It is estimated, from timing of the construction by the Hata clan of Kadono oi (the Kadono dam) as part of irrigation works for the present-day Katsura-gawa River (the Yodo-gawa River system), that the Uzumasa in Yamashiro Province has its origins around the sixth century.
秦氏が現在の桂川(淀川水系)に灌漑工事として葛野大堰を築いた点から山背国太秦の起点は6世紀頃と推定される。