Technical doubts
• Over 60 per cent of the catchment area of the Arun river falls in Tibet; little is known about the hydrological behaviour of the river in this part.
• inadequate study of the discharge pattern of the Arun river. critics say that the data collected does not go back more than 10 years, which is insufficient.
• Some studies have predicted that the Lower Barun glacial lake, located above the project site, can burst, causing a flood which would wipe out all the invest- ment on the project.
• Inadequate seismic study of the area.
• For a run-of-the-river project, a 68 m high concrete gravity dam is too big.
• The project envisages an 11 km tunnel. In some stretches the tunnel goes through an overburden of 1,506 m. Chances of coming across hydraulic columns are high in. such a case, which can leave the engineers with no option but to abandon the tunnel and try another one. This Is bound to throw the cost calculations haywire.
• The 2 stages of the project envisage 2 separate tunnels, which is highly cost-ineffective. One large tunnel would have served the purpose, besides bringing down the costs as well.
• The desanding basins are underground; needlessly. Critics say that extravagance like this In design and conception has led to the high costs of the project. • The Ist phase can generate as much as 270 mw power, but has been designed for only 201 mw. This is sub-optimal utilisation of the resources.
• The selection of the turbines has not been transparent.
• The permitted slope and the curvature width of the access road violate the Nepal Roads Standards 204S.