The Ima-gawa River, the Nagao-gawa River, and the lower part of the Harai-gawa River constitute of the urban area of Yukuhashi City, and the urban area of Chikujo Town is located at the mouth of the Kii-kawa River.
今川、長峡川、祓川下流部には行橋市市街地を成し、城井川河口部には築上町の市街地を成す。