From 1910 to 1927, on Watarase-gawa River were done the large-scale river works such as changing the whole ex-Yanaka Village into a control basin and diverting the stream of Watarase-gawa River; and in fact, those works decreased floods.
1910年から1927年にかけ、谷中村を遊水地にし、渡良瀬川の流れの向きを変えるなど、大規模な河川工事が行われ、洪水は減少した。