Wetenschap - 31 oktober 2002

Dam troubles in Kalimantan

Dam troubles in Kalimantan

In the coming years, the Indonesian government plans to build several hydroelectric dams. But protest is rising because of the negative social and environmental consequences. Dr Hermawan Indrabudi found evidence of the problems dams cause in the area close to the Riam Kanan dam in South Kalimantan.

The Riam Kanan dam was built in the river Riam Kanan to create a 9000 hectare reservoir. The hydropower plant provides electricity for people outside the river basin, but the bad news is that the slopes surrounding the reservoir are now suffering from soil erosion. The local people were forced to move to less fertile lands and are still without electricity.

Indrabudi investigated the situation near the reservoir for his PhD research in forest management, and he graduated in Wageningen on 21 October. The idea for his research arose while he was stationed in South Kalimantan as a government official attached to the Ministry of Forestry between 1989 and 1993.

He interviewed the local people in several villages. "To reach the mouth of the reservoir, I used a jeep. I needed a small boat to reach the inner villages, most of which are located close to the tip of the reservoir. The people living there originate from East Sumatra and are far more developed than, for example, the Dayak people in the remote areas of Central Kalimantan, or the local people in the centre of Papua."

The interviews did not paint a positive picture. "The people, mostly farmers, had to move up to lands of poorer quality. Before inundation of the area, they lived on the lower level of the Riam Kanan river bed, which is mostly more fertile than the soil in the sloping areas." The people have moved into a forested and environmentally valuable area. The forests originally stabilise the hillsides and protect them from erosion. But because the new inhabitants have to make a living, they cut down trees to make place for farmland and their cattle. The result is severe surface and gully erosion, degrading the environment even more.

"Erosion and sedimentation are high, mostly because the local people do not practice soil protection such as terracing. The soil quality is marginal, basically because the soil types are infertile and farmers do not use much fertiliser. Moreover, the burning of grassland also decreases the soil quality, as well as hampering the reforestation efforts of the local authorities. Their low education level also contributes to the land use problems."

The authorities are aware that the area is environmentally vulnerable, and have declared it 'Protection Forest', but this clearly has little effect. The river basin cannot be viewed without taking its inhabitants into account. Indrabudi plans to advise the forest authorities in Jakarta to grant the local people formal land rights, so as to make sure they manage their land more carefully. He also identified areas that are not very sensitive to erosion and suitable for agriculture, mainly unoccupied, gentle slopes. Reforestation can then be carried out on the steep slopes. When the forests regrow, it will also lead to a more continuous flow of water down the rivers and into the reservoir, and therefore a more steady supply of hydroelectricity.

Hugo Bouter

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