Nam Sam 3 (Nam Xam 3) Dam Hydropower Info by Hobo Maps - Go to Hydropower Projects Page - - Home

Nam Sam 3 project is sometimes spelled Nam Xam 3 and Nam Sum 3 in the past. Nam Sam is pronounced "Nam Sahm".

The project is located in rural Xam Tai District, Houaphan Province, Lao PDR. It is southeast of the towns Sam Neua and Vieng Xay and south of National Road 6 not far from the border with Vietnam. The dam structure site is close to Pieng Salua village.

Nam Sam 3 project location on satellite image below:

Nam Sam 3 and 3A project locations both shown on satellite image map below:

Nam Sam 3 and 3A project locations both shown on topographic map below:

The project has a total investment of more than $300 million USD by Nam Sam 3 Power Co., Ltd. which is 100% owner – an affiliate of Phongsubthavy Group.

The project started in October 2019 with SCI E&C JSC Company (a part of the SCI JSC Group in Vietnam) as Engineering, Procurement and Construction contractor.

The project is under construction in 2023 and is hoped to become operational soon.

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 for 12 km long water conduit:

Nam Sam 3 dam site construction images below at coordinates 20°09'00.9"N 104°30'38.3"E (20.150237, 104.510650).

Nam Sam 3 power plant site construction images below at coordinates 20°04'49.1"N 104°33'49.3"E (20.080311, 104.563695)

The main dam of Nam Sam 3 is constructed by SCI Group using RCC advanced roller compacted concrete technology. The main dam height is 121.7 meters with the crest length of 321.4 meters. The elevation of the main dam is about 518 meters above mean sea level.

Nam Sam 3 dam construction images below:

Concept images of what Nam Sam 3 project may look like below:


Nam Sam 3 is one of 11 hydro plants being developed by the Phongsubthavy Group in Lao PDR on the Nam Mo (river) and its tributaries. Tha Nam Mo in turn is a main tributary of the Ca river in Vietnam. The source of the Nam Mo is in Laos and it flows eastward into Vietnam with much of the left bank of the upper Nam Mo within Laos territory in Xiang Khouang Province.

Construction work began in October 2019 and in November 2021 around 16 per cent of the project’s Roller-Compacted Concrete (RCC) dam structure had been completed. In March 2022 another report by SCI Group indicated they are working around the clock 24/7 to push construction progress as fast as possible to complete the project by June 2023.

Voith Hydro has the main contract to supply complete electromechanical equipment for the Nam Sam 3 hydropower plant. Voith Hydro will supply three 52 MW Francis vertical turbine units as well as provide technical services for supervision, installation and commissioning.

India-based Generators and Motors Ltd. (GIM) signed a sub-contract in October 2021 for the design, production, factory testing and transport of three Francis vertical generators for the Nam Sam 3 project including associated excitation and monitoring systems.

Statistics for Nam Sam 3 project below:

Catchment area – 2,520 sq 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 construction site images below with most showing progress as of 2023:

Nam Sam 3 construction site images below with most showing progress as of early 2022:

On June 24, 2019, Phongsubthavy Group signed a Power Purchase Agreement with EVN (Electricity of Viet Nam) for offtake of the Nam Sam 3 hydropower project output.

The project will be connected to Vietnam's electricity system transmission grid at the 220 kV Nong Cong Station (Thanh Hoa Province, Vietnam)

Export Transmission Lines for Nam Sam 1A & 3 hydropower projects shown in map below on upper right side. See enlarged version HERE.