GUWAHATI, Sept 3 - The reservoirs being built on the rivers of the NE region must have the provision of flood cushions. This is the opinion expressed by highly placed sources in the Brahmaputra Board here. Striking a balance between the cost of hydropower generation and the cost of preserving the environment is the good approach towards building the hydel projects in this geological region, they maintained.
The sources told this correspondent that the Brahmaputra Board is always for dedicated flood cushions in the storage reservoirs. In its master plans prepared for the rivers of the NE region, it emphatically recommended such dedicated flood cushions in the storage reservoirs.
It perhaps needs no mention here that the Brahmaputra Board prepared master plans for 50 rivers of the NE region, and recommended multipurpose projects on 14 of them.
Between the 1980s and 2000, it prepared detailed project reports (DPRs) for five of the multipurpose projects proposed on these rivers, including the Subansiri, the Siang, the Tipaimukh, Pagladiya and Bhairabi. During that period, it conducted investigations for another nine projects including two each on the Subansiri and Siang and one each on the Lohit and the Dibang in Arunachal Pradesh and one project on each of the Simsang, Kynshi, and Umngot in Meghalaya, among others.
Last year, the Board submitted DPRs on two multipurpose projects, one each on the Kulsi on the Meghalaya-Assam border and on the Noadihing in Arunachal Pradesh.
Sources said most of the hydel projects proposed to be built in the NE region are run-of-the-river ones and these are likely to create some environmental as well as flood problems in the downstream areas.
In the main master plan prepared by the Board, an assessment was made on the Brahmaputra flow in relation to the Siang and the Subansiri multipurpose projects proposed by the Board during the 1980s. It showed that the lean season flow of the Brahmaputra would have increased substantially due to the water being released from the reservoirs of the above projects, besides controlling flood during the rainy season, sources said.
Way back in the year of 2009-'10, the Board told the Union Ministry of Water Resources that the Ranganadi Hydel Project of the North Eastern Electric Power Corporation (NEEPCO) does not allow the bed load of the river to be carried off by its flow in the lean season. It was because of the diversion of the river's flow to the Dikrong that the river has lost its own course management capacity, said the sources.
Sources claimed that multipurpose river projects would not only moderate flood but would also help in generating more power and in maintaining the health of the river. Besides, such projects would augment the lean period flow, which is gradually becoming a major issue.