Nam Song Diversion Dam info by Hobo Maps- Go to Hydropower Projects Page - - Home
The Nam Song Diversion project is owned by EDL GEN and was funded by the Asian Development Bank (ADB) at a cost of US$ 31.5 million. It was designed to divert water into the Nam Ngum reservoir to increase the generating capacity of the existing Nam Ngum 1 Dam hydropower station. It also has a small power station of its own located on the diversion canal.
The project is located in Vang Vieng District of Vientiane Province, Lao PDR.
Nam Song Diversion powerhouse image below at coordinates - 18°48'16.0"N 102°27'26.8"E (18.804452, 102.457448):
Nam Song Diversion weir/dam image below at coordinates - 18°47'55.4"N 102°25'37.9"E (18.798712, 102.427183)
Satellite image below shows the Nam Song river dam weir on upper left side while the powerhouse is upper center. The diversion canal continues on the right side until crossing underneath Highway 13 where the waters enter the upper part of Nam Ngum Reservoir.
The project has an installed capacity of 6 MW and generates about 13.2 GWh of electricity annually. The energy generated from Nam Song Hydropower Plant is sent to the 22 kv EDL system. The project was fully completed in 2012.
The Nam Song Diversion project is a run-of-river style hydroelectric project. It has a 21 meter high weir dam that creates a head pond to raise the water level behind the dam so it can feed into a new diversion canal. A small power station generates electricity further down the diversion canal. From there the water flows under Highway 13 into the far northwest part of Nam Ngum Reservoir.
A minimum flow of 2 cubic meters per second is continuously allowed to spill over the weir dam so the original Nam Song river channel always has a flow downstream of the weir.
This project is designed to divert water flows into the Nam Ngum Reservoir to increase the power generating capacity of the existing Nam Ngum 1 power station. The Nam Song & Nam Leuk HPP diversions are planned as inexpensive ways to generate additional clean and green electricity.
was the main contractor for the project.
The project was funded by the Asian Development Bank (ADB) at a cost of US$ 31.5 million and was completed in 1996.
Nam Song Diversion view image below:
Nam Song Diversion project map below:
Nam Song diversion shown in basin map below:
Nam Song Dam image below:
Nam Song forebay images below:
Nam Song Diversion project statistics below:
Nam Song Diversion works summary below from 1997 ADB report after completion.
The diversion scheme consists of :
(i) a 2.5 kilometer (km) canal across the low ridge between the Nam Song valley and the Nam Ngum reservoir;
(ii) 3 regulating/control/drop structures along the canal;
(iii) a concrete and earthfill dam, 21 meters high, on the Nam Song to raise the headpond water level to that of the canal;
(iv) power supplies to the dam and gate control structure; and
(v) access roads to all the structures.
The diversion is designed for a maximum flow of 210 cubic meters per second with an estimated average flow of 65 cubic meters per second.
A minimum flow of 2 cubic meters per second is designed to be maintained on the existing riverbed past the Nam Song dam for downstream users. The Nam Ken river, a significant tributary, enters the Nam Song about 800 meters downstream of the dam.
Nam Song Diversion project location shown on middle left side of map below:
Road to Nam Song Hydropower Plant starts from Highway 13 near the km 122 marker as shown below. The road is paved at first but not sure if the entire distance is paved.
