jakartas area being submerged due to sea water by 2100, will stop.

"We have experienced similar subsidence phenomenon in Japan. In the period between 1920 to 1970, the ground surface in Tokyo dropped by 4 meters due to excessive groundwater use," Moriyasu remarked.

At that time, Tokyo city administration made arrangements for alternative water supply, either through sewage treatment or normalization of rivers, constructing dams and taking a number of other measures.

The administration also rearranged the entire city by relocating some of the industries to other cities to reduce the demand for water.

"As alternative water supply became reliable, we prohibited residents and businesses to dig wells or use groundwater. These measures helped in successfully restoring the ground level in Tokyo to its original condition," Moriyasu said.

However, Moriyasu said despite the fact that these measures were a success in Japan, these cannot necessarily be applied in Jakarta and any steps will have to be such that these can adapt to the local culture.

Construction and Disaster Management attache of the embassy of Japan to Indonesia Hisayuki Yokota said reduced water usage can complement the efforts of the Jakarta administration in stemming the rise in sea level by building a Giant Sea Wall in the sea north of Jakarta.(*)

Editor: Heru Purwanto
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