Probable risk estimation due to reservoir induced seismicity at Jamrani dam Project,Kumaon Himalaya,India

A lake of about 4.5 sq. km. spread having 208 millions cubic meter storage capacity is proposed to be created in outer Himalaya for meeting irrigation, industrial and domestic supplies, downstream of 130 m high Jamrani dam. The bedrock around the lake consists of alternate bands of sandstone, clayshale and siltstone of siwalik Formations, (Middle Miocene to Pliocene) and thrust mass of Amritpur granite. The tectonic plane (Main Boundary fault) lies about 3.5 km upstream of the dam. The problem of Reservoir Induced Seismicity (RIS) though complex and unpredictable has been studied the world over at several major dam projects which provide some information on the factors responsible for RIS such as (i) geo-tectonic, setting (ii) pore-water pressure (iii) background seismicity and (iv) reservoir water load. Any one or the combination of these factors play an important role in inducing, earthquakes. The subject of RIS has been discussed in the light of the analysis of the seismic risk related to Jamrani reservoir in its geo-tectonic setting.