The dredging was classified into three: Okawazarae (dredging of the Yodo-gawa River), uchikawazarae (dredging of branches of the Yodo-gawa River), and ryokawaguchizarae (dredging of the Aji-gawa River and the Kizu-gawa River).
川浚えは、大川浚（淀川）、内川浚（淀川の諸分流）および両川口浚（安治川河口、木津川(大阪府)河口）の3つに分かれていた。