Dam & Reservoir

The Project reservoir has inundated 40% of the Nakai Plateau by creating a shallow reservoir (on average 7 m deep) with a surface area of 450 km2 at full supply level. This will reduce in size to a surface area of a little as 70 km2 at the end of the dry season.

The reservoir has been formed by construction of a 39-m high gravity dam with a crest length of 325 m across the Nam Theun, plus 13 small earthwork saddle dams along the west bank of the reservoir. A spillway and stilling basin have been specially designed for the purpose of reservoir level control.