Kami Shiiba Dam, Miyazaki: Japan’s First Major Arch Dam

The village of Shiiba, in the mountains of Miyazaki Prefecture, is considered one of Japan’s great out-of-the-way places. It has been designated a Globally Important Agricultural Heritage System by the United Nations Food and Agriculture Organization. Many folk customs thrive to this day in this historically important village, known as the place where the Taira clan fled in defeat after the Genpei War, its struggle with the Minamoto for political supremacy in 1180–85.

About 1.5 kilometers from the center of the village is Kami Shiiba Dam, situated on the uppermost stretch of the Mimi River, which flows eastward to the Pacific. Completed in 1955, it is Japan’s first large-scale arch-shaped concrete dam.

Kami Shiiba Dam and its reservoir, Hyūga Shiiba Lake.

The dam stands 110 meters high at its tallest point and spans 341 meters. Hyūga Shiiba Lake, the reservoir behind the dam, has a capacity of 92 million cubic meters. Designed with safety in mind, there are spillways, shaped like ski jumps, on either end of the dam, to be used in the event of flooding. These are designed to cause the streams of floodwaters to collide in midair, dispersing the force of their flow.

When floodwaters must be released, they spill from the ski-jump-shaped ramps at either end of the dam and collide, reducing the force of their flow.

Construction of the dam took more than five years and involved some 5 million laborers. Of these, 105 workers died in the course of the work. The Statue of the Three Goddesses was erected nearby as a memorial to their sacrifice. The novelist Yoshikawa Eiji gave the reservoir its Hyūga Shiiba name. With beautiful views year-round, the site, also included in a list of Japan’s 100 best reservoirs, is popular with tourists.

The names of those who died building the dam are engraved beside the Statue of the Three Goddesses.

Kami Shiiba Dam

• Location: Hariganebashi, Shimofukura, Shiiba-son, Miyazaki Prefecture
• Access: Approx. 2.5 hours by Miyazaki Kōtsū Bus from Hyūgashi Station on the JR Nippō Line, then 30 minutes’ walk from the last bus stop, Kami-Shiiba

(Originally published in Japanese. Video by Bunkazai Kyōdō. Banner photo: Kami Shiiba Dam and Hyūga Shiiba Lake.)