Heavy metal concentrations within Hii and Iinashi River sediments were measured
uniformly from its headwaters to the coast. Sediment samples were collected at 35 locations along the rivers and lakes course and analyzed for: As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. Results show a very little influence of human impact upon heavy metal concentrations in river and lake sediments. There is a natural decrease in river sediment-bound heavy metal concentration, due to interaction effect between sediment fragment and river water. And there is a natural increase in lake sediment-bound heavy metal concentration by basin effect that is differentiation by gravity.