Date of interview: Sunday, May 26, 2013

After visiting Tainai No. 2 Dam, Oishi Dam, and Iwafune Dam, I finally landed in Yamagata Prefecture for the first time. To tell the truth, I wanted to visit the Yokogawa Dam, but as I had to work the next day, Akashiba Dam had to be the last place I visited this time, considering that I had to travel to Aichi.

View of the upstream face of the embankment from the left bank

Unfortunately, it is off-limits. The snow shed on Route 113 is pictured on the left.

View upstream of the embankment from the no-entry gate

It looks more like a Tadao Ando-designed building made of cast concrete than a dam. Also, the "COVALENTcovalentThe "+" sign design gives the whole place a European feel.

COVALENT" is an unfamiliar name, but the company that owns this Akashiba Dam is somewhat complicated. First, Electric Finance Corporation built a factory in Oguni-cho to manufacture electrical products, and then built the Akashiba Dam and Akashiba Power Plant to augment postwar electricity.

Denki Kinyu Kabushiki Kaisha then became part of Toshiba Corporation and was renamed Toshiba Denko Kabushiki Kaisha. Toshiba Denko merged with Toshiba Rozai and became Toshiba Ceramics Co. The company began to manufacture silicon wafers and semiconductor manufacturing equipment, as well as electrical products, which it had manufactured until then.

Furthermore, Toshiba Ceramics Co., Ltd. will no longer be part of Toshiba and will be renamed Covalent Materials Corporation (now Quarztec Corporation).

In February 2010, a new company was formed from Covalent Materials Corporation as Akashiba Hydroelectric Power Corporation, and furthermore, Covalent Materials sold a portion of its shares in Akashiba Hydroelectric Power to another entity and is no longer a subsidiary of Quarztec as it is no longer consolidated. (The buyer of the sold shares is unknown as it is not publicly traded.)

Incidentally, Akashiba Dam is the first and only dam owned by a private company in Yamagata Prefecture.

I have used quite a few lines just on the history of the company name change, but it is such a complicated process.

Route 113 on the left bank

I tried to find a better place to take pictures, but the national highway is also quite scary with no sidewalks. Fortunately, there was not much traffic, but it seemed that there were drivers who were too proud to drive in such a small area.... However, compared to the area where I live in Nagoya, there were no cars going that fast, perhaps due to the calm nature of the area.

View of Akashiba Power Plant and Akashiba Dam from the national road on the left bank

It has been several years since the company name was changed from Covalent Materials, but at that time the "COVALENT" sign was still displayed. Later, in 2015, the sign seems to have been removed. Downstream is the second Akashiba power plant.

View of the downstream face of the embankment from the national road on the left bank...

Unfortunately, it is almost invisible due to overgrowth💦.
Too bad it seems to be discharging.

View of the upstream face of the levee from Prefectural Road 15

Prefectural Route 15, which branches off from the national highway, runs along the Tamagawa River, so a half-loop bridge (can we call it that?) is built over the Arakawa River to allow it to pass under the national highway and the JR Yonesaka Line. The bridge is a half-loop bridge (or is it?) over the Arakawa River, from which the upstream side of the embankment can be seen from a slightly frontal angle.

It's a bit difficult to explain in text, but here's what I'm talking about.

The river called Tamagawa joins the Arakawa River from the left side of the photo above, but it looks like Tokyo only in the name of the river.

This concludes our tour of all Niigata (+ Yamagata) dams for attending a wedding at Uchikura Dam. There are still many attractive dams in Niigata, and we hope to introduce more on this site.

Akashiba Dam Specifications

Location	Aza Tokisusawa, Oaza Tamagawa, Oguni-machi, Nishi-Oshiki-gun, Yamagata
River Name	Arakawa River System Arakawa
Objective	P(Power generation)
Model	G(gravity-fed concrete dam)
Bank height	31.8m
Bank length	57.3m
Dam volume	15,000 m3
Watershed Area	736.8km2
Reservoir area	23ha
Total storage capacity	2,078,000 m3
Effective water storage capacity	1,632,000 m3
Dam operator	Akashiba Hydroelectric Power Co.
Main body constructor	Kumagai Gumi
Year of launch	1953.
Year Completed	1954
Name of Dam Lake	-