HYDROLOGIC INVESTIGATIONS OF AGHANASHINI HYDRO ELECTRIC PROJECT, KARNATAKA

Abstract

The present study deals with the hydrologic investigations of Aghanashini Hydro Electric Project of Karnataka State. Aghanashini is a major west flowing rivers in North Kanara District of Karnataka state. It originates in the high peaks of we-stern ghats. After flowing through gentle bed fall initially,the river enters a zone of rapids and drops by about 550 m in its course including a vertical drop of 108 m. Heavy rainfall in the basin together with the high head available in this river provides good scope for hydro power generation. The project contemplates utilisation of Aghanashini river waters for power generation by constructing a barrage across the river Aghanashini and a power house near Marshe. This is planned as a run-of-the river scheme, since large storage cannot be provided due to submersion and rehabilitation problems. The 90% dependable yield of the river is 1361 Mcum which works out to 43 cumecs and a discharge of about 160 cumecs is available for about 40 days during monsoon months of July and August. Hence it is proposed to install 4 of 150 MW capacity. The reservoir operation studies reveal that an average annual energy of 1497 MU can be generated. This has also been verified from flow duration studies. This scheme provides peaking benefit to the grid in addition to contributing energy. The two day storm has been selected for the design flood for which the probable maximum flood works out to 7912 cumecs which is in close agreement with the flood obtained by emperical relationship.