The Supreme Court on Friday scrapped a lower court ruling involving the floodgates of a dike at Isahaya Bay, sending a protracted legal battle over a state-run land reclamation project in Nagasaki Prefecture back to the Fukuoka High Court.
The high court will conduct further hearings between the central government and local fishermen in the contentious court battle over whether to open the gates of the dike in Nagasaki Prefecture.
In July last year, the Fukuoka court ruled the gates should remain closed in a decision that effectively overturned a 2010 ruling ordering the state to open them.
The state had filed a suit with the Fukuoka court in 2014, demanding that the 2010 ruling be nullified.
The floodgates of the 7-km-long dike, enclosing part of the Ariake Sea, have been shut since 1997 for a land reclamation project requested by Nagasaki Prefecture.
That created 670 hectares of farmland and a reservoir for use in farming at a cost of ¥253 billion ($2.3 billion).
The gates have been a major topic of debate between local fishermen, who claim the closure has damaged their livelihoods, and farmers, who are concerned that opening them will damage the farmland.
Isahaya Bay is part of the Ariake Sea, a nearly landlocked body of water encircled by Nagasaki, Kumamoto, Saga and Fukuoka prefectures in Kyushu.
The state has said the reclamation will also help protect local communities from flood damage.