Impounding starts at Nam Ngiep 1 Hydropower Project
Nam Ngiep 1 Hydropower Project (NNP1) commenced impounding water in its re-regulation reservoir on 15th May 2017 with electricity generation scheduled to start before the mandated date in early 2019 after all electrical and mechanical installation is completed and the 115 kV transmission line is built by Electricite du Laos.
Impounding is expected to last for 10 days and during this period not less than the prescribed minimum riparian release will allowed to flow downstream with the water level in the reservoir controlled to increase by approximately one metre per day unless a natural rain event upstream causes extreme flood conditions during the expected impounding period.
After completion of impounding the water will have reached the top of the labyrinth weir, 179 m above sea level, and thereafter water will continuously overflow from the re-regulating reservoir with flows proportional to the natural inflow into the river as usual.
Some minimal disturbance to the flow and the water level of the Ngiep River downstream of the re-regulating dam is expected during this short period of impounding.
An impounding ceremony took place on 15th May 2017 at the re-regulation dam in Bolikhan District, Bolikhamxay Province, Lao PDR and was attended by Dr. Kongkeo Xaysongkham, Governor of Bolikhamxay Province, provincial government officials, community members, and the senior management and staff of NNP1.
“I would like to congratulate and thank everyone who has worked tirelessly towards this milestone. This is another remarkable achievement and one step closer to completion of the construction of the NNP1 Project,” said Mr. Yoshihiro Yamabayashi, the Managing Director of Nam Ngiep 1 Power Company Limited.
NNP1 is a hydropower project with an installed capacity of 290 megawatt which is under construction in the Bolikhamxay and Xaysomboun Provinces. The Project consists of the construction of two dams and two powerhouses along the Ngiep River in Bolikhamxay Province, the Lao PDR. It is the smaller of the two dams which have now been completed.
The construction of the Project started in late 2014 and, as the end of April 2017, approximately 68% by value of work was completed, with all critical parts of the works on, or ahead of schedule. The progress is expected to be 90% by value by the end of 2017 and substantial early completion of the construction of the Project is planned by August 2018.
The impounding of the main reservoir is expected to start prior to the rainy season in 2018 after completion of the 167 m high roller-compacted concrete main dam which is the tallest of its kind, both in Laos and in the region.
Other major works, including the construction of the 120 kilometers long 230 kV transmission line from the main dam in Bolikhan District to the Nabong Substation, Vientiane Capital, have made steady progress. The 230 kV supply from NNP1 will be stepped up to 500 kV supply at Nabong, the expansion of which is currently under construction before it is transmitted across the Mekong River as an export to Thailand.
The resettlement of approximately 500 households in both Bolikhamxay and Xaysomboun Provinces is underway, with the first resettlement of one village in Bolikhan District completed in late November 2016. The final overall resettlement is expected to be concluded by the end of 2017.
NNP1 is being built and will be operated by the Nam Ngiep 1 Power Company whose shareholders are Kansai Electric of Japan, EGAT International, and Lao Holding State Enterprise.
The Project expects to begin to generate electricity in late 2018 or early 2019 and approximately 95% of this power will be exported to Thailand, the remainder being used for domestic consumption.
The Project expects to generate more than USD 600 million in direct revenue and other indirect benefits to the Lao Government during its 27-year concession period, after which ownership will be transferred to the Lao Government.
Photo credit by Viennakhone Moonivong
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