A large amount of radioactive material was released from Fukushima Daiichi Nuclear Power Plant into the atmospheric and coastal environments including water environment in lake and inner bay. The present study aims to clarify the movement of radioactive cesium-134 and -137 in urban watershed, river and lake. For this purpose, we conducted field measurements of radioactive cesium-134 and -137 in sediments in the watershed of Lake Teganuma. The results revealed that 1) the radioactive cesium concentration in roofs was appreciably larger than that in roads and general farmland mainly due to difference of sediment thickness, and 2) the radioactive cesium concentration of the bottom sediment was larger than 1000 Bq/kg over whole Lake Teganuma. The budget of the radioactive cesium concentration in the watershed was evaluated.