Oirase River
Oirase keiryuu.JPG
Oirase River gorge
Oirase River is located in Aomori Prefecture
Oirase River
Location of the mouth in Japan
Oirase River is located in Japan
Oirase River
Oirase River (Japan)
Native name奥入瀬川  (Japanese)
Physical characteristics
SourceLake Towada
 • locationAomori & Akita Prefectures, Japan
 • coordinates40°28′N 140°52′E / 40.467°N 140.867°E / 40.467; 140.867
 • elevation401 m (1,316 ft)
 • location
Pacific Ocean
 • coordinates
40°36′28″N 141°27′40″E / 40.60778°N 141.46111°E / 40.60778; 141.46111Coordinates: 40°36′28″N 141°27′40″E / 40.60778°N 141.46111°E / 40.60778; 141.46111
 • elevation
0 m (0 ft)
Length67 km (42 mi)
Basin size820 km2 (320 sq mi)

The Oirase River (奥入瀬川, Oirase-gawa) is a river located in eastern Aomori Prefecture, in the Tōhoku region of northern Japan.

The Oirase River is the only river that drains Lake Towada, a large caldera lake that lies on the border of Aomori and Akita Prefectures. The river flows in a generally eastern direction, through the municipalities of Towada, Rokunohe, Oirase, and Hachinohe before exiting into the Pacific Ocean. The upper reaches of the river form a scenic gorge with numerous rapids and waterfalls, and is one of the major tourist attractions of the Towada-Hachimantai National Park. The lower reaches of the river are used extensively for irrigation.

In 1996 the sound of flowing water at the Oirase River was selected by the Ministry of the Environment as one of the 100 Soundscapes of Japan.[1]