Nam Theun 2 HydroelectricWater engineering innovative hydropower design

Nam Theun 2 is a 1,086 MW hydropower project located in Khammouane Province, PDR Lao. The project was a trans-basin scheme, diverting water from the Nam Theun River catchment into the Xe Bang FaI River system, producing 348 m of net head to drive the generating units.

Aurecon was engaged to undertake tender, preliminary and detailed design and documentation of the downstream channel works for the Nam Theun 2 Hydropower Project. 

Wide range of services provided

Aurecon provided the following services:

• Assessment of the hydraulic performance of the channel using Manning’s equation and HEC-RAS models
• Design of riprap and gabion mattress channel linings to prevent scour in high gradient/velocity sections of the channel
• Assessment and design of protection works required to prevent scouring at two junctions where natural streams merge with the artificial channel
• Design of control weir structures to regulate velocities in the open channel to acceptable levels, thus preventing scour along the channel
• Assessment and design of an aeration weir intended to aerate water discharged from the regulating dam, thereby maintaining water quality
• Tunnel analysis and design of the associated energy dissipation structure, including a weir and hydraulic jump dissipation basin
• Design of a diversion waterway, including stepped cascade and culvert structures, to divert a natural waterway beneath the regulating dam discharge channel
• Design of an inverted siphon to convey flow in the channel underneath a natural river
• Design of local drainage and irrigation infrastructure, including side drains, culverts, inverted siphons, and irrigation water outlets