NEW DELHI, Oct 27 � Expert panel�s report on downstream impact study of National Hydro Power Corporation�s (NHPC) 2,000 MW Subansiri Lower Hydroelectric Project has run into trouble, with the Expert Appraisal Committee (EAC) under the Ministry of Environment and Forests (MoEF) questioning its findings.
The EAC of the MoEF has criticised the downstream impact study submitted for NHPC's 2,000 MW Subansiri Lower claiming that there were several deficiencies, relating to river characteristics, sediment load and water quality, according to reports.
The State Government panel�s report is coming up for further deliberation at the next meeting of the EAC, scheduled on November 12 and 13.
The EAC discussed the panel�s report at its 42nd meeting held on the first week of this month and observed that the data used by the expert group is too old to reflect the current ground realities, the report said.
Further, the EAC felt that the frequency analyses, again based on outdated data, presented for the formulation of a rainfall-runoff model is of no use due to the significant changes that have occurred during the last 30-40 years.
On the dam break analysis performed by the expert panel, the committee was of the opinion that since dam break floods are a fully dynamic wave, application of a simplified diffusive wave model, as has been observed, is not warranted.
Further, the study deals only with clear water, whereas the channel is very erodible and, thus, the rigid boundary assumption was erroneous.
Meanwhile, the EAC has recommended cancellation of four hydropower projects in Arunachal Pradesh planned over the Bichom River to ensure the natural flow of the river over a longer length.
The EAC�s recommendation to the MoEF was on the basis of the report submitted by WAPCOS Limited, an international consultant under the Ministry of Water Resources (MoWR), the report said.
The Bichom River basin study covered the 20 MW Dimijin, 60 MW Nazong, 15 MW Dikhri and 10 MW Dinan hydro electric projects. All the projects were proposed at upstream and downstream of KSK Energy's 120 MW Dibbin hydro power project.
Report said that on the basis of the EAC�s recommendation, the MoEF is likely to formally ask Arunachal Pradesh Government to drop its plans for these projects.
WAPCOS was commissioned to undertake the river basin study by EAC and at the expense of the developers of the four projects on pro-rata basis per MW to help the committee analyse the environmental effects on the basin.
WAPCOS also studied the Dibbin, Utung, Nafra, Gongri, Jameri and Dinchang Hydro electric projects.
However, the EAC has recommended clearance of pre-construction activities at three projects proposed in Arunachal Pradesh, for which the terms of reference for the preparation of EIA reports has been cleared.
The projects included Coastal Projects Private Limited's 55 MW Para, 70 MW Badao hydroelectric Projects in East Kameng district and 141 MW Rho Power Corporation Private Limited�s in Tawang district.
The Para project involves construction of a 44 meter high concrete gravity dam across river Para, a tributary of Kameng river, near Badao village, to generate 55 MW power.
