Okirihata Dam Disaster Recovery Construction Site Visit

The Okirihata Dam in Nishihara, Aso, before being damaged by the 2016 Kumamoto Earthquakes, irrigated 71 hectares of rice fields and 108 hectares of farmland in Nishihara and as well as 135 hectares of farmland in Mashiki. Additionally, it sent winter water to the nearby Fukasako Dam, creating the indirect benefit of irrigating 403 hectares of farmland in Kikuyo. However, the dam was severely damaged in the Kumamoto Earthquakes, including to the main dam body. Post-disaster investigations revealed that there were surface earthquake faults running through the dam body and the dam reservoir. As a result, Kumamoto Prefecture set up the Okirihata Dam Reconstruction Office and is working swiftly to repair the dam. Construction of the main embankment began in August 2023, and currently embankment fill work, spillway construction, and other construction work continues aimed at resuming operations in FY2026.

Technical Visit Overview
Tour plan overview:
Okirihata Dam disaster recovery construction site visit explanation
Dam site tour
Location:
2057-20 Komori, Nishihara, Aso District, 861-2402
Time required:
60 min
Number of participants:
Up to 40 ppl
Start time:
Open year-round
Languages supported:
Please contact us for more information.
Important:
Deadline: 1 month before tour
Availability: during construction periods, weekdays only
Access:
16 min by car from Aso Kumamoto Airport
30 min by car from Kumamoto IC
50 min by car from Sakuramachi Bus Terminal
Notes:
Please contact us for more information.
Contact:
Kumamoto International Convention & Tourism Bureau
Phone: 096-359-1788
E-mail: mice★kumamoto-icb.or.jp (Please change the ★ to an @ when emailing us)
Point
Take the rare opportunity to visit a dam construction site and hear explanation from a knowledgeable guide.