Groundwater flow around Misogawa Dam at the initial filling

evaluation of permeability of bed rock by investigation of water quality

Abstract

To evaluate the permeability of bedrock of Misogawa Dam, water quality of seepage water was measured at the initial filling of the reservoir. The variation of ion concentration showed that the reservoir water has not yet arrived at the collecting weirs. The travel time to the collecting weir of PW3 for river bed seepage estimated from the variation of ion concentration is more than 3 years. This travel time is longer than the travel time of 8 months obtained from the unsteady seepage analysis using particle tracking method. So, we can conclude that the foundation bedrock of Misogawa Dam was grouted sufficiently.