Nam Mo 2 Dam Hydropower by Hobo Maps - Go to Hydropower Projects Page - - - HOME

The Nam Mo (river) originates in eastern Xieng Khouang province Laos and flows in a circular manner to the Vietnam-Laos border where it continues along the border line for a while before flowing eastward into Vietnam.

On the Laos side, the Nam Mo 1 and Nam Mo 2 hydropower projects are in development while a different and completed Nam Mo 1 project exists on the Vietnam side so there are two hydropower projects with the same name of Nam Mo 1 on the same river.

This web page concerns the Nam Mo 2 hydropower project on the Laos side. We have a separate web page for the Nam Mo 1 dam on the Lao side HERE.

Nam Mo 2 dam and reservoir concept image below:

The governments of Vietnam and Lao PDR have an agreement to develop hydropower projects on the Nam Mo (river) which is a main tributary of the Ca River in Vietnam. The Nam Mo begins in Laos and flows eastward into Vietnam with much of the left bank of upper Nam Mo within Laos territory in Xiang Khoang Province.

A Nam Mo hydropower project has been completed further down the Nam Mo in Vietnam and both Lao PDR and Vietnam want to construct other hydropower projects on the upper Nam Mo. An agreement between the two Governments in 2016 sets forth the cooperation of the two countries to develop Nam Mo hydropower projects in both countries.

Nam Mo 2 hydropower project is located on the Nam Mo (river) near Ban Houay Soi, Muong Moc (Mok) district, Xieng Khouang province, Lao PDR. The damsite location is about 70 km upstream of where the Nam Mo river meets the Vietnam-Laos border. The project area is located on highlands with elevation ranging from 500 meters to 1,300 meters above sea level.

The lead developer of the Nam Mo Hydropower projects in Laos is Lao-based Phongsupthavy Group. The plan is for some or all of this output to be exported to Vietnam as there is a MOU cooperation agreement with the government of Vietnam signed in 2021.

The locations of the Nam Mo 1 & 2 hydropower projects are shown in image below:

Nam Mo 2 plant below is at coordinates 19°02'28.4"N 103°59'60.0"E (19.041222, 103.999998).

Nam Mo 2 powerhouse is to have either 3 Pelton vertical turbine-generator sets of 40 MW each for total installed capacity of 120 MW or two sets at 60 MW each for 120 MW total. Annual output may come up to 484 GWh.

The Project in early stages involved China-based companies planning to do most of the work. Dongfang Electric Corporation was the original engineering, procurement and construction contractor while Sinohydro Bureau 10 Co. Ltd. was the original subcontractor for the CW1 section. Not sure what happened but they seem to have been replaced by Lao and Vietnamese companies. In 2023 these two companies are no longer involved with the project.

The construction project was initially estimated to take 3.5 years. The project began in October 2015 and was scheduled for completion in January 2019 but due to the pandemic and contractor changes the project will take much longer to complete. In 2024 there appears to be good construction progress.

The Nam Mo 2 hydropower project is now a joint venture between Phongsubthavy Road And Bridge Construction Co., Ltd. (37%), Nam Mo Company of Vietnam (23%), Duangchaleun Group Company (21%), Dong Tanh Trade Company of Vietnam (14%) and Sengchanh Construction Company (5%).

The Nam Mo 2 power plant will have approximate capital investment of US $240 million. In December 2015, Vietnam Bank for Investment and Development (BIDV) signed a loan agreement of US$152 million to partially fund the project.

The project will operate under a 27 year concession period starting from the Commercial Operation Date.

Location of Nam Mo 2 hydropower project shown in image below:

Vietnam-based SCI Joint Stock Company has been chosen as the EPC Contractor under a contract with validity from August 2023. Immediately after signing the contract SCI completed surveys and prepared technical designs which were approved by the Lao government according to Document No. 1157/MEM/DESM dated 28/11/2023.

