S. Sulawesi's Lake Tempe may disappear in 20 years<\/p>\n
Hasanuddin Hamid, Contributor, Makassar, South Sulawesi<\/p>\n
Unchecked deforestation has brought closer to home the threat
\nof Lake Tempe, some 200km northeast of Makassar in Wajo regency,
\ndisappearing in the not-too-distant future.<\/p>\n
The lake's reduced capacity was blamed for the major flooding
\nlast May that claimed eight lives and inundated 15,795 houses and
\n7,669 hectares of rice fields. The worst-hit areas were those
\nalong the lake.<\/p>\n
The flood was the biggest in almost five years, worse than in
\nOctober 1998 when about 10,000 hectares of rice fields ready for
\nharvest, were inundated. No lives were lost then.<\/p>\n
During the 1998 flooding, the water level of the lake was at
\n7.5 meters, but last May, that level rose to 9.5 m. The latest
\nflooding hit the neighboring regencies of Soppeng and Sidrap,
\ncausing considerable material damage and losses.<\/p>\n
Ludvie Achmad, head of the South Sulawesi soil conservation
\nand land rehabilitation center (BRLKT), said the popular lake was
\ndeteriorating due to sedimentation.<\/p>\n
\"If things continue to go unchecked, the lake's disappearance
\nis simply a matter of time,\" he said.<\/p>\n
During the wet season, the lake is about 30,000 hectares in
\narea, but during the dry season it shrinks to half that size.
\nFifty thousand people live around it, with most making a living
\nfrom agriculture and fishing activities, Wajo regent Naharuddin
\nTinulu, said.<\/p>\n
Meanwhile, Ludvie said that a study conducted by the agency he
\nheads had concluded that the Bila and Walanae rivers, which empty
\ninto the lake, carry some 50,000 tons of silt into the lake every
\nyear.<\/p>\n
Soil and garbage make up the sediment that causes the bed of
\nthe lake to rise 5 centimeters to 7 cm annually.<\/p>\n
Nine smaller rivers in five regencies located in the river
\nbasins of the Bila, Walanae and Beloka rivers also contribute in
\nbringing mud into the lake. The lake's water, meanwhile, can
\ndrain only through one river, the Cenranae, which empties into
\nBone Bay.<\/p>\n
\"When there is a heavy rain, the water level in the lake
\nincreases to six or seven meters, causing the lake to overflow.
\nDuring the dry season, the water level of the lake drops to only
\none meter,\" he said.<\/p>\n
Ludvie also said that unless serious measures were taken soon,
\nthe sediment would increase by 10,000 tons a year. Over the past
\ntwo decades, the lake's area has shrunk 900 hectares a year.
\nThis, he said, meant that the whole lake would be covered by
\nsediment in 12 years time.<\/p>\n
He added, however, that the lake could be saved if soil
\nconservation measures were immediately taken. Unfortunately, the
\nhandling of river basins in this area is quite complicated and
\nneeds the cooperation of several agencies.<\/p>\n
The siltation of the lake has not only made the lake shallow
\nin depth and shrink in size, but it has also resulted in a
\nreduction in the diversity of the lake's biota and a decrease in
\nthe fishermen's haul.<\/p>\n
Over the past five years, the lake has generated 5,000 tons to
\n7,000 tons of freshwater fish a year. Two decades ago, the lake
\ncould yield 50,000 tons of fish a year and was the major source
\nof fish for Java, said Tinulu.<\/p>\n
He also said that to save the lake, the Wajo regency
\nadministration and other local administration agencies had
\nconducted a special study on possible dredging and water control.
\nThe result of the study was submitted to the National Development
\nPlanning Board (Bappenas) for fund allocation.<\/p>\n
Meanwhile, the head of the South Sulawesi water control
\nservice, Jantahin, said his office had drawn up a detailed plan
\nfor the construction of a flood control dam, but that they were
\nwaiting for a donor country that could finance the proposed
\nproject, which was estimated to need some Rp 250 billion (about
\nUS$27.7 million).<\/p>\n
This dam, he said, would keep the water of the lake from
\noverflowing and prevent the water level from drastically dropping
\nin the dry season.<\/p>\n
During the dry season, the dam would regulate the lake's water
\nlevel, while during the wet season it would keep the lake's water
\nat a desired level and channel any of the excess into the
\nCenranae River.<\/p>\n
The local office for soil conservation and land rehabilitation
\nhas found it difficult to include forest rehabilitation in the
\nlake's catchment as the community has cleared the areas around
\nthe forest.<\/p>\n
Degradation of the lake has been largely attributed to
\ndeforestation in the upstream areas. Among those responsible is
\nstate-owned plantation company PT Perkebunan Nusantara XIV. The
\nforests have also been badly affected by mining activities.<\/p>\n
Sampe Paembonan, a professor at the School of Forestry at
\nHasanuddin University (Unhas), who is involved in forest
\nconservation in South Sulawesi, said a study conducted by the
\nuniversity concluded that the mining and plantation activities
\nhad left most of the upstream area denuded.<\/p>\n
Research undertaken by the Center for Environmental Studies of
\nUnhas in cooperation with the Institute of Agriculture of Bogor
\n(IPB) sometime ago showed that siltation of the lake had reached
\n5 cm to 7 cm a year. However, Paembonan estimated that the
\nsiltation level could be as high as 20 cm a year.<\/p>\n
He said that immediate action must be taken by allowing the
\nwater to flow into other places. He agreed with a proposal for
\nexpanding the Cenranae's river basin.<\/p>\n
Paembonan attributed the siltation process to two factors: the
\nmovement of the Earth's crust and siltation.<\/p>\n
He said although Lake Limboto in the province of Gorontalo was
\nalso deteriorating and only 2 meters deep at present, Lake Tempe
\nwould undergo more rapid damage unless efforts were immediately
\ntaken to overcome the siltation problem.<\/p>\n
He said to improve maintenance in the future, the local
\ngovernment needs to state the purpose of the lake: is it intended
\nto boost fishery and recreation or agriculture? A clear purpose
\nwould determine how the lake would have to be redeveloped, he
\nsaid.<\/p>\n
To prevent Lake Tempe from drying up, Paembonan advised that
\nthe most important action to take was to establish an
\norganization to oversee management of the lake.<\/p>",
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