Small lakes latest idea to combat Jakarta's floods

BOGOR, West Java (JP): The latest flood prevention suggestion is to build small lakes in the city, a Bogor expert said.

A. Sjarifuddin Karama, director of Bogor's Land and Agroclimate Research Center, said recently the building of small lakes in Jakarta should be added to flood prevention measures.

Ongoing efforts are replanting or regreening, digging catchment wells and dredging rivers in and around Jakarta.

He said the lakes could not possibly retain all the rainwater, but the run-off could be diverted to rivers.

Sjarifuddin said it was possible to build lakes in crowded Jakarta.

"Jakarta still has 6,000 hectares of paddy fields," he said. Unproductive rice fields could be converted into ponds cultivating fish and the kangkung vegetable. Other vegetables and fruit trees could be planted on surrounding land, he said.

Sjarifuddin said the Land and Agroclimate Research Center had prepared five hectares in Sukapura, Jakarta, to test a pond project.

Small lakes were not expensive to build, he said.

On a 100-hectare plot, the cost should not exceed Rp 2 billion, he said.

"What's more, if we can, we will get local farmers to join us. They will be paid an incentive of Rp 2 million, for instance, to make a small lake. Maybe we can keep total costs at Rp 1 billion," he said.

Sjarifuddin said he tried a similar project on five hectares, which cost less than Rp 6 million.

Small lakes could be dug manually without heavy construction equipment and the lakes would not need complicated maintenance, he said.

He suggested the lakes be 200 square meters wide, with a depth of three to four meters. Sjarifuddin could not say how many lakes should be built.

Earlier Siswoko, an official in charge of a river improvement project under the Ministry of Public Works, said the city's flood control measures were unable to keep up with unchecked construction activity along river basin areas in West Java.

He said construction may not be avoidable, given the need for more houses, but developers should observe environmental regulations. These include checking sites to see whether they were likely to flood, retaining and creating water catchment sites including lakes.

Siswoko's office of the Ciliwung-Cisadane river improvement project, is also in charge of rehabilitating lakes in Jakarta's surrounding areas. He said around 70 percent of lakes have been lost to construction works or neglect, with former lakes being covered by plants or waste.

Sjarifuddin said 221 lakes were built by the Dutch colonial government in the 19th century because a large section of the city was lowland and vulnerable to floods.

Lakes were built in Cisarua, Ciawi, Bogor, and Depok, and even in the heart of Jakarta. After they were built, floods decreased for a long time, Sjarifuddin said.

Members of the Jakarta city council earlier quoted 1994 figures on the decreasing lake area around the city, though they did not mention the specific time frame.

The Indonesian Democratic Party faction said lakes in Bogor, Tangerang and Bekasi reduced drastically from 2,049 hectares to 1,294 hectares in the last six years.

The faction supported earlier suggestions from former environment minister Emil Salim, that Jabotabek -- Jakarta, Bogor, Tangerang and Bekasi, should be grouped under one authority to ensure an integrated development plan.

A land and water conservation expert, Oteng Haridjaya, at the Bogor Agriculture Institute, also supported the idea.

He said from 1981 to 1990, 4,353 hectares of forest around Bogor was cut down to 3,361 hectares, enlarging the residential area from 770 hectares to 2,008 hectares.

"We got the information in 1990. Construction proceeded rapidly from 1990," Oteng said.

Data from the Forestry Services and the Bogor Land Conservation, revealed more than 19,000 hectares around the upstream areas of the Ciliwung, Cisadane, Cidurian and the Bekasi rivers, were in a critical condition, Oteng said. (24)