Fishways
In the Nagaragawa Estuary Barrage, attraction-flow-type fishways, lock-type fishways and a naturally shaped fishway have been built for upstream and downstream travel of fish.
The attraction-flow-type fishways and the lock-type fishways are given priority in the supply of water: at a rate of 11 m3/sec while ayu are traveling upstream (February 1 to June 30) and 4 m3/sec in other months.