1001-Hiraoka Dam

Location: Tenryu Village, Shimoina-gun, Nagano Prefecture
Date of interview：2011/03/24 (Thursday)

View of the embankment on the lake side from the left bank

After leaving the Taifu Dam (989-Yasuoka Dam), we drove downstream along the Tenryu River. I remember that it looked close, but it was surprisingly far.

View of the right bank intake screen from the left bank

Water intake to the power plant. Water taken in from this intake is delivered to the power plant downstream.

Hiraoka Dam Management Station, Chubu Electric Power Co.

Like the Taifu Dam, the Hiraoka Dam is currently owned by Chubu Electric Power Co. Later, it was taken over by Nippon Hatsuden and completed in 1951 by Chubu Electric Power Company, which took over the project after the war. It is also a dam with a negative construction record because of the Pacific War during its construction, but that topic will be discussed later.

View of the embankment on the lake side from the left bank

The crest gate is a radial gate with a total of 16 gates. It is similar to the Taifu Dam upstream. The gates, which fill the entire width of the river, are spectacular.

View of the entrance to the skyline from the left bank

Access to the top edge is possible on foot.

View of the levee downstream from the left bank

The color of the gate is the traditional ? Chuden Red. The gate color of Chubu Electric Power Company's dam must be like this. The gate piers, each of which has its own staircase, are lined up all the way to the other side of the river.

Structure on the left bank

Walking downstream for a bit, I saw some kind of structure. It looks like some kind of foundation for construction.

View of the top edge from the left bank

Then cross the top edge.

View of the dam lake from the top

It looks secluded. The dam lake has a color unique to the Tenryu River.

View of the top edge from the right bank

Gate winders are lined up in a row. Personally, I wish the winders were installed on the lake side of the dam. Otherwise, you can't see downstream from the top of the dam, and you can't experience the power of the dam.

View of the gate pier on the dam lake side from the right bank

The dam lake side also provides a reasonable experience of the slurry and lined feeling. Also, it is very nice to experience the old concrete feel.

View of the top edge from the right bank

We crossed over to the right bank.

View of the entrance to the skyline from the right bank

This "HIRAOKA DAM" logo is old and nice. It looks very postwar. (I don't know when this logo was added, but...)

View of the gates from the right bank

I took many photos of the gate group here. That is why I find this area so attractive. A dam with gates, radial gates in particular, spreading across the entire width of the river is a very picturesque sight by itself.

View of the levee downstream from the right bank

We also aim at the gate from various angles and locations. This is the last photo. It was near evening, and the western sun was shining between the gate and the pier, which made a cool contrast with the shadows.

Looking downstream from the left bank

There is a power plant just up ahead.

Stone monument "Martyred Chinese Martyrs in Japan Eternal and Timeless

This is why I said at the beginning that it has a negative construction record. During the Pacific War, this dam brought in many foreign workers (mainly from mainland China and Korea) and forced them to engage in forced labor. The environment was so poor that many people died from accidents and diseases.

It seems that not only this dam but also other places in Japan at that time had such a national policy, but it gives me mixed feelings, though. The flowers and paper cranes seem to indicate that someone is still watching over them.

Hiraoka Dam Specifications

Other facilities/observations