Nagaragawa Estuary Barrage has several type fishways, which are the fishladders with guide flow, the lock type fishway and the brook type fishway, etc. The fishways account for 12% of the total width of the river at the barrage. The fishladders with guide flows were improved on the original type, for example the top of fishladder shapes. In springs of 1994 and 1995, surveys were conducted to confirm the state of fishways and fishes travelling up the fishways.