Restoration and cleaning work at the Kurichhu Hydropower Project was “in full swing”, according to the director of the Department of Energy, Sonam Tshering.  Sonam Tshering told Kuensel that 60 to 70 employees of the Bhutan Power Corporation have begun re-building the 27th transmission tower, three hours walk from Kurichhu downstream, after it was completely destroyed by the flood. The flood washed away the whole foundation of the tower. “The new transmission tower is expected to be completed in three weeks at the earliest,” Sonam Tshering said.  Cleaning operations were also in full progress to remove the silt and logs clogging the tailrace tunnel. The clogging was caused by the breaching of the Tsatichhu lake, about 35 kilometres from the Kurichhu Project, at about 4.20 pm on Saturday, July 10. The first waves of the flood reached the Kurichhu dam at about 6.30 pm. The furious flood, with tonnes of logs and debris, had passed through the dam by 8.00 pm. According to the Kurichhu officials all the deposited silt and logs will have to be flushed out to restart generation.  With the Kurichhu project shut down and the Indian grid not available Mongar, Lhuentse, Trashigang and Trashiyangtse are expected to be without power from Kurichhu project for at least three to four weeks.  Meanwhile, the 1.1 MW Rangjung power plant, which was reinstated on July 13, was shut down at 6.00 am yesterday since the intake area was full of boulders. The plant, however, will start generation today. Trashigang town is expected to get electricity through the Rangjung line. The intake at the Chenary micro plant which started generation last October was completely washed away. So has been the Khaling power house which was flooded on July 10.  Kurichhu has been incurring a daily revenue loss of Nu. 2.5 million since it shut down on July 10.

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Tsatichhu lake bursts, Kurichhu shut down

Kuensel July 11, 2004

Gyalpoishing, Mongar: 11 July 2004 - The Tsatichhu lake, about 35 kilometres from the Kurichu Hydropower Project, burst (breached) at about 4.20 pm on Saturday, July 10, cutting off power supply from the project and causing other damages downstream.  The first waves of the flood reached the Kurichhu dam at about 6.30 pm but, by then, advance warning from a flood warning unit in Ladrong village, opposite Tsatichhu lake, had enabled the Kurichhu project officials to lower the reservoir level to withstand the onslaught of the flood. The furious flood with tonnes of logs and debris, had passed through the dam by 8.00 pm.  While the project authorities are in the process of assessing flood related damages and its effect on the project they have reported that the dam and power house were not damaged by the flood. "At first hand, mostly scouring is evident in the reservoir area and downstream of the power house and these will not affect the operation of the project," said the managing director of Bhutan Power Corporation (BPC), Chhewang Rinzin. "However a lot of silt and logs have been deposited in the tailrace area of the power house and all this would have to be flushed out to restart generation."  The flushing is expected to take some time, depending on the flow in the Kurichhu river.  The flood washed away a transmission tower about 15 kilometres downstream of the Kurichhu project. Other adjacent towers were also bent. Without the towers and the line, the Kurichhu project is now desynchronized from the Indian grid. "BPC is mobilizing its resources to put the line back into operation at the earliest," said the managing director. "But, with the need to construct new towers, it will be a formidable task because all tower/line and construction material will have to be head-loaded." He said that this was further complicated because nearly all the roads in eastern Bhutan were blocked after incessant rain over the past week. It took a minimum of three weeks to construct a new tower and restore the line even under normal conditions. With the Kurichhu project shut down and the Indian grid not available Mongar, Lhuntshi, Trashigang and Trashi Yangsti are expected to be without power from Kurichhu project for at least three to four weeks. Meanwhile BPC's Khaling power house was flooded on July 10 and BPC had to temporarily evacuate its staff from the colony. The intakes of both the Rangjung and Chenari power houses in Trashigang have also been washed away. BPC has also lost a number of its distribution network systems because of landslides in the region.  The mini hydropower plants in Lhuntshi and Mongar are working but, if the rain continues, the scenario could change any day, Chhewang Rinzin told Kuensel.  To add to BPC's woes a number of towers between Pema Gatshel and Deothang had already collapsed after heavy rains last week, cutting off Kurichhu power to Deothang and Samdrup Jongkhar. Efforts to restore the line were being seriously hampered by the continuing rain. BPC has not been able to arrange an alternate power supply from Rangia, India, for Samdrup Jongkhar and Deothang because, according to the Assam State Electricity Board, a number of poles have collapsed between Rangia and Samdrup Jongkhar and ASEB was not able to restore the line because of rain and floods in Assam.  "BPC requests all to bear with the inconveniences," the managing director announced. "We are mobilizing all our resources in all parts of the country to deal with the situation."