Kanno Dam

Overview

Kanno Dam was a gravity concrete dam that once stood on the Okitama-Nogawa River of the Mogami River system in Nagai, Yamagata Prefecture. Standing 44.5 meters tall, it was the first subsidized multipurpose dam built by Yamagata Prefecture, serving flood control, irrigation, and hydropower. When the downstream Nagai Dam was built and completed its test impoundment in 2010, Kanno Dam was fully submerged. Today it is, in effect, a vanished dam resting on the lakebed.

Highlights

• ●Its pioneering role as Yamagata Prefecture's first subsidized multipurpose dam
• ●A 44.5-meter-tall gravity concrete dam structure
• ●Flood control, irrigation, and power generation linked with the upstream Kijiyama Dam
• ●The story of a vanished dam submerged by the construction of Nagai Dam

History

Kanno Dam was constructed as Yamagata Prefecture's very first subsidized multipurpose dam, working together with the upstream Kijiyama Dam to provide flood control for Nagai, supply agricultural water, and generate hydroelectric power. Later the Tohoku Regional Bureau of the Ministry of Land built the large Nagai Dam just downstream. When Nagai Dam's test impoundment was completed in 2010, Kanno Dam was submerged and ceased to exist, its role fulfilled.

Map

38.1056, 139.9506 · Wikidata

Suggested itinerary

1. 1Head from central Nagai toward the Okitama-Nogawa basin
2. 2Tour the successor Nagai Dam and look out over the former Kanno Dam site
3. 3Take in the natural scenery and related exhibits around the reservoir
4. 4Return to Nagai and enjoy the landscapes of the Okitama region

Did you know?

💡 Though pioneering as Yamagata Prefecture's first subsidized multipurpose dam, it disappeared beneath the lakebed when its successor was completed. A dam being submerged by a newer dam is a rare case, making it a fascinating episode in engineering history that tells of a generational handover in flood control.

Nearby spots