Owing to the completion (in 1670) an embankment along the Kamo-gawa River (the Yodo-gawa River System) on which construction began immediately afterwards, the natural conditions dividing Rakuchu from Rakugai changed significantly when the river beach of the Kamo-gawa River was eliminated and the river transformed into a channel while channels to the north of Gojo disappeared.
また、直後に始まった鴨川(淀川水系)の堤防設置工事にの完成（1670年）によって鴨川の河原が消えて水路化し、逆に五条以北の水路が消えたために洛中と洛外を区切る自然条件が大きく変化した。