Schematic | Hydrology | Dam/Reservoir | Waterways | Power House | Transmission Lines | Safety

HYDROLOGY

The Project benefits from fifty years of hydrological records and direct flow measurements that have been studied extensively by the Sponsors. The flows of the Nam Theun River have also been measured, either directly or indirectly, since 1950. It was found that an average 7.5 billion m3 of water flows through the Nam Theun each year.

The reservoir capacity is 3.9 billion m3 and, based on the long-term average, could be filled easily in the wet season. Indeed, based on the statistics available, the water flows of the Nam Theun were greater than the reservoir’s total capacity in 49 out of the 50 years since records began, meaning that the water flows of the Nam Theun would have filled the reservoir’s “live capacity” (i.e. the water volume that can be used for generating purposes) in only a year time.

Such statistics provided the Sponsors with sufficient comfort to design and develop the scheme, and to negotiate confidently a long term Power Purchase Agreement. Nevertheless, as the ability of NTPC to supply energy to EGAT depends on, inter alia, hydrological conditions, the PPA has been negotiated to establish a mechanism that stabilises the Company’s cash flow by dampening the effects of hydrological variation from one year to the other

Hydrology Data (PDF file ~78KB)