Nam Sam 3 (Nam Xam 3) Dam Hydropower Info by Hobo Maps - Go to Hydropower Projects Page - - Home
Nam Sam 3 project is pronounced "Nam Sahm" and is sometimes spelled Nam Xam 3 and Nam Sum 3.
The project is located in rural Xam Tai District, Houaphan Province, Lao PDR, southeast of the towns Sam Neua and Vieng Xay and south of National Road 6 not far from the border with Vietnam. The site is near Pieng Salua village.
Nam Sam 3 dam site images below:
Nam Sam 3 project location on satellite images below at coordinates 20°09'00.9"N 104°30'38.3"E (20.150237, 104.510650) - along with Nam Sam 1A & Nam Sam 3A locations:
Nam Sam 3 is one of 11 hydropower plants being developed by the Phongsupthavy Group in Lao PDR on the Nam Mo (river) which in turn is a main tributary of the Ca river in Vietnam.
Investment was provided by the project owner Nam Sam 3 Power Sole Co., Ltd., an affiliate of Phongsupthavy Group.
Construction started in October 2019 with SCI E&C JSC Company (a part of the SCI JSC Group in Vietnam) as Engineering, Procurement and Construction (EPC) contractor.
The project completed construction in 2024 and became commercially operational on February 5, 2025.
Nam Sam 3 powerhouse & switchyard images below at coordinates 20°04'49.1"N 104°33'49.3"E (20.080311, 104.563695)
Switchyard image below:
Nam Sam 3 main dam is roller compacted concrete type (RCC) with a height of 121.7 meters and a crest length of 321.4 meters.
The project includes a 9.1 km-long main tunnel with a 225 meter-high surge tank.
The project has a total capacity of 156 MW and may provide up to 626 GWh output per year.
Nam Sam 3 hydropower project layout below shows estimated route of main underground tunnel by direct line.
Nam Sam 3 controls and generator images below.
Voith Hydro has the main contract to supply complete electro-mechanical equipment for the project with three 52 MW Francis vertical turbine units as well as technical supervision, installation and commissioning services.
Nam Sam 3 site image below:
Surge tower image below:
Nam Sam 3 Project Management facility location is seen in image below north of the powerhouse site.
Nam Sam 3 dam construction site image below around year 2024:
Statistics for Nam Sam 3 project below:
Catchment area - 2,520 square km
Reservoir full supply level- 595 meters above sea level
Reservoir minimum operating level - 560 meters above sea level
Reservoir gross storage - 443 million cubic meters
Reservoir active storage - 283 million cubic meters
Reservoir minimum operating storage - 160 million cubic meters
Net head - 206 meters
Installed capacity- 156 MW
Annual output capacity - 626 GWh
Nam Sam 3 image below shows water release event in July 2024 when the reservoir impoundment was up to full capacity.
Nam Sam 3 tunnel construction images below with most showing progress as of year 2023:
Nam Sam 3 and 3A project locations both shown on old topographic map below:
Concept image of what Nam Sam 3 power plant area is planned to look like below:
On June 24, 2019, Phongsupthavy Group signed a Power Purchase Agreement with EVN (Electricity of Viet Nam) for offtake and export of the Nam Sam 3 hydropower project output.
The project is to be connected to Vietnam's electricity system transmission grid at the 220 kV Nong Cong Station (Thanh Hoa Province, Vietnam).
On December 21, 2024, the Vietnamese National Power Transmission Corporation announced the successful completion and energizing of the 220 kV Nam Sam-Nong Cong transmission line project within Vietnam. This line is for export of power to Vietnam from the Nam Sam area hydropower cluster which may include output from Nam Sam 1A, Nam Sam 3, Nam Sam 3A, Nam Neun 1 & 3, Nam Peun & the 6 dams of the Nam Yeuang cascade.
Export Transmission Lines for Nam Sam 1A & 3 hydropower projects shown in map below on upper right side. See enlarged version HERE.
