It is said that unlike other areas, Morita Village (present Morita, Ota City), Yamada County, Gunma Prefecture and its surroundings, where the water for fields had been drawn directly from Watarase-gawa River, had an increase in damage by the mining pollution after the Taisho period.
他の地域と異なり、渡良瀬川から直接農業用水を取水していた群馬県山田郡(群馬県)毛里田村（現太田市毛里田）とその周辺では、大正期以降、逆に鉱毒被害が増加したと言われる。