Abstract: For the lack of macro prototype monitoring data during construction of a hydropower station,
water quality as one of seepage micro regimes can be used to reflect hydrogeology features and anti-seepage
effect of an impervious curtain concerned. The Xiangjiaba dam was taken as a case and its groundwater
samples were collected and analyzed. First, a qualitative evaluation of water quality characteristics at
different dam sections was shown by using hydrochemistry diagrams, and then saturation indexes were
calculated for each of the four major location groups divided by a hierarchical cluster analysis. Last, inverse
geochemical models of the groups were developed using PHREEQC to elucidate the dissolution or
precipitation quality of different minerals and the percentage of different seepage sources. The conclusion is
that the hydrogeochemical methods previously described, both qualitatively and quantitatively, are useful for
revealing the seepage behaviors around the damsite during construction.