During Kyoho period and afterward, in order to take a drastic measure against floods, people had petitioned Edo bakufu (Japanese feudal government headed by shoguns) for implementation of a plan of controlling floods by excavating diversion aqueducts from around present-day Bunsui District, Tsubame City (former Bunsui-machi), which is located at the upper stream of a fork of the two rivers and the closest to the Japan Sea, but the plan wasn't executed due to the enormous amount of the construction cost and conflicts of interests among the watershed domains.
この抜本的治水策として、2つの川の分岐点より上流に当たり、且つ日本海に最も近い現在の燕市分水地区（旧分水町）付近から分水路を掘削する計画が享保年間より江戸幕府に嘆願されてきたが、莫大な工事費と、流域各藩の利害対立により実現しなかった。