Lower Kopili Dam - Central Water Corporation (CWC) approves flood holding capacity

Lower Kopili Dam - Central Water Corporation (CWC) approves flood holding capacity

   The Assam Power Generation Corporation Ltd (APGCL) has said that the Lower Kopili Dam is designed for a maximum flood of 11030 cubic metres per second (Cumecs). The design flood for the Lower Kopili Hydroelectric (HE) project of 11030 Cumecs was approved by the Central Water Corporation (CWC) on October 30, 2012.
   The design of the dam concerning its capacity to hold the maximum flood, is based on the India Meteorology Department (IMD) data of precipitation over the entire catchment area covering Khandong and Lower Kopili Dam, that is, of 1288 square km and 788 square km respectively (total area of 2076 sq km).
   The above statement was made by the APGCL in its reply submitted to the Expert Appraisal Committee (EAC) on the River Valley and Hydro Electric Project of the Ministry of Environment and Forests (MoEF) in response to the observations made by the South Asia Network of Dam River People (SANDRP) on the Lower Kopili Hydro-electric Project.
   The LKHE dam, about 25 km downstream of the existing Khandong Dam, will moderate the flood due to inflow from the undisturbed intervening catchment area of 788 sq km between Khandong Dam and the proposed Lower Kopili Dam and the excess inflow that spilled over from the Khandong reservoir.
   Myntang, a major tributary of the Kopili river, having a catchment area of 512 sq km, is included in the intervening catchment area of 788 sq km of the Lower Kopili Dam. As such the inflow from Myntang river was already included in the design flood of 11030 Cumecs for LKHEP and approved by the CWC in 2012.
   The design spillway capacity of the proposed LKHEP is evaluated as 11030 Cumecs, as approved by the CWC after a detailed hydrological study made with the data acquired from IMD Pune and New Delhi, it said.
   Since the water of the Kopili is acidic at the proposed LKHE project site, special measures are to be adopted, to protect the electro- mechanical and hydro mechanical equipment and river water exposed surface of concrete of the proposed project.
   The APGCL has decided to adopt similar measures taken by the Meghalaya State Electricity Board (MeSEB) for Myntdu Leshka HEP, Meghalaya, for the purpose. The acidity in the river is only due to open cast mining in the upper catchment areas located in the state of Meghalaya.

Source: Assam Tribune (12 Nov 2013) Reported by AJIT PATOWARY.