Tama River

The Tama River (多摩川, Tama-gawa) is a major river in Yamanashi, Kanagawa and Tokyo Prefectures on Honshū, Japan. It is officially classified as a Class 1 river by the Japanese government. Its total length is 138 kilometres (86 mi), and the total of the river's basin area spans 1,240 square kilometres (480 sq mi).

The river flows through Tokyo, on the dividing line between Tokyo and Kanagawa. In the city, its banks are lined with parks and sports fields, making the river a popular picnic spot.

Course

Its source is located at Mt. Kasadori in Koshu in Yamanashi Prefecture. From there, it flows eastward into mountainous western Tokyo, where the Ogōchi Dam forms Lake Okutama. Below the dam, it takes the name Tama and flows eastwards through Chichibu Tama Kai National Park towards Ōme, Tokyo. It then flows southeast between Tama Hills and Musashino Terrace. At Hamura is the source of the historic Tamagawa Aqueduct built by the Tamagawa brothers in 1653 to supply water to Edo (present day Tokyo). Further downstream, the river forms the boundary between Tokyo and the city of Kawasaki in Kanagawa Prefecture. Its mouth on the heavily industrialised Tokyo Bay is next to Haneda Airport.