​IKK Corporation, a group company, has developed the nation's first movable watertight barrier for roadways, which has begun operation in the Akita Central Road Tunnel.

During heavy rain, watertight walls rise from the road surface to prevent rainwater from entering the tunnel.

Following the flooding of the Akita Central Road Tunnel due to record-breaking heavy rains in July 2023, movable watertight walls (revolving type) for roadways were adopted at the east entrance/exit of Akita Station and the central district exit as a measure to prevent similar damage from recurring.

To coincide with the start of operations on October 1, 2026, a completion commemoration event was held, hosted by the Construction Department of the Akita Prefectural Regional Development Bureau. Local elementary school students also participated in the event and were able to witness the watertight wall actually being erected.