Nam Mo 2 construction images below:

Info below copied from SCI website Jan. 2024 at - https://www.scigroup.vn/en/nam-mo-2-hydropower-project-sticking-to-the-scheduled-plan

After 4 months of implementation, SCI completed auxiliary works and prepared for construction site, including:
   + Crushing plants, Conventional Mass Concrete mixing plants
   + Completion of power lines for construction, construction roads, storage yard of materials for dam embarkment 
   + Completion of camp site for employees that supply accommodation for more than 600 persons
   + And other auxiliary works, to ensure main construction works are being carried out at the construction site.
Especially ensuring to serve diversion work of Phase 1, the project has launched “60 days and nights campaign”, which has so far achieved the remarkable results as follows:
   + Excavation work of main dam foundation has been completed 152.890m3/208.456m3 of soil and rock, reaching 73%.
   + Excavation work of spillway foundation pit, scoured pit, and downstream of spillway has been completed reaching 74%.
   + Diversion tunnel: Upstream slope protection for diversion tunnel has been completed by 78%, reinforcement work of diversion tunnel is reaching 46%.
   + Intake: The slope protection of phase 1 of intake is being constructed with final concrete blocks, currently completed by 92%.
   + Tunnel Face No.1: Completion of concreting tunnel inlet. Excavation work for Tunnel Face No.1 has been implemented since 20/12/2023.
   + Adit tunnel: Reached chainage of Km0+355m, reaching 27% of the design volume. Sticking to the scheduled plan.
   + Powerhouse: Completed by 89% of excavation progress of foundation pit.
   + Tailrace channel: Phase 1 of excavation of foundation pit for tailrace channel has been completed by 50%
In the first quarter of 2024 SCI is confident to stick to the proposed plan.

March 2024 progress report image below from SCI website:

Location of Nam Mo 2 hydropower site and construction camp is shown in image below:

Mekong Investment Holding JSC. (MIH) entered into an agreement with GE Hydro France for Electro-mechanical Equipment and Technical Services for the Nam Mo 2 Hydropower Plant. The Signing Ceremony took place on 22th December 2021 in Hanoi, Vietnam.

The project has a high head of about 750 meters.

Nam Mo 1 & 2 project terrain map below shows estimated locations and sites including a tunnel that may direct water from the Nam Mo 2 reservoir down to the Nam 2 powerhouse but the location has not been verified by us yet.

Images below from Nam Mo 2 SCI project site uploaded to the web Dec. 2023:

See a concept planning video for Nam Mo 2 hydropower HERE. This video shows the various construction phases of the hydropower project and a few screenshot images are shown below. Since the video uses a perspective view (airplane-window view) the video isn't useful for visualizing precise locations of the project components.

The video begins by showing a temporary diversion tunnel 265 meters long that will only be used during construction to divert the Nam Mo river water away from the dam structure construction site. A free-fall style spillway is later shown overlaying this tunnel at a higher elevation close to the reservoir surface. This spillway is to be 48 meters wide and have a 40 meter by 60 meter chute as shown below.

The main earth-filled dam structure will be 51.5 meters high and 136.7 meters long.

The catchment area of the projet in the video is reported to be only 61.4 square kilometers.

The Nam Mo 2 reservoir is also reported to be rather small with only 80 million cubic meter capacity as shown below.

Somewhere in the reservoir there will be an intake structure as shown below.

From the intake structure water will flow in an underground headrace tunnel (3.4 meters by 3.7 meters interior diameter) for 4,087 meters to the surge tank location. The water will then drop straight down a vertical tunnel (2.4 meter diameter) for 241 meters and then continue horizontally in the same direction as the headrace tunnel was going for 1,419 meters in a non-lined penstock (4 meters by 4 meters diameter) to the powerhouse.

The total distance between the intake structure and the powerhouse would thus be 4,087 plus 1,419 = 5,506 meters.

At the powerhouse the water flow is split equally into 3 tubes to the 3 Pelton vertical turbines (40 MW each) giving the project 120 MW capacity in total.

The powerhouse building dimensions are to be 28 meters by 65 meters as shown below.

The Nam Mo 2 plant site shown below also contains other buildings and an outdoor switchyard.

Images below from Nam Mo 2 project construction site in 2021:

Nam Mo 2 project office building in Vientiane below:

Nam Mo 2 project office building location in Vientiane below on our Hobo Map:

Phongsubthavy Group is active in other hydropower projects in northern Laos and in 2020 and 2021 entered into various Memorandums of Understandings (MOUs) with Electricity of Vietnam (EVN) agreeing to offtake the output as purchaser.

Nam Mo 2 hydropower project is one of 11 hydropower plants being developed by Phongsubthavy Group to sell electricity to Vietnam through a 79 km 220kV transmission line Nam Mo - Tuong Duong (Nghe An) invested by Phongsubthavy Group for the section in Laos and Electricity of Viet Nam for the section in Vietnam. The transmission line was originally scheduled for completion in 2022. See images below.

Nam Mo 2 connects to transmission line for export to Vietnam in map below. See enlarged version HERE.