Nanakura Dam

Overview

Nanakura Dam is a hydroelectric power dam located in Omachi City, Nagano Prefecture. It's a central core-type rockfill dam, the same type as the Takase Dam immediately upstream. While Takase Dam's height (second tallest in Japan) often overshadows it, Nanakura Dam is also remarkably tall at 125.0 meters, ranking among the highest rockfill dams in Japan. It forms the lower reservoir for Tokyo Electric Power Company Renewable Power's Shin-Takasegawa Pumped Storage Power Plant. Furthermore, the company's Nakanosawa Power Plant utilizes the water stored in Nanakura Dam to efficiently regulate the water level of Ryujin Lake (behind Omachi Dam downstream), optimizing power generation. The Takase River boasts a series of dams—Takase, Nanakura, and Omachi—each approximately 100 meters high, creating breathtaking autumn scenery with the lake reflecting the brilliant fall colors. Viewed from downstream, Nanakura Dam resembles a massive rock mountain; its 125.0-meter-high embankment is truly awe-inspiring. Nanakura Dam, alongside Takase Dam, is a popular spot among dam enthusiasts. The panoramic view from the top of the dam is majestic and deeply calming. Well-maintained hiking trails around the dam offer opportunities to enjoy both the dam and the surrounding nature. When visiting Nanakura Dam, be sure to take in the breathtaking view from the top.