Yūzen nagashi (flowing yūzen) in Horikawa river in 1954, Kyō Yūzen

This step, known as yūzen nagashi (flowing yūzen), was formerly done in the main rivers of Kyoto: Kamo, Hori, Katsura, Shirakawa, and Kamiya. The river would change color, depending on the hue of the dye used. Mounting environmental awareness led to the Water Pollution Control Act of 1970. Washing of dyed textiles is no longer done in the river, but in workshops using artificial waterways.