The Yodo-gawa River is an extremely important water resource that runs through two of Japan's major cities, Osaka and Kyoto, and the utilization of its water and flood-control of the river have been regularly carried out from ancient times, but even so frequent floods repeatedly caused problems for rulers in those days.
淀川は大阪市・京都市といった日本屈指の大都市を貫流する極めて重要な水系であり、古来より治水・利水は間断なく繰り返されていたが、洪水も頻繁であり当時の為政者達の悩みの種でもあった。