The theory, proposed by Tsuneo TSUKAMOTO in 1932, holds that: the lower Kamogawa River up to the junction with the Takano River and the waterway between the junction and that of the Kamogawa and Shira-kawa Rivers are artificial waterways; originally, the Kamogawa River ran due south and merged with the Hori-kawa River; the Takano River flowed south-west from the current junction and merged with the Hori-kawa River at around the Choho-ji Temple.
1932年（昭和7年）に塚本常雄が提唱した学説で、賀茂川の下流部分と高野川との合流地点から白川との合流地点までは人工河川であり、本来賀茂川はまっすぐ南下して堀川に合流、高野川は現在の合流地点から南西方向に流れ頂法寺付近で堀川に合流していたという説である。