Wasti Atmodjo, The Jakarta Post, Bedugul, Bali
Climate change, land conversion, deforestation and the unchecked use of ground water are threatening water levels in the Bedugal catchment area, an expert warned recently.
"The local administration must act immediately to protect this precious area.
Conservation, reforestation and firm controls on development are needed very soon," Sandi Adnyana, a soil expert at Udayana University's Center for Environmental Research (PPLH), said last week.
Bedugul is located 60 kilometers north of Denpasar in a hilly, cool area dotted with trees. The area is home to three of the island's four lakes -- Beratan, Buyan and Tamblingan.
These lakes are the primary source of water for human consumption and farm irrigation in the Buleleng, Tabanan and Badung regencies, as well as in Denpasar. Bedugul's beautiful scenery and climate have also made it one of the island's most popular tourist destinations, particularly among domestic visitors. Many of the island's wealthier inhabitants have purchased land there to construct villas and hotels.
"We know that for several years water levels at Buyan Lake have steadily been decreasing. At one point the water level reached two meters," a senior official at the island's Environmental Impacts Management Agency (Bapedalda), AA Sastrawan, said last week. Sastrawan said climate change was one of the primary causes of declining water levels in the area as during the last few years, annual rainfall had been less than average.
Research conducted by PPLH last year concluded there were several reasons for declining water supplies in the area. "Our results suggest climate change, land conversion and the unchecked use of water have played a big role in the decline of water supplies," Sandi said.
PPLH researchers compared data from several time periods to get a clearer picture of the effects of land conversion in the area. "Satellite images and aerial photos show that the size of coffee plantations and primary forests around the two lakes have decreased compared to their size in 1981," Sandi said. "There has been a 87.90 percent decrease in the size of coffee plantations." Sandi said coffee plants, which were the primary crop in the area, had the ability to improve the structure and strength of soil. Coffee plants store water in the rainy season and release it into springs and ground water sources during the dry season, he added. The decreasing size of coffee plantations in the area surrounding Buyan and Tamblingan means that the lakes have lost one of their primary supporting systems.
The images studied by PPLH researches also indicated that man-made structures were increasingly being built, as were farms. "The decrease in water levels is also caused by the unchecked use of ground water by villagers living in close proximity to the lakes," Sandi said.
In Wanagiri village, residents pump water out of the lake for 10 hours straight on any given day. On average they use 72 cubic meters of water each day. Water pumped out of the lake is used for the daily needs of residents as well as meeting the water requirements of several restaurants in the area.
The situation at Tamblingan Lake is much the same. Residents from Gobleg and Pedawa villages pump water from the lake in large quantities to meet their irrigation needs. The combined water consumption of 500 households in the villages was estimated to be as high as 1,250 cubic meters per day. Sandi said there were at least 46 man-made wells surrounding Buyan Lake.
"Another probable cause of these low water levels is that water in the lakes is being drawn out through underground channels, which cause water springs to form in other areas," he said.
He said conservation efforts around the lakes should include large-scale reforestation projects.
"Stop illegal logging, minimize land conversion, reduce the speed of housing development in the area and if possible start cultivating coffee again," he said.
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