The purpose of this paper is to understand document life cycle in flood control for Kiso three rivers by the three Takagi families. They conducted flood control as the Mizuyuki Bugyo from 1705 to the end of the Edo period. They made lots of logs and they also sent and received enormous letters and documents from administrators who were in charge of flood control in Kasamatsu Jin’ya and villages in Kiso three rivers basins. In flood control by the three Takagi families, there were some rules for dealing with documents. In addition, after reduction of the area where the three Takagi families were in charge of in 1766, there was seen some distinctive use and transfer of documents.