Nagaragawa Estuary Barrage

The Nagaragawa Estuary Barrage is a water control structure spanning 661 meters with ten adjustable gates that manage river flow and prevent saltwater intrusion. Fish ladders on both banks allow species such as sweetfish and crabs to move between upstream and downstream sections.

Construction of the barrage began in 1988 and was completed in 1995, following three decades of planning and discussion about the project. Its completion represented a significant moment for water management in the Gifu region.

The Aqua Plaza Nagara visitor center offers exhibits about the river's history and how the barrage operates through interactive displays. Visitors can learn about the relationship between this infrastructure and the local environment.

The barrage is accessible from the visitor center, which provides context about how the structure operates. Weather conditions can change quickly along this large river section, so prepare accordingly.

Before this barrage was built, the Nagara River was the last major river on Honshu island without a dam on its main flow. This distinction made it ecologically important for migratory species